Create scene data structure

demo.c

@@ -15,7 +15,9 @@
 static const vec3_t camera_pos = { 0.0, 1.5, -2.0 };
 static const vec3_t camera_target = { 0.0, 1.0, 1.0 };
 
-static const obj_t scene[] = {
+static const vec3_t sky = { 0.6, 0.7, 1.0 };
+
+static const obj_t objs[] = {
 	SPHERE(1.0, 1.0, 3.0, 1.0, LAMBERTIAN(0.6, 0.2, 0.8)),
 	SPHERE(-0.8, 1.0, 3.8, 1.0, LAMBERTIAN(1.0, 1.0, 1.0)),
 	SPHERE(-1.0, 0.2, 2.6, 0.2, LAMBERTIAN(0.2, 0.9, 0.3)),
@@ -30,10 +32,16 @@ static pix_t pixbuf[W * H];
 
 int main()
 {
+	const scene_t scene = {
+		.sky_colour = sky,
+		.objs = objs,
+		.obj_count = NELEMS(objs),
+	};
+
 	img_t img = { .pix = pixbuf };
 	camera_t camera = camera_init(
 	    camera_pos, camera_target, FOV, W, H, SAMPLES_PER_PIXEL);
-	camera_render(&camera, scene, NELEMS(scene), &img);
+	camera_render(&camera, &scene, &img);
 
 	ff_write(STDOUT_FILENO, img);
 

include/camera.h

@@ -2,8 +2,7 @@
 #define CAMERA_H
 
 #include "img.h"
-#include "obj.h"
-#include "vec3.h"
+#include "scene.h"
 
 #include <stdint.h>
 
@@ -19,7 +18,6 @@ camera_t camera_init(
     uint32_t img_height, unsigned samples_per_pixel);
 
 void camera_render(
-    const camera_t *camera, const obj_t *scene, unsigned scene_count,
-    img_t *img_out);
+    const camera_t *camera, const scene_t *scene, img_t *img_out);
 
 #endif

include/scene.h

@@ -0,0 +1,12 @@
+#ifndef SCENE_H
+#define SCENE_H
+
+#include "obj.h"
+
+typedef struct {
+	vec3_t sky_colour;
+	obj_t *objs;
+	unsigned obj_count;
+} scene_t;
+
+#endif

src/camera.c

@@ -23,35 +23,34 @@
 
 typedef struct {
 	const camera_t *camera;
-	const obj_t *scene;
+	const scene_t *scene;
 	pix_t *pixels;
 	rng_t rng;
-	unsigned start_y, row_count, scene_count;
+	unsigned start_y, row_count;
 	atomic_uint *progress;
 } work_slice_t;
 
 static const vec3_t up = { 0.0, 1.0, 0.0 };
 
-static const vec3_t lightblue = { 0.6, 0.7, 1.0 };
 static const vec3_t white = { 1.0, 1.0, 1.0 };
 static const vec3_t black = { 0.0, 0.0, 0.0 };
 
-static vec3_t
-trace(ray_t ray, const obj_t *scene, unsigned scene_count, rng_t *rng)
+static vec3_t trace(ray_t ray, const scene_t *scene, rng_t *rng)
 {
 	vec3_t colour = white;
 	for (unsigned i = 0; i < MAX_ITER; ++i) {
 		hit_t hit = { .t = DBL_MAX };
 		material_t material = {};
-		for (unsigned j = 0; j < scene_count; ++j) {
-			if (scene[j].intersect(scene[j].params, ray, &hit, MIN_T, hit.t))
-				material = scene[j].material;
+		for (unsigned j = 0; j < scene->obj_count; ++j) {
+			const obj_t *obj = scene->objs + j;
+			if (obj->intersect(obj->params, ray, &hit, MIN_T, hit.t))
+				material = obj->material;
 		}
 
 		if (hit.t == DBL_MAX) {
 			const double a = (ray.dir.y + 1.0) / 2.0;
 			const vec3_t bg = vec3_add(
-			    vec3_scale(lightblue, a), vec3_scale(white, 1 - a));
+			    vec3_scale(scene->sky_colour, a), vec3_scale(white, 1 - a));
 			return vec3_hadamard(colour, bg);
 		}
 
@@ -104,8 +103,7 @@ static int render_thread(void *arg)
 					.orig = camera->pos,
 					.dir = vec3_unit(vec3_sub(jittered_pix, camera->pos)),
 				};
-				const vec3_t sample = trace(
-				    ray, slice->scene, slice->scene_count, &slice->rng);
+				const vec3_t sample = trace(ray, slice->scene, &slice->rng);
 
 				colour = vec3_add(colour, vec3_scale(sample, sample_weight));
 			}
@@ -155,8 +153,7 @@ camera_t camera_init(
 }
 
 void camera_render(
-    const camera_t *camera, const obj_t *scene, unsigned scene_count,
-    img_t *img_out)
+    const camera_t *camera, const scene_t *scene, img_t *img_out)
 {
 	img_out->w = camera->img_width;
 	img_out->h = camera->img_height;
@@ -172,7 +169,6 @@ void camera_render(
 	for (unsigned i = 0; i < NTHREADS; ++i) {
 		slices[i].camera = camera;
 		slices[i].scene = scene;
-		slices[i].scene_count = scene_count;
 		slices[i].pixels = img_out->pix;
 		slices[i].rng = rng_init(i);