From: John Tsiombikas <nuclear@mutantstargoat.com>
Date: Sun, 24 Jul 2016 21:29:17 +0000 (+0300)
Subject: cybergrid
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=vrfileman;a=commitdiff_plain;h=dd39621d642e417f1e343cbf813205a658272639

cybergrid
---

diff --git a/Makefile b/Makefile
index 5d666ac..dcb3c86 100644
--- a/Makefile
+++ b/Makefile
@@ -5,12 +5,14 @@ dbg = -g
 # -----------------
 
 src = $(wildcard src/*.cc)
-obj = $(src:.cc=.o)
+csrc = $(wildcard src/*.c)
+obj = $(src:.cc=.o) $(csrc:.c=.o)
 dep = $(obj:.o=.d)
 bin = vrfileman
 
 warn = -pedantic -Wall
 
+CFLAGS = $(warn) $(opt) $(dbg) $(inc) `pkg-config --cflags sdl2`
 CXXFLAGS = $(warn) $(opt) $(dbg) $(inc) `pkg-config --cflags sdl2`
 LDFLAGS = $(libgl) -lgmath `pkg-config --libs sdl2`
 
diff --git a/sdr/grid.p.glsl b/sdr/grid.p.glsl
new file mode 100644
index 0000000..86a30a5
--- /dev/null
+++ b/sdr/grid.p.glsl
@@ -0,0 +1,23 @@
+varying vec3 pos, vpos;
+
+float grid(vec2 p, float duty)
+{
+	float w = duty * 0.5;
+	p = fract(p);
+	return smoothstep(1.0 - w, 1.0, p.x) + (1.0 - smoothstep(0.0, w, p.x)) +
+		smoothstep(1.0 - w, 1.0, p.y) + (1.0 - smoothstep(0.0, w, p.y));
+}
+
+void main()
+{
+	vec3 p = pos * 500.0;
+
+	const vec3 grid_color = vec3(1.0, 0.2, 0.8);
+	const vec3 bg_color = vec3(0.5, 0.1, 1.0);
+	vec3 color = grid_color * grid(p.xz, 0.2);
+
+	float fog = min(abs(vpos.z) * 0.05, 1.0);
+
+	gl_FragColor.xyz = mix(color, bg_color, fog);
+	gl_FragColor.a = 1.0;
+}
diff --git a/sdr/grid.v.glsl b/sdr/grid.v.glsl
new file mode 100644
index 0000000..9f102eb
--- /dev/null
+++ b/sdr/grid.v.glsl
@@ -0,0 +1,8 @@
+varying vec3 pos, vpos;
+
+void main()
+{
+	gl_Position = ftransform();
+	pos = gl_Vertex.xyz;
+	vpos = (gl_ModelViewMatrix * gl_Vertex).xyz;
+}
diff --git a/src/app.cc b/src/app.cc
new file mode 100644
index 0000000..1de3f89
--- /dev/null
+++ b/src/app.cc
@@ -0,0 +1,135 @@
+#include <stdio.h>
+#include <assert.h>
+#include "opengl.h"
+#include "app.h"
+#include "gmath/gmath.h"
+#include "mesh.h"
+#include "meshgen.h"
+#include "sdr.h"
+
+int win_width, win_height;
+float win_aspect;
+long time_msec;
+
+static float cam_theta, cam_phi;
+static Mesh *mesh_torus;
+
+static bool bnstate[16];
+static int prev_x, prev_y;
+
+static unsigned int sdr_grid;
+
+bool app_init(int argc, char **argv)
+{
+	if(init_opengl() == -1) {
+		return false;
+	}
+
+	glEnable(GL_MULTISAMPLE);
+
+	int aasamples = 0;
+	glGetIntegerv(GL_SAMPLES, &aasamples);
+	printf("got %d samples per pixel\n", aasamples);
+
+	glEnable(GL_CULL_FACE);
+	glEnable(GL_DEPTH_TEST);
+	//glEnable(GL_LIGHTING);
+	glEnable(GL_LIGHT0);
+
+	Mesh::use_custom_sdr_attr = false;
+
+	mesh_torus = new Mesh;
+	gen_torus(mesh_torus, 1.0, 0.25, 32, 32);
+
+	if(!(sdr_grid = create_program_load("sdr/grid.v.glsl", "sdr/grid.p.glsl"))) {
+		return false;
+	}
+
+	return true;
+}
+
+void app_cleanup()
+{
+}
+
+void app_draw()
+{
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+	Mat4 view_mat;
+	view_mat.pre_rotate_x(deg_to_rad(cam_phi));
+	view_mat.pre_rotate_y(deg_to_rad(cam_theta));
+	view_mat.pre_translate(0, -1.65, 0);
+	glMatrixMode(GL_MODELVIEW);
+	glLoadMatrixf(view_mat[0]);
+
+	//mesh_torus->draw();
+
+	Mat4 xform;
+	xform.scaling(500.0);
+	glPushMatrix();
+	glMultMatrixf(xform[0]);
+
+	bind_program(sdr_grid);
+	glBegin(GL_QUADS);
+	glNormal3f(0, 1, 0);
+	glVertex3f(-1, 0, 1);
+	glVertex3f(1, 0, 1);
+	glVertex3f(1, 0, -1);
+	glVertex3f(-1, 0, -1);
+	glEnd();
+	bind_program(0);
+
+	glPopMatrix();
+
+	app_swap_buffers();
+	assert(glGetError() == GL_NO_ERROR);
+}
+
+void app_reshape(int x, int y)
+{
+	glViewport(0, 0, x, y);
+
+	Mat4 mat;
+	mat.perspective(deg_to_rad(50), win_aspect, 0.5, 500.0);
+
+	glMatrixMode(GL_PROJECTION);
+	glLoadMatrixf(mat[0]);
+}
+
+void app_keyboard(int key, bool pressed)
+{
+	if(pressed) {
+		switch(key) {
+		case 27:
+			app_quit();
+			break;
+		}
+	}
+}
+
+void app_mouse_button(int bn, bool pressed, int x, int y)
+{
+	bnstate[bn] = pressed;
+	prev_x = x;
+	prev_y = y;
+}
+
+void app_mouse_motion(int x, int y)
+{
+	int dx = x - prev_x;
+	int dy = y - prev_y;
+	prev_x = x;
+	prev_y = y;
+
+	if(!dx && !dy) return;
+
+	if(bnstate[0]) {
+		cam_theta += dx * 0.5;
+		cam_phi += dy * 0.5;
+
+		if(cam_phi < -90) cam_phi = -90;
+		if(cam_phi > 90) cam_phi = 90;
+	}
+	app_redraw();
+}
diff --git a/src/app.h b/src/app.h
index ee34a44..bfe96cb 100644
--- a/src/app.h
+++ b/src/app.h
@@ -15,6 +15,7 @@ void app_mouse_button(int bn, bool pressed, int x, int y);
 void app_mouse_motion(int x, int y);
 
 // the following functions are implemented by the window system backend
+void app_quit();
 void app_redraw();
 void app_swap_buffers();
 long app_get_msec();
diff --git a/src/geom.cc b/src/geom.cc
new file mode 100644
index 0000000..23391a7
--- /dev/null
+++ b/src/geom.cc
@@ -0,0 +1,334 @@
+#include <assert.h>
+#include <float.h>
+#include <algorithm>
+#include "geom.h"
+
+GeomObject::~GeomObject()
+{
+}
+
+
+Sphere::Sphere()
+{
+	radius = 1.0;
+}
+
+Sphere::Sphere(const Vec3 &cent, float radius)
+	: center(cent)
+{
+	this->radius = radius;
+}
+
+void Sphere::set_union(const GeomObject *obj1, const GeomObject *obj2)
+{
+	const Sphere *sph1 = dynamic_cast<const Sphere*>(obj1);
+	const Sphere *sph2 = dynamic_cast<const Sphere*>(obj2);
+
+	if(!sph1 || !sph2) {
+		fprintf(stderr, "Sphere::set_union: arguments must be spheres");
+		return;
+	}
+
+	float dist = length(sph1->center - sph2->center);
+	float surf_dist = dist - (sph1->radius + sph2->radius);
+	float d1 = sph1->radius + surf_dist / 2.0;
+	float d2 = sph2->radius + surf_dist / 2.0;
+	float t = d1 / (d1 + d2);
+
+	if(t < 0.0) t = 0.0;
+	if(t > 1.0) t = 1.0;
+
+	center = sph1->center * t + sph2->center * (1.0 - t);
+	radius = std::max(dist * t + sph2->radius, dist * (1.0f - t) + sph1->radius);
+}
+
+void Sphere::set_intersection(const GeomObject *obj1, const GeomObject *obj2)
+{
+	fprintf(stderr, "Sphere::intersection undefined\n");
+}
+
+bool Sphere::intersect(const Ray &ray, HitPoint *hit) const
+{
+	float a = dot(ray.dir, ray.dir);
+	float b = 2.0 * ray.dir.x * (ray.origin.x - center.x) +
+		2.0 * ray.dir.y * (ray.origin.y - center.y) +
+		2.0 * ray.dir.z * (ray.origin.z - center.z);
+	float c = dot(ray.origin, ray.origin) + dot(center, center) -
+		2.0 * dot(ray.origin, center) - radius * radius;
+
+	float discr = b * b - 4.0 * a * c;
+	if(discr < 1e-4) {
+		return false;
+	}
+
+	float sqrt_discr = sqrt(discr);
+	float t0 = (-b + sqrt_discr) / (2.0 * a);
+	float t1 = (-b - sqrt_discr) / (2.0 * a);
+
+	if(t0 < 1e-4)
+		t0 = t1;
+	if(t1 < 1e-4)
+		t1 = t0;
+
+	float t = t0 < t1 ? t0 : t1;
+	if(t < 1e-4) {
+		return false;
+	}
+
+	// fill the HitPoint structure
+	if(hit) {
+		hit->obj = this;
+		hit->dist = t;
+		hit->pos = ray.origin + ray.dir * t;
+		hit->normal = (hit->pos - center) / radius;
+	}
+	return true;
+}
+
+
+AABox::AABox()
+{
+}
+
+AABox::AABox(const Vec3 &vmin, const Vec3 &vmax)
+	: min(vmin), max(vmax)
+{
+}
+
+void AABox::set_union(const GeomObject *obj1, const GeomObject *obj2)
+{
+	const AABox *box1 = dynamic_cast<const AABox*>(obj1);
+	const AABox *box2 = dynamic_cast<const AABox*>(obj2);
+
+	if(!box1 || !box2) {
+		fprintf(stderr, "AABox::set_union: arguments must be AABoxes too\n");
+		return;
+	}
+
+	min.x = std::min(box1->min.x, box2->min.x);
+	min.y = std::min(box1->min.y, box2->min.y);
+	min.z = std::min(box1->min.z, box2->min.z);
+
+	max.x = std::max(box1->max.x, box2->max.x);
+	max.y = std::max(box1->max.y, box2->max.y);
+	max.z = std::max(box1->max.z, box2->max.z);
+}
+
+void AABox::set_intersection(const GeomObject *obj1, const GeomObject *obj2)
+{
+	const AABox *box1 = dynamic_cast<const AABox*>(obj1);
+	const AABox *box2 = dynamic_cast<const AABox*>(obj2);
+
+	if(!box1 || !box2) {
+		fprintf(stderr, "AABox::set_intersection: arguments must be AABoxes too\n");
+		return;
+	}
+
+	for(int i=0; i<3; i++) {
+		min[i] = std::max(box1->min[i], box2->min[i]);
+		max[i] = std::min(box1->max[i], box2->max[i]);
+
+		if(max[i] < min[i]) {
+			max[i] = min[i];
+		}
+	}
+}
+
+bool AABox::intersect(const Ray &ray, HitPoint *hit) const
+{
+	Vec3 param[2] = {min, max};
+	Vec3 inv_dir(1.0 / ray.dir.x, 1.0 / ray.dir.y, 1.0 / ray.dir.z);
+	int sign[3] = {inv_dir.x < 0, inv_dir.y < 0, inv_dir.z < 0};
+
+	float tmin = (param[sign[0]].x - ray.origin.x) * inv_dir.x;
+	float tmax = (param[1 - sign[0]].x - ray.origin.x) * inv_dir.x;
+	float tymin = (param[sign[1]].y - ray.origin.y) * inv_dir.y;
+	float tymax = (param[1 - sign[1]].y - ray.origin.y) * inv_dir.y;
+
+	if(tmin > tymax || tymin > tmax) {
+		return false;
+	}
+	if(tymin > tmin) {
+		tmin = tymin;
+	}
+	if(tymax < tmax) {
+		tmax = tymax;
+	}
+
+	float tzmin = (param[sign[2]].z - ray.origin.z) * inv_dir.z;
+	float tzmax = (param[1 - sign[2]].z - ray.origin.z) * inv_dir.z;
+
+	if(tmin > tzmax || tzmin > tmax) {
+		return false;
+	}
+	if(tzmin > tmin) {
+		tmin = tzmin;
+	}
+	if(tzmax < tmax) {
+		tmax = tzmax;
+	}
+
+	float t = tmin < 1e-4 ? tmax : tmin;
+	if(t >= 1e-4) {
+
+		if(hit) {
+			hit->obj = this;
+			hit->dist = t;
+			hit->pos = ray.origin + ray.dir * t;
+
+			float min_dist = FLT_MAX;
+			Vec3 offs = min + (max - min) / 2.0;
+			Vec3 local_hit = hit->pos - offs;
+
+			static const Vec3 axis[] = {
+				Vec3(1, 0, 0), Vec3(0, 1, 0), Vec3(0, 0, 1)
+			};
+			//int tcidx[][2] = {{2, 1}, {0, 2}, {0, 1}};
+
+			for(int i=0; i<3; i++) {
+				float dist = fabs((max[i] - offs[i]) - fabs(local_hit[i]));
+				if(dist < min_dist) {
+					min_dist = dist;
+					hit->normal = axis[i] * (local_hit[i] < 0.0 ? 1.0 : -1.0);
+					//hit->texcoord = Vec2(hit->pos[tcidx[i][0]], hit->pos[tcidx[i][1]]);
+				}
+			}
+		}
+		return true;
+	}
+	return false;
+
+}
+
+Plane::Plane()
+	: normal(0.0, 1.0, 0.0)
+{
+}
+
+Plane::Plane(const Vec3 &p, const Vec3 &norm)
+	: pt(p)
+{
+	normal = normalize(norm);
+}
+
+Plane::Plane(const Vec3 &p1, const Vec3 &p2, const Vec3 &p3)
+	: pt(p1)
+{
+	normal = normalize(cross(p2 - p1, p3 - p1));
+}
+
+Plane::Plane(const Vec3 &normal, float dist)
+{
+	this->normal = normalize(normal);
+	pt = this->normal * dist;
+}
+
+void Plane::set_union(const GeomObject *obj1, const GeomObject *obj2)
+{
+	fprintf(stderr, "Plane::set_union undefined\n");
+}
+
+void Plane::set_intersection(const GeomObject *obj1, const GeomObject *obj2)
+{
+	fprintf(stderr, "Plane::set_intersection undefined\n");
+}
+
+bool Plane::intersect(const Ray &ray, HitPoint *hit) const
+{
+	float ndotdir = dot(normal, ray.dir);
+	if(fabs(ndotdir) < 1e-4) {
+		return false;
+	}
+
+	if(hit) {
+		Vec3 ptdir = pt - ray.origin;
+		float t = dot(normal, ptdir) / ndotdir;
+
+		hit->pos = ray.origin + ray.dir * t;
+		hit->normal = normal;
+		hit->obj = this;
+	}
+	return true;
+}
+
+float sphere_distance(const Vec3 &cent, float rad, const Vec3 &pt)
+{
+	return length(pt - cent) - rad;
+}
+
+// TODO version which takes both radii into account
+float capsule_distance(const Vec3 &a, float ra, const Vec3 &b, float rb, const Vec3 &pt)
+{
+	Vec3 ab_dir = b - a;
+	float ab_len_sq = length_sq(ab_dir);
+
+	if(fabs(ab_len_sq) < 1e-5) {
+		// if a == b, the capsule is a sphere with radius the maximum of the capsule radii
+		return sphere_distance(a, std::max(ra, rb), pt);
+	}
+	float ab_len = sqrt(ab_len_sq);
