#include <stdlib.h>
#include <string.h>
#include <math.h>
-#include "csgray.h"
+#include "csgimpl.h"
#include "matrix.h"
+#include "geom.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 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 struct camera cam;
-static csg_object *root;
+static csg_object *oblist;
int csg_init(void)
{
- if(!(root = csg_null(0, 0, 0))) {
- return -1;
- }
-
+ oblist = 0;
csg_view(0, 0, 5, 0, 0, 0);
csg_fov(50);
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)
return 0; /* TODO */
}
-#define OBPTR(o) ((struct object*)(o))
-
-void csg_add_object(csg_object *parent, csg_object *child)
+void csg_add_object(csg_object *o)
{
- if(!parent) {
- parent = root;
- }
-
- if(parent->ob.clist) {
- parent->ob.ctail->next = OBPTR(child);
- parent->ob.ctail = OBPTR(child);
- } else {
- parent->ob.clist = parent->ob.ctail = OBPTR(child);
- }
- child->ob.parent = OBPTR(parent);
+ o->ob.next = oblist;
+ oblist = o;
}
-void csg_remove_object(csg_object *parent, csg_object *child)
+int csg_remove_object(csg_object *o)
{
- csg_object *c;
+ csg_object dummy, *n;
- if(!parent) {
- parent = root;
- }
+ dummy.ob.next = oblist;
+ n = &dummy;
- c = (csg_object*)parent->ob.clist;
- while(c->ob.next) {
- if(c->ob.next == OBPTR(child)) {
- c->ob.next = child->ob.next;
- child->ob.next = 0;
- child->ob.parent = 0;
- return;
+ while(n->ob.next) {
+ if(n->ob.next == o) {
+ n->ob.next = o->ob.next;
+ return 1;
}
- c = (csg_object*)c->ob.next;
+ n = n->ob.next;
}
+ return 0;
}
void csg_free_object(csg_object *o)
{
- csg_object *c = (csg_object*)o->ob.clist;
- while(c) {
- csg_object *tmp = c;
- c = (csg_object*)c->ob.next;
- csg_free_object(tmp);
+ if(o->ob.destroy) {
+ o->ob.destroy(o);
}
free(o);
}
-static union csg_object *alloc_object(void)
+static union csg_object *alloc_object(int type)
{
csg_object *o;
if(!(o = calloc(sizeof *o, 1))) {
return 0;
}
- o->ob.type = OB_NULL;
+ 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_object *csg_null(float x, float y, float z)
{
- return alloc_object();
+ return alloc_object(OB_NULL);
}
csg_object *csg_sphere(float x, float y, float z, float r)
{
csg_object *o;
- if(!(o = alloc_object())) {
+ 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)
{
- return 0;
+ 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 0;
}
return 0;
}
-
csg_object *csg_union(csg_object *a, csg_object *b)
{
- return 0;
+ 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)
{
- return 0;
+ 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)
{
- return 0;
+ csg_object *o;
+
+ if(!(o = alloc_object(OB_SUBTRACTION))) {
+ return 0;
+ }
+ o->sub.a = a;
+ o->sub.b = b;
+ return o;
}
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_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)
+{
+ float px, py;
+
+ px = aspect * ((float)x / (float)w * 2.0f - 1.0f);
+ py = 1.0f - (float)y / (float)h * 2.0f;
+
+ ray->x = px;
+ ray->y = py;
+ ray->z = cam.z;
+
+ ray->dx = ray->dy = 0.0f;
+ ray->dz = -1.0f;
+}
+
+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;
+}
+
+static void shade(float *col, struct ray *ray, struct hit *hit)
+{
+ col[0] = 1.0f;
+ col[1] = col[2] = 0.0f;
+}
+
+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)
+{
+ csg_object *o;
+ struct hit *hit;
+
+ best->t = 1e-6f;
+ best->o = 0;
+
+ o = oblist;
+ while(o) {
+ if((hit = ray_intersect(ray, o)) && hit->t < best->t) {
+ *best = *hit;
+ }
+ free_hit(hit);
+ o = o->ob.next;
+ }
+
+ return best->o != 0;
}
--- /dev/null
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include "geom.h"
