nuclear@2: #include <string.h>
nuclear@2: #include <limits.h>
nuclear@2: #include <chrono>
nuclear@2: #include <random>
nuclear@2: #include "erebus.h"
nuclear@2: #include "vmath/vector.h"
nuclear@2: #include "image.h"
nuclear@4: #include "scene.h"
nuclear@4: #include "geomobj.h"
nuclear@5: #include "rt.h"
nuclear@2: 
nuclear@8: #define INF_SAMPLES		(INT_MAX / 2)
nuclear@8: 
nuclear@2: using namespace std::chrono;
nuclear@2: 
nuclear@2: struct Rect {
nuclear@2: 	int x, y, width, height;
nuclear@2: 
nuclear@2: 	bool operator ==(const Rect &r) { return memcmp(this, &r, sizeof r) == 0; }
nuclear@2: 	bool operator !=(const Rect &r) { return memcmp(this, &r, sizeof r) != 0; }
nuclear@2: };
nuclear@2: 
nuclear@2: #define INVALID_RECT	Rect{0, 0, 0, 0}
nuclear@2: 
nuclear@2: struct erebus {
nuclear@4: 	Scene *scn;
nuclear@4: 
nuclear@2: 	Image<float> fbimg;
nuclear@8: 	Image<float> accum;	// sample accumulator per pixel
nuclear@2: 	Vector4 options[ERB_NUM_OPTIONS];
nuclear@2: 
nuclear@2: 	// render state
nuclear@2: 	long cur_time;
nuclear@2: 	int cur_pixel_x, cur_pixel_y;
nuclear@2: 	Rect cur_rect;
nuclear@8: 	int cur_sample;
nuclear@2: };
nuclear@2: 
nuclear@8: static void render_pixel(struct erebus *ctx, int x, int y, int sample);
nuclear@2: 
nuclear@2: static std::mt19937 rnd_gen;
nuclear@2: 
nuclear@2: extern "C" {
nuclear@2: 
nuclear@2: struct erebus *erb_init(void)
nuclear@2: {
nuclear@2: 	struct erebus *ctx;
nuclear@2: 	try {
nuclear@2: 		ctx = new struct erebus;
nuclear@2: 	}
nuclear@2: 	catch(...) {
nuclear@2: 		return 0;
nuclear@2: 	}
nuclear@2: 
nuclear@4: 	ctx->scn = 0;
nuclear@2: 	ctx->cur_time = 0;
nuclear@2: 	ctx->cur_rect = INVALID_RECT;
nuclear@8: 
nuclear@8: 	ctx->options[ERB_OPT_MAX_SAMPLES].x = (float)INF_SAMPLES;
nuclear@2: 	return ctx;
nuclear@2: }
nuclear@2: 
nuclear@2: void erb_destroy(struct erebus *ctx)
nuclear@2: {
nuclear@2: 	delete ctx;
nuclear@2: }
nuclear@2: 
nuclear@2: void erb_setopti(struct erebus *ctx, enum erb_option opt, int val)
nuclear@2: {
nuclear@2: 	ctx->options[opt].x = val;
nuclear@2: }
nuclear@2: void erb_setoptf(struct erebus *ctx, enum erb_option opt, float val)
nuclear@2: {
nuclear@2: 	ctx->options[opt].x = val;
nuclear@2: }
nuclear@2: void erb_setoptfv(struct erebus *ctx, enum erb_option opt, float *vec)
nuclear@2: {
nuclear@2: 	for(int i=0; i<4; i++) {
nuclear@2: 		ctx->options[opt][i] = vec[i];
nuclear@2: 	}
nuclear@2: }
nuclear@2: 
nuclear@2: int erb_getopti(struct erebus *ctx, enum erb_option opt)
nuclear@2: {
nuclear@2: 	return ctx->options[opt].x;
nuclear@2: }
nuclear@2: float erb_getoptf(struct erebus *ctx, enum erb_option opt)
nuclear@2: {
nuclear@2: 	return ctx->options[opt].x;