+
+	Vec3 ap_dir = pt - a;
+
+	float t = dot(ap_dir, ab_dir / ab_len) / ab_len;
+	if(t < 0.0) {
+		return sphere_distance(a, ra, pt);
+	}
+	if(t >= 1.0) {
+		return sphere_distance(b, rb, pt);
+	}
+
+	Vec3 pproj = a + ab_dir * t;
+	return length(pproj - pt) - ra;
+}
+
+#if 0
+float capsule_distance(const Vec3 &a, float ra, const Vec3 &b, float rb, const Vec3 &pt)
+{
+	Vec3 ab_dir = b - a;
+
+	if(fabs(length_sq(ab_dir)) < 1e-5) {
+		// if a == b, the capsule is a sphere with radius the maximum of the capsule radii
+		return sphere_distance(a, std::max(ra, rb), pt);
+	}
+	float ab_len = length(ab_dir);
+
+	Vec3 ap_dir = pt - a;
+	Vec3 rotaxis = normalize(cross(ab_dir, ap_dir));
+
+	Mat4 rmat;
+	rmat.set_rotation(rotaxis, M_PI / 2.0);
+	Vec3 right = rmat * ab_dir / ab_len;
+
+	// XXX I think this check is redundant, always false, due to the cross product order
+	//assert(dot(right, ab_dir) >= 0.0);
+	if(dot(right, ab_dir) < 0.0) {
+		right = -right;
+	}
+	Vec3 aa = a + right * ra;
+	Vec3 bb = b + right * rb;
+
+	// project pt to the line segment bb-aa, see if the projection lies within the interval [0, 1)
+	Vec3 aabb_dir = bb - aa;
+	float aabb_len = length(aabb_dir);
+	Vec3 aap_dir = pt - aa;
+
+	float t = dot(aap_dir, aabb_dir / aabb_len) / aabb_len;
+	if(t < 0.0) {
+		return sphere_distance(a, ra, pt);
+	}
+	if(t >= 1.0) {
+		return sphere_distance(b, rb, pt);
+	}
+
+	Vec3 ppt = aa + aabb_dir * t;
+	Vec3 norm = ppt - pt;
+	float dist = length(norm);
+
+	if(dot(norm, right) < 0.0) {
+		// inside the cone
+		dist = -dist;
+	}
+	return dist;
+}
+#endif
diff --git a/src/geom.h b/src/geom.h
new file mode 100644
index 0000000..aabf266
--- /dev/null
+++ b/src/geom.h
@@ -0,0 +1,73 @@
+#ifndef GEOMOBJ_H_
+#define GEOMOBJ_H_
+
+#include "gmath/gmath.h"
+
+class GeomObject;
+class SceneNode;
+
+struct HitPoint {
+	float dist;				//< parametric distance along the ray
+	Vec3 pos;			//< position of intersection (orig + dir * dist)
+	Vec3 normal;			//< normal at the point of intersection
+	const void *obj;		//< pointer to the intersected object
+	const SceneNode *node;
+	Ray ray;
+};
+
+class GeomObject {
+public:
+	virtual ~GeomObject();
+
+	virtual void set_union(const GeomObject *obj1, const GeomObject *obj2) = 0;
+	virtual void set_intersection(const GeomObject *obj1, const GeomObject *obj2) = 0;
+
+	virtual bool intersect(const Ray &ray, HitPoint *hit = 0) const = 0;
+};
+
+class Sphere : public GeomObject {
+public:
+	Vec3 center;
+	float radius;
+
+	Sphere();
+	Sphere(const Vec3 &center, float radius);
+
+	void set_union(const GeomObject *obj1, const GeomObject *obj2);
+	void set_intersection(const GeomObject *obj1, const GeomObject *obj2);
+
+	bool intersect(const Ray &ray, HitPoint *hit = 0) const;
+};
+
+class AABox : public GeomObject {
+public:
+	Vec3 min, max;
+
+	AABox();
+	AABox(const Vec3 &min, const Vec3 &max);
+
+	void set_union(const GeomObject *obj1, const GeomObject *obj2);
+	void set_intersection(const GeomObject *obj1, const GeomObject *obj2);
+
+	bool intersect(const Ray &ray, HitPoint *hit = 0) const;
+};
+
+class Plane : public GeomObject {
+public:
+	Vec3 pt, normal;
+
+	Plane();
+	Plane(const Vec3 &pt, const Vec3 &normal);
+	Plane(const Vec3 &p1, const Vec3 &p2, const Vec3 &p3);
+	Plane(const Vec3 &normal, float dist);
+
+	void set_union(const GeomObject *obj1, const GeomObject *obj2);
+	void set_intersection(const GeomObject *obj1, const GeomObject *obj2);
+
+	bool intersect(const Ray &ray, HitPoint *hit = 0) const;
+};
+
+float sphere_distance(const Vec3 &cent, float rad, const Vec3 &pt);
+float capsule_distance(const Vec3 &a, float ra, const Vec3 &b, float rb, const Vec3 &pt);
+
+#endif	// GEOMOBJ_H_
diff --git a/src/main.cc b/src/main.cc
index 66e8e98..942db47 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -17,6 +17,10 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
+	SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
+	SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 1);
+	SDL_GL_SetAttribute(SDL_GL_FRAMEBUFFER_SRGB_CAPABLE, 1);
+
 	int x = SDL_WINDOWPOS_UNDEFINED;
 	int y = SDL_WINDOWPOS_UNDEFINED;
 	unsigned int flags = SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI;
@@ -27,17 +31,17 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
-	SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
-	SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
-	SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
-	SDL_GL_SetAttribute(SDL_GL_FRAMEBUFFER_SRGB_CAPABLE, 1);
-
 	if(!(ctx = SDL_GL_CreateContext(win))) {
 		fprintf(stderr, "failed to create OpenGL context\n");
 		return 1;
 	}
 	SDL_GL_GetDrawableSize(win, &win_width, &win_height);
+	win_aspect = (float)win_width / (float)win_height;
+
+	if(!app_init(argc, argv)) {
+		SDL_Quit();
+		return 1;
+	}
 	app_reshape(win_width, win_height);
 
 	while(!quit) {
@@ -68,6 +72,11 @@ break_evloop:
 	return 0;
 }
 
+void app_quit()
+{
+	quit = true;
+}
+
 void app_redraw()
 {
 	redraw_pending = true;
@@ -82,3 +91,36 @@ long app_get_msec()
 {
 	return SDL_GetTicks();
 }
+
+static void process_event(SDL_Event *ev)
+{
+	switch(ev->type) {
+	case SDL_QUIT:
+		quit = true;
+		break;
+
+	case SDL_KEYDOWN:
+	case SDL_KEYUP:
+		app_keyboard(ev->key.keysym.sym, ev->key.state == SDL_PRESSED);
+		break;
+
+	case SDL_MOUSEBUTTONDOWN:
+	case SDL_MOUSEBUTTONUP:
+		app_mouse_button(ev->button.button - SDL_BUTTON_LEFT, ev->button.state == SDL_PRESSED,
+				ev->button.x, ev->button.y);
+		break;
+
+	case SDL_MOUSEMOTION:
+		app_mouse_motion(ev->motion.x, ev->motion.y);
+		break;
+
+	case SDL_WINDOWEVENT:
+		if(ev->window.event == SDL_WINDOWEVENT_RESIZED) {
+			win_width = ev->window.data1;
+			win_height = ev->window.data2;
+			win_aspect = (float)win_width / (float)win_height;
+			app_reshape(win_width, win_height);
+		}
+		break;
+	}
+}
diff --git a/src/mesh.cc b/src/mesh.cc
new file mode 100644
index 0000000..d3ccc8b
--- /dev/null
+++ b/src/mesh.cc
@@ -0,0 +1,1362 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <float.h>
+#include <assert.h>
+#include "opengl.h"
+#include "mesh.h"
+//#include "xform_node.h"
+
+#define USE_OLDGL
+
+bool Mesh::use_custom_sdr_attr = true;
+int Mesh::global_sdr_loc[NUM_MESH_ATTR] = { 0, 1, 2, 3, 4, 5, 6 };
+/*
+	(int)SDR_ATTR_VERTEX,
+	(int)SDR_ATTR_NORMAL,
+	(int)SDR_ATTR_TANGENT,
+	(int)SDR_ATTR_TEXCOORD,
+	(int)SDR_ATTR_COLOR,
+	-1, -1};
+*/
+unsigned int Mesh::intersect_mode = ISECT_DEFAULT;
+float Mesh::vertex_sel_dist = 0.01;
+float Mesh::vis_vecsize = 1.0;
+
+Mesh::Mesh()
+{
+	clear();
+
+	glGenBuffers(NUM_MESH_ATTR + 1, buffer_objects);
+
+	for(int i=0; i<NUM_MESH_ATTR; i++) {
+		vattr[i].vbo = buffer_objects[i];
+	}
+	ibo = buffer_objects[NUM_MESH_ATTR];
+	wire_ibo = 0;
+}
+
+Mesh::~Mesh()
+{
+	glDeleteBuffers(NUM_MESH_ATTR + 1, buffer_objects);
+
+	if(wire_ibo) {
+		glDeleteBuffers(1, &wire_ibo);
+	}
+}
+
+Mesh::Mesh(const Mesh &rhs)
+{
+	clear();
+
+	glGenBuffers(NUM_MESH_ATTR + 1, buffer_objects);
+
+	for(int i=0; i<NUM_MESH_ATTR; i++) {
+		vattr[i].vbo = buffer_objects[i];
+	}
+	ibo = buffer_objects[NUM_MESH_ATTR];
+	wire_ibo = 0;
+
+	clone(rhs);
+}
+
+Mesh &Mesh::operator =(const Mesh &rhs)
+{
+	if(&rhs != this) {
+		clone(rhs);
+	}
+	return *this;
+}
+
+bool Mesh::clone(const Mesh &m)
+{
+	clear();
+
+	for(int i=0; i<NUM_MESH_ATTR; i++) {
+		if(m.has_attrib(i)) {
+			m.get_attrib_data(i);	// force validation of the actual data on the source mesh
+
+			vattr[i].nelem = m.vattr[i].nelem;
+			vattr[i].data = m.vattr[i].data;	// copy the actual data
+			vattr[i].data_valid = true;
+		}
+	}
+
+	if(m.is_indexed()) {
+		m.get_index_data();		// again, force validation
+
+		// copy the index data
+		idata = m.idata;
+		idata_valid = true;
+	}
+
+	name = m.name;
+	nverts = m.nverts;
+	nfaces = m.nfaces;
+
+	//bones = m.bones;
+
+	memcpy(cur_val, m.cur_val, sizeof cur_val);
+
+	aabb = m.aabb;
+	aabb_valid = m.aabb_valid;
+	bsph = m.bsph;
+	bsph_valid = m.bsph_valid;
+
+	hitface = m.hitface;
+	hitvert = m.hitvert;
+
+	intersect_mode = m.intersect_mode;
+	vertex_sel_dist = m.vertex_sel_dist;
+	vis_vecsize = m.vis_vecsize;
+
+	return true;
+}
+
+void Mesh::set_name(const char *name)
+{
+	this->name = name;
+}
+
+const char *Mesh::get_name() const
+{
+	return name.c_str();
+}
+
+bool Mesh::has_attrib(int attr) const
+{
+	if(attr < 0 || attr >= NUM_MESH_ATTR) {
+		return false;
+	}
+
+	// if neither of these is valid, then nobody has set this attribute
+	return vattr[attr].vbo_valid || vattr[attr].data_valid;
+}
+
+bool Mesh::is_indexed() const
+{
+	return ibo_valid || idata_valid;
+}
+
+void Mesh::clear()
+{
+	//bones.clear();
+
+	for(int i=0; i<NUM_MESH_ATTR; i++) {
+		vattr[i].nelem = 0;
+		vattr[i].vbo_valid = false;
+		vattr[i].data_valid = false;
+		//vattr[i].sdr_loc = -1;
+		vattr[i].data.clear();
+	}
+	ibo_valid = idata_valid = false;
+	idata.clear();
+
+	wire_ibo_valid = false;
+
+	nverts = nfaces = 0;
+
+	bsph_valid = false;
+	aabb_valid = false;
+}
+
+float *Mesh::set_attrib_data(int attrib, int nelem, unsigned int num, const float *data)
+{
+	if(attrib < 0 || attrib >= NUM_MESH_ATTR) {
+		fprintf(stderr, "%s: invalid attrib: %d\n", __FUNCTION__, attrib);
+		return 0;
+	}
+
+	if(nverts && num != nverts) {
+		fprintf(stderr, "%s: attribute count missmatch (%d instead of %d)\n", __FUNCTION__, num, nverts);
+		return 0;
+	}
+	nverts = num;
+
+	vattr[attrib].data.clear();
+	vattr[attrib].nelem = nelem;
+	vattr[attrib].data.resize(num * nelem);
+
+	if(data) {
+		memcpy(&vattr[attrib].data[0], data, num * nelem * sizeof *data);
+	}
+
+	vattr[attrib].data_valid = true;
+	vattr[attrib].vbo_valid = false;
+	return &vattr[attrib].data[0];
+}
+
+float *Mesh::get_attrib_data(int attrib)
+{
+	if(attrib < 0 || attrib >= NUM_MESH_ATTR) {
+		fprintf(stderr, "%s: invalid attrib: %d\n", __FUNCTION__, attrib);
+		return 0;
+	}
+
+	vattr[attrib].vbo_valid = false;
+	return (float*)((const Mesh*)this)->get_attrib_data(attrib);
+}
+
+const float *Mesh::get_attrib_data(int attrib) const
+{
+	if(attrib < 0 || attrib >= NUM_MESH_ATTR) {
+		fprintf(stderr, "%s: invalid attrib: %d\n", __FUNCTION__, attrib);
+		return 0;
+	}
+
+	if(!vattr[attrib].data_valid) {
+#if GL_ES_VERSION_2_0
+		fprintf(stderr, "%s: can't read back attrib data on CrippledGL ES\n", __FUNCTION__);
+		return 0;
+#else
+		if(!vattr[attrib].vbo_valid) {
+			fprintf(stderr, "%s: unavailable attrib: %d\n", __FUNCTION__, attrib);
+			return 0;
+		}
+
+		// local data copy is unavailable, grab the data from the vbo
+		Mesh *m = (Mesh*)this;
+		m->vattr[attrib].data.resize(nverts * vattr[attrib].nelem);
+
+		glBindBuffer(GL_ARRAY_BUFFER, vattr[attrib].vbo);
+		void *data = glMapBuffer(GL_ARRAY_BUFFER, GL_READ_ONLY);
+		memcpy(&m->vattr[attrib].data[0], data, nverts * vattr[attrib].nelem * sizeof(float));
+		glUnmapBuffer(GL_ARRAY_BUFFER);
+
+		vattr[attrib].data_valid = true;
+#endif
+	}
+
+	return &vattr[attrib].data[0];
+}
+
+void Mesh::set_attrib(int attrib, int idx, const Vec4 &v)
+{
+	float *data = get_attrib_data(attrib);
+	if(data) {
+		data += idx * vattr[attrib].nelem;
+		for(int i=0; i<vattr[attrib].nelem; i++) {
+			data[i] = v[i];
+		}
+	}
+}
+
+Vec4 Mesh::get_attrib(int attrib, int idx) const
+{
+	Vec4 v(0.0, 0.0, 0.0, 1.0);
