1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/sdr/rt.glsl	Sun Nov 09 13:03:36 2014 +0200
     1.3 @@ -0,0 +1,523 @@
     1.4 +/* vi:set filetype=glsl ts=4 sw=4: */
     1.5 +#version 120
     1.6 +#extension GL_ARB_gpu_shader5 : enable
     1.7 +
     1.8 +#define M_PI	3.1415926
     1.9 +
    1.10 +#define INIT_EVERYTHING
    1.11 +#define USE_XFORM
    1.12 +#define OBJ_LINE_WIDTH	16.0
    1.13 +
    1.14 +struct Ray {
    1.15 +	vec3 origin, dir;
    1.16 +};
    1.17 +
    1.18 +struct Material {
    1.19 +	vec3 diffuse, specular;
    1.20 +	float shininess;
    1.21 +	vec4 megatex_rect;
    1.22 +	float reflectivity;
    1.23 +};
    1.24 +
    1.25 +struct HitPoint {
    1.26 +	float dist;
    1.27 +	vec3 pos, normal;
    1.28 +	vec2 texcoord;
    1.29 +	struct Material mat;
    1.30 +};
    1.31 +
    1.32 +struct Sphere {
    1.33 +	float index;
    1.34 +	vec3 pos;
    1.35 +	float radius;
    1.36 +	struct Material mat;
    1.37 +};
    1.38 +
    1.39 +struct Plane {
    1.40 +	float index;
    1.41 +	vec3 normal;
    1.42 +	float dist;
    1.43 +	struct Material mat;
    1.44 +};
    1.45 +
    1.46 +struct Box {
    1.47 +	float index;
    1.48 +	vec3 min, max;
    1.49 +	struct Material mat;
    1.50 +};
    1.51 +
    1.52 +struct Light {
    1.53 +	vec3 pos, color;
    1.54 +};
    1.55 +
    1.56 +vec3 shade(in Ray ray, in HitPoint hit);
    1.57 +bool find_intersection(in Ray ray, out HitPoint hit);
    1.58 +bool sphere_intersect(in Sphere sph, in Ray ray, out HitPoint pt);
    1.59 +bool plane_intersect(in Plane plane, in Ray ray, out HitPoint pt);
    1.60 +bool box_intersect(in Box box, in Ray ray, out HitPoint pt);
    1.61 +vec3 transform(in vec3 v, in mat4 inv_xform);
    1.62 +Ray transform(in Ray ray, in mat4 xform, in mat4 inv_xform);
    1.63 +Ray get_primary_ray();
    1.64 +
    1.65 +Sphere read_sphere(in float idx);
    1.66 +Plane read_plane(in float idx);
    1.67 +Box read_box(in float idx);
    1.68 +Material read_material(in sampler2D tex, in float ty);
    1.69 +void read_xform(in float idx, out mat4 xform, out mat4 inv_xform);
    1.70 +
    1.71 +uniform sampler2D tex_raydir;
    1.72 +uniform sampler2D tex_spheres, tex_planes, tex_boxes;
    1.73 +uniform sampler2D tex_megatex;
    1.74 +uniform sampler2D tex_xforms;
    1.75 +uniform samplerCube tex_env;
    1.76 +uniform vec2 fog;
    1.77 +
    1.78 +uniform Light lights[8];
    1.79 +uniform int num_lights;
    1.80 +
    1.81 +int num_spheres, num_planes, num_boxes;
    1.82 +float sph_tex_sz, plane_tex_sz, box_tex_sz, xform_tex_sz;
    1.83 +
    1.84 +#ifdef INIT_EVERYTHING
    1.85 +Material default_material;
    1.86 +#endif
