X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=csgray;a=blobdiff_plain;f=src%2Fcsgray.c;h=35bb5a84bd6bf8ac640349458108ab5c6412ebc0;hp=2c60be37bb69f30614744397acf8aa048ef013b9;hb=07f86df1b104515376419c7a214253fb435fc396;hpb=d7bf88ecc329f85167bcb420909773ba21078001

diff --git a/src/csgray.c b/src/csgray.c
index 2c60be3..35bb5a8 100644
--- a/src/csgray.c
+++ b/src/csgray.c
@@ -1,64 +1,29 @@
-#include "csgray.h"
-
-enum {
-	OB_NULL,
-	OB_SPHERE,
-	OB_CYLINDER,
-	OB_PLANE,
-	OB_BOX,
-	OB_UNION,
-	OB_INTERSECTION,
-	OB_SUBTRACTION
-};
-
-struct object {
-	int type;
-
-	float r, g, b;
-	float emr, emg, emb;
-	float roughness;
-	float opacity;
-
-	float xform[16];
-
-	struct object *next;
-	struct object *clist, *ctail;
-	struct object *parent;
-};
-
-struct sphere {
-	struct object ob;
-	float rad;
-};
-
-struct plane {
-	struct object ob;
-	float nx, ny, nz;
-	float d;
-};
-
-union csg_object {
-	struct object ob;
-	struct sphere sph;
-	struct plane plane;
-};
-
-struct camera {
-	float x, y, z;
-	float tx, ty, tz;
-	float fov;
-};
-
-static camera cam;
-static object *root;
-static float identity[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <float.h>
+#include "csgimpl.h"
+#include "matrix.h"
+#include "geom.h"
+
+static void calc_primary_ray(struct ray *ray, int x, int y, int w, int h, float aspect);
+static int ray_trace(struct ray *ray, float *col);
+static void shade(float *col, struct ray *ray, struct hit *hit);
+static void background(float *col, struct ray *ray);
+static int find_intersection(struct ray *ray, struct hit *best);
+
+static float ambient[3];
+static struct camera cam;
+static csg_object *oblist;
+static csg_object *plights;
 
 int csg_init(void)
 {
-	if(!(root = csg_null(0, 0, 0))) {
-		return -1;
-	}
+	oblist = 0;
+	plights = 0;
 
+	csg_ambient(0, 0, 0);
 	csg_view(0, 0, 5, 0, 0, 0);
 	csg_fov(50);
 
@@ -67,8 +32,12 @@ int csg_init(void)
 
 void csg_destroy(void)
 {
-	csg_free_object(root);
-	root = 0;
+	while(oblist) {
+		csg_object *o = oblist;
+		oblist = oblist->ob.next;
+		csg_free_object(o);
+	}
+	oblist = 0;
 }
 
 void csg_view(float x, float y, float z, float tx, float ty, float tz)
@@ -97,115 +66,390 @@ int csg_save(const char *fname)
 	return 0;	/* TODO */
 }
 
-void csg_add_object(csg_object *parent, csg_object *child)
+void csg_add_object(csg_object *o)
 {
-	if(parent->clist) {
-		parent->ctail->next = child;
-		parent->ctail = child;
-	} else {
-		parent->clist = parent->ctail = child;
+	o->ob.next = oblist;
+	oblist = o;
+
+	if(o->ob.type == OB_NULL && (o->ob.emr > 0.0f || o->ob.emg > 0.0f || o->ob.emb > 0.0f)) {
+		o->ob.plt_next = plights;
+		plights = o;
 	}
-	child->parent = parent;
 }
 