+	const float *data = get_attrib_data(attrib);
+	if(data) {
+		data += idx * vattr[attrib].nelem;
+		for(int i=0; i<vattr[attrib].nelem; i++) {
+			v[i] = data[i];
+		}
+	}
+	return v;
+}
+
+int Mesh::get_attrib_count(int attrib) const
+{
+	return has_attrib(attrib) ? nverts : 0;
+}
+
+
+unsigned int *Mesh::set_index_data(int num, const unsigned int *indices)
+{
+	int nidx = nfaces * 3;
+	if(nidx && num != nidx) {
+		fprintf(stderr, "%s: index count missmatch (%d instead of %d)\n", __FUNCTION__, num, nidx);
+		return 0;
+	}
+	nfaces = num / 3;
+
+	idata.clear();
+	idata.resize(num);
+
+	if(indices) {
+		memcpy(&idata[0], indices, num * sizeof *indices);
+	}
+
+	idata_valid = true;
+	ibo_valid = false;
+
+	return &idata[0];
+}
+
+unsigned int *Mesh::get_index_data()
+{
+	ibo_valid = false;
+	return (unsigned int*)((const Mesh*)this)->get_index_data();
+}
+
+const unsigned int *Mesh::get_index_data() const
+{
+	if(!idata_valid) {
+#if GL_ES_VERSION_2_0
+		fprintf(stderr, "%s: can't read back index data in CrippledGL ES\n", __FUNCTION__);
+		return 0;
+#else
+		if(!ibo_valid) {
+			fprintf(stderr, "%s: indices unavailable\n", __FUNCTION__);
+			return 0;
+		}
+
+		// local data copy is unavailable, gram the data from the ibo
+		Mesh *m = (Mesh*)this;
+		int nidx = nfaces * 3;
+		m->idata.resize(nidx);
+
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
+		void *data = glMapBuffer(GL_ELEMENT_ARRAY_BUFFER, GL_READ_ONLY);
+		memcpy(&m->idata[0], data, nidx * sizeof(unsigned int));
+		glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER);
+
+		idata_valid = true;
+#endif
+	}
+
+	return &idata[0];
+}
+
+int Mesh::get_index_count() const
+{
+	return nfaces * 3;
+}
+
+void Mesh::append(const Mesh &mesh)
+{
+	unsigned int idxoffs = nverts;
+
+	if(!nverts) {
+		clone(mesh);
+		return;
+	}
+
+	nverts += mesh.nverts;
+	nfaces += mesh.nfaces;
+
+	for(int i=0; i<NUM_MESH_ATTR; i++) {
+		if(has_attrib(i) && mesh.has_attrib(i)) {
+			// force validating the data arrays
+			get_attrib_data(i);
+			mesh.get_attrib_data(i);
+
+			// append the mesh data
+			vattr[i].data.insert(vattr[i].data.end(), mesh.vattr[i].data.begin(), mesh.vattr[i].data.end());
+		}
+	}
+
+	if(ibo_valid || idata_valid) {
+		// make index arrays valid
+		get_index_data();
+		mesh.get_index_data();
+
+		size_t orig_sz = idata.size();
+
+		idata.insert(idata.end(), mesh.idata.begin(), mesh.idata.end());
+
+		// fixup all the new indices
+		for(size_t i=orig_sz; i<idata.size(); i++) {
+			idata[i] += idxoffs;
+		}
+	}
+
+	// fuck everything
+	wire_ibo_valid = false;
+	aabb_valid = false;
+	bsph_valid = false;
+}
+
+// assemble a complete vertex by adding all the useful attributes
+void Mesh::vertex(float x, float y, float z)
+{
+	cur_val[MESH_ATTR_VERTEX] = Vec4(x, y, z, 1.0f);
+	vattr[MESH_ATTR_VERTEX].data_valid = true;
+	vattr[MESH_ATTR_VERTEX].nelem = 3;
+
+	for(int i=0; i<NUM_MESH_ATTR; i++) {
+		if(vattr[i].data_valid) {
+			for(int j=0; j<vattr[MESH_ATTR_VERTEX].nelem; j++) {
+				vattr[i].data.push_back(cur_val[i][j]);
+			}
+		}
+		vattr[i].vbo_valid = false;
+	}
+
+	if(idata_valid) {
+		idata.clear();
+	}
+	ibo_valid = idata_valid = false;
+}
+
+void Mesh::normal(float nx, float ny, float nz)
+{
+	cur_val[MESH_ATTR_NORMAL] = Vec4(nx, ny, nz, 1.0f);
+	vattr[MESH_ATTR_NORMAL].data_valid = true;
+	vattr[MESH_ATTR_NORMAL].nelem = 3;
+}
+
+void Mesh::tangent(float tx, float ty, float tz)
+{
+	cur_val[MESH_ATTR_TANGENT] = Vec4(tx, ty, tz, 1.0f);
+	vattr[MESH_ATTR_TANGENT].data_valid = true;
+	vattr[MESH_ATTR_TANGENT].nelem = 3;
+}
+
+void Mesh::texcoord(float u, float v, float w)
+{
+	cur_val[MESH_ATTR_TEXCOORD] = Vec4(u, v, w, 1.0f);
+	vattr[MESH_ATTR_TEXCOORD].data_valid = true;
+	vattr[MESH_ATTR_TEXCOORD].nelem = 3;
+}
+
+void Mesh::boneweights(float w1, float w2, float w3, float w4)
+{
+	cur_val[MESH_ATTR_BONEWEIGHTS] = Vec4(w1, w2, w3, w4);
+	vattr[MESH_ATTR_BONEWEIGHTS].data_valid = true;
+	vattr[MESH_ATTR_BONEWEIGHTS].nelem = 4;
+}
+
+void Mesh::boneidx(int idx1, int idx2, int idx3, int idx4)
+{
+	cur_val[MESH_ATTR_BONEIDX] = Vec4(idx1, idx2, idx3, idx4);
+	vattr[MESH_ATTR_BONEIDX].data_valid = true;
+	vattr[MESH_ATTR_BONEIDX].nelem = 4;
+}
+
+int Mesh::get_poly_count() const
+{
+	if(nfaces) {
+		return nfaces;
+	}
+	if(nverts) {
+		return nverts / 3;
+	}
+	return 0;
+}
+
+/// static function
+void Mesh::set_attrib_location(int attr, int loc)
+{
+	if(attr < 0 || attr >= NUM_MESH_ATTR) {
+		return;
+	}
+	Mesh::global_sdr_loc[attr] = loc;
+}
+
+/// static function
+int Mesh::get_attrib_location(int attr)
+{
+	if(attr < 0 || attr >= NUM_MESH_ATTR) {
+		return -1;
+	}
+	return Mesh::global_sdr_loc[attr];
+}
+
+/// static function
+void Mesh::clear_attrib_locations()
+{
+	for(int i=0; i<NUM_MESH_ATTR; i++) {
+		Mesh::global_sdr_loc[i] = -1;
+	}
+}
+
+/// static function
+void Mesh::set_vis_vecsize(float sz)
+{
+	Mesh::vis_vecsize = sz;
+}
+
+float Mesh::get_vis_vecsize()
+{
+	return Mesh::vis_vecsize;
+}
+
+void Mesh::apply_xform(const Mat4 &xform)
+{
+	Mat4 dir_xform = xform.upper3x3();
+	apply_xform(xform, dir_xform);
+}
+
+void Mesh::apply_xform(const Mat4 &xform, const Mat4 &dir_xform)
+{
+	for(unsigned int i=0; i<nverts; i++) {
+		Vec4 v = get_attrib(MESH_ATTR_VERTEX, i);
+		set_attrib(MESH_ATTR_VERTEX, i, xform * v);
+
+		if(has_attrib(MESH_ATTR_NORMAL)) {
+			Vec3 n = Vec3(get_attrib(MESH_ATTR_NORMAL, i));
+			set_attrib(MESH_ATTR_NORMAL, i, Vec4(dir_xform * n));
+		}
+		if(has_attrib(MESH_ATTR_TANGENT)) {
+			Vec3 t = Vec3(get_attrib(MESH_ATTR_TANGENT, i));
+			set_attrib(MESH_ATTR_TANGENT, i, Vec4(dir_xform * t));
+		}
+	}
+}
+
+void Mesh::flip()
+{
+	flip_faces();
+	flip_normals();
+}
+
+void Mesh::flip_faces()
+{
+	if(is_indexed()) {
+		unsigned int *indices = get_index_data();
+		if(!indices) return;
+
+		int idxnum = get_index_count();
+		for(int i=0; i<idxnum; i+=3) {
+			unsigned int tmp = indices[i + 2];
+			indices[i + 2] = indices[i + 1];
+			indices[i + 1] = tmp;
+		}
+
+	} else {
+		Vec3 *verts = (Vec3*)get_attrib_data(MESH_ATTR_VERTEX);
+		if(!verts) return;
+
+		int vnum = get_attrib_count(MESH_ATTR_VERTEX);
+		for(int i=0; i<vnum; i+=3) {
+			Vec3 tmp = verts[i + 2];
+			verts[i + 2] = verts[i + 1];
+			verts[i + 1] = tmp;
+		}
+	}
+}
+
+void Mesh::flip_normals()
+{
+	Vec3 *normals = (Vec3*)get_attrib_data(MESH_ATTR_NORMAL);
+	if(!normals) return;
+
+	int num = get_attrib_count(MESH_ATTR_NORMAL);
+	for(int i=0; i<num; i++) {
+		normals[i] = -normals[i];
+	}
+}
+
+/*
+int Mesh::add_bone(XFormNode *bone)
+{
+	int idx = bones.size();
+	bones.push_back(bone);
+	return idx;
+}
+
+const XFormNode *Mesh::get_bone(int idx) const
+{
+	if(idx < 0 || idx >= (int)bones.size()) {
+		return 0;
+	}
+	return bones[idx];
+}
+
+int Mesh::get_bones_count() const
+{
+	return (int)bones.size();
+}
+*/
+
+bool Mesh::pre_draw() const
+{
+	cur_sdr = 0;
+	glGetIntegerv(GL_CURRENT_PROGRAM, &cur_sdr);
+
+	((Mesh*)this)->update_buffers();
+
+	if(!vattr[MESH_ATTR_VERTEX].vbo_valid) {
+		fprintf(stderr, "%s: invalid vertex buffer\n", __FUNCTION__);
+		return false;
+	}
+
+	if(cur_sdr && use_custom_sdr_attr) {
+		// rendering with shaders
+		if(global_sdr_loc[MESH_ATTR_VERTEX] == -1) {
+			fprintf(stderr, "%s: shader attribute location for vertices unset\n", __FUNCTION__);
+			return false;
+		}
+
+		for(int i=0; i<NUM_MESH_ATTR; i++) {
+			int loc = global_sdr_loc[i];
+			if(loc >= 0 && vattr[i].vbo_valid) {
+				glBindBuffer(GL_ARRAY_BUFFER, vattr[i].vbo);
+				glVertexAttribPointer(loc, vattr[i].nelem, GL_FLOAT, GL_FALSE, 0, 0);
+				glEnableVertexAttribArray(loc);
+			}
+		}
+	} else {
+#ifndef GL_ES_VERSION_2_0
+		// rendering with fixed-function (not available in GLES2)
+		glBindBuffer(GL_ARRAY_BUFFER, vattr[MESH_ATTR_VERTEX].vbo);
+		glVertexPointer(vattr[MESH_ATTR_VERTEX].nelem, GL_FLOAT, 0, 0);
+		glEnableClientState(GL_VERTEX_ARRAY);
+
+		if(vattr[MESH_ATTR_NORMAL].vbo_valid) {
+			glBindBuffer(GL_ARRAY_BUFFER, vattr[MESH_ATTR_NORMAL].vbo);
+			glNormalPointer(GL_FLOAT, 0, 0);
+			glEnableClientState(GL_NORMAL_ARRAY);
+		}
+		if(vattr[MESH_ATTR_TEXCOORD].vbo_valid) {
+			glBindBuffer(GL_ARRAY_BUFFER, vattr[MESH_ATTR_TEXCOORD].vbo);
+			glTexCoordPointer(vattr[MESH_ATTR_TEXCOORD].nelem, GL_FLOAT, 0, 0);
+			glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+		}
+		if(vattr[MESH_ATTR_COLOR].vbo_valid) {
+			glBindBuffer(GL_ARRAY_BUFFER, vattr[MESH_ATTR_COLOR].vbo);
+			glColorPointer(vattr[MESH_ATTR_COLOR].nelem, GL_FLOAT, 0, 0);
+			glEnableClientState(GL_COLOR_ARRAY);
+		}
+#endif
+	}
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+	return true;
+}
+
+void Mesh::draw() const
+{
+	if(!pre_draw()) return;
+
+	if(ibo_valid) {
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
+		glDrawElements(GL_TRIANGLES, nfaces * 3, GL_UNSIGNED_INT, 0);
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+	} else {
+		glDrawArrays(GL_TRIANGLES, 0, nverts);
+	}
+
+	post_draw();
+}
+
+void Mesh::post_draw() const
+{
+	if(cur_sdr && use_custom_sdr_attr) {
+		// rendered with shaders
+		for(int i=0; i<NUM_MESH_ATTR; i++) {
+			int loc = global_sdr_loc[i];
+			if(loc >= 0 && vattr[i].vbo_valid) {
+				glDisableVertexAttribArray(loc);
+			}
+		}
+	} else {
+#ifndef GL_ES_VERSION_2_0
+		// rendered with fixed-function
+		glDisableClientState(GL_VERTEX_ARRAY);
+		if(vattr[MESH_ATTR_NORMAL].vbo_valid) {
+			glDisableClientState(GL_NORMAL_ARRAY);
+		}
+		if(vattr[MESH_ATTR_TEXCOORD].vbo_valid) {
+			glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+		}
+		if(vattr[MESH_ATTR_COLOR].vbo_valid) {
+			glDisableClientState(GL_COLOR_ARRAY);
+		}
+#endif
+	}
+}
+
+void Mesh::draw_wire() const
+{
+	if(!pre_draw()) return;
+
+	((Mesh*)this)->update_wire_ibo();
+
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, wire_ibo);
+	glDrawElements(GL_LINES, nfaces * 6, GL_UNSIGNED_INT, 0);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+
+	post_draw();
+}
+
+void Mesh::draw_vertices() const
+{
+	if(!pre_draw()) return;
+
+	glDrawArrays(GL_POINTS, 0, nverts);
+
+	post_draw();
+}
+
+void Mesh::draw_normals() const
+{
+#ifdef USE_OLDGL
+	int cur_sdr = 0;
+	glGetIntegerv(GL_CURRENT_PROGRAM, &cur_sdr);
+
+	Vec3 *varr = (Vec3*)get_attrib_data(MESH_ATTR_VERTEX);
+	Vec3 *norm = (Vec3*)get_attrib_data(MESH_ATTR_NORMAL);
+	if(!varr || !norm) {
+		return;
+	}
+
+	glBegin(GL_LINES);
+	if(cur_sdr && use_custom_sdr_attr) {
+		int vert_loc = global_sdr_loc[MESH_ATTR_VERTEX];
+		if(vert_loc < 0) {
+			glEnd();
+			return;
+		}
+
+		for(size_t i=0; i<nverts; i++) {
+			glVertexAttrib3f(vert_loc, varr[i].x, varr[i].y, varr[i].z);
+			Vec3 end = varr[i] + norm[i] * vis_vecsize;
+			glVertexAttrib3f(vert_loc, end.x, end.y, end.z);
+		}
+	} else {
+		for(size_t i=0; i<nverts; i++) {
+			glVertex3f(varr[i].x, varr[i].y, varr[i].z);
+			Vec3 end = varr[i] + norm[i] * vis_vecsize;
+			glVertex3f(end.x, end.y, end.z);
+		}
+	}
+	glEnd();
+#endif	// USE_OLDGL
+}
+
+void Mesh::draw_tangents() const
+{
+#ifdef USE_OLDGL
+	int cur_sdr = 0;
+	glGetIntegerv(GL_CURRENT_PROGRAM, &cur_sdr);
+
+	Vec3 *varr = (Vec3*)get_attrib_data(MESH_ATTR_VERTEX);
+	Vec3 *tang = (Vec3*)get_attrib_data(MESH_ATTR_TANGENT);
+	if(!varr || !tang) {
+		return;
+	}
+
+	glBegin(GL_LINES);
+	if(cur_sdr && use_custom_sdr_attr) {
