nuclear@4: #include <stdio.h>
nuclear@0: #include <assert.h>
nuclear@4: #include <algorithm>
nuclear@0: #include "scene.h"
nuclear@0: #include "image.h"
nuclear@0: #include "rend.h"
nuclear@0: #include "opengl.h"
nuclear@0: #include "glsdr.h"
nuclear@0: 
nuclear@0: enum {
nuclear@0: 	TEX_RAYDIR,
nuclear@0: 	TEX_SPHERES,
nuclear@0: 	TEX_PLANES,
nuclear@0: 	TEX_BOXES,
nuclear@4: 	TEX_CONES,
nuclear@0: 	TEX_TEXTURES,
nuclear@0: 	TEX_ENV,
nuclear@0: 	TEX_XFORM,
nuclear@0: 
nuclear@0: 	NUM_SDR_TEXTURES
nuclear@0: };
nuclear@0: 
nuclear@0: bool reload_shader();
nuclear@0: void gen_ray_texture(unsigned int tex, int xsz, int ysz, float vfov);
nuclear@0: static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg);
nuclear@0: static int round_pow2(int x);
nuclear@0: 
nuclear@0: static GPUScene *scn;
nuclear@0: 
nuclear@0: static unsigned int sdr;
nuclear@0: static unsigned int textures[NUM_SDR_TEXTURES];
nuclear@0: 
nuclear@0: bool init_renderer(GPUScene *s, int xsz, int ysz)
nuclear@0: {
nuclear@0: 	scn = s;
nuclear@0: 
nuclear@4: 	int max_tex_units;
nuclear@4: 	glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &max_tex_units);
nuclear@4: 	printf("maximum texture units: %d\n", max_tex_units);
nuclear@4: 	if(NUM_SDR_TEXTURES > max_tex_units) {
nuclear@4: 		fprintf(stderr, "not enough texture units available!\n");
nuclear@4: 		return false;
nuclear@4: 	}
nuclear@4: 
nuclear@0: 	glGenTextures(1, textures + TEX_RAYDIR);
nuclear@0: 	glBindTexture(GL_TEXTURE_2D, textures[TEX_RAYDIR]);
nuclear@0: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
nuclear@0: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
nuclear@0: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
nuclear@0: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
nuclear@0: 
nuclear@0: 	if(!(s->create_textures())) {
nuclear@0: 		fprintf(stderr, "failed to create scene textures\n");
nuclear@0: 		return false;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	textures[TEX_SPHERES] = s->get_texture(GPUScene::TEX_SPHERE);
nuclear@0: 	textures[TEX_PLANES] = s->get_texture(GPUScene::TEX_PLANE);
nuclear@0: 	textures[TEX_BOXES] = s->get_texture(GPUScene::TEX_BOX);
nuclear@4: 	textures[TEX_CONES] = s->get_texture(GPUScene::TEX_CONE);
nuclear@0: 	textures[TEX_TEXTURES] = s->get_texture(GPUScene::TEX_TEXTURE);
nuclear@0: 	textures[TEX_ENV] = s->get_texture(GPUScene::TEX_ENV);
nuclear@0: 	textures[TEX_XFORM] = s->get_texture(GPUScene::TEX_XFORM);
nuclear@0: 
nuclear@0: 	if(!reload_shader()) {
nuclear@0: 		return false;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	resize_renderer(xsz, ysz);
nuclear@0: 
nuclear@0: 	return true;
nuclear@0: }
nuclear@0: 
nuclear@0: bool reload_shader()
nuclear@0: {
nuclear@0: 	if(sdr) {