-void csg_remove_object(csg_object *parent, csg_object *child)
+int csg_remove_object(csg_object *o)
 {
-	csg_object *c = parent->clist;
-	while(c->next) {
-		if(c->next == child) {
-			c->next = child->next;
-			child->next = 0;
-			child->parent = 0;
-			return;
+	csg_object dummy, *n;
+
+	dummy.ob.next = oblist;
+	n = &dummy;
+
+	while(n->ob.next) {
+		if(n->ob.next == o) {
+			n->ob.next = o->ob.next;
+			return 1;
 		}
-		c = c->next;
+		n = n->ob.next;
 	}
+	return 0;
 }
 
 void csg_free_object(csg_object *o)
 {
-	csg_object *c = o->clist;
-	while(c) {
-		csg_object *tmp = c;
-		c = c->next;
-		csg_free_object(tmp);
+	if(o->ob.destroy) {
+		o->ob.destroy(o);
 	}
 	free(o);
 }
 
-static void init_object(union csg_object *o)
+static union csg_object *alloc_object(int type)
 {
-	o->ob.type = OBJ_NULL;
-	memcpy(o->ob.xform, identity, sizeof identity);
+	csg_object *o;
+
+	if(!(o = calloc(sizeof *o, 1))) {
+		return 0;
+	}
+	o->ob.type = type;
+	mat4_identity(o->ob.xform);
+	mat4_identity(o->ob.inv_xform);
 
 	csg_emission(o, 0, 0, 0);
 	csg_color(o, 1, 1, 1);
 	csg_roughness(o, 1);
 	csg_opacity(o, 1);
+
+	return o;
 }
 
 csg_object *csg_null(float x, float y, float z)
 {
 	csg_object *o;
 
-	if(!(o = calloc(sizeof *o, 1))) {
+	if(!(o = alloc_object(OB_NULL))) {
 		return 0;
 	}
-	init_object(o);
+
+	mat4_translation(o->ob.xform, x, y, z);
 	return o;
 }
 
 csg_object *csg_sphere(float x, float y, float z, float r)
 {
+	csg_object *o;
+
+	if(!(o = alloc_object(OB_SPHERE))) {
+		return 0;
+	}
+
+	o->sph.rad = r;
+	mat4_translation(o->ob.xform, x, y, z);
+	mat4_copy(o->ob.inv_xform, o->ob.xform);
+	mat4_inverse(o->ob.inv_xform);
+	return o;
 }
 
 csg_object *csg_cylinder(float x0, float y0, float z0, float x1, float y1, float z1, float r)
 {
+	csg_object *o;
+	float dx, dy, dz;
+	int major;
+
+	if(!(o = alloc_object(OB_CYLINDER))) {
+		return 0;
+	}
+
+	dx = x1 - x0;
+	dy = y1 - y0;
+	dz = z1 - z0;
+
+	if(fabs(dx) > fabs(dy) && fabs(dx) > fabs(dz)) {
+		major = 0;
+	} else if(fabs(dy) > fabs(dz)) {
+		major = 1;
+	} else {
+		major = 2;
+	}
+
+	o->cyl.rad = r;
+	mat4_lookat(o->ob.xform, x0, y0, z0, x1, y1, z1, 0, major == 2 ? 1 : 0, major == 2 ? 0 : 1);
+	mat4_copy(o->ob.inv_xform, o->ob.xform);
+	mat4_inverse(o->ob.inv_xform);
+	return o;
 }
 
 csg_object *csg_plane(float x, float y, float z, float nx, float ny, float nz)
 {
+	csg_object *o;
+	float len;
+
+	if(!(o = alloc_object(OB_PLANE))) {
+		return 0;
+	}
+
+	len = sqrt(nx * nx + ny * ny + nz * nz);
+	if(len != 0.0f) {
+		float s = 1.0f / len;
+		nx *= s;
+		ny *= s;
+		nz *= s;
+	}
+
+	o->plane.nx = nx;
+	o->plane.ny = ny;
+	o->plane.nz = nz;
+	o->plane.d = x * nx + y * ny + z * nz;
+	return o;
 }
 
 csg_object *csg_box(float x, float y, float z, float xsz, float ysz, float zsz)
 {
+	return 0;
 }
 