+		int vert_loc = global_sdr_loc[MESH_ATTR_VERTEX];
+		if(vert_loc < 0) {
+			glEnd();
+			return;
+		}
+
+		for(size_t i=0; i<nverts; i++) {
+			glVertexAttrib3f(vert_loc, varr[i].x, varr[i].y, varr[i].z);
+			Vec3 end = varr[i] + tang[i] * vis_vecsize;
+			glVertexAttrib3f(vert_loc, end.x, end.y, end.z);
+		}
+	} else {
+		for(size_t i=0; i<nverts; i++) {
+			glVertex3f(varr[i].x, varr[i].y, varr[i].z);
+			Vec3 end = varr[i] + tang[i] * vis_vecsize;
+			glVertex3f(end.x, end.y, end.z);
+		}
+	}
+	glEnd();
+#endif	// USE_OLDGL
+}
+
+void Mesh::get_aabbox(Vec3 *vmin, Vec3 *vmax) const
+{
+	if(!aabb_valid) {
+		((Mesh*)this)->calc_aabb();
+	}
+	*vmin = aabb.min;
+	*vmax = aabb.max;
+}
+
+const AABox &Mesh::get_aabbox() const
+{
+	if(!aabb_valid) {
+		((Mesh*)this)->calc_aabb();
+	}
+	return aabb;
+}
+
+float Mesh::get_bsphere(Vec3 *center, float *rad) const
+{
+	if(!bsph_valid) {
+		((Mesh*)this)->calc_bsph();
+	}
+	*center = bsph.center;
+	*rad = bsph.radius;
+	return bsph.radius;
+}
+
+const Sphere &Mesh::get_bsphere() const
+{
+	if(!bsph_valid) {
+		((Mesh*)this)->calc_bsph();
+	}
+	return bsph;
+}
+
+/// static function
+void Mesh::set_intersect_mode(unsigned int mode)
+{
+	Mesh::intersect_mode = mode;
+}
+
+/// static function
+unsigned int Mesh::get_intersect_mode()
+{
+	return Mesh::intersect_mode;
+}
+
+/// static function
+void Mesh::set_vertex_select_distance(float dist)
+{
+	Mesh::vertex_sel_dist = dist;
+}
+
+/// static function
+float Mesh::get_vertex_select_distance()
+{
+	return Mesh::vertex_sel_dist;
+}
+
+bool Mesh::intersect(const Ray &ray, HitPoint *hit) const
+{
+	assert((Mesh::intersect_mode & (ISECT_VERTICES | ISECT_FACE)) != (ISECT_VERTICES | ISECT_FACE));
+
+	const Vec3 *varr = (Vec3*)get_attrib_data(MESH_ATTR_VERTEX);
+	const Vec3 *narr = (Vec3*)get_attrib_data(MESH_ATTR_NORMAL);
+	if(!varr) {
+		return false;
+	}
+	const unsigned int *idxarr = get_index_data();
+
+	// first test with the bounding box
+	AABox box;
+	get_aabbox(&box.min, &box.max);
+	if(!box.intersect(ray)) {
+		return false;
+	}
+
+	HitPoint nearest_hit;
+	nearest_hit.dist = FLT_MAX;
+	nearest_hit.obj = 0;
+
+	if(Mesh::intersect_mode & ISECT_VERTICES) {
+		// we asked for "intersections" with the vertices of the mesh
+		long nearest_vidx = -1;
+		float thres_sq = Mesh::vertex_sel_dist * Mesh::vertex_sel_dist;
+
+		for(unsigned int i=0; i<nverts; i++) {
+
+			if((Mesh::intersect_mode & ISECT_FRONT) && dot(narr[i], ray.dir) > 0) {
+				continue;
+			}
+
+			// project the vertex onto the ray line
+			float t = dot(varr[i] - ray.origin, ray.dir);
+			Vec3 vproj = ray.origin + ray.dir * t;
+
+			float dist_sq = length_sq(vproj - varr[i]);
+			if(dist_sq < thres_sq) {
+				if(!hit) {
+					return true;
+				}
+				if(t < nearest_hit.dist) {
+					nearest_hit.dist = t;
+					nearest_vidx = i;
+				}
+			}
+		}
+
+		if(nearest_vidx != -1) {
+			hitvert = varr[nearest_vidx];
+			nearest_hit.obj = &hitvert;
+		}
+
+	} else {
+		// regular intersection test with polygons
+
+		for(unsigned int i=0; i<nfaces; i++) {
+			Triangle face(i, varr, idxarr);
+
+			// ignore back-facing polygons if the mode flags include ISECT_FRONT
+			if((Mesh::intersect_mode & ISECT_FRONT) && dot(face.get_normal(), ray.dir) > 0) {
+				continue;
+			}
+
+			HitPoint fhit;
+			if(face.intersect(ray, hit ? &fhit : 0)) {
+				if(!hit) {
+					return true;
+				}
+				if(fhit.dist < nearest_hit.dist) {
+					nearest_hit = fhit;
+					hitface = face;
+				}
+			}
+		}
+	}
+
+	if(nearest_hit.obj) {
+		if(hit) {
+			*hit = nearest_hit;
+
+			// if we are interested in the mesh and not the faces set obj to this
+			if(Mesh::intersect_mode & ISECT_FACE) {
+				hit->obj = &hitface;
+			} else if(Mesh::intersect_mode & ISECT_VERTICES) {
+				hit->obj = &hitvert;
+			} else {
+				hit->obj = this;
+			}
+		}
+		return true;
+	}
+	return false;
+}
+
+
+// texture coordinate manipulation
+void Mesh::texcoord_apply_xform(const Mat4 &xform)
+{
+	if(!has_attrib(MESH_ATTR_TEXCOORD)) {
+		return;
+	}
+
+	for(unsigned int i=0; i<nverts; i++) {
+		Vec4 tc = get_attrib(MESH_ATTR_TEXCOORD, i);
+		set_attrib(MESH_ATTR_TEXCOORD, i, xform * tc);
+	}
+}
+
+void Mesh::texcoord_gen_plane(const Vec3 &norm, const Vec3 &tang)
+{
+	if(!nverts) return;
+
+	if(!has_attrib(MESH_ATTR_TEXCOORD)) {
+		// allocate texture coordinate attribute array
+		set_attrib_data(MESH_ATTR_TEXCOORD, 2, nverts);
+	}
+
+	Vec3 n = normalize(norm);
+	Vec3 b = normalize(cross(n, tang));
+	Vec3 t = cross(b, n);
+
+	for(unsigned int i=0; i<nverts; i++) {
+		Vec3 pos = Vec3(get_attrib(MESH_ATTR_VERTEX, i));
+
+		// distance along the tangent direction
+		float u = dot(pos, t);
+		// distance along the bitangent direction
+		float v = dot(pos, b);
+
+		set_attrib(MESH_ATTR_TEXCOORD, i, Vec4(u, v, 0, 1));
+	}
+}
+
+void Mesh::texcoord_gen_box()
+{
+	if(!nverts || !has_attrib(MESH_ATTR_NORMAL)) return;
+
+	if(!has_attrib(MESH_ATTR_TEXCOORD)) {
+		// allocate texture coordinate attribute array
+		set_attrib_data(MESH_ATTR_TEXCOORD, 2, nverts);
+	}
+
+	for(unsigned int i=0; i<nverts; i++) {
+		Vec3 pos = Vec3(get_attrib(MESH_ATTR_VERTEX, i)) * 0.5 + Vec3(0.5, 0.5, 0.5);
+		Vec3 norm = Vec3(get_attrib(MESH_ATTR_NORMAL, i));
+
+		float abs_nx = fabs(norm.x);
+		float abs_ny = fabs(norm.y);
+		float abs_nz = fabs(norm.z);
+		int dom = abs_nx > abs_ny && abs_nx > abs_nz ? 0 : (abs_ny > abs_nz ? 1 : 2);
+
+		float uv[2], *uvptr = uv;
+		for(int j=0; j<3; j++) {
+			if(j == dom) continue;	// skip dominant axis
+
+			*uvptr++ = pos[j];
+		}
+		set_attrib(MESH_ATTR_TEXCOORD, i, Vec4(uv[0], uv[1], 0, 1));
+	}
+}
+
+void Mesh::texcoord_gen_cylinder()
+{
+	if(!nverts) return;
+
+	if(!has_attrib(MESH_ATTR_TEXCOORD)) {
+		// allocate texture coordinate attribute array
+		set_attrib_data(MESH_ATTR_TEXCOORD, 2, nverts);
+	}
+
+	for(unsigned int i=0; i<nverts; i++) {
+		Vec3 pos = Vec3(get_attrib(MESH_ATTR_VERTEX, i));
+
+		float rho = sqrt(pos.x * pos.x + pos.z * pos.z);
+		float theta = rho == 0.0 ? 0.0 : atan2(pos.z / rho, pos.x / rho);
+
+		float u = theta / (2.0 * M_PI) + 0.5;
+		float v = pos.y;
+
+		set_attrib(MESH_ATTR_TEXCOORD, i, Vec4(u, v, 0, 1));
+	}
+}
+
+
+bool Mesh::dump(const char *fname) const
+{
+	FILE *fp = fopen(fname, "wb");
+	if(fp) {
+		bool res = dump(fp);
+		fclose(fp);
+		return res;
+	}
+	return false;
+}
+
+bool Mesh::dump(FILE *fp) const
+{
+	if(!has_attrib(MESH_ATTR_VERTEX)) {
+		return false;
+	}
+
+	fprintf(fp, "VERTEX ATTRIBUTES\n");
+	static const char *label[] = { "pos", "nor", "tan", "tex", "col", "bw", "bid" };
+	static const char *elemfmt[] = { 0, " %s(%g)", " %s(%g, %g)", " %s(%g, %g, %g)", " %s(%g, %g, %g, %g)", 0 };
+
+	for(int i=0; i<(int)nverts; i++) {
+		fprintf(fp, "%5u:", i);
+		for(int j=0; j<NUM_MESH_ATTR; j++) {
+			if(has_attrib(j)) {
+				Vec4 v = get_attrib(j, i);
+				int nelem = vattr[j].nelem;
+				fprintf(fp, elemfmt[nelem], label[j], v.x, v.y, v.z, v.w);
+			}
+		}
+		fputc('\n', fp);
+	}
+
+	if(is_indexed()) {
+		const unsigned int *idx = get_index_data();
+		int numidx = get_index_count();
+		int numtri = numidx / 3;
+		assert(numidx % 3 == 0);
+
+		fprintf(fp, "FACES\n");
+
+		for(int i=0; i<numtri; i++) {
+			fprintf(fp, "%5d: %d %d %d\n", i, idx[0], idx[1], idx[2]);
+			idx += 3;
+		}
+	}
+	return true;
+}
+
+bool Mesh::dump_obj(const char *fname) const
+{
+	FILE *fp = fopen(fname, "wb");
+	if(fp) {
+		bool res = dump_obj(fp);
+		fclose(fp);
+		return res;
+	}
+	return false;
+}
+
+bool Mesh::dump_obj(FILE *fp) const
+{
+	if(!has_attrib(MESH_ATTR_VERTEX)) {
+		return false;
+	}
+
+	for(int i=0; i<(int)nverts; i++) {
+		Vec4 v = get_attrib(MESH_ATTR_VERTEX, i);
+		fprintf(fp, "v %g %g %g\n", v.x, v.y, v.z);
+	}
+
+	if(has_attrib(MESH_ATTR_NORMAL)) {
+		for(int i=0; i<(int)nverts; i++) {
+			Vec4 v = get_attrib(MESH_ATTR_NORMAL, i);
+			fprintf(fp, "vn %g %g %g\n", v.x, v.y, v.z);
+		}
+	}
+
+	if(has_attrib(MESH_ATTR_TEXCOORD)) {
+		for(int i=0; i<(int)nverts; i++) {
+			Vec4 v = get_attrib(MESH_ATTR_TEXCOORD, i);
+			fprintf(fp, "vt %g %g\n", v.x, v.y);
+		}
+	}
+
+	if(is_indexed()) {
+		const unsigned int *idxptr = get_index_data();
+		int numidx = get_index_count();
+		int numtri = numidx / 3;
+		assert(numidx % 3 == 0);
+
+		for(int i=0; i<numtri; i++) {
+			fputc('f', fp);
+			for(int j=0; j<3; j++) {
+				unsigned int idx = *idxptr++ + 1;
+				fprintf(fp, " %u/%u/%u", idx, idx, idx);
+			}
+			fputc('\n', fp);
+		}
+	} else {
+		int numtri = nverts / 3;
+		unsigned int idx = 1;
+		for(int i=0; i<numtri; i++) {
+			fputc('f', fp);
+			for(int j=0; j<3; j++) {
+				fprintf(fp, " %u/%u/%u", idx, idx, idx);
+				++idx;
+			}
+			fputc('\n', fp);
+		}
+	}
+	return true;
+}
+
+// ------ private member functions ------
+
+void Mesh::calc_aabb()
+{
+	// the cast is to force calling the const version which doesn't invalidate
+	if(!((const Mesh*)this)->get_attrib_data(MESH_ATTR_VERTEX)) {
+		return;
+	}
+
+	aabb.min = Vec3(FLT_MAX, FLT_MAX, FLT_MAX);
+	aabb.max = -aabb.min;
+
+	for(unsigned int i=0; i<nverts; i++) {
+		Vec4 v = get_attrib(MESH_ATTR_VERTEX, i);
+		for(int j=0; j<3; j++) {
+			if(v[j] < aabb.min[j]) {
+				aabb.min[j] = v[j];
+			}
+			if(v[j] > aabb.max[j]) {
+				aabb.max[j] = v[j];
+			}
+		}
+	}
+	aabb_valid = true;
+}
+
+void Mesh::calc_bsph()
+{
+	// the cast is to force calling the const version which doesn't invalidate
+	if(!((const Mesh*)this)->get_attrib_data(MESH_ATTR_VERTEX)) {
+		return;
+	}
+
+	Vec3 v;
+	bsph.center = Vec3(0, 0, 0);
+
+	// first find the center
+	for(unsigned int i=0; i<nverts; i++) {
+		v = Vec3(get_attrib(MESH_ATTR_VERTEX, i));
+		bsph.center += v;
+	}
+	bsph.center /= (float)nverts;
+
+	bsph.radius = 0.0f;
+	for(unsigned int i=0; i<nverts; i++) {
+		v = Vec3(get_attrib(MESH_ATTR_VERTEX, i));
+		float dist_sq = length_sq(v - bsph.center);
+		if(dist_sq > bsph.radius) {
+			bsph.radius = dist_sq;
+		}
+	}
+	bsph.radius = sqrt(bsph.radius);
+
+	bsph_valid = true;
+}
+
+void Mesh::update_buffers()
+{
+	for(int i=0; i<NUM_MESH_ATTR; i++) {
+		if(has_attrib(i) && !vattr[i].vbo_valid) {
+			glBindBuffer(GL_ARRAY_BUFFER, vattr[i].vbo);
+			glBufferData(GL_ARRAY_BUFFER, nverts * vattr[i].nelem * sizeof(float), &vattr[i].data[0], GL_STATIC_DRAW);
+			vattr[i].vbo_valid = true;
+		}
+	}
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+	if(idata_valid && !ibo_valid) {
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
+		glBufferData(GL_ELEMENT_ARRAY_BUFFER, nfaces * 3 * sizeof(unsigned int), &idata[0], GL_STATIC_DRAW);
+		ibo_valid = true;
+	}
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+}
+
+void Mesh::update_wire_ibo()
+{
+	update_buffers();
+
+	if(wire_ibo_valid) {
+		return;
+	}
+
+	if(!wire_ibo) {
+		glGenBuffers(1, &wire_ibo);
+	}
+
+	unsigned int *wire_idxarr = new unsigned int[nfaces * 6];
+	unsigned int *dest = wire_idxarr;
+
+	if(ibo_valid) {
+		// we're dealing with an indexed mesh
+		const unsigned int *idxarr = ((const Mesh*)this)->get_index_data();
+
+		for(unsigned int i=0; i<nfaces; i++) {
+			*dest++ = idxarr[0];
+			*dest++ = idxarr[1];
+			*dest++ = idxarr[1];
+			*dest++ = idxarr[2];
+			*dest++ = idxarr[2];
+			*dest++ = idxarr[0];
+			idxarr += 3;
+		}
+	} else {
+		// not an indexed mesh ...