nuclear@2: }
nuclear@2: float *erb_getoptfv(struct erebus *ctx, enum erb_option opt)
nuclear@2: {
nuclear@2: 	return &ctx->options[opt].x;
nuclear@2: }
nuclear@2: 
nuclear@2: float *erb_get_framebuffer(struct erebus *ctx)
nuclear@2: {
nuclear@2: 	return ctx->fbimg.get_pixels();
nuclear@2: }
nuclear@2: 
nuclear@2: void erb_begin_frame(struct erebus *ctx, long ms)
nuclear@2: {
nuclear@8: 	printf("starting new frame...\n");
nuclear@2: 	ctx->cur_time = ms;
nuclear@4: 
nuclear@4: 	int xsz = ctx->options[ERB_OPT_WIDTH].x;
nuclear@4: 	int ysz = ctx->options[ERB_OPT_HEIGHT].x;
nuclear@4: 
nuclear@4: 	ctx->fbimg.create(xsz, ysz);
nuclear@8: 	ctx->accum.create(xsz, ysz);
nuclear@2: }
nuclear@2: 
nuclear@2: int erb_render(struct erebus *ctx, long timeout)
nuclear@2: {
nuclear@2: 	return erb_render_rect(ctx, 0, 0, ctx->fbimg.get_width(), ctx->fbimg.get_height(), timeout);
nuclear@2: }
nuclear@2: 
nuclear@2: int erb_render_rect(struct erebus *ctx, int x, int y, int width, int height, long timeout)
nuclear@2: {
nuclear@2: 	if(!width || !height) return -1;
nuclear@2: 
nuclear@2: 	Rect rect{x, y, width, height};
nuclear@2: 	if(ctx->cur_rect != rect) {
nuclear@8: 		// starting a new rendering apparently
nuclear@2: 		ctx->cur_rect = rect;
nuclear@2: 		ctx->cur_pixel_x = x;
nuclear@2: 		ctx->cur_pixel_y = y;
nuclear@8: 		ctx->cur_sample = 0;
nuclear@2: 	}
nuclear@2: 
nuclear@4: 	ctx->scn->update();
nuclear@4: 
nuclear@8: 	int max_samples = ctx->options[ERB_OPT_MAX_SAMPLES].x;
nuclear@8: 
nuclear@2: 	if(timeout > 0) {
nuclear@2: 		auto start_time = steady_clock::now();
nuclear@2: 		while(duration_cast<milliseconds>(steady_clock::now() - start_time).count() < timeout) {
nuclear@8: 			render_pixel(ctx, ctx->cur_pixel_x, ctx->cur_pixel_y, ctx->cur_sample);
nuclear@2: 
nuclear@2: 			if(++ctx->cur_pixel_x >= ctx->cur_rect.width) {
nuclear@8: 				ctx->cur_pixel_x = ctx->cur_rect.x;
nuclear@2: 				if(++ctx->cur_pixel_y >= ctx->cur_rect.height) {
nuclear@8: 					ctx->cur_pixel_y = ctx->cur_rect.y;
nuclear@8: 					if(++ctx->cur_sample >= max_samples) {
nuclear@8: 						ctx->cur_rect = INVALID_RECT;
nuclear@8: 						return 0;
nuclear@8: 					}
nuclear@2: 				}
nuclear@2: 			}
nuclear@2: 		}
nuclear@2: 		return 1;
nuclear@2: 	}
nuclear@2: 
nuclear@8: 	if(ctx->options[ERB_OPT_MAX_SAMPLES].x == (float)INF_SAMPLES) {
nuclear@8: 		max_samples = 128;
nuclear@8: 	}
nuclear@8: 
nuclear@2: 	for(int i=0; i<height; i++) {
nuclear@2: 		for(int j=0; j<width; j++) {
nuclear@8: 			for(int k=0; k<max_samples; k++) {
nuclear@8: 				render_pixel(ctx, j, i, k);
nuclear@8: 			}
nuclear@2: 		}
nuclear@2: 	}
nuclear@2: 	return 0;
nuclear@2: }
nuclear@2: 
nuclear@2: int erb_get_progress(struct erebus *ctx)