-
 csg_object *csg_union(csg_object *a, csg_object *b)
 {
+	csg_object *o;
+
+	if(!(o = alloc_object(OB_UNION))) {
+		return 0;
+	}
+	o->un.a = a;
+	o->un.b = b;
+	return o;
 }
 
 csg_object *csg_intersection(csg_object *a, csg_object *b)
 {
+	csg_object *o;
+
+	if(!(o = alloc_object(OB_INTERSECTION))) {
+		return 0;
+	}
+	o->isect.a = a;
+	o->isect.b = b;
+	return o;
 }
 
 csg_object *csg_subtraction(csg_object *a, csg_object *b)
 {
+	csg_object *o;
+
+	if(!(o = alloc_object(OB_SUBTRACTION))) {
+		return 0;
+	}
+	o->sub.a = a;
+	o->sub.b = b;
+	return o;
 }
 
+void csg_ambient(float r, float g, float b)
+{
+	ambient[0] = r;
+	ambient[1] = g;
+	ambient[2] = b;
+}
 
 void csg_emission(csg_object *o, float r, float g, float b)
 {
+	o->ob.emr = r;
+	o->ob.emg = g;
+	o->ob.emb = b;
 }
 
 void csg_color(csg_object *o, float r, float g, float b)
 {
+	o->ob.r = r;
+	o->ob.g = g;
+	o->ob.b = b;
 }
 
 void csg_roughness(csg_object *o, float r)
 {
+	o->ob.roughness = r;
 }
 
 void csg_opacity(csg_object *o, float p)
 {
+	o->ob.opacity = p;
+}
+
+void csg_metallic(csg_object *o, int m)
+{
+	o->ob.metallic = m;
 }
 
 
-void csg_render_pixel(int x, int y, float *color)
+void csg_render_pixel(int x, int y, int width, int height, float aspect, float *color)
 {
+	struct ray ray;
+
+	calc_primary_ray(&ray, x, y, width, height, aspect);
+	ray_trace(&ray, color);
 }
 