+		for(unsigned int i=0; i<nfaces; i++) {
+			int vidx = i * 3;
+			*dest++ = vidx;
+			*dest++ = vidx + 1;
+			*dest++ = vidx + 1;
+			*dest++ = vidx + 2;
+			*dest++ = vidx + 2;
+			*dest++ = vidx;
+		}
+	}
+
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, wire_ibo);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, nfaces * 6 * sizeof(unsigned int), wire_idxarr, GL_STATIC_DRAW);
+	delete [] wire_idxarr;
+	wire_ibo_valid = true;
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+}
+
+
+// ------ class Triangle ------
+Triangle::Triangle()
+{
+	normal_valid = false;
+	id = -1;
+}
+
+Triangle::Triangle(const Vec3 &v0, const Vec3 &v1, const Vec3 &v2)
+{
+	v[0] = v0;
+	v[1] = v1;
+	v[2] = v2;
+	normal_valid = false;
+	id = -1;
+}
+
+Triangle::Triangle(int n, const Vec3 *varr, const unsigned int *idxarr)
+{
+	if(idxarr) {
+		v[0] = varr[idxarr[n * 3]];
+		v[1] = varr[idxarr[n * 3 + 1]];
+		v[2] = varr[idxarr[n * 3 + 2]];
+	} else {
+		v[0] = varr[n * 3];
+		v[1] = varr[n * 3 + 1];
+		v[2] = varr[n * 3 + 2];
+	}
+	normal_valid = false;
+	id = n;
+}
+
+void Triangle::calc_normal()
+{
+	normal = normalize(cross(v[1] - v[0], v[2] - v[0]));
+	normal_valid = true;
+}
+
+const Vec3 &Triangle::get_normal() const
+{
+	if(!normal_valid) {
+		((Triangle*)this)->calc_normal();
+	}
+	return normal;
+}
+
+void Triangle::transform(const Mat4 &xform)
+{
+	v[0] = xform * v[0];
+	v[1] = xform * v[1];
+	v[2] = xform * v[2];
+	normal_valid = false;
+}
+
+void Triangle::draw() const
+{
+	Vec3 n[3];
+	n[0] = n[1] = n[2] = get_normal();
+
+	int vloc = Mesh::get_attrib_location(MESH_ATTR_VERTEX);
+	int nloc = Mesh::get_attrib_location(MESH_ATTR_NORMAL);
+
+	glEnableVertexAttribArray(vloc);
+	glVertexAttribPointer(vloc, 3, GL_FLOAT, GL_FALSE, 0, &v[0].x);
+	glVertexAttribPointer(nloc, 3, GL_FLOAT, GL_FALSE, 0, &n[0].x);
+
+	glDrawArrays(GL_TRIANGLES, 0, 3);
+
+	glDisableVertexAttribArray(vloc);
+	glDisableVertexAttribArray(nloc);
+}
+
+void Triangle::draw_wire() const
+{
+	static const int idxarr[] = {0, 1, 1, 2, 2, 0};
+	int vloc = Mesh::get_attrib_location(MESH_ATTR_VERTEX);
+
+	glEnableVertexAttribArray(vloc);
+	glVertexAttribPointer(vloc, 3, GL_FLOAT, GL_FALSE, 0, &v[0].x);
+
+	glDrawElements(GL_LINES, 6, GL_UNSIGNED_INT, idxarr);
+
+	glDisableVertexAttribArray(vloc);
+}
+
+Vec3 Triangle::calc_barycentric(const Vec3 &pos) const
+{
+	Vec3 norm = get_normal();
+
+	float area_sq = fabs(dot(cross(v[1] - v[0], v[2] - v[0]), norm));
+	if(area_sq < 1e-5) {
+		return Vec3(0, 0, 0);
+	}
+
+	float asq0 = fabs(dot(cross(v[1] - pos, v[2] - pos), norm));
+	float asq1 = fabs(dot(cross(v[2] - pos, v[0] - pos), norm));
+	float asq2 = fabs(dot(cross(v[0] - pos, v[1] - pos), norm));
+
+	return Vec3(asq0 / area_sq, asq1 / area_sq, asq2 / area_sq);
+}
+
+bool Triangle::intersect(const Ray &ray, HitPoint *hit) const
+{
+	Vec3 normal = get_normal();
+
+	float ndotdir = dot(ray.dir, normal);
+	if(fabs(ndotdir) < 1e-4) {
+		return false;
+	}
+
+	Vec3 vertdir = v[0] - ray.origin;
+	float t = dot(normal, vertdir) / ndotdir;
+
+	Vec3 pos = ray.origin + ray.dir * t;
+	Vec3 bary = calc_barycentric(pos);
+
+	if(bary.x + bary.y + bary.z > 1.00001) {
+		return false;
+	}
+
+	if(hit) {
+		hit->dist = t;
+		hit->pos = ray.origin + ray.dir * t;
+		hit->normal = normal;
+		hit->obj = this;
+	}
+	return true;
+}
diff --git a/src/mesh.h b/src/mesh.h
new file mode 100644
index 0000000..bff49f7
--- /dev/null
+++ b/src/mesh.h
@@ -0,0 +1,243 @@
+#ifndef MESH_H_
+#define MESH_H_
+
+#include <stdio.h>
+#include <string>
+#include <vector>
+#include "gmath/gmath.h"
+#include "geom.h"
+
+enum {
+	MESH_ATTR_VERTEX,
+	MESH_ATTR_NORMAL,
+	MESH_ATTR_TANGENT,
+	MESH_ATTR_TEXCOORD,
+	MESH_ATTR_COLOR,
+	MESH_ATTR_BONEWEIGHTS,
+	MESH_ATTR_BONEIDX,
+
+	NUM_MESH_ATTR
+};
+
+// intersection mode flags
+enum {
+	ISECT_DEFAULT	= 0,	// default (whole mesh, all intersections)
+	ISECT_FRONT		= 1,	// front-faces only
+	ISECT_FACE		= 2,	// return intersected face pointer instead of mesh
+	ISECT_VERTICES	= 4		// return (?) TODO
+};
+
+//class XFormNode;
+
+
+class Triangle {
+public:
+	Vec3 v[3];
+	Vec3 normal;
+	bool normal_valid;
+	int id;
+
+	Triangle();
+	Triangle(const Vec3 &v0, const Vec3 &v1, const Vec3 &v2);
+	Triangle(int n, const Vec3 *varr, const unsigned int *idxarr = 0);
+
+	/// calculate normal (quite expensive)
+	void calc_normal();
+	const Vec3 &get_normal() const;
+
+	void transform(const Mat4 &xform);
+
+	void draw() const;
+	void draw_wire() const;
+
+	/// calculate barycentric coordinates of a point
+	Vec3 calc_barycentric(const Vec3 &pos) const;
+
+	bool intersect(const Ray &ray, HitPoint *hit = 0) const;
+};
+
+
+class Mesh {
+private:
+	std::string name;
+	unsigned int nverts, nfaces;
+
+	// current value for each attribute for the immedate mode
+	// interface.
+	Vec4 cur_val[NUM_MESH_ATTR];
+
+	unsigned int buffer_objects[NUM_MESH_ATTR + 1];
+
+	// vertex attribute data and buffer objects
+	struct {
+		int nelem;					// number of elements per attribute range: [1, 4]
+		std::vector<float> data;
+		unsigned int vbo;
+		mutable bool vbo_valid;		// if this is false, the vbo needs updating from the data
+		mutable bool data_valid;	// if this is false, the data needs to be pulled from the vbo
+		//int sdr_loc;
+	} vattr[NUM_MESH_ATTR];
+
+	static int global_sdr_loc[NUM_MESH_ATTR];
+
+	//std::vector<XFormNode*> bones;	// bones affecting this mesh
+
+	// index data and buffer object
+	std::vector<unsigned int> idata;
+	unsigned int ibo;
+	mutable bool ibo_valid;
+	mutable bool idata_valid;
+
+	// index buffer object for wireframe rendering (constructed on demand)
+	unsigned int wire_ibo;
+	mutable bool wire_ibo_valid;
+
+	// axis-aligned bounding box
+	mutable AABox aabb;
+	mutable bool aabb_valid;
+
+	// bounding sphere
+	mutable Sphere bsph;
+	mutable bool bsph_valid;
+
+	// keeps the last intersected face
+	mutable Triangle hitface;
+	// keeps the last intersected vertex position
+	mutable Vec3 hitvert;
+
+	void calc_aabb();
+	void calc_bsph();
+
+	static unsigned int intersect_mode;
+	static float vertex_sel_dist;
+
+	static float vis_vecsize;
+
+	/// update the VBOs after data has changed (invalid vbo/ibo)
+	void update_buffers();
+	/// construct/update the wireframe index buffer (called from draw_wire).
+	void update_wire_ibo();
+
+	mutable int cur_sdr;
+	bool pre_draw() const;
+	void post_draw() const;
+
+
+public:
+	static bool use_custom_sdr_attr;
+
+	Mesh();
+	~Mesh();
+
+	Mesh(const Mesh &rhs);
+	Mesh &operator =(const Mesh &rhs);
+	bool clone(const Mesh &m);
+
+	void set_name(const char *name);
+	const char *get_name() const;
+
+	bool has_attrib(int attr) const;
+	bool is_indexed() const;
+
+	// clears everything about this mesh, and returns to the newly constructed state
+	void clear();
+
+	// access the vertex attribute data
+	// if vdata == 0, space is just allocated
+	float *set_attrib_data(int attrib, int nelem, unsigned int num, const float *vdata = 0); // invalidates vbo
+	float *get_attrib_data(int attrib);	// invalidates vbo
+	const float *get_attrib_data(int attrib) const;
+
+	// simple access to any particular attribute
+	void set_attrib(int attrib, int idx, const Vec4 &v); // invalidates vbo
+	Vec4 get_attrib(int attrib, int idx) const;
+
+	int get_attrib_count(int attrib) const;
+
+	// ... same for index data
+	unsigned int *set_index_data(int num, const unsigned int *indices = 0); // invalidates ibo
+	unsigned int *get_index_data();	// invalidates ibo
+	const unsigned int *get_index_data() const;
+
+	int get_index_count() const;
+
+	void append(const Mesh &mesh);
+
+	// immediate-mode style mesh construction interface
+	void vertex(float x, float y, float z);
+	void normal(float nx, float ny, float nz);
+	void tangent(float tx, float ty, float tz);
+	void texcoord(float u, float v, float w);
+	void boneweights(float w1, float w2, float w3, float w4);
+	void boneidx(int idx1, int idx2, int idx3, int idx4);
+
+	int get_poly_count() const;
+
+	/* apply a transformation to the vertices and its inverse-transpose
+	 * to the normals and tangents.
+	 */
+	void apply_xform(const Mat4 &xform);
+	void apply_xform(const Mat4 &xform, const Mat4 &dir_xform);
+
+	void flip();	// both faces and normals
+	void flip_faces();
+	void flip_normals();
+
+	// adds a bone and returns its index
+	/*int add_bone(XFormNode *bone);
+	const XFormNode *get_bone(int idx) const;
+	int get_bones_count() const;*/
+
+	// access the shader attribute locations
+	static void set_attrib_location(int attr, int loc);
+	static int get_attrib_location(int attr);
+	static void clear_attrib_locations();
+
+	static void set_vis_vecsize(float sz);
+	static float get_vis_vecsize();
+
+	void draw() const;
+	void draw_wire() const;
+	void draw_vertices() const;
+	void draw_normals() const;
+	void draw_tangents() const;
+
+	/** get the bounding box in local space. The result will be cached, and subsequent
+	 * calls will return the same box. The cache gets invalidated by any functions that can affect
+	 * the vertex data (non-const variant of get_attrib_data(MESH_ATTR_VERTEX, ...) included).
+	 * @{ */
+	void get_aabbox(Vec3 *vmin, Vec3 *vmax) const;
+	const AABox &get_aabbox() const;
+	/// @}
+
+	/** get the bounding sphere in local space. The result will be cached, and subsequent
+	 * calls will return the same box. The cache gets invalidated by any functions that can affect
+	 * the vertex data (non-const variant of get_attrib_data(MESH_ATTR_VERTEX, ...) included).
+	 * @{ */
+	float get_bsphere(Vec3 *center, float *rad) const;
+	const Sphere &get_bsphere() const;
+
+	static void set_intersect_mode(unsigned int mode);
+	static unsigned int get_intersect_mode();
+	static void set_vertex_select_distance(float dist);
+	static float get_vertex_select_distance();
+
+	/** Find the intersection between the mesh and a ray.
+	 * XXX Brute force at the moment, not intended to be used for anything other than picking in tools.
+	 *     If you intend to use it in a speed-critical part of the code, you'll *have* to optimize it!