nuclear@0: 		free_program(sdr);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	printf("loading shader...\n");
nuclear@0: 
nuclear@0: 	if(!(sdr = create_program_load("sdr/vertex.glsl", "sdr/rt.glsl"))) {
nuclear@0: 		return false;
nuclear@0: 	}
nuclear@0: 	set_uniform_int(sdr, "tex_raydir", TEX_RAYDIR);
nuclear@0: 	set_uniform_int(sdr, "tex_spheres", TEX_SPHERES);
nuclear@0: 	set_uniform_int(sdr, "tex_planes", TEX_PLANES);
nuclear@0: 	set_uniform_int(sdr, "tex_boxes", TEX_BOXES);
nuclear@4: 	set_uniform_int(sdr, "tex_cones", TEX_CONES);
nuclear@0: 	set_uniform_int(sdr, "tex_megatex", TEX_TEXTURES);
nuclear@0: 	set_uniform_int(sdr, "tex_env", TEX_ENV);
nuclear@0: 	set_uniform_int(sdr, "tex_xforms", TEX_XFORM);
nuclear@0: 
nuclear@0: 	set_uniform_int(sdr, "num_lights", scn->get_light_count());
nuclear@0: 
nuclear@0: 	for(int i=0; i<scn->get_light_count(); i++) {
nuclear@0: 		const Light *lt = scn->get_light(i);
nuclear@0: 
nuclear@0: 		char name[64];
nuclear@0: 		sprintf(name, "lights[%d].pos", i);
nuclear@0: 		set_uniform_float3(sdr, name, lt->pos.x, lt->pos.y, lt->pos.z);
nuclear@0: 
nuclear@0: 		sprintf(name, "lights[%d].color", i);
nuclear@0: 		set_uniform_float3(sdr, name, lt->color.x, lt->color.y, lt->color.z);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	Vector2 fog;
nuclear@0: 	scn->get_fog(&fog.x, &fog.y);
nuclear@0: 	if(fog.x < 0.0 && fog.y < 0.0) {
nuclear@0: 		fog.x = 0.0;
nuclear@0: 		fog.y = 100000.0;
nuclear@0: 	}
nuclear@0: 	set_uniform_float2(sdr, "fog", fog.x, fog.y);
nuclear@0: 	return true;
nuclear@0: }
nuclear@0: 
nuclear@0: void destroy_renderer()
nuclear@0: {
nuclear@0: 	free_program(sdr);
nuclear@0: 	sdr = 0;
nuclear@0: }
nuclear@0: 
nuclear@0: void resize_renderer(int xsz, int ysz)
nuclear@0: {
nuclear@0: 	gen_ray_texture(textures[TEX_RAYDIR], xsz, ysz, 45.0f);
nuclear@0: }
nuclear@0: 
nuclear@0: float *render_frame(long msec)
nuclear@0: {
nuclear@0: 	scn->prepare_xform(msec);
nuclear@0: 	scn->update_xform_texture();
nuclear@0: 
nuclear@0: 	Camera *cam = scn->get_camera();
nuclear@0: 	glMatrixMode(GL_MODELVIEW);
nuclear@0: 	glLoadIdentity();
nuclear@0: 	Vector3 cpos = cam->get_position();
nuclear@0: 	glTranslatef(cpos.x, cpos.y, cpos.z);
nuclear@0: 	Matrix4x4 cmat = cam->get_matrix();
nuclear@0: 	glMultTransposeMatrixf(cmat[0]);
nuclear@0: 
nuclear@0: 	for(int i=0; i<NUM_SDR_TEXTURES; i++) {
nuclear@0: 		glActiveTexture(GL_TEXTURE0 + i);
nuclear@0: 		if(i == TEX_ENV) {
nuclear@0: 			glBindTexture(GL_TEXTURE_CUBE_MAP, textures[i]);
nuclear@0: 		} else {
nuclear@0: 			glBindTexture(GL_TEXTURE_2D, textures[i]);
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 	glActiveTexture(GL_TEXTURE0);
nuclear@0: 
nuclear@0: 	glUseProgram(sdr);
nuclear@0: 
