foo

diff --git a/liberebus/src/erebus.c b/liberebus/src/erebus.c
index da07635..af2b2d9 100644 (file)
--- a/liberebus/src/erebus.c
+++ b/liberebus/src/erebus.c
@@ -1,10 +1,95 @@
+#include <stdio.h>
 #include "erebus.h"
 
-int erb_init(void)
+struct erb_rend {
+       int fb_width, fb_height, fb_npix;
+       float *fb_pixels;
+       int *fb_nsamples;
+};
+
+struct erb_rend *erb_create(void)
+{
+       struct erb_rend *erb;
+
+       if(!(erb = calloc(1, sizeof *erb))) {
+               return 0;
+       }
+       return erb;
+}
+
+void erb_destroy(struct erb_rend *erb)
 {
+       if(!erb) return;
+       free(erb->fb_pixels);
+       free(erb);
+}
+
+int erb_allocframe(struct erb_rend *erb, int width, int height)
+{
+       float *newfb;
+       int *newns;
+       int npix;
+
+       if(width == erb->fb_width && height == erb->fb_height) {
+               return 0;
+       }
+
+       npix = width * height;
+
+       if(!(newfb = malloc(npix * 3 * sizeof *erb->fb_pixels))) {
+               goto err;
+       }
+       if(!(newns = malloc(npix * sizeof *erb->fb_nsamples))) {
+               free(newfb);
+               goto err;
+       }
+
+       free(erb->fb_pixels);
+       free(erb->fb_nsamples);
+
+       erb->fb_pixels = newfb;
+       erb->fb_nsamples = newns;
+       erb->fb_width = width;
+       erb->fb_height = height;
+       erb->fb_npix = npix;
        return 0;
+
+err:
+       fprintf(stderr, "erb_allocframe: failed to allocate %dx%d framebuffer\n", width, height);
+       return -1;
+}
+
+float *erb_getframe(struct erb_rend *erb)
+{
+       return erb->fb_pixels;
 }
 
-void erb_cleanup(void)
+void erb_begin(struct erb_rend *erb)
 {
+       memset(erb->fb_pixels, 0, erb->fb_npix * 3 * sizeof *erb->fb_pixels);
+       memset(erb->fb_nsamples, 0, erb->fb_npix * sizeof *erb->fb_nsamples);
+}
+
+float *erb_end(struct erb_rend *erb)
+{
+       int i, n;
+       float s;
+       float *pptr = erb->fb_pixels;
+       int *nptr = erb->fb_nsamples;
+
+       for(i=0; i<erb->fb_npix; i++) {
+               n = *nptr;
+               if(n > 1) {
+                       s = 1.0f / n;
+                       *pptr++ *= s;
+                       *pptr++ *= s;
+                       *pptr++ *= s;
+                       *nptr++ = 1;
+               } else {
+                       pptr += 3;
+                       nptr++;
+               }
+       }
+
+       return erb->fb_pixels;
 }

diff --git a/liberebus/src/erebus.h b/liberebus/src/erebus.h
index 6ec33e3..fcb097b 100644 (file)
--- a/liberebus/src/erebus.h
+++ b/liberebus/src/erebus.h
@@ -3,6 +3,7 @@
 
 #include <cgmath/cgmath.h>
 
+struct erb_rend;
 struct erb_node;
 struct erb_surf;
 struct erb_ray;
@@ -10,6 +11,7 @@ struct erb_hit;
 struct erb_aabb;
 
 typedef int (*erb_intersect_func)(struct erb_surf *surf, struct erb_ray *ray, struct erb_hit *hit);
+typedef void (*erb_hitgeom_func)(struct erb_surf *surf, struct erb_hit *hit);
 typedef void (*erb_sample_func)(struct erb_surf *surf, cgm_vec3 *pos);
 typedef void (*erb_bbox_func)(struct erb_surf *surf, struct erb_aabb *bb);
 
@@ -32,6 +34,7 @@ struct erb_surf {
        int bbox_valid;
 
        erb_intersect_func isect;       /* intersection routine */
+       erb_hitgeom_func hitgeom;       /* calculate derived values of the erb_hit structure */
        erb_sample_func sample;         /* random sample generation */
        erb_bbox_func calc_bbox;        /* bounds calculation */
 
@@ -47,11 +50,25 @@ struct erb_ray {
 
 struct erb_hit {
        float t, err;
+       cgm_vec3 pos, lpos;             /* global and local space hit positions */
        struct erb_surf *surf;
+       float total_dist;
+
+       /* derived by calc_hit */
+       cgm_vec3 norm, tang;
+       float u, v;
 };
 