+	 */
+	bool intersect(const Ray &ray, HitPoint *hit = 0) const;
+
+	// texture coordinate manipulation
+	void texcoord_apply_xform(const Mat4 &xform);
+	void texcoord_gen_plane(const Vec3 &norm, const Vec3 &tang);
+	void texcoord_gen_box();
+	void texcoord_gen_cylinder();
+
+	bool dump(const char *fname) const;
+	bool dump(FILE *fp) const;
+	bool dump_obj(const char *fname) const;
+	bool dump_obj(FILE *fp) const;
+};
+
+#endif	// MESH_H_
diff --git a/src/meshgen.cc b/src/meshgen.cc
new file mode 100644
index 0000000..412f763
--- /dev/null
+++ b/src/meshgen.cc
@@ -0,0 +1,881 @@
+#include <stdio.h>
+#include "meshgen.h"
+#include "mesh.h"
+
+// -------- sphere --------
+
+#define SURAD(u)	((u) * 2.0 * M_PI)
+#define SVRAD(v)	((v) * M_PI)
+
+static Vec3 sphvec(float theta, float phi)
+{
+	return Vec3(sin(theta) * sin(phi),
+			cos(phi),
+			cos(theta) * sin(phi));
+}
+
+void gen_sphere(Mesh *mesh, float rad, int usub, int vsub, float urange, float vrange)
+{
+	if(usub < 4) usub = 4;
+	if(vsub < 2) vsub = 2;
+
+	int uverts = usub + 1;
+	int vverts = vsub + 1;
+
+	int num_verts = uverts * vverts;
+	int num_quads = usub * vsub;
+	int num_tri = num_quads * 2;
+
+	mesh->clear();
+	Vec3 *varr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
+	Vec3 *narr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
+	Vec3 *tarr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
+	Vec2 *uvarr = (Vec2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
+	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
+
+	float du = urange / (float)(uverts - 1);
+	float dv = vrange / (float)(vverts - 1);
+
+	float u = 0.0;
+	for(int i=0; i<uverts; i++) {
+		float theta = u * 2.0 * M_PI;
+
+		float v = 0.0;
+		for(int j=0; j<vverts; j++) {
+			float phi = v * M_PI;
+
+			Vec3 pos = sphvec(theta, phi);
+
+			*varr++ = pos * rad;
+			*narr++ = pos;
+			*tarr++ = normalize(sphvec(theta + 0.1f, (float)M_PI / 2.0f) - sphvec(theta - 0.1f, (float)M_PI / 2.0f));
+			*uvarr++ = Vec2(u * urange, v * vrange);
+
+			if(i < usub && j < vsub) {
+				int idx = i * vverts + j;
+				*idxarr++ = idx;
+				*idxarr++ = idx + 1;
+				*idxarr++ = idx + vverts + 1;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts + 1;
+				*idxarr++ = idx + vverts;
+			}
+
+			v += dv;
+		}
+		u += du;
+	}
+}
+
+// ------ geosphere ------
+#define PHI		1.618034
+
+static Vec3 icosa_pt[] = {
+	Vec3(PHI, 1, 0),
+	Vec3(-PHI, 1, 0),
+	Vec3(PHI, -1, 0),
+	Vec3(-PHI, -1, 0),
+	Vec3(1, 0, PHI),
+	Vec3(1, 0, -PHI),
+	Vec3(-1, 0, PHI),
+	Vec3(-1, 0, -PHI),
+	Vec3(0, PHI, 1),
+	Vec3(0, -PHI, 1),
+	Vec3(0, PHI, -1),
+	Vec3(0, -PHI, -1)
+};
+enum { P11, P12, P13, P14, P21, P22, P23, P24, P31, P32, P33, P34 };
+static int icosa_idx[] = {
+	P11, P31, P21,
+	P11, P22, P33,
+	P13, P21, P32,
+	P13, P34, P22,
+	P12, P23, P31,
+	P12, P33, P24,
+	P14, P32, P23,
+	P14, P24, P34,
+
+	P11, P33, P31,
+	P12, P31, P33,
+	P13, P32, P34,
+	P14, P34, P32,
+
+	P21, P13, P11,
+	P22, P11, P13,
+	P23, P12, P14,
+	P24, P14, P12,
+
+	P31, P23, P21,
+	P32, P21, P23,
+	P33, P22, P24,
+	P34, P24, P22
+};
+
+static void geosphere(std::vector<Vec3> *verts, const Vec3 &v1, const Vec3 &v2, const Vec3 &v3, int iter)
+{
+	if(!iter) {
+		verts->push_back(v1);
+		verts->push_back(v2);
+		verts->push_back(v3);
+		return;
+	}
+
+	Vec3 v12 = normalize(v1 + v2);
+	Vec3 v23 = normalize(v2 + v3);
+	Vec3 v31 = normalize(v3 + v1);
+
+	geosphere(verts, v1, v12, v31, iter - 1);
+	geosphere(verts, v2, v23, v12, iter - 1);
+	geosphere(verts, v3, v31, v23, iter - 1);
+	geosphere(verts, v12, v23, v31, iter - 1);
+}
+
+void gen_geosphere(Mesh *mesh, float rad, int subdiv, bool hemi)
+{
+	int num_tri = (sizeof icosa_idx / sizeof *icosa_idx) / 3;
+
+	std::vector<Vec3> verts;
+	for(int i=0; i<num_tri; i++) {
+		Vec3 v[3];
+
+		for(int j=0; j<3; j++) {
+			int vidx = icosa_idx[i * 3 + j];
+			v[j] = normalize(icosa_pt[vidx]);
+		}
+
+		if(hemi && (v[0].y < 0.0 || v[1].y < 0.0 || v[2].y < 0.0)) {
+			continue;
+		}
+
+		geosphere(&verts, v[0], v[1], v[2], subdiv);
+	}
+
+	int num_verts = (int)verts.size();
+
+	mesh->clear();
+	Vec3 *varr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
+	Vec3 *narr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
+	Vec3 *tarr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
+	Vec2 *uvarr = (Vec2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
+
+	for(int i=0; i<num_verts; i++) {
+		*varr++ = verts[i] * rad;
+		*narr++ = verts[i];
+
+		float theta = atan2(verts[i].z, verts[i].x);
+		float phi = acos(verts[i].y);
+
+		*tarr++ = normalize(sphvec(theta + 0.1f, (float)M_PI / 2.0f) - sphvec(theta - 0.1f, (float)M_PI / 2.0f));
+
+		float u = 0.5 * theta / M_PI + 0.5;
+		float v = phi / M_PI;
+		*uvarr++ = Vec2(u, v);
+	}
+}
+
+// -------- torus -----------
+static Vec3 torusvec(float theta, float phi, float mr, float rr)
+{
+	theta = -theta;
+
+	float rx = -cos(phi) * rr + mr;
+	float ry = sin(phi) * rr;
+	float rz = 0.0;
+
+	float x = rx * sin(theta) + rz * cos(theta);
+	float y = ry;
+	float z = -rx * cos(theta) + rz * sin(theta);
+
+	return Vec3(x, y, z);
+}
+
+void gen_torus(Mesh *mesh, float mainrad, float ringrad, int usub, int vsub, float urange, float vrange)
+{
+	if(usub < 4) usub = 4;
+	if(vsub < 2) vsub = 2;
+
+	int uverts = usub + 1;
+	int vverts = vsub + 1;
+
+	int num_verts = uverts * vverts;
+	int num_quads = usub * vsub;
+	int num_tri = num_quads * 2;
+
+	mesh->clear();
+	Vec3 *varr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
+	Vec3 *narr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
+	Vec3 *tarr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
+	Vec2 *uvarr = (Vec2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
+	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
+
+	float du = urange / (float)(uverts - 1);
+	float dv = vrange / (float)(vverts - 1);
+
+	float u = 0.0;
+	for(int i=0; i<uverts; i++) {
+		float theta = u * 2.0 * M_PI;
+
+		float v = 0.0;
+		for(int j=0; j<vverts; j++) {
+			float phi = v * 2.0 * M_PI;
+
+			Vec3 pos = torusvec(theta, phi, mainrad, ringrad);
+			Vec3 cent = torusvec(theta, phi, mainrad, 0.0);
+
+			*varr++ = pos;
+			*narr++ = (pos - cent) / ringrad;
+
+			Vec3 pprev = torusvec(theta - 0.1f, phi, mainrad, ringrad);
+			Vec3 pnext = torusvec(theta + 0.1f, phi, mainrad, ringrad);
+
+			*tarr++ = normalize(pnext - pprev);
+			*uvarr++ = Vec2(u * urange, v * vrange);
+
+			if(i < usub && j < vsub) {
+				int idx = i * vverts + j;
+				*idxarr++ = idx;
+				*idxarr++ = idx + 1;
+				*idxarr++ = idx + vverts + 1;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts + 1;
+				*idxarr++ = idx + vverts;
+			}
+
+			v += dv;
+		}
+		u += du;
+	}
+}
+
+
+// -------- cylinder --------
+
+static Vec3 cylvec(float theta, float height)
+{
+	return Vec3(sin(theta), height, cos(theta));
+}
+
+void gen_cylinder(Mesh *mesh, float rad, float height, int usub, int vsub, int capsub, float urange, float vrange)
+{
+	if(usub < 4) usub = 4;
+	if(vsub < 1) vsub = 1;
+
+	int uverts = usub + 1;
+	int vverts = vsub + 1;
+
+	int num_body_verts = uverts * vverts;
+	int num_body_quads = usub * vsub;
+	int num_body_tri = num_body_quads * 2;
+
+	int capvverts = capsub ? capsub + 1 : 0;
+	int num_cap_verts = uverts * capvverts;
+	int num_cap_quads = usub * capsub;
+	int num_cap_tri = num_cap_quads * 2;
+
+	int num_verts = num_body_verts + num_cap_verts * 2;
+	int num_tri = num_body_tri + num_cap_tri * 2;
+
+	mesh->clear();
+	Vec3 *varr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
+	Vec3 *narr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
+	Vec3 *tarr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
+	Vec2 *uvarr = (Vec2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
+	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
+
+	float du = urange / (float)(uverts - 1);
+	float dv = vrange / (float)(vverts - 1);
+
+	float u = 0.0;
+	for(int i=0; i<uverts; i++) {
+		float theta = SURAD(u);
+
+		float v = 0.0;
+		for(int j=0; j<vverts; j++) {
+			float y = (v - 0.5) * height;
+			Vec3 pos = cylvec(theta, y);
+
+			*varr++ = Vec3(pos.x * rad, pos.y, pos.z * rad);
+			*narr++ = Vec3(pos.x, 0.0, pos.z);
+			*tarr++ = normalize(cylvec(theta + 0.1, 0.0) - cylvec(theta - 0.1, 0.0));
+			*uvarr++ = Vec2(u * urange, v * vrange);
+
+			if(i < usub && j < vsub) {
+				int idx = i * vverts + j;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts + 1;
+				*idxarr++ = idx + 1;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts;
+				*idxarr++ = idx + vverts + 1;
+			}
+
+			v += dv;
+		}
+		u += du;
+	}
+
+
+	// now the cap!
+	if(!capsub) {
+		return;
+	}
+
+	dv = 1.0 / (float)(capvverts - 1);
+
+	u = 0.0;
+	for(int i=0; i<uverts; i++) {
+		float theta = SURAD(u);
+
+		float v = 0.0;
+		for(int j=0; j<capvverts; j++) {
+			float r = v * rad;
+
+			Vec3 pos = cylvec(theta, height / 2.0) * r;
+			pos.y = height / 2.0;
+			Vec3 tang = normalize(cylvec(theta + 0.1, 0.0) - cylvec(theta - 0.1, 0.0));
+
+			*varr++ = pos;
+			*narr++ = Vec3(0, 1, 0);
+			*tarr++ = tang;
+			*uvarr++ = Vec2(u * urange, v);
+
+			pos.y = -height / 2.0;
+			*varr++ = pos;
+			*narr++ = Vec3(0, -1, 0);
+			*tarr++ = -tang;
+			*uvarr++ = Vec2(u * urange, v);
+
+			if(i < usub && j < capsub) {
+				unsigned int idx = num_body_verts + (i * capvverts + j) * 2;
+
+				unsigned int vidx[4] = {
+					idx,
+					idx + capvverts * 2,
+					idx + (capvverts + 1) * 2,
+					idx + 2
+				};
+
+				*idxarr++ = vidx[0];
+				*idxarr++ = vidx[2];
+				*idxarr++ = vidx[1];
+				*idxarr++ = vidx[0];
+				*idxarr++ = vidx[3];
+				*idxarr++ = vidx[2];
+
+				*idxarr++ = vidx[0] + 1;
+				*idxarr++ = vidx[1] + 1;
+				*idxarr++ = vidx[2] + 1;
+				*idxarr++ = vidx[0] + 1;
+				*idxarr++ = vidx[2] + 1;
+				*idxarr++ = vidx[3] + 1;
+			}
+
+			v += dv;
+		}
+		u += du;
+	}
+}
+
+// -------- cone --------
+
+static Vec3 conevec(float theta, float y, float height)
+{
+	float scale = 1.0 - y / height;
+	return Vec3(sin(theta) * scale, y, cos(theta) * scale);
+}
+
+void gen_cone(Mesh *mesh, float rad, float height, int usub, int vsub, int capsub, float urange, float vrange)
+{
+	if(usub < 4) usub = 4;
+	if(vsub < 1) vsub = 1;
+
+	int uverts = usub + 1;
+	int vverts = vsub + 1;
+
+	int num_body_verts = uverts * vverts;
+	int num_body_quads = usub * vsub;
+	int num_body_tri = num_body_quads * 2;
+
+	int capvverts = capsub ? capsub + 1 : 0;
+	int num_cap_verts = uverts * capvverts;
+	int num_cap_quads = usub * capsub;
+	int num_cap_tri = num_cap_quads * 2;
+
+	int num_verts = num_body_verts + num_cap_verts;
+	int num_tri = num_body_tri + num_cap_tri;
+
+	mesh->clear();
+	Vec3 *varr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
+	Vec3 *narr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
+	Vec3 *tarr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
+	Vec2 *uvarr = (Vec2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
+	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
+
+	float du = urange / (float)(uverts - 1);
+	float dv = vrange / (float)(vverts - 1);
+
+	float u = 0.0;
+	for(int i=0; i<uverts; i++) {
+		float theta = SURAD(u);
+
+		float v = 0.0;
+		for(int j=0; j<vverts; j++) {
+			float y = v * height;
+			Vec3 pos = conevec(theta, y, height);
+
+			Vec3 tang = normalize(conevec(theta + 0.1, 0.0, height) - conevec(theta - 0.1, 0.0, height));
+			Vec3 bitang = normalize(conevec(theta, y + 0.1, height) - pos);
+
+			*varr++ = Vec3(pos.x * rad, pos.y, pos.z * rad);
+			*narr++ = cross(tang, bitang);
+			*tarr++ = tang;
+			*uvarr++ = Vec2(u * urange, v * vrange);
+
+			if(i < usub && j < vsub) {
+				int idx = i * vverts + j;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts + 1;
+				*idxarr++ = idx + 1;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts;
+				*idxarr++ = idx + vverts + 1;
+			}
+
+			v += dv;
+		}
+		u += du;
+	}
+
+
+	// now the bottom cap!