nuclear@0: 	glBegin(GL_QUADS);
nuclear@0: 	glTexCoord2f(0, 1);
nuclear@0: 	glVertex2f(-1, -1);
nuclear@0: 	glTexCoord2f(1, 1);
nuclear@0: 	glVertex2f(1, -1);
nuclear@0: 	glTexCoord2f(1, 0);
nuclear@0: 	glVertex2f(1, 1);
nuclear@0: 	glTexCoord2f(0, 0);
nuclear@0: 	glVertex2f(-1, 1);
nuclear@0: 	glEnd();
nuclear@0: 
nuclear@0: 	glUseProgram(0);
nuclear@0: 
nuclear@0: 	assert(glGetError() == GL_NO_ERROR);
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: void gen_ray_texture(unsigned int tex, int xsz, int ysz, float vfov)
nuclear@0: {
nuclear@0: 	int tex_xsz = round_pow2(xsz);
nuclear@0: 	int tex_ysz = round_pow2(ysz);
nuclear@0: 	float *teximg, *dir;
nuclear@0: 
nuclear@0: 	teximg = new float[3 * tex_xsz * tex_ysz];
nuclear@0: 	dir = teximg;
nuclear@0: 
nuclear@0: 	for(int i=0; i<tex_ysz; i++) {
nuclear@0: 		for(int j=0; j<tex_xsz; j++) {
nuclear@0: 			if(j < xsz && i < ysz) {
nuclear@0: 				Vector3 rdir = get_primary_ray_dir(j, i, xsz, ysz, vfov);
nuclear@0: 				dir[0] = rdir.x;
nuclear@0: 				dir[1] = rdir.y;
nuclear@0: 				dir[2] = rdir.z;
nuclear@0: 			} else {
nuclear@0: 				dir[0] = dir[1] = 0.0f;
nuclear@0: 				dir[2] = 1.0f;
nuclear@0: 			}
nuclear@0: 
nuclear@0: 			dir += 3;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	glBindTexture(GL_TEXTURE_2D, tex);
nuclear@0: 	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, tex_xsz, tex_ysz, 0, GL_RGB, GL_FLOAT, teximg);
nuclear@0: 	delete [] teximg;
nuclear@0: }
nuclear@0: 
nuclear@0: static Vector3 calc_sample_pos(int x, int y, int xsz, int ysz)
nuclear@0: {
nuclear@0: 	float ppos[2];
nuclear@0: 	float aspect = (float)xsz / (float)ysz;
nuclear@0: 
nuclear@0: 	float pwidth = 2.0 * aspect / (float)xsz;
nuclear@0: 	float pheight = 2.0 / (float)ysz;
nuclear@0: 
nuclear@0: 	ppos[0] = (float)x * pwidth - aspect;
nuclear@0: 	ppos[1] = 1.0 - (float)y * pheight;
nuclear@0: 
nuclear@0: 	return Vector3(ppos[0], ppos[1], 0.0f);
nuclear@0: }
nuclear@0: 
nuclear@0: 
nuclear@0: static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg)
nuclear@0: {
nuclear@0: 	float vfov = M_PI * vfov_deg / 180.0;
nuclear@0: 
nuclear@0: 	Vector3 dir = calc_sample_pos(x, y, w, h);
nuclear@0: 	dir.z = 1.0 / tan(vfov / 2.0);
nuclear@0: 	dir.normalize();
nuclear@0: 
nuclear@0: 	return dir;
nuclear@0: }
nuclear@0: 
nuclear@0: static int round_pow2(int x)
nuclear@0: {
nuclear@0: 	x--;
nuclear@0: 	x = (x >> 1) | x;
nuclear@0: 	x = (x >> 2) | x;
nuclear@0: 	x = (x >> 4) | x;
nuclear@0: 	x = (x >> 8) | x;
nuclear@0: 	x = (x >> 16) | x;
nuclear@0: 	return x + 1;
nuclear@0: }
nuclear@0: 
nuclear@0: 
nuclear@0: #if 0
nuclear@0: Color trace_ray(const Scene *scn, const Ray &ray, int rdepth)
nuclear@0: {
nuclear@0: 	HitPoint hit;
nuclear@0: 
nuclear@0: 	if(scn->intersect(ray, &hit)) {