 void csg_render_image(float *pixels, int width, int height)
 {
+	int i, j;
+	float aspect = (float)width / (float)height;
+
+	for(i=0; i<height; i++) {
+		for(j=0; j<width; j++) {
+			csg_render_pixel(j, i, width, height, aspect, pixels);
+			pixels += 3;
+		}
+	}
+}
+
+static void calc_primary_ray(struct ray *ray, int x, int y, int w, int h, float aspect)
+{
+	/* TODO */
+	ray->dx = aspect * ((float)x / (float)w * 2.0f - 1.0f);
+	ray->dy = 1.0f - (float)y / (float)h * 2.0f;
+	ray->dz = -1.0f / tan(cam.fov * 0.5f);
+
+	ray->x = cam.x;
+	ray->y = cam.y;
+	ray->z = cam.z;
+}
+
+static int ray_trace(struct ray *ray, float *col)
+{
+	struct hit hit;
+
+	if(!find_intersection(ray, &hit)) {
+		background(col, ray);
+		return 0;
+	}
+
+	shade(col, ray, &hit);
+	return 1;
+}
+
+#define NULLXPOS(o)	((o)->ob.xform[12])
+#define NULLYPOS(o)	((o)->ob.xform[13])
+#define NULLZPOS(o)	((o)->ob.xform[14])
+
+static void shade(float *col, struct ray *ray, struct hit *hit)
+{
+	float ndotl, ndoth, len, falloff, spec;
+	csg_object *o, *lt = plights;
+	float dcol[3], scol[3] = {0};
+	float ldir[3], lcol[3], hdir[3];
+	struct ray sray;
+	struct hit tmphit;
+
+	o = hit->o;
+	dcol[0] = ambient[0];
+	dcol[1] = ambient[1];
+	dcol[2] = ambient[2];
+
+	while(lt) {
+		ldir[0] = NULLXPOS(lt) - hit->x;
+		ldir[1] = NULLYPOS(lt) - hit->y;
+		ldir[2] = NULLZPOS(lt) - hit->z;
+
+		sray.x = hit->x;
+		sray.y = hit->y;
+		sray.z = hit->z;
+		sray.dx = ldir[0];
+		sray.dy = ldir[1];
+		sray.dz = ldir[2];
+
+		if(!find_intersection(&sray, &tmphit) || tmphit.t > 1.0f) {
+			if((len = sqrt(ldir[0] * ldir[0] + ldir[1] * ldir[1] + ldir[2] * ldir[2])) != 0.0f) {
+				float s = 1.0f / len;
+				ldir[0] *= s;
+				ldir[1] *= s;
+				ldir[2] *= s;
+			}
+			falloff = 1.0f / (len * len);
+
+			lcol[0] = lt->ob.emr * falloff;
+			lcol[1] = lt->ob.emg * falloff;
+			lcol[2] = lt->ob.emb * falloff;
+
+			if((ndotl = hit->nx * ldir[0] + hit->ny * ldir[1] + hit->nz * ldir[2]) < 0.0f) {
+				ndotl = 0.0f;
+			}
+
+			dcol[0] += o->ob.r * lcol[0] * ndotl;
+			dcol[1] += o->ob.g * lcol[1] * ndotl;
+			dcol[2] += o->ob.b * lcol[2] * ndotl;
+
+			if(o->ob.roughness < 1.0f) {
+				float gloss = 1.0f - o->ob.roughness;
+
+				hdir[0] = ldir[0] - ray->dx;
+				hdir[1] = ldir[1] - ray->dy;
+				hdir[2] = ldir[2] - ray->dz;
+				if((len = sqrt(hdir[0] * hdir[0] + hdir[1] * hdir[1] + hdir[2] * hdir[2])) != 0.0f) {
+					float s = 1.0f / len;
+					hdir[0] *= s;
+					hdir[1] *= s;
+					hdir[2] *= s;
+				}
+
+				if((ndoth = hit->nx * hdir[0] + hit->ny * hdir[1] + hit->nz * hdir[2]) < 0.0f) {
+					ndoth = 0.0f;
+				}
+				spec = gloss * pow(ndoth, 100.0f * gloss);
+
+				if(o->ob.metallic) {
+					lcol[0] *= o->ob.r;
+					lcol[1] *= o->ob.g;
+					lcol[2] *= o->ob.b;
+				}
+				scol[0] += lcol[0] * spec;
+				scol[1] += lcol[1] * spec;
+				scol[2] += lcol[2] * spec;
+			}
+		}
+
+		lt = lt->ob.plt_next;
+	}
+
+	col[0] = dcol[0] + scol[0];
+	col[1] = dcol[1] + scol[1];
+	col[2] = dcol[2] + scol[2];
+}
+
+static void background(float *col, struct ray *ray)
+{
+	col[0] = col[1] = col[2] = 0.0f;
+}
+
+static int find_intersection(struct ray *ray, struct hit *best)
+{
+	int idx = 0;
+	csg_object *o;
+	struct hinterv *hit, *it;
+
+	best->t = FLT_MAX;
+	best->o = 0;
+
+	o = oblist;
+	while(o) {
+		if((hit = ray_intersect(ray, o))) {
+			it = hit;
+			while(it) {
+				if(it->end[0].t > 1e-6) {
+					idx = 0;
+					break;
+				}
+				if(it->end[1].t > 1e-6) {
+					idx = 1;
+					break;
+				}
+				it = it->next;
+			}
+
+			if(it && it->end[idx].t < best->t) {
+				*best = it->end[idx];
+			}
+		}
+		free_hit_list(hit);
+		o = o->ob.next;
+	}
+
+	return best->o != 0;
 }