+	if(!capsub) {
+		return;
+	}
+
+	dv = 1.0 / (float)(capvverts - 1);
+
+	u = 0.0;
+	for(int i=0; i<uverts; i++) {
+		float theta = SURAD(u);
+
+		float v = 0.0;
+		for(int j=0; j<capvverts; j++) {
+			float r = v * rad;
+
+			Vec3 pos = conevec(theta, 0.0, height) * r;
+			Vec3 tang = normalize(cylvec(theta + 0.1, 0.0) - cylvec(theta - 0.1, 0.0));
+
+			*varr++ = pos;
+			*narr++ = Vec3(0, -1, 0);
+			*tarr++ = tang;
+			*uvarr++ = Vec2(u * urange, v);
+
+			if(i < usub && j < capsub) {
+				unsigned int idx = num_body_verts + i * capvverts + j;
+
+				unsigned int vidx[4] = {
+					idx,
+					idx + capvverts,
+					idx + (capvverts + 1),
+					idx + 1
+				};
+
+				*idxarr++ = vidx[0];
+				*idxarr++ = vidx[1];
+				*idxarr++ = vidx[2];
+				*idxarr++ = vidx[0];
+				*idxarr++ = vidx[2];
+				*idxarr++ = vidx[3];
+			}
+
+			v += dv;
+		}
+		u += du;
+	}
+}
+
+
+// -------- plane --------
+
+void gen_plane(Mesh *mesh, float width, float height, int usub, int vsub)
+{
+	gen_heightmap(mesh, width, height, usub, vsub, 0);
+}
+
+
+// ----- heightmap ------
+
+void gen_heightmap(Mesh *mesh, float width, float height, int usub, int vsub, float (*hf)(float, float, void*), void *hfdata)
+{
+	if(usub < 1) usub = 1;
+	if(vsub < 1) vsub = 1;
+
+	mesh->clear();
+
+	int uverts = usub + 1;
+	int vverts = vsub + 1;
+	int num_verts = uverts * vverts;
+
+	int num_quads = usub * vsub;
+	int num_tri = num_quads * 2;
+
+	Vec3 *varr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
+	Vec3 *narr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
+	Vec3 *tarr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
+	Vec2 *uvarr = (Vec2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
+	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
+
+	float du = 1.0 / (float)usub;
+	float dv = 1.0 / (float)vsub;
+
+	float u = 0.0;
+	for(int i=0; i<uverts; i++) {
+		float v = 0.0;
+		for(int j=0; j<vverts; j++) {
+			float x = (u - 0.5) * width;
+			float y = (v - 0.5) * height;
+			float z = hf ? hf(u, v, hfdata) : 0.0;
+
+			Vec3 normal = Vec3(0, 0, 1);
+			if(hf) {
+				float u1z = hf(u + du, v, hfdata);
+				float v1z = hf(u, v + dv, hfdata);
+
+				Vec3 tang = Vec3(du * width, 0, u1z - z);
+				Vec3 bitan = Vec3(0, dv * height, v1z - z);
+				normal = normalize(cross(tang, bitan));
+			}
+
+			*varr++ = Vec3(x, y, z);
+			*narr++ = normal;
+			*tarr++ = Vec3(1, 0, 0);
+			*uvarr++ = Vec2(u, v);
+
+			if(i < usub && j < vsub) {
+				int idx = i * vverts + j;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts + 1;
+				*idxarr++ = idx + 1;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts;
+				*idxarr++ = idx + vverts + 1;
+			}
+
+			v += dv;
+		}
+		u += du;
+	}
+}
+
+// ----- box ------
+void gen_box(Mesh *mesh, float xsz, float ysz, float zsz, int usub, int vsub)
+{
+	static const float face_angles[][2] = {
+		{0, 0},
+		{M_PI / 2.0, 0},
+		{M_PI, 0},
+		{3.0 * M_PI / 2.0, 0},
+		{0, M_PI / 2.0},
+		{0, -M_PI / 2.0}
+	};
+
+	if(usub < 1) usub = 1;
+	if(vsub < 1) vsub = 1;
+
+	mesh->clear();
+
+	for(int i=0; i<6; i++) {
+		Mat4 xform, dir_xform;
+		Mesh m;
+
+		gen_plane(&m, 1, 1, usub, vsub);
+		xform.rotate(Vec3(face_angles[i][1], face_angles[i][0], 0));
+		dir_xform = xform;
+		xform.translate(Vec3(0, 0, 0.5));
+		m.apply_xform(xform, dir_xform);
+
+		mesh->append(m);
+	}
+
+	Mat4 scale;
+	scale.scaling(xsz, ysz, zsz);
+	mesh->apply_xform(scale, Mat4::identity);
+}
+
+/*
+void gen_box(Mesh *mesh, float xsz, float ysz, float zsz)
+{
+	mesh->clear();
+
+	const int num_faces = 6;
+	int num_verts = num_faces * 4;
+	int num_tri = num_faces * 2;
+
+	float x = xsz / 2.0;
+	float y = ysz / 2.0;
+	float z = zsz / 2.0;
+
+	Vec3 *varr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
+	Vec3 *narr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
+	Vec3 *tarr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
+	Vec2 *uvarr = (Vec2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
+	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
+
+	static const Vec2 uv[] = { Vec2(0, 0), Vec2(1, 0), Vec2(1, 1), Vec2(0, 1) };
+
+	// front
+	for(int i=0; i<4; i++) {
+		*narr++ = Vec3(0, 0, 1);
+		*tarr++ = Vec3(1, 0, 0);
+		*uvarr++ = uv[i];
+	}
+	*varr++ = Vec3(-x, -y, z);
+	*varr++ = Vec3(x, -y, z);
+	*varr++ = Vec3(x, y, z);
+	*varr++ = Vec3(-x, y, z);
+	// right
+	for(int i=0; i<4; i++) {
+		*narr++ = Vec3(1, 0, 0);
+		*tarr++ = Vec3(0, 0, -1);
+		*uvarr++ = uv[i];
+	}
+	*varr++ = Vec3(x, -y, z);
+	*varr++ = Vec3(x, -y, -z);
+	*varr++ = Vec3(x, y, -z);
+	*varr++ = Vec3(x, y, z);
+	// back
+	for(int i=0; i<4; i++) {
+		*narr++ = Vec3(0, 0, -1);
+		*tarr++ = Vec3(-1, 0, 0);
+		*uvarr++ = uv[i];
+	}
+	*varr++ = Vec3(x, -y, -z);
+	*varr++ = Vec3(-x, -y, -z);
+	*varr++ = Vec3(-x, y, -z);
+	*varr++ = Vec3(x, y, -z);
+	// left
+	for(int i=0; i<4; i++) {
+		*narr++ = Vec3(-1, 0, 0);
+		*tarr++ = Vec3(0, 0, 1);
+		*uvarr++ = uv[i];
+	}
+	*varr++ = Vec3(-x, -y, -z);
+	*varr++ = Vec3(-x, -y, z);
+	*varr++ = Vec3(-x, y, z);
+	*varr++ = Vec3(-x, y, -z);
+	// top
+	for(int i=0; i<4; i++) {
+		*narr++ = Vec3(0, 1, 0);
+		*tarr++ = Vec3(1, 0, 0);
+		*uvarr++ = uv[i];
+	}
+	*varr++ = Vec3(-x, y, z);
+	*varr++ = Vec3(x, y, z);
+	*varr++ = Vec3(x, y, -z);
+	*varr++ = Vec3(-x, y, -z);
+	// bottom
+	for(int i=0; i<4; i++) {
+		*narr++ = Vec3(0, -1, 0);
+		*tarr++ = Vec3(1, 0, 0);
+		*uvarr++ = uv[i];
+	}
+	*varr++ = Vec3(-x, -y, -z);
+	*varr++ = Vec3(x, -y, -z);
+	*varr++ = Vec3(x, -y, z);
+	*varr++ = Vec3(-x, -y, z);
+
+	// index array
+	static const int faceidx[] = {0, 1, 2, 0, 2, 3};
+	for(int i=0; i<num_faces; i++) {
+		for(int j=0; j<6; j++) {
+			*idxarr++ = faceidx[j] + i * 4;
+		}
+	}
+}
+*/
+
+static inline Vec3 rev_vert(float u, float v, Vec2 (*rf)(float, float, void*), void *cls)
+{
+	Vec2 pos = rf(u, v, cls);
+
+	float angle = u * 2.0 * M_PI;
+	float x = pos.x * cos(angle);
+	float y = pos.y;
+	float z = pos.x * sin(angle);
+
+	return Vec3(x, y, z);
+}
+
+// ------ surface of revolution -------
+void gen_revol(Mesh *mesh, int usub, int vsub, Vec2 (*rfunc)(float, float, void*), void *cls)
+{
+	gen_revol(mesh, usub, vsub, rfunc, 0, cls);
+}
+
+void gen_revol(Mesh *mesh, int usub, int vsub, Vec2 (*rfunc)(float, float, void*),
+		Vec2 (*nfunc)(float, float, void*), void *cls)
+{
+	if(!rfunc) return;
+	if(usub < 3) usub = 3;
+	if(vsub < 1) vsub = 1;
+
+	mesh->clear();
+
+	int uverts = usub + 1;
+	int vverts = vsub + 1;
+	int num_verts = uverts * vverts;
+
+	int num_quads = usub * vsub;
+	int num_tri = num_quads * 2;
+
+	Vec3 *varr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
+	Vec3 *narr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
+	Vec3 *tarr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
+	Vec2 *uvarr = (Vec2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
+	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
+
+	float du = 1.0 / (float)(uverts - 1);
+	float dv = 1.0 / (float)(vverts - 1);
+
+	float u = 0.0;
+	for(int i=0; i<uverts; i++) {
+		float v = 0.0;
+		for(int j=0; j<vverts; j++) {
+			Vec3 pos = rev_vert(u, v, rfunc, cls);
+
+			Vec3 nextu = rev_vert(fmod(u + du, 1.0), v, rfunc, cls);
+			Vec3 tang = nextu - pos;
+			if(length_sq(tang) < 1e-6) {
+				float new_v = v > 0.5 ? v - dv * 0.25 : v + dv * 0.25;
+				nextu = rev_vert(fmod(u + du, 1.0), new_v, rfunc, cls);
+				tang = nextu - pos;
+			}
+
+			Vec3 normal;
+			if(nfunc) {
+				normal = rev_vert(u, v, nfunc, cls);
+			} else {
+				Vec3 nextv = rev_vert(u, v + dv, rfunc, cls);
+				Vec3 bitan = nextv - pos;
+				if(length_sq(bitan) < 1e-6) {
+					nextv = rev_vert(u, v - dv, rfunc, cls);
+					bitan = pos - nextv;
+				}
+
+				normal = cross(tang, bitan);
+			}
+
+			*varr++ = pos;
+			*narr++ = normalize(normal);
+			*tarr++ = normalize(tang);
+			*uvarr++ = Vec2(u, v);
+
+			if(i < usub && j < vsub) {
+				int idx = i * vverts + j;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts + 1;
+				*idxarr++ = idx + 1;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts;
+				*idxarr++ = idx + vverts + 1;
+			}
+
+			v += dv;
+		}
+		u += du;
+	}
+}
+
+
+static inline Vec3 sweep_vert(float u, float v, float height, Vec2 (*sf)(float, float, void*), void *cls)
+{
+	Vec2 pos = sf(u, v, cls);
+
+	float x = pos.x;
+	float y = v * height;
+	float z = pos.y;
+
+	return Vec3(x, y, z);
+}
+
+// ---- sweep shape along a path ----
+void gen_sweep(Mesh *mesh, float height, int usub, int vsub, Vec2 (*sfunc)(float, float, void*), void *cls)
+{
+	if(!sfunc) return;
+	if(usub < 3) usub = 3;
+	if(vsub < 1) vsub = 1;
+
+	mesh->clear();
+
+	int uverts = usub + 1;
+	int vverts = vsub + 1;
+	int num_verts = uverts * vverts;
+
+	int num_quads = usub * vsub;
+	int num_tri = num_quads * 2;
+
+	Vec3 *varr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_VERTEX, 3, num_verts, 0);
+	Vec3 *narr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_NORMAL, 3, num_verts, 0);
+	Vec3 *tarr = (Vec3*)mesh->set_attrib_data(MESH_ATTR_TANGENT, 3, num_verts, 0);
+	Vec2 *uvarr = (Vec2*)mesh->set_attrib_data(MESH_ATTR_TEXCOORD, 2, num_verts, 0);
+	unsigned int *idxarr = mesh->set_index_data(num_tri * 3, 0);
+
+	float du = 1.0 / (float)(uverts - 1);
+	float dv = 1.0 / (float)(vverts - 1);
+
+	float u = 0.0;
+	for(int i=0; i<uverts; i++) {
+		float v = 0.0;
+		for(int j=0; j<vverts; j++) {
+			Vec3 pos = sweep_vert(u, v, height, sfunc, cls);
+
+			Vec3 nextu = sweep_vert(fmod(u + du, 1.0), v, height, sfunc, cls);
+			Vec3 tang = nextu - pos;
+			if(length_sq(tang) < 1e-6) {
+				float new_v = v > 0.5 ? v - dv * 0.25 : v + dv * 0.25;
+				nextu = sweep_vert(fmod(u + du, 1.0), new_v, height, sfunc, cls);
+				tang = nextu - pos;
+			}
+
+			Vec3 normal;
+			Vec3 nextv = sweep_vert(u, v + dv, height, sfunc, cls);
+			Vec3 bitan = nextv - pos;
+			if(length_sq(bitan) < 1e-6) {
+				nextv = sweep_vert(u, v - dv, height, sfunc, cls);
+				bitan = pos - nextv;
+			}
+
+			normal = cross(tang, bitan);
+
+			*varr++ = pos;
+			*narr++ = normalize(normal);
+			*tarr++ = normalize(tang);
+			*uvarr++ = Vec2(u, v);
+
+			if(i < usub && j < vsub) {
+				int idx = i * vverts + j;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts + 1;
+				*idxarr++ = idx + 1;
+
+				*idxarr++ = idx;
+				*idxarr++ = idx + vverts;
+				*idxarr++ = idx + vverts + 1;
+			}
+
+			v += dv;
+		}
+		u += du;
+	}
+}
diff --git a/src/meshgen.h b/src/meshgen.h
new file mode 100644
index 0000000..f154c24
--- /dev/null
+++ b/src/meshgen.h
@@ -0,0 +1,23 @@
+#ifndef MESHGEN_H_
+#define MESHGEN_H_
+
+#include "gmath/gmath.h"
+
+class Mesh;
+
+void gen_sphere(Mesh *mesh, float rad, int usub, int vsub, float urange = 1.0, float vrange = 1.0);
+void gen_geosphere(Mesh *mesh, float rad, int subdiv, bool hemi = false);
+void gen_torus(Mesh *mesh, float mainrad, float ringrad, int usub, int vsub, float urange = 1.0, float vrange = 1.0);
+void gen_cylinder(Mesh *mesh, float rad, float height, int usub, int vsub, int capsub = 0, float urange = 1.0, float vrange = 1.0);
+void gen_cone(Mesh *mesh, float rad, float height, int usub, int vsub, int capsub = 0, float urange = 1.0, float vrange = 1.0);
+void gen_plane(Mesh *mesh, float width, float height, int usub = 1, int vsub = 1);
+void gen_heightmap(Mesh *mesh, float width, float height, int usub, int vsub, float (*hf)(float, float, void*), void *hfdata = 0);
+void gen_box(Mesh *mesh, float xsz, float ysz, float zsz, int usub = 1, int vsub = 1);
+
+void gen_revol(Mesh *mesh, int usub, int vsub, Vec2 (*rfunc)(float, float, void*), void *cls = 0);
+void gen_revol(Mesh *mesh, int usub, int vsub, Vec2 (*rfunc)(float, float, void*), Vec2 (*nfunc)(float, float, void*), void *cls);
+
+/* callback args: (float u, float v, void *cls) -> Vec2 XZ offset u,v in [0, 1] */
+void gen_sweep(Mesh *mesh, float height, int usub, int vsub, Vec2 (*sfunc)(float, float, void*), void *cls = 0);
+
+#endif	// MESHGEN_H_
diff --git a/src/opengl.c b/src/opengl.c
new file mode 100644