nuclear@2: {
nuclear@2: 	return 0;	// TODO
nuclear@2: }
nuclear@2: 
nuclear@2: int erb_load_scene(struct erebus *ctx, const char *fname)
nuclear@2: {
nuclear@4: 	delete ctx->scn;
nuclear@4: 	ctx->scn = new Scene;
nuclear@2: 
nuclear@4: 	// XXX for now just create a test scene here
nuclear@4: 	Sphere *sph = new Sphere;
nuclear@8: 	sph->mtl.set_attrib("albedo", Color(1.0, 0.3, 0.2));
nuclear@4: 	SceneNode *sph_node = new SceneNode(sph);
nuclear@4: 	ctx->scn->add_object(sph);
nuclear@4: 	ctx->scn->add_node(sph_node);
nuclear@4: 
nuclear@8: 	sph = new Sphere;
nuclear@8: 	sph->mtl.set_attrib("albedo", Color(0.3, 0.4, 1.0));
nuclear@8: 	sph_node = new SceneNode(sph);
nuclear@8: 	sph_node->set_position(Vector3(0, -3.0, 0));
nuclear@8: 	//sph_node->set_scaling(Vector3(4.0, 4.0, 4.0) * 0.3);
nuclear@8: 	ctx->scn->add_object(sph);
nuclear@8: 	ctx->scn->add_node(sph_node);
nuclear@8: 
nuclear@8: 	Sphere *lt = new Sphere;
nuclear@8: 	lt->mtl.set_attrib("emissive", Color(10, 10, 10));
nuclear@8: 	SceneNode *lt_node = new SceneNode(lt);
nuclear@8: 	lt_node->set_position(Vector3(-15, 15, -10));
nuclear@8: 	lt_node->set_scaling(Vector3(5, 5, 5));
nuclear@8: 	ctx->scn->add_object(lt);
nuclear@8: 	ctx->scn->add_node(lt_node);
nuclear@8: 
nuclear@8: 	TargetCamera *cam = new TargetCamera(Vector3(0, 4, -8), Vector3(0, 0, 0));
nuclear@4: 	//ctx->scn->add_object(cam);
nuclear@4: 	ctx->scn->use_camera(cam);
nuclear@4: 
nuclear@4: 	return 0;
nuclear@2: }
nuclear@2: 
nuclear@2: }	// extern "C"
nuclear@2: 
nuclear@2: float randf(float low, float high)
nuclear@2: {
nuclear@2: 	std::uniform_real_distribution<float> unirnd(low, high);
nuclear@2: 	return unirnd(rnd_gen);
nuclear@2: }
nuclear@2: 
nuclear@8: static void render_pixel(struct erebus *ctx, int x, int y, int sample)
nuclear@2: {
nuclear@5: 	Camera *cam = ctx->scn->get_active_camera();
nuclear@5: 	if(!cam) return;
nuclear@5: 
nuclear@5: 	int xsz = ctx->fbimg.get_width();
nuclear@5: 	int ysz = ctx->fbimg.get_height();
nuclear@8: 	int offs = (y * xsz + x) * 4;
nuclear@5: 
nuclear@8: 	float *pix = ctx->fbimg.get_pixels() + offs;
nuclear@8: 	float *accum = ctx->accum.get_pixels() + offs;
nuclear@8: 
nuclear@8: 	Ray ray = cam->get_primary_ray(x, y, xsz, ysz, sample);
nuclear@8: 	Color c = ray_trace(ray, ctx->scn, 0);
nuclear@8: 	accum[0] += c.x;
nuclear@8: 	accum[1] += c.y;
nuclear@8: 	accum[2] += c.z;
nuclear@8: 	accum[3] += c.w;
nuclear@8: 
nuclear@8: 	float inv_samples = 1.0f / (float)(sample + 1);
nuclear@8: 	pix[0] = accum[0] * inv_samples;
nuclear@8: 	pix[1] = accum[1] * inv_samples;
nuclear@8: 	pix[2] = accum[2] * inv_samples;
nuclear@8: 	pix[3] = accum[3] * inv_samples;
nuclear@2: }