    1.87 +
    1.88 +void main()
    1.89 +{
    1.90 +#ifdef INIT_EVERYTHING
    1.91 +	default_material.diffuse = default_material.specular = vec3(0.0, 0.0, 0.0);
    1.92 +	default_material.shininess = 1.0;
    1.93 +	default_material.reflectivity = 0.0;
    1.94 +	default_material.megatex_rect = vec4(0.0, 0.0, 0.0, 0.0);
    1.95 +#endif
    1.96 +
    1.97 +	Ray ray = get_primary_ray();
    1.98 +
    1.99 +	/* read the various descriptors specifying dimensions and counts for
   1.100 +	 * all the relevant data textures
   1.101 +	 */
   1.102 +	vec4 desc = texture2D(tex_spheres, vec2(0.0, 0.0));
   1.103 +	num_spheres = int(desc.x);
   1.104 +	sph_tex_sz = desc.y;
   1.105 +
   1.106 +	desc = texture2D(tex_planes, vec2(0.0, 0.0));
   1.107 +	num_planes = int(desc.x);
   1.108 +	plane_tex_sz = desc.y;
   1.109 +
   1.110 +	desc = texture2D(tex_boxes, vec2(0.0, 0.0));
   1.111 +	num_boxes = int(desc.x);
   1.112 +	box_tex_sz = desc.y;
   1.113 +
   1.114 +	xform_tex_sz = texture2D(tex_xforms, vec2(0.0, 0.0)).x;
   1.115 +
   1.116 +
   1.117 +	HitPoint hit;
   1.118 +#ifdef INIT_EVERYTHING
   1.119 +	hit.dist = 0.0;
   1.120 +	hit.pos = hit.normal = vec3(0.0, 0.0, 0.0);
   1.121 +#endif
   1.122 +
   1.123 +	vec3 color = vec3(0.0, 0.0, 0.0);
   1.124 +	float energy = 1.0;
   1.125 +
   1.126 +	int iter = 0;
   1.127 +	while(energy > 0.01 && iter++ < 4) {
   1.128 +		vec3 envcol = textureCube(tex_env, ray.dir).xyz;
   1.129 +
   1.130 +		if(find_intersection(ray, hit)) {
   1.131 +			float fog_t = clamp((hit.dist - fog.x) / (fog.y - fog.x), 0.0, 1.0);
   1.132 +			color += mix(shade(ray, hit), envcol, fog_t) * energy;
   1.133 +			energy *= hit.mat.reflectivity * (1.0 - fog_t);
   1.134 +			ray.origin = hit.pos;
   1.135 +			ray.dir = reflect(ray.dir, hit.normal);
   1.136 +		} else {
   1.137 +			color += envcol * energy;
   1.138 +			energy = 0.0;
   1.139 +			iter = 100;
   1.140 +		}
   1.141 +	}
   1.142 +
   1.143 +	gl_FragColor.xyz = color;
   1.144 +	gl_FragColor.w = 1.0;
   1.145 +}
   1.146 +
   1.147 +vec3 shade(in Ray ray, in HitPoint hit)
   1.148 +{
   1.149 +	vec3 normal = faceforward(hit.normal, ray.dir, hit.normal);
   1.150 +
   1.151 +	vec3 vdir = normalize(ray.dir);
   1.152 +	vec3 vref = reflect(vdir, normal);
   1.153 +
   1.154 +	/* if there's no texture rect.zw will be (0, 0, 0, 0) so this will map onto
   1.155 +	 * the top-left 1x1 null texture which is all white (having no effect)
   1.156 +	 */
   1.157 +	vec2 tc = mod(hit.texcoord, vec2(1.0, 1.0)) * hit.mat.megatex_rect.zw + hit.mat.megatex_rect.xy;
   1.158 +
   1.159 +	vec3 diffuse_color = hit.mat.diffuse * texture2D(tex_megatex, tc).xyz;