index 0000000..78b5591
--- /dev/null
+++ b/src/opengl.c
@@ -0,0 +1,9 @@
+#include "opengl.h"
+
+int init_opengl(void)
+{
+#ifdef __glew_h__
+	glewInit();
+#endif
+	return 0;
+}
diff --git a/src/opengl.h b/src/opengl.h
new file mode 100644
index 0000000..6d5387e
--- /dev/null
+++ b/src/opengl.h
@@ -0,0 +1,43 @@
+#ifndef OPENGL_H_
+#define OPENGL_H_
+
+#ifdef HAVE_CONFIG_H_
+#include "config.h"
+#endif
+
+#if defined(IPHONE) || defined(__IPHONE__)
+#include <OpenGLES/ES2/gl.h>
+
+#define glClearDepth	glClearDepthf
+#define GLDEF
+#include "sanegl.h"
+
+#elif defined(ANDROID)
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+#define GLDEF
+#include "sanegl.h"
+
+#else
+
+#include <GL/glew.h>
+
+#ifdef __APPLE__
+#include <GLUT/glut.h>
+#else
+#include <GL/glut.h>
+#endif	/* __APPLE__ */
+
+#endif	/* IPHONE */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int init_opengl(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* OPENGL_H_ */
diff --git a/src/sdr.c b/src/sdr.c
new file mode 100644
index 0000000..7103fb0
--- /dev/null
+++ b/src/sdr.c
@@ -0,0 +1,407 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <assert.h>
+#include "opengl.h"
+
+#if defined(unix) || defined(__unix__)
+#include <unistd.h>
+#include <sys/stat.h>
+#endif	/* unix */
+
+#include "sdr.h"
+
+static const char *sdrtypestr(unsigned int sdrtype);
+
+unsigned int create_vertex_shader(const char *src)
+{
+	return create_shader(src, GL_VERTEX_SHADER);
+}
+
+unsigned int create_pixel_shader(const char *src)
+{
+	return create_shader(src, GL_FRAGMENT_SHADER);
+}
+
+unsigned int create_tessctl_shader(const char *src)
+{
+#ifdef GL_TESS_CONTROL_SHADER
+	return create_shader(src, GL_TESS_CONTROL_SHADER);
+#else
+	return 0;
+#endif
+}
+
+unsigned int create_tesseval_shader(const char *src)
+{
+#ifdef GL_TESS_EVALUATION_SHADER
+	return create_shader(src, GL_TESS_EVALUATION_SHADER);
+#else
+	return 0;
+#endif
+}
+
+unsigned int create_geometry_shader(const char *src)
+{
+#ifdef GL_GEOMETRY_SHADER
+	return create_shader(src, GL_GEOMETRY_SHADER);
+#else
+	return 0;
+#endif
+}
+
+unsigned int create_shader(const char *src, unsigned int sdr_type)
+{
+	unsigned int sdr;
+	int success, info_len;
+	char *info_str = 0;
+	GLenum err;
+
+	sdr = glCreateShader(sdr_type);
+	assert(glGetError() == GL_NO_ERROR);
+	glShaderSource(sdr, 1, &src, 0);
+	err = glGetError();
+	assert(err == GL_NO_ERROR);
+	glCompileShader(sdr);
+	assert(glGetError() == GL_NO_ERROR);
+
+	glGetShaderiv(sdr, GL_COMPILE_STATUS, &success);
+	assert(glGetError() == GL_NO_ERROR);
+	glGetShaderiv(sdr, GL_INFO_LOG_LENGTH, &info_len);
+	assert(glGetError() == GL_NO_ERROR);
+
+	if(info_len) {
+		if((info_str = malloc(info_len + 1))) {
+			glGetShaderInfoLog(sdr, info_len, 0, info_str);
+			assert(glGetError() == GL_NO_ERROR);
+			info_str[info_len] = 0;
+		}
+	}
+
+	if(success) {
+		fprintf(stderr, info_str ? "done: %s\n" : "done\n", info_str);
+	} else {
+		fprintf(stderr, info_str ? "failed: %s\n" : "failed\n", info_str);
+		glDeleteShader(sdr);
+		sdr = 0;
+	}
+
+	free(info_str);
+	return sdr;
+}
+
+void free_shader(unsigned int sdr)
+{
+	glDeleteShader(sdr);
+}
+
+unsigned int load_vertex_shader(const char *fname)
+{
+	return load_shader(fname, GL_VERTEX_SHADER);
+}
+
+unsigned int load_pixel_shader(const char *fname)
+{
+	return load_shader(fname, GL_FRAGMENT_SHADER);
+}
+
+unsigned int load_tessctl_shader(const char *fname)
+{
+#ifdef GL_TESS_CONTROL_SHADER
+	return load_shader(fname, GL_TESS_CONTROL_SHADER);
+#else
+	return 0;
+#endif
+}
+
+unsigned int load_tesseval_shader(const char *fname)
+{
+#ifdef GL_TESS_EVALUATION_SHADER
+	return load_shader(fname, GL_TESS_EVALUATION_SHADER);
+#else
+	return 0;
+#endif
+}
+
+unsigned int load_geometry_shader(const char *fname)
+{
+#ifdef GL_GEOMETRY_SHADER
+	return load_shader(fname, GL_GEOMETRY_SHADER);
+#else
+	return 0;
+#endif
+}
+
+unsigned int load_shader(const char *fname, unsigned int sdr_type)
+{
+	unsigned int sdr;
+	size_t filesize;
+	FILE *fp;
+	char *src;
+
+	if(!(fp = fopen(fname, "rb"))) {
+		fprintf(stderr, "failed to open shader %s: %s\n", fname, strerror(errno));
+		return 0;
+	}
+
+	fseek(fp, 0, SEEK_END);
+	filesize = ftell(fp);
+	fseek(fp, 0, SEEK_SET);
+
+	if(!(src = malloc(filesize + 1))) {
+		fclose(fp);
+		return 0;
+	}
+	fread(src, 1, filesize, fp);
+	src[filesize] = 0;
+	fclose(fp);
+
+	fprintf(stderr, "compiling %s shader: %s... ", sdrtypestr(sdr_type), fname);
+	sdr = create_shader(src, sdr_type);
+
+	free(src);
+	return sdr;
+}
+
+
+/* ---- gpu programs ---- */
+
+unsigned int create_program(void)
+{
+	unsigned int prog = glCreateProgram();
+	assert(glGetError() == GL_NO_ERROR);
+	return prog;
+}
+
+unsigned int create_program_link(unsigned int sdr0, ...)
+{
+	unsigned int prog, sdr;
+	va_list ap;
+
+	if(!(prog = create_program())) {
+		return 0;
+	}
+
+	attach_shader(prog, sdr0);
+	if(glGetError()) {
+		return 0;
+	}
+
+	va_start(ap, sdr0);
+	while((sdr = va_arg(ap, unsigned int))) {
+		attach_shader(prog, sdr);
+		if(glGetError()) {
+			return 0;
+		}
+	}
+	va_end(ap);
+
+	if(link_program(prog) == -1) {
+		free_program(prog);
+		return 0;
+	}
+	return prog;
+}
+
+unsigned int create_program_load(const char *vfile, const char *pfile)
+{
+	unsigned int vs = 0, ps = 0;
+
+	if(vfile && *vfile && !(vs = load_vertex_shader(vfile))) {
+		return 0;
+	}
+	if(pfile && *pfile && !(ps = load_pixel_shader(pfile))) {
+		return 0;
+	}
+	return create_program_link(vs, ps, 0);
+}
+
+void free_program(unsigned int sdr)
+{
+	glDeleteProgram(sdr);
+}
+
+void attach_shader(unsigned int prog, unsigned int sdr)
+{
+	int err;
+
+	if(prog && sdr) {
+		assert(glGetError() == GL_NO_ERROR);
+		glAttachShader(prog, sdr);
+		if((err = glGetError()) != GL_NO_ERROR) {
+			fprintf(stderr, "failed to attach shader %u to program %u (err: 0x%x)\n", sdr, prog, err);
+			abort();
+		}
+	}
+}
+
+int link_program(unsigned int prog)
+{
+	int linked, info_len, retval = 0;
+	char *info_str = 0;
+
+	glLinkProgram(prog);
+	assert(glGetError() == GL_NO_ERROR);
+	glGetProgramiv(prog, GL_LINK_STATUS, &linked);
+	assert(glGetError() == GL_NO_ERROR);
+	glGetProgramiv(prog, GL_INFO_LOG_LENGTH, &info_len);
+	assert(glGetError() == GL_NO_ERROR);
+
+	if(info_len) {
+		if((info_str = malloc(info_len + 1))) {
+			glGetProgramInfoLog(prog, info_len, 0, info_str);
+			assert(glGetError() == GL_NO_ERROR);
+			info_str[info_len] = 0;
+		}
+	}
+
+	if(linked) {
+		fprintf(stderr, info_str ? "linking done: %s\n" : "linking done\n", info_str);
+	} else {
+		fprintf(stderr, info_str ? "linking failed: %s\n" : "linking failed\n", info_str);
+		retval = -1;
+	}
+
+	free(info_str);
+	return retval;
+}
+
+int bind_program(unsigned int prog)
+{
+	GLenum err;
+
+	glUseProgram(prog);
+	if(prog && (err = glGetError()) != GL_NO_ERROR) {
+		/* maybe the program is not linked, try linking first */
+		if(err == GL_INVALID_OPERATION) {
+			if(link_program(prog) == -1) {
+				return -1;
+			}
+			glUseProgram(prog);
+			return glGetError() == GL_NO_ERROR ? 0 : -1;
+		}
+		return -1;
+	}
+	return 0;
+}
+
+/* ugly but I'm not going to write the same bloody code over and over */
+#define BEGIN_UNIFORM_CODE \
+	int loc, curr_prog; \
+	glGetIntegerv(GL_CURRENT_PROGRAM, &curr_prog); \
+	if((unsigned int)curr_prog != prog && bind_program(prog) == -1) { \
+		return -1; \
+	} \
+	if((loc = glGetUniformLocation(prog, name)) != -1)
+
+#define END_UNIFORM_CODE \
+	if((unsigned int)curr_prog != prog) { \
+		bind_program(curr_prog); \
+	} \
+	return loc == -1 ? -1 : 0
+
+int set_uniform_int(unsigned int prog, const char *name, int val)
+{
+	BEGIN_UNIFORM_CODE {
+		glUniform1i(loc, val);
+	}
+	END_UNIFORM_CODE;
+}
+
+int set_uniform_float(unsigned int prog, const char *name, float val)
+{
+	BEGIN_UNIFORM_CODE {
+		glUniform1f(loc, val);
+	}
+	END_UNIFORM_CODE;
+}
+
+int set_uniform_float2(unsigned int prog, const char *name, float x, float y)
+{
+	BEGIN_UNIFORM_CODE {
+		glUniform2f(loc, x, y);
+	}
+	END_UNIFORM_CODE;
+}
+
+int set_uniform_float3(unsigned int prog, const char *name, float x, float y, float z)
+{
+	BEGIN_UNIFORM_CODE {
+		glUniform3f(loc, x, y, z);
+	}
+	END_UNIFORM_CODE;
+}
+
+int set_uniform_float4(unsigned int prog, const char *name, float x, float y, float z, float w)
+{
+	BEGIN_UNIFORM_CODE {
+		glUniform4f(loc, x, y, z, w);
+	}
+	END_UNIFORM_CODE;
+}
+
+int set_uniform_matrix4(unsigned int prog, const char *name, float *mat)
+{
+	BEGIN_UNIFORM_CODE {
+		glUniformMatrix4fv(loc, 1, GL_FALSE, mat);
+	}
+	END_UNIFORM_CODE;
+}
+
+int set_uniform_matrix4_transposed(unsigned int prog, const char *name, float *mat)
+{
+	BEGIN_UNIFORM_CODE {
+		glUniformMatrix4fv(loc, 1, GL_TRUE, mat);
+	}
+	END_UNIFORM_CODE;
+}
+
+int get_attrib_loc(unsigned int prog, const char *name)
+{
+	int loc, curr_prog;
+
+	glGetIntegerv(GL_CURRENT_PROGRAM, &curr_prog);
+	if((unsigned int)curr_prog != prog && bind_program(prog) == -1) {
+		return -1;
+	}
+
+	loc = glGetAttribLocation(prog, (char*)name);
+
+	if((unsigned int)curr_prog != prog) {
+		bind_program(curr_prog);
+	}
+	return loc;
+}
+
+void set_attrib_float3(int attr_loc, float x, float y, float z)
+{
+	glVertexAttrib3f(attr_loc, x, y, z);
+}
+
+static const char *sdrtypestr(unsigned int sdrtype)
+{
+	switch(sdrtype) {
+	case GL_VERTEX_SHADER:
+		return "vertex";
+	case GL_FRAGMENT_SHADER:
+		return "pixel";
+#ifdef GL_TESS_CONTROL_SHADER
+	case GL_TESS_CONTROL_SHADER:
+		return "tessellation control";
+#endif
+#ifdef GL_TESS_EVALUATION_SHADER
+	case GL_TESS_EVALUATION_SHADER:
+		return "tessellation evaluation";
+#endif
+#ifdef GL_GEOMETRY_SHADER
+	case GL_GEOMETRY_SHADER:
+		return "geometry";
+#endif
+
+	default:
+		break;
+	}
+	return "<unknown>";
+}
diff --git a/src/sdr.h b/src/sdr.h
new file mode 100644
index 0000000..df23bcd
--- /dev/null
+++ b/src/sdr.h
@@ -0,0 +1,52 @@
+#ifndef SDR_H_
+#define SDR_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif	/* __cplusplus */
+
+/* ---- shaders ---- */
+unsigned int create_vertex_shader(const char *src);
+unsigned int create_pixel_shader(const char *src);
+unsigned int create_tessctl_shader(const char *src);
+unsigned int create_tesseval_shader(const char *src);
+unsigned int create_geometry_shader(const char *src);
+unsigned int create_shader(const char *src, unsigned int sdr_type);
+void free_shader(unsigned int sdr);
+
+unsigned int load_vertex_shader(const char *fname);
+unsigned int load_pixel_shader(const char *fname);
+unsigned int load_tessctl_shader(const char *fname);
+unsigned int load_tesseval_shader(const char *fname);
+unsigned int load_geometry_shader(const char *fname);
+unsigned int load_shader(const char *src, unsigned int sdr_type);
+
+int add_shader(const char *fname, unsigned int sdr);
+int remove_shader(const char *fname);
+
+/* ---- gpu programs ---- */
+unsigned int create_program(void);
+unsigned int create_program_link(unsigned int sdr0, ...);
+unsigned int create_program_load(const char *vfile, const char *pfile);
+void free_program(unsigned int sdr);
+
+void attach_shader(unsigned int prog, unsigned int sdr);
+int link_program(unsigned int prog);
+int bind_program(unsigned int prog);
+
+int set_uniform_int(unsigned int prog, const char *name, int val);
+int set_uniform_float(unsigned int prog, const char *name, float val);
+int set_uniform_float2(unsigned int prog, const char *name, float x, float y);
+int set_uniform_float3(unsigned int prog, const char *name, float x, float y, float z);
+int set_uniform_float4(unsigned int prog, const char *name, float x, float y, float z, float w);
+int set_uniform_matrix4(unsigned int prog, const char *name, float *mat);
+int set_uniform_matrix4_transposed(unsigned int prog, const char *name, float *mat);
+
+int get_attrib_loc(unsigned int prog, const char *name);
+void set_attrib_float3(int attr_loc, float x, float y, float z);
+
+#ifdef __cplusplus
+}
+#endif	/* __cplusplus */
+
+#endif	/* SDR_H_ */