-int erb_init(void);
-void erb_cleanup(void);
+struct erb_rend *erb_create(void);
+void erb_destroy(struct erb_rend *erb);
+
+int erb_allocframe(struct erb_rend *erb, int width, int height);
+float *erb_getframe(struct erb_rend *erb);
+
+/* clears the framebuffer and sample counters to begin rendering a new frame */
+void erb_begin(struct erb_rend *erb);
+/* finalizes the frame, averaging samples (optional) */
+float *erb_end(struct erb_rend *erb);
 
 /* transformation nodes */
 struct erb_node *erb_node(void);
@@ -61,10 +78,8 @@ int erb_node_rmchild(struct erb_node *n, struct erb_node *c);
 int erb_node_addsurf(struct erb_node *n, struct erb_surf *s);
 int erb_node_rmsurf(struct erb_node *n, struct erb_surf *s);
 
+/* sets the transformation matrix and also calculates the inverse */
 void erb_node_setxform(struct erb_node *n, float *mat);
-void erb_node_mulxform(struct erb_node *n, float *mat);
-void erb_node_translate(struct erb_node *n, float x, float y, float z);
-/* TODO ... more ... */
 
 /* surfaces */
 struct erb_surf *erb_surface(int datasz);
@@ -73,6 +88,6 @@ struct erb_surf *erb_surf_sphere(float rad);
 struct erb_surf *erb_surf_box(float xsz, float ysz, float zsz);
 
 /* utility functions */
-void erb_xform_ray(struct erb_ray *ray, float *mat);
+void erb_xform_ray(struct erb_ray *inray, float *mat, cgm_vec3 *org, cgm_vec3 *dir);
 
 #endif /* RENDLIB_H_ */

diff --git a/liberebus/src/surf.c b/liberebus/src/surf.c
index 7d8d38a..8f2d4db 100644 (file)
--- a/liberebus/src/surf.c
+++ b/liberebus/src/surf.c
@@ -9,14 +9,17 @@ struct box_data {
 };
 
 static int null_isect(struct erb_surf *surf, struct erb_ray *ray, struct erb_hit *hit);
+static void null_hitgeom(struct erb_surf *surf, struct erb_hit *hit);
 static void null_sample(struct erb_surf *surf, cgm_vec3 *pos);
 static void null_bbox(struct erb_surf *surf, struct erb_aabb *bb);
 
 static int sph_isect(struct erb_surf *surf, struct erb_ray *ray, struct erb_hit *hit);
+static void sph_hitgeom(struct erb_surf *surf, struct erb_hit *hit);
 static void sph_sample(struct erb_surf *surf, cgm_vec3 *pos);
 static void sph_bbox(struct erb_surf *surf, struct erb_aabb *bb);
 
 static int box_isect(struct erb_surf *surf, struct erb_ray *ray, struct erb_hit *hit);
+static void box_hitgeom(struct erb_surf *surf, struct erb_hit *hit);
 static void box_sample(struct erb_surf *surf, cgm_vec3 *pos);
 static void box_bbox(struct erb_surf *surf, struct erb_aabb *bb);
 
@@ -30,6 +33,7 @@ struct erb_surf *erb_surface(int datasz)
                return 0;
        }
        surf->isect = null_isect;
+       surf->hitgeom = null_hitgeom;
        surf->sample = null_sample;
        surf->calc_bbox = null_bbox;
        return surf;
@@ -52,6 +56,7 @@ struct erb_surf *erb_surf_sphere(float rad)
                return 0;
        }
        surf->isect = sph_isect;
+       surf->hitgeom = sph_hitgeom;
        surf->sample = sph_sample;
        surf->calc_bbox = sph_bbox;
        sdata = (struct sph_data*)surf->data;
@@ -68,6 +73,7 @@ struct erb_surf *erb_surf_box(float xsz, float ysz, float zsz)
                return 0;
        }
        surf->isect = box_isect;
+       surf->hitgeom = box_hitgeom;
        surf->sample = box_sample;
        surf->calc_bbox = box_bbox;
        bdata = (struct box_data*)surf->data;
@@ -81,6 +87,11 @@ static int null_isect(struct erb_surf *surf, struct erb_ray *ray, struct erb_hit
        return 0;
 }
 