   1.160 +
   1.161 +	vec3 color = vec3(0.0, 0.0, 0.0);
   1.162 +	for(int i=0; i<num_lights; i++) {
   1.163 +		Ray shadow_ray;
   1.164 +		shadow_ray.origin = hit.pos;
   1.165 +		shadow_ray.dir = lights[i].pos - hit.pos;
   1.166 +
   1.167 +		HitPoint shadow_hit;
   1.168 +		if(!find_intersection(shadow_ray, shadow_hit) || shadow_hit.dist > 1.0) {
   1.169 +			vec3 ldir = normalize(shadow_ray.dir);
   1.170 +
   1.171 +			float diffuse = max(dot(ldir, normal), 0.0);
   1.172 +			float specular = pow(max(dot(ldir, vref), 0.0), hit.mat.shininess);
   1.173 +
   1.174 +			color += (diffuse_color * diffuse + hit.mat.specular * specular) * lights[i].color;
   1.175 +		}
   1.176 +	}
   1.177 +
   1.178 +	return color;
   1.179 +}
   1.180 +
   1.181 +bool find_intersection(in Ray ray, out HitPoint hit)
   1.182 +{
   1.183 +	hit.dist = 100000.0;
   1.184 +#ifdef INIT_EVERYTHING
   1.185 +	hit.pos = hit.normal = vec3(0.0, 0.0, 0.0);
   1.186 +	hit.mat = default_material;
   1.187 +	hit.texcoord = vec2(0.0, 0.0);
   1.188 +#endif
   1.189 +	bool found = false;
   1.190 +
   1.191 +	for(int i=0; i<num_spheres; i++) {
   1.192 +		Sphere sph = read_sphere(i);
   1.193 +
   1.194 +		HitPoint tmphit;
   1.195 +		if(sphere_intersect(sph, ray, tmphit) && tmphit.dist < hit.dist) {
   1.196 +			hit = tmphit;
   1.197 +			found = true;
   1.198 +		}
   1.199 +	}
   1.200 +
   1.201 +	for(int i=0; i<num_planes; i++) {
   1.202 +		Plane plane = read_plane(i);
   1.203 +
   1.204 +		HitPoint tmphit;
   1.205 +		if(plane_intersect(plane, ray, tmphit) && tmphit.dist < hit.dist) {
   1.206 +			hit = tmphit;
   1.207 +			found = true;
   1.208 +		}
   1.209 +	}
   1.210 +
   1.211 +	for(int i=0; i<num_boxes; i++) {
   1.212 +		Box box = read_box(i);
   1.213 +
   1.214 +		HitPoint tmphit;
   1.215 +		if(box_intersect(box, ray, tmphit) && tmphit.dist < hit.dist) {
   1.216 +			hit = tmphit;
   1.217 +			found = true;
   1.218 +		}
   1.219 +	}
   1.220 +
   1.221 +	return found;
   1.222 +}
   1.223 +
   1.224 +#define EPSILON	1e-4
   1.225 +#define SQ(x)	((x) * (x))
   1.226 +
   1.227 +bool sphere_intersect(in Sphere sph, in Ray inray, out HitPoint pt)
   1.228 +{
   1.229 +#ifdef USE_XFORM
   1.230 +	mat4 xform, inv_xform;
   1.231 +	read_xform(sph.index, xform, inv_xform);
   1.232 +
   1.233 +	Ray ray = transform(inray, inv_xform, xform);
   1.234 +#else
   1.235 +	Ray ray = inray;
   1.236 +#endif
   1.237 +
   1.238 +#ifdef INIT_EVERYTHING
   1.239 +	pt.dist = 0.0;
   1.240 +	pt.pos = pt.normal = vec3(0.0, 0.0, 0.0);
   1.241 +	pt.mat = default_material;
   1.242 +	pt.texcoord = vec2(0.0, 0.0);
   1.243 +#endif
   1.244 +
