1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/rend.cc	Sun Nov 09 13:03:36 2014 +0200
     1.3 @@ -0,0 +1,372 @@
     1.4 +#include <assert.h>
     1.5 +#include "scene.h"
     1.6 +#include "image.h"
     1.7 +#include "rend.h"
     1.8 +#include "opengl.h"
     1.9 +#include "glsdr.h"
    1.10 +
    1.11 +enum {
    1.12 +	TEX_RAYDIR,
    1.13 +	TEX_SPHERES,
    1.14 +	TEX_PLANES,
    1.15 +	TEX_BOXES,
    1.16 +	TEX_TEXTURES,
    1.17 +	TEX_ENV,
    1.18 +	TEX_XFORM,
    1.19 +
    1.20 +	NUM_SDR_TEXTURES
    1.21 +};
    1.22 +
    1.23 +bool reload_shader();
    1.24 +void gen_ray_texture(unsigned int tex, int xsz, int ysz, float vfov);
    1.25 +static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg);
    1.26 +static int round_pow2(int x);
    1.27 +
    1.28 +static GPUScene *scn;
    1.29 +
    1.30 +static unsigned int sdr;
    1.31 +static unsigned int textures[NUM_SDR_TEXTURES];
    1.32 +
    1.33 +bool init_renderer(GPUScene *s, int xsz, int ysz)
    1.34 +{
    1.35 +	scn = s;
    1.36 +
    1.37 +	glGenTextures(1, textures + TEX_RAYDIR);
    1.38 +	glBindTexture(GL_TEXTURE_2D, textures[TEX_RAYDIR]);
    1.39 +	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    1.40 +	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    1.41 +	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    1.42 +	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    1.43 +
    1.44 +	if(!(s->create_textures())) {
    1.45 +		fprintf(stderr, "failed to create scene textures\n");
    1.46 +		return false;
    1.47 +	}
    1.48 +
    1.49 +	textures[TEX_SPHERES] = s->get_texture(GPUScene::TEX_SPHERE);
    1.50 +	textures[TEX_PLANES] = s->get_texture(GPUScene::TEX_PLANE);
    1.51 +	textures[TEX_BOXES] = s->get_texture(GPUScene::TEX_BOX);
    1.52 +	textures[TEX_TEXTURES] = s->get_texture(GPUScene::TEX_TEXTURE);
    1.53 +	textures[TEX_ENV] = s->get_texture(GPUScene::TEX_ENV);
    1.54 +	textures[TEX_XFORM] = s->get_texture(GPUScene::TEX_XFORM);
    1.55 +
    1.56 +	if(!reload_shader()) {
    1.57 +		return false;
    1.58 +	}
    1.59 +
    1.60 +	resize_renderer(xsz, ysz);
    1.61 +
    1.62 +	return true;
    1.63 +}
    1.64 +
    1.65 +bool reload_shader()
    1.66 +{
    1.67 +	if(sdr) {
    1.68 +		free_program(sdr);
    1.69 +	}
    1.70 +
    1.71 +	printf("loading shader...\n");
    1.72 +
    1.73 +	if(!(sdr = create_program_load("sdr/vertex.glsl", "sdr/rt.glsl"))) {
    1.74 +		return false;
    1.75 +	}
    1.76 +	set_uniform_int(sdr, "tex_raydir", TEX_RAYDIR);
    1.77 +	set_uniform_int(sdr, "tex_spheres", TEX_SPHERES);
    1.78 +	set_uniform_int(sdr, "tex_planes", TEX_PLANES);
    1.79 +	set_uniform_int(sdr, "tex_boxes", TEX_BOXES);
    1.80 +	set_uniform_int(sdr, "tex_megatex", TEX_TEXTURES);
    1.81 +	set_uniform_int(sdr, "tex_env", TEX_ENV);
    1.82 +	set_uniform_int(sdr, "tex_xforms", TEX_XFORM);
    1.83 +
    1.84 +	set_uniform_int(sdr, "num_lights", scn->get_light_count());
    1.85 +
    1.86 +	for(int i=0; i<scn->get_light_count(); i++) {
    1.87 +		const Light *lt = scn->get_light(i);
    1.88 +
    1.89 +		char name[64];
    1.90 +		sprintf(name, "lights[%d].pos", i);
    1.91 +		set_uniform_float3(sdr, name, lt->pos.x, lt->pos.y, lt->pos.z);
    1.92 +
    1.93 +		sprintf(name, "lights[%d].color", i);
    1.94 +		set_uniform_float3(sdr, name, lt->color.x, lt->color.y, lt->color.z);