+static void null_hitgeom(struct erb_surf *surf, struct erb_hit *hit)
+{
+       fprintf(stderr, "BUG: null_hitgeom called\n");
+}
+
 static void null_sample(struct erb_surf *surf, cgm_vec3 *pos)
 {
        pos->x = pos->y = pos->z = 0;
@@ -94,22 +105,102 @@ static void null_bbox(struct erb_surf *surf, struct erb_aabb *bb)
 
 static int sph_isect(struct erb_surf *surf, struct erb_ray *ray, struct erb_hit *hit)
 {
-       return 0;
+       float a, b, c, d, sqrt_d, q, t, t0, t1;
+       cgm_vec3 org, dir;
+       struct sph_data *sdata = (struct sph_data*)surf->data;
+
+       if(surf->node) {
+               erb_xform_ray(ray, surf->node->inv_xform, &org, &dir);
+       } else {
+               org = ray->o;
+               dir = ray->d;
+       }
+
+       a = cgm_vdot(&dir, &dir);
+       b = 2.0f * cgm_vdot(&org, &dir);
+       c = cgm_vdot(&org, &org) - sdata->rad * sdata->rad;
+
+       d = b * b - 4.0f * a * c;
+       if(d <= 0.0f) return 0;
+
+       sqrt_d = sqrt(d);
+       q = b < 0.0f ? -0.5f * (b - sqrt_d) : -0.5f * (b + sqrt_d);
+
+       t0 = q / a;
+       t1 = c / q;
+       if(t1 < t0) {
+               float ttmp = t0;
+               t0 = t1;
+               t1 = ttmp;
+       }
+
+       if(t0 > ray->tmax || t1 < ray->tmin) {
+               return 0;
+       }
+       t = t0 < ray->tmin ? t1 : t0;
+       if(t > ray->tmax) {
+               return 0;
+       }
+
+       if(hit) {
+               hit->t = t;
+               hit->err = 5e-4f * t;   /* PBR 3.2.6 */
+               hit->surf = surf;
+               hit->pos = ray->o;
+               cgm_vadd_scaled(&hit->pos, &ray->d, t);
+               hit->lpos = org;
+               cgm_vadd_scaled(&hit->lpos, &dir, t);
+               hit->total_dist = ray->total_dist + t;
+       }
+
+       return 1;
+}
+
+static void sph_hitgeom(struct erb_surf *surf, struct erb_hit *hit)
+{
+       float theta, phi;
+
+       hit->norm = hit->lpos;
+       cgm_vnormalize(&hit->norm);
+
+       cgm_uvec_to_sph(&theta, &phi, &hit->norm);
+
+       hit->u = (theta + M_PI) / (2.0 * M_PI);
+       hit->v = phi / M_PI;
+
+       hit->tang.x = hit->norm.z;
+       hit->tang.y = hit->norm.y;
+       hit->tang.z = -hit->norm.x;
+
+       if(surf->node) {
+               cgm_vmul_m3v3(&hit->norm, surf->node->xform);
+               cgm_vmul_m3v3(&hit->tang, surf->node->xform);
+       }
 }
 
 static void sph_sample(struct erb_surf *surf, cgm_vec3 *pos)
 {
+       /* TODO */
 }
 
 static void sph_bbox(struct erb_surf *surf, struct erb_aabb *bb)
 {
+       struct sph_data *sdata = (struct sph_data*)surf->data;
+
+       cgm_vcons(&bb->pos, 0, 0, 0);
+       bb->sz.x = bb->sz.y = bb->sz.z = sdata->rad;
 }
 
+/* TODO boxen */
 static int box_isect(struct erb_surf *surf, struct erb_ray *ray, struct erb_hit *hit)
 {
        return 0;
 }
 
+static void box_hitgeom(struct erb_surf *surf, struct erb_hit *hit)
+{
+}
+
 static void box_sample(struct erb_surf *surf, cgm_vec3 *pos)
 {
 }

diff --git a/liberebus/src/util.c b/liberebus/src/util.c
index a52f35a..dc0eb98 100644 (file)
--- a/liberebus/src/util.c
+++ b/liberebus/src/util.c
@@ -1,7 +1,9 @@
 #include "erebus.h"
 
-void erb_xform_ray(struct erb_ray *ray, float *mat)
+void erb_xform_ray(struct erb_ray *ray, float *mat, cgm_vec3 *org, cgm_vec3 *dir)
 {
-       cgm_vmul_m4v3(&ray->o, mat);
-       cgm_vmul_m3v3(&ray->d, mat);
+       *org = ray->o;
+       *dir = ray->d;
+       cgm_vmul_m4v3(org, mat);
+       cgm_vmul_m3v3(dir, mat);
 }