   1.245 +	float a = dot(ray.dir, ray.dir);
   1.246 +	float b = dot(ray.dir, ray.origin - sph.pos) * 2.0;
   1.247 +	float c = dot(ray.origin, ray.origin) + dot(sph.pos, sph.pos) -
   1.248 +		2.0 * dot(ray.origin, sph.pos) - sph.radius * sph.radius;
   1.249 +
   1.250 +	float discr = b * b - 4.0 * a * c;
   1.251 +	if(discr < EPSILON)
   1.252 +		return false;
   1.253 +
   1.254 +	float sqrt_discr = sqrt(discr);
   1.255 +	float t0 = (-b + sqrt_discr) / (2.0 * a);
   1.256 +	float t1 = (-b - sqrt_discr) / (2.0 * a);
   1.257 +
   1.258 +	if(t0 < EPSILON)
   1.259 +		t0 = t1;
   1.260 +	if(t1 < EPSILON)
   1.261 +		t1 = t0;
   1.262 +
   1.263 +	float t = min(t0, t1);
   1.264 +	if(t < EPSILON)
   1.265 +		return false;
   1.266 +
   1.267 +	// fill the HitPoint structure
   1.268 +	pt.dist = t;
   1.269 +	pt.pos = ray.origin + ray.dir * t;
   1.270 +	pt.normal = (pt.pos - sph.pos) / sph.radius;
   1.271 +	pt.mat = sph.mat;
   1.272 +
   1.273 +	pt.texcoord.x = 0.5 * atan(pt.normal.z, pt.normal.x) / M_PI + 0.5;
   1.274 +	pt.texcoord.y = acos(pt.normal.y) / M_PI;
   1.275 +
   1.276 +#ifdef USE_XFORM
   1.277 +	pt.pos = (xform * vec4(pt.pos, 1.0)).xyz;
   1.278 +	pt.normal = normalize(transform(pt.normal, xform));
   1.279 +#endif
   1.280 +	return true;
   1.281 +}
   1.282 +
   1.283 +bool plane_intersect(in Plane plane, in Ray inray, out HitPoint pt)
   1.284 +{
   1.285 +#ifdef USE_XFORM
   1.286 +	mat4 xform, inv_xform;
   1.287 +	read_xform(plane.index, xform, inv_xform);
   1.288 +
   1.289 +	Ray ray = transform(inray, inv_xform, xform);
   1.290 +#else
   1.291 +	Ray ray = inray;
   1.292 +#endif
   1.293 +
   1.294 +#ifdef INIT_EVERYTHING
   1.295 +	pt.dist = 0.0;
   1.296 +	pt.pos = pt.normal = vec3(0.0, 0.0, 0.0);
   1.297 +	pt.mat = default_material;
   1.298 +	pt.texcoord = vec2(0.0, 0.0);
   1.299 +#endif
   1.300 +
   1.301 +	float ndotdir = dot(plane.normal, ray.dir);
   1.302 +	if(abs(ndotdir) < EPSILON) {
   1.303 +		return false;
   1.304 +	}
   1.305 +
   1.306 +	vec3 planept = plane.normal * plane.dist;
   1.307 +	vec3 pptdir = planept - ray.origin;
   1.308 +
   1.309 +	float t = dot(plane.normal, pptdir) / ndotdir;
   1.310 +	if(t < EPSILON) {
   1.311 +		return false;
   1.312 +	}
   1.313 +
   1.314 +	pt.dist = t;
   1.315 +	pt.pos = ray.origin + ray.dir * t;
   1.316 +	pt.normal = plane.normal;
   1.317 +	pt.mat = plane.mat;
   1.318 +	pt.texcoord.x = pt.pos.x;
   1.319 +	pt.texcoord.y = pt.pos.z;
   1.320 +
   1.321 +#ifdef USE_XFORM
   1.322 +	pt.pos = (xform * vec4(pt.pos, 1.0)).xyz;
   1.323 +	pt.normal = normalize(transform(pt.normal, xform));
   1.324 +#endif
   1.325 +	return true;
   1.326 +}
   1.327 +