    1.95 +	}
    1.96 +
    1.97 +	Vector2 fog;
    1.98 +	scn->get_fog(&fog.x, &fog.y);
    1.99 +	if(fog.x < 0.0 && fog.y < 0.0) {
   1.100 +		fog.x = 0.0;
   1.101 +		fog.y = 100000.0;
   1.102 +	}
   1.103 +	set_uniform_float2(sdr, "fog", fog.x, fog.y);
   1.104 +	return true;
   1.105 +}
   1.106 +
   1.107 +void destroy_renderer()
   1.108 +{
   1.109 +	free_program(sdr);
   1.110 +	sdr = 0;
   1.111 +}
   1.112 +
   1.113 +void resize_renderer(int xsz, int ysz)
   1.114 +{
   1.115 +	gen_ray_texture(textures[TEX_RAYDIR], xsz, ysz, 45.0f);
   1.116 +}
   1.117 +
   1.118 +float *render_frame(long msec)
   1.119 +{
   1.120 +	scn->prepare_xform(msec);
   1.121 +	scn->update_xform_texture();
   1.122 +
   1.123 +	Camera *cam = scn->get_camera();
   1.124 +	glMatrixMode(GL_MODELVIEW);
   1.125 +	glLoadIdentity();
   1.126 +	Vector3 cpos = cam->get_position();
   1.127 +	glTranslatef(cpos.x, cpos.y, cpos.z);
   1.128 +	Matrix4x4 cmat = cam->get_matrix();
   1.129 +	glMultTransposeMatrixf(cmat[0]);
   1.130 +
   1.131 +	for(int i=0; i<NUM_SDR_TEXTURES; i++) {
   1.132 +		glActiveTexture(GL_TEXTURE0 + i);
   1.133 +		if(i == TEX_ENV) {
   1.134 +			glBindTexture(GL_TEXTURE_CUBE_MAP, textures[i]);
   1.135 +		} else {
   1.136 +			glBindTexture(GL_TEXTURE_2D, textures[i]);
   1.137 +		}
   1.138 +	}
   1.139 +	glActiveTexture(GL_TEXTURE0);
   1.140 +
   1.141 +	glUseProgram(sdr);
   1.142 +
   1.143 +	glBegin(GL_QUADS);
   1.144 +	glTexCoord2f(0, 1);
   1.145 +	glVertex2f(-1, -1);
   1.146 +	glTexCoord2f(1, 1);
   1.147 +	glVertex2f(1, -1);
   1.148 +	glTexCoord2f(1, 0);
   1.149 +	glVertex2f(1, 1);
   1.150 +	glTexCoord2f(0, 0);
   1.151 +	glVertex2f(-1, 1);
   1.152 +	glEnd();
   1.153 +
   1.154 +	glUseProgram(0);
   1.155 +
   1.156 +	assert(glGetError() == GL_NO_ERROR);
   1.157 +	return 0;
   1.158 +}
   1.159 +
   1.160 +void gen_ray_texture(unsigned int tex, int xsz, int ysz, float vfov)
   1.161 +{
   1.162 +	int tex_xsz = round_pow2(xsz);
   1.163 +	int tex_ysz = round_pow2(ysz);
   1.164 +	float *teximg, *dir;
   1.165 +
   1.166 +	teximg = new float[3 * tex_xsz * tex_ysz];
   1.167 +	dir = teximg;
   1.168 +
   1.169 +	for(int i=0; i<tex_ysz; i++) {
   1.170 +		for(int j=0; j<tex_xsz; j++) {
   1.171 +			if(j < xsz && i < ysz) {
   1.172 +				Vector3 rdir = get_primary_ray_dir(j, i, xsz, ysz, vfov);
   1.173 +				dir[0] = rdir.x;
   1.174 +				dir[1] = rdir.y;
   1.175 +				dir[2] = rdir.z;
   1.176 +			} else {
   1.177 +				dir[0] = dir[1] = 0.0f;
   1.178 +				dir[2] = 1.0f;
   1.179 +			}
   1.180 +
   1.181 +			dir += 3;
   1.182 +		}
   1.183 +	}
   1.184 +
   1.185 +	glBindTexture(GL_TEXTURE_2D, tex);
   1.186 +	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, tex_xsz, tex_ysz, 0, GL_RGB, GL_FLOAT, teximg);
   1.187 +	delete [] teximg;
   1.188 +}
   1.189 +
   1.190 +static Vector3 calc_sample_pos(int x, int y, int xsz, int ysz)
   1.191 +{
   1.192 +	float ppos[2];
   1.193 +	float aspect = (float)xsz / (float)ysz;
   1.194 +
   1.195 +	float pwidth = 2.0 * aspect / (float)xsz;
   1.196 +	float pheight = 2.0 / (float)ysz;
   1.197 +
   1.198 +	ppos[0] = (float)x * pwidth - aspect;
   1.199 +	ppos[1] = 1.0 - (float)y * pheight;
   1.200 +
   1.201 +	return Vector3(ppos[0], ppos[1], 0.0f);
   1.202 +}
   1.203 +
   1.204 +