+#include "matrix.h"
+
+/* TODO custom hit allocator */
+struct hit *alloc_hit(void)
+{
+ struct hit *hit = calloc(sizeof *hit, 1);
+ if(!hit) {
+ perror("failed to allocate ray hit node");
+ abort();
+ }
+ return hit;
+}
+
+void free_hit(struct hit *hit)
+{
+ free(hit);
+}
+
+void free_hit_list(struct hit *hit)
+{
+ while(hit) {
+ struct hit *tmp = hit;
+ hit = hit->next;
+ free_hit(tmp);
+ }
+}
+
+struct hit *ray_intersect(struct ray *ray, csg_object *o)
+{
+ switch(o->ob.type) {
+ case OB_SPHERE:
+ return ray_sphere(ray, o);
+ case OB_CYLINDER:
+ return ray_cylinder(ray, o);
+ case OB_PLANE:
+ return ray_plane(ray, o);
+ case OB_UNION:
+ return ray_csg_un(ray, o);
+ case OB_INTERSECTION:
+ return ray_csg_isect(ray, o);
+ case OB_SUBTRACTION:
+ return ray_csg_sub(ray, o);
+ default:
+ break;
+ }
+ return 0;
+}
+
+struct hit *ray_sphere(struct ray *ray, csg_object *o)
+{
+ float a, b, c, d, sqrt_d, t0, t1, t, sq_rad;
+ struct hit *hit;
+ struct ray locray = *ray;
+
+ if(o->sph.rad == 0.0f) {
+ return 0;
+ }
+ sq_rad = o->sph.rad * o->sph.rad;
+
+ xform_ray(&locray, o->ob.inv_xform);
+
+ a = locray.dx * locray.dx + locray.dy * locray.dy + locray.dz * locray.dz;
+ b = 2.0f * (locray.dx * locray.x + locray.dy * locray.y + locray.dz * locray.z);
+ c = (locray.x * locray.x + locray.y * locray.y + locray.z * locray.z) - sq_rad;
+
+ d = b * b - 4.0f * a * c;
+ if(d < 1e-6) return 0;
+
+ sqrt_d = sqrt(d);
+ t0 = (-b + sqrt_d) / (2.0f * a);
+ t1 = (-b - sqrt_d) / (2.0f * a);
+
+ if(t0 < 1e-6) t0 = t1;
+ if(t1 < 1e-6) t1 = t0;
+ t = t0 < t1 ? t0 : t1;
+ if(t < 1e-6) return 0;
+
+ hit = alloc_hit();
+ hit->t = t;
+ hit->x = ray->x + ray->dx * t;
+ hit->y = ray->y + ray->dy * t;
+ hit->z = ray->z + ray->dz * t;
+ hit->nx = hit->x / o->sph.rad;
+ hit->ny = hit->y / o->sph.rad;
+ hit->nz = hit->z / o->sph.rad;
+ hit->o = o;
+ return hit;
+}
+
+struct hit *ray_cylinder(struct ray *ray, csg_object *o)
+{
+ struct ray locray = *ray;
+
+ xform_ray(&locray, o->ob.inv_xform);
+ return 0; /* TODO */
+}
+
+struct hit *ray_plane(struct ray *ray, csg_object *o)
+{
+ float vx, vy, vz, ndotv, ndotr, t;
+ struct hit *hit = 0;
+ struct ray locray = *ray;
+
+ xform_ray(&locray, o->ob.inv_xform);
+
+ vx = o->plane.nx * o->plane.d - locray.x;
+ vy = o->plane.ny * o->plane.d - locray.y;
+ vz = o->plane.nz * o->plane.d - locray.z;
+
+ ndotv = o->plane.nx * vx + o->plane.ny * vy + o->plane.nz * vz;
+ if(fabs(ndotv) < 1e-6) return 0;
+
+ ndotr = o->plane.nx * locray.dx + o->plane.ny * locray.dy + o->plane.nz * locray.dz;
+ t = ndotr / ndotv;
+
+ if(t > 1e-6) {
+ hit = alloc_hit();
+ hit->t = t;
+ hit->x = ray->x + ray->dx * t;
+ hit->y = ray->y + ray->dy * t;
+ hit->z = ray->z + ray->dz * t;
+ hit->nx = o->plane.nx;
+ hit->ny = o->plane.ny;
+ hit->nz = o->plane.nz;
+ hit->o = o;
+ }
+ return hit;
+}
+
+struct hit *ray_csg_un(struct ray *ray, csg_object *o)
+{
+ struct hit *hita, *hitb;
+
+ hita = ray_intersect(ray, o->un.a);
+ hitb = ray_intersect(ray, o->un.a);
+
+ if(!hita) return hitb;
+ if(!hitb) return hita;
+
+ if(hita->t < hitb->t) {
+ free_hit(hitb);
+ return hita;
+ }
+ free_hit(hita);
+ return hitb;
+}
+
+struct hit *ray_csg_isect(struct ray *ray, csg_object *o)
+{
+ return 0;
+}
+
+struct hit *ray_csg_sub(struct ray *ray, csg_object *o)
+{
+ return 0;
+}
+
+
+void xform_ray(struct ray *ray, float *mat)
+{
+ float m3x3[16];
+
+ mat4_copy(m3x3, mat);
+ mat4_upper3x3(m3x3);
+
+ mat4_xform3(&ray->x, mat, &ray->x);
+ mat4_xform3(&ray->dx, m3x3, &ray->dx);
+}
projects / csgray / commitdiff