nuclear@0: 		float t;
nuclear@0: 		if(scn->fog_start >= 0.0 && (t = (hit.dist - scn->fog_start) / (scn->fog_end - scn->fog_start)) > 0.0) {
nuclear@0: 			return lerp(shade(scn, ray, hit, rdepth), scn->env_color(ray), t > 1.0 ? 1.0 : t);
nuclear@0: 		}
nuclear@0: 		return shade(scn, ray, hit, rdepth);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	return scn->env_color(ray);
nuclear@0: }
nuclear@0: 
nuclear@0: Color shade(const Scene *scn, const Ray &ray, const HitPoint &hit, int rdepth)
nuclear@0: {
nuclear@0: 	const Material *mat = &hit.obj->material;
nuclear@0: 
nuclear@0: 	// if we're leaving the object, we need to invert the normal (and ior)
nuclear@0: 	Vector3 normal;
nuclear@0: 	bool entering;
nuclear@0: 	if(dot_product(hit.normal, ray.dir) <= 0.0) {
nuclear@0: 		normal = hit.normal;
nuclear@0: 		entering = true;
nuclear@0: 	} else {
nuclear@0: 		normal = -hit.normal;
nuclear@0: 		entering = false;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	Vector3 vdir = -ray.dir;
nuclear@0: 
nuclear@0: 	Color diffuse_color = mat->diffuse;
nuclear@0: 	Color tex_color{1, 1, 1};
nuclear@0: 	if(mat->tex) {
nuclear@0: 		tex_color *= mat->tex->sample(hit);
nuclear@0: 		diffuse_color *= tex_color;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	Color color = mat->emission * tex_color;
nuclear@0: 
nuclear@0: 	// image-based lighting
nuclear@0: 	if(scn->envmap_conv) {
nuclear@0: 		// pick a random direction and create a sampling ray
nuclear@0: 		Ray envray;
nuclear@0: 		envray.origin = hit.pos;
nuclear@0: 		rand_dir(&envray.dir.x, &envray.dir.y, &envray.dir.z, (unsigned int*)ray.user);
nuclear@0: 		if(dot_product(envray.dir, normal) < 0.0) {
nuclear@0: 			envray.dir = -envray.dir;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		HitPoint env_hit;
nuclear@0: 		if(!scn->intersect(envray, &env_hit)) {
nuclear@0: 			Vector3 dir = envray.dir;
nuclear@0: 			color += scn->envmap_conv->sample(dir.x, dir.y, dir.z) * diffuse_color;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	for(Light *lt: scn->lights) {
nuclear@0: 
nuclear@0: 		/* construct a shadow ray to determine if there is an uninterrupted
nuclear@0: 		 * path between the intersection point and the light source
nuclear@0: 		 */
nuclear@0: 		Ray shadow_ray = ray;
nuclear@0: 		shadow_ray.origin = hit.pos;
nuclear@0: 		shadow_ray.dir = lt->pos - hit.pos;
nuclear@0: 
nuclear@0: 		/* the interval [0, 1] represents the part of the ray from the origin
nuclear@0: 		 * to the light. We don't care about intersections behind the origin
nuclear@0: 		 * of the shadow ray (behind the surface of the object), or after the
nuclear@0: 		 * light source. We only care if there's something in between hiding the
nuclear@0: 		 * light.