   1.205 +static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg)
   1.206 +{
   1.207 +	float vfov = M_PI * vfov_deg / 180.0;
   1.208 +
   1.209 +	Vector3 dir = calc_sample_pos(x, y, w, h);
   1.210 +	dir.z = 1.0 / tan(vfov / 2.0);
   1.211 +	dir.normalize();
   1.212 +
   1.213 +	return dir;
   1.214 +}
   1.215 +
   1.216 +static int round_pow2(int x)
   1.217 +{
   1.218 +	x--;
   1.219 +	x = (x >> 1) | x;
   1.220 +	x = (x >> 2) | x;
   1.221 +	x = (x >> 4) | x;
   1.222 +	x = (x >> 8) | x;
   1.223 +	x = (x >> 16) | x;
   1.224 +	return x + 1;
   1.225 +}
   1.226 +
   1.227 +
   1.228 +#if 0
   1.229 +Color trace_ray(const Scene *scn, const Ray &ray, int rdepth)
   1.230 +{
   1.231 +	HitPoint hit;
   1.232 +
   1.233 +	if(scn->intersect(ray, &hit)) {
   1.234 +		float t;
   1.235 +		if(scn->fog_start >= 0.0 && (t = (hit.dist - scn->fog_start) / (scn->fog_end - scn->fog_start)) > 0.0) {
   1.236 +			return lerp(shade(scn, ray, hit, rdepth), scn->env_color(ray), t > 1.0 ? 1.0 : t);
   1.237 +		}
   1.238 +		return shade(scn, ray, hit, rdepth);
   1.239 +	}
   1.240 +
   1.241 +	return scn->env_color(ray);
   1.242 +}
   1.243 +
   1.244 +Color shade(const Scene *scn, const Ray &ray, const HitPoint &hit, int rdepth)
   1.245 +{
   1.246 +	const Material *mat = &hit.obj->material;
   1.247 +
   1.248 +	// if we're leaving the object, we need to invert the normal (and ior)
   1.249 +	Vector3 normal;
   1.250 +	bool entering;
   1.251 +	if(dot_product(hit.normal, ray.dir) <= 0.0) {
   1.252 +		normal = hit.normal;
   1.253 +		entering = true;
   1.254 +	} else {
   1.255 +		normal = -hit.normal;
   1.256 +		entering = false;
   1.257 +	}
   1.258 +
   1.259 +	Vector3 vdir = -ray.dir;
   1.260 +
   1.261 +	Color diffuse_color = mat->diffuse;
   1.262 +	Color tex_color{1, 1, 1};
   1.263 +	if(mat->tex) {
   1.264 +		tex_color *= mat->tex->sample(hit);
   1.265 +		diffuse_color *= tex_color;
   1.266 +	}
   1.267 +
   1.268 +	Color color = mat->emission * tex_color;
   1.269 +
   1.270 +	// image-based lighting
   1.271 +	if(scn->envmap_conv) {
   1.272 +		// pick a random direction and create a sampling ray
   1.273 +		Ray envray;
   1.274 +		envray.origin = hit.pos;
   1.275 +		rand_dir(&envray.dir.x, &envray.dir.y, &envray.dir.z, (unsigned int*)ray.user);
   1.276 +		if(dot_product(envray.dir, normal) < 0.0) {
   1.277 +			envray.dir = -envray.dir;
   1.278 +		}
   1.279 +
   1.280 +		HitPoint env_hit;
   1.281 +		if(!scn->intersect(envray, &env_hit)) {
   1.282 +			Vector3 dir = envray.dir;
   1.283 +			color += scn->envmap_conv->sample(dir.x, dir.y, dir.z) * diffuse_color;
   1.284 +		}
   1.285 +	}
   1.286 +
   1.287 +	for(Light *lt: scn->lights) {
   1.288 +
   1.289 +		/* construct a shadow ray to determine if there is an uninterrupted
   1.290 +		 * path between the intersection point and the light source
   1.291 +		 */
   1.292 +		Ray shadow_ray = ray;
   1.293 +		shadow_ray.origin = hit.pos;
   1.294 +		shadow_ray.dir = lt->pos - hit.pos;
   1.295 +
   1.296 +		/* the interval [0, 1] represents the part of the ray from the origin
   1.297 +		 * to the light. We don't care about intersections behind the origin
   1.298 +		 * of the shadow ray (behind the surface of the object), or after the
   1.299 +		 * light source. We only care if there's something in between hiding the
   1.300 +		 * light.
   1.301 +		 */
   1.302 +		HitPoint shadow_hit;
   1.303 +		if(scn->intersect(shadow_ray, &shadow_hit) && shadow_hit.dist < 1.0f) {
   1.304 +			continue;	// skip this light, it's hidden from view
   1.305 +		}
   1.306 +
   1.307 +		// calculate the light direction
   1.308 +		Vector3 ldir = shadow_ray.dir.normalized();
   1.309 +		// calculate the reflected light direction
   1.310 +		Vector3 lref = ldir.reflection(normal);
   1.311 +
   1.312 +		float diffuse = std::max(dot_product(ldir, normal), 0.0f);
   1.313 +		float specular = pow(std::max(dot_product(lref, vdir), 0.0f), mat->shininess);
   1.314 +
   1.315 +		color += (diffuse_color * diffuse + mat->specular * specular) * lt->color;
   1.316 +	}
   1.317 +
   1.318 +	Color spec_col;
   1.319 +
   1.320 +	if(mat->reflectivity > 0.001f && rdepth < MAX_RAY_DEPTH) {
   1.321 +		Ray refl_ray{ray};
   1.322 +		refl_ray.origin = hit.pos;
   1.323 +		refl_ray.dir = -ray.dir.reflection(normal);
   1.324 +
   1.325 +		spec_col += trace_ray(scn, refl_ray, rdepth + 1) * mat->reflectivity;
   1.326 +	}
   1.327 +
   1.328 +	if(mat->transparency > 0.001f && rdepth < MAX_RAY_DEPTH) {
   1.329 +		float from_ior = entering ? 1.0 : mat->ior;
   1.330 +		float to_ior = entering ? mat->ior : 1.0;
   1.331 +
   1.332 +		Ray refr_ray{ray};
   1.333 +		refr_ray.origin = hit.pos;
   1.334 +		refr_ray.dir = ray.dir.refraction(normal, from_ior / to_ior);
   1.335 +
   1.336 +		Color tcol = trace_ray(scn, refr_ray, rdepth + 1) * mat->transparency;
   1.337 +
   1.338 +		float fres = fresnel(ray.dir, refr_ray.dir, normal, from_ior, to_ior);
   1.339 +		spec_col = spec_col * fres + tcol * (1.0 - fres);
   1.340 +	}
   1.341 +
   1.342 +	return color + spec_col;
   1.343 +}
   1.344 +
   1.345 +
   1.346 +static void rand_dir(float *x, float *y, float *z, unsigned int *seedp)
   1.347 +{
   1.348 +	float u = (float)rand_r(seedp) / RAND_MAX;
   1.349 +	float v = (float)rand_r(seedp) / RAND_MAX;
   1.350 +
   1.351 +	float theta = 2.0 * M_PI * u;
   1.352 +	float phi = acos(2.0 * v - 1.0);
   1.353 +
   1.354 +	*x = cos(theta) * sin(phi);
   1.355 +	*y = sin(theta) * sin(phi);
   1.356 +	*z = cos(phi);
   1.357 +}
   1.358 +
   1.359 +static float fresnel(const Vector3 &inc, const Vector3 &trans, const Vector3 &norm, float ior_inc, float ior_trans)
   1.360 +{
   1.361 +	float cos_inc = dot_product(-inc, norm);
   1.362 +	float cos_trans = dot_product(-trans, norm);
   1.363 +
   1.364 +	return fresnel(cos_inc, cos_trans, ior_inc, ior_trans);
   1.365 +}
   1.366 +
   1.367 +static float fresnel(float cos_inc, float cos_trans, float ior_inc, float ior_trans)
   1.368 +{
   1.369 +	float r0 = ((ior_trans * cos_inc) - (ior_inc * cos_trans)) /
   1.370 +		((ior_trans * cos_inc) + (ior_inc * cos_trans));
   1.371 +	float r1 = ((ior_inc * cos_inc) - (ior_trans * cos_trans)) /
   1.372 +		((ior_inc * cos_inc) + (ior_trans * cos_trans));
   1.373 +	return (r0 * r0 + r1 * r1) * 0.5f;
   1.374 +}
   1.375 +#endif