nuclear@0: 		 */
nuclear@0: 		HitPoint shadow_hit;
nuclear@0: 		if(scn->intersect(shadow_ray, &shadow_hit) && shadow_hit.dist < 1.0f) {
nuclear@0: 			continue;	// skip this light, it's hidden from view
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		// calculate the light direction
nuclear@0: 		Vector3 ldir = shadow_ray.dir.normalized();
nuclear@0: 		// calculate the reflected light direction
nuclear@0: 		Vector3 lref = ldir.reflection(normal);
nuclear@0: 
nuclear@0: 		float diffuse = std::max(dot_product(ldir, normal), 0.0f);
nuclear@0: 		float specular = pow(std::max(dot_product(lref, vdir), 0.0f), mat->shininess);
nuclear@0: 
nuclear@0: 		color += (diffuse_color * diffuse + mat->specular * specular) * lt->color;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	Color spec_col;
nuclear@0: 
nuclear@0: 	if(mat->reflectivity > 0.001f && rdepth < MAX_RAY_DEPTH) {
nuclear@0: 		Ray refl_ray{ray};
nuclear@0: 		refl_ray.origin = hit.pos;
nuclear@0: 		refl_ray.dir = -ray.dir.reflection(normal);
nuclear@0: 
nuclear@0: 		spec_col += trace_ray(scn, refl_ray, rdepth + 1) * mat->reflectivity;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	if(mat->transparency > 0.001f && rdepth < MAX_RAY_DEPTH) {
nuclear@0: 		float from_ior = entering ? 1.0 : mat->ior;
nuclear@0: 		float to_ior = entering ? mat->ior : 1.0;
nuclear@0: 
nuclear@0: 		Ray refr_ray{ray};
nuclear@0: 		refr_ray.origin = hit.pos;
nuclear@0: 		refr_ray.dir = ray.dir.refraction(normal, from_ior / to_ior);
nuclear@0: 
nuclear@0: 		Color tcol = trace_ray(scn, refr_ray, rdepth + 1) * mat->transparency;
nuclear@0: 
nuclear@0: 		float fres = fresnel(ray.dir, refr_ray.dir, normal, from_ior, to_ior);
nuclear@0: 		spec_col = spec_col * fres + tcol * (1.0 - fres);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	return color + spec_col;
nuclear@0: }
nuclear@0: 
nuclear@0: 
nuclear@0: static void rand_dir(float *x, float *y, float *z, unsigned int *seedp)
nuclear@0: {
nuclear@0: 	float u = (float)rand_r(seedp) / RAND_MAX;
nuclear@0: 	float v = (float)rand_r(seedp) / RAND_MAX;
nuclear@0: 
nuclear@0: 	float theta = 2.0 * M_PI * u;
nuclear@0: 	float phi = acos(2.0 * v - 1.0);
nuclear@0: 
nuclear@0: 	*x = cos(theta) * sin(phi);
nuclear@0: 	*y = sin(theta) * sin(phi);
nuclear@0: 	*z = cos(phi);
nuclear@0: }
nuclear@0: 
nuclear@0: static float fresnel(const Vector3 &inc, const Vector3 &trans, const Vector3 &norm, float ior_inc, float ior_trans)
nuclear@0: {
nuclear@0: 	float cos_inc = dot_product(-inc, norm);
nuclear@0: 	float cos_trans = dot_product(-trans, norm);
nuclear@0: 
nuclear@0: 	return fresnel(cos_inc, cos_trans, ior_inc, ior_trans);
nuclear@0: }
nuclear@0: 
nuclear@0: static float fresnel(float cos_inc, float cos_trans, float ior_inc, float ior_trans)
nuclear@0: {
nuclear@0: 	float r0 = ((ior_trans * cos_inc) - (ior_inc * cos_trans)) /
nuclear@0: 		((ior_trans * cos_inc) + (ior_inc * cos_trans));
nuclear@0: 	float r1 = ((ior_inc * cos_inc) - (ior_trans * cos_trans)) /
nuclear@0: 		((ior_inc * cos_inc) + (ior_trans * cos_trans));
nuclear@0: 	return (r0 * r0 + r1 * r1) * 0.5f;
nuclear@0: }
nuclear@0: #endif