   1.328 +bool box_intersect(in Box box, in Ray inray, out HitPoint pt)
   1.329 +{
   1.330 +#ifdef USE_XFORM
   1.331 +	mat4 xform, inv_xform;
   1.332 +	read_xform(box.index, xform, inv_xform);
   1.333 +
   1.334 +	Ray ray = transform(inray, inv_xform, xform);
   1.335 +#else
   1.336 +	Ray ray = inray;
   1.337 +#endif
   1.338 +
   1.339 +#ifdef INIT_EVERYTHING
   1.340 +	pt.dist = 0.0;
   1.341 +	pt.pos = pt.normal = vec3(0.0, 0.0, 0.0);
   1.342 +	pt.mat = default_material;
   1.343 +	pt.texcoord = vec2(0.0, 0.0);
   1.344 +#endif
   1.345 +
   1.346 +	vec3 param[2];
   1.347 +	param[0] = box.min;
   1.348 +	param[1] = box.max;
   1.349 +
   1.350 +	vec3 inv_dir = 1.0 / ray.dir;
   1.351 +	int sgn[3];
   1.352 +	sgn[0] = inv_dir.x < 0.0 ? 1 : 0;
   1.353 +	sgn[1] = inv_dir.y < 0.0 ? 1 : 0;
   1.354 +	sgn[2] = inv_dir.z < 0.0 ? 1 : 0;
   1.355 +
   1.356 +	float tmin = (param[sgn[0]].x - ray.origin.x) * inv_dir.x;
   1.357 +	float tmax = (param[1 - sgn[0]].x - ray.origin.x) * inv_dir.x;
   1.358 +	float tymin = (param[sgn[1]].y - ray.origin.y) * inv_dir.y;
   1.359 +	float tymax = (param[1 - sgn[1]].y - ray.origin.y) * inv_dir.y;
   1.360 +
   1.361 +	pt.normal = vec3(ray.origin.x > 0.0 ? 1.0 : -1.0, 0.0, 0.0);
   1.362 +
   1.363 +	if(tmin > tymax || tymin > tmax) {
   1.364 +		return false;
   1.365 +	}
   1.366 +	if(tymin > tmin) {
   1.367 +		pt.normal = vec3(0.0, ray.origin.y > 0.0 ? 1.0 : -1.0, 0.0);
   1.368 +		tmin = tymin;
   1.369 +	}
   1.370 +	if(tymax < tmax) {
   1.371 +		tmax = tymax;
   1.372 +	}
   1.373 +
   1.374 +	float tzmin = (param[sgn[2]].z - ray.origin.z) * inv_dir.z;
   1.375 +	float tzmax = (param[1 - sgn[2]].z - ray.origin.z) * inv_dir.z;
   1.376 +
   1.377 +	if(tmin > tzmax || tzmin > tmax) {
   1.378 +		return false;
   1.379 +	}
   1.380 +	if(tzmin > tmin) {
   1.381 +		pt.normal = vec3(0.0, 0.0, ray.origin.z > 0.0 ? 1.0 : -1.0);
   1.382 +		tmin = tzmin;
   1.383 +	}
   1.384 +	if(tzmax < tmax) {
   1.385 +		tmax = tzmax;
   1.386 +	}
   1.387 +
   1.388 +	float t = tmin < EPSILON ? tmax : tmin;
   1.389 +	if(t >= 1e-4) {
   1.390 +		pt.dist = t;
   1.391 +		pt.pos = ray.origin + ray.dir * t;
   1.392 +		pt.mat = box.mat;
   1.393 +
   1.394 +		float min_dist = 10000.0;
   1.395 +
   1.396 +		vec3 offs = box.min + (box.max - box.min) / 2.0;
   1.397 +		vec3 local_pt = pt.pos - offs;
   1.398 +
   1.399 +		vec3 dist = abs((box.max - offs) - abs(local_pt));
   1.400 +		if(dist.x < min_dist) {
   1.401 +			min_dist = dist.x;
   1.402 +			pt.normal = sign(local_pt.x) * vec3(1.0, 0.0, 0.0);
   1.403 +			pt.texcoord = pt.pos.zy;
   1.404 +		}
   1.405 +		if(dist.y < min_dist) {
   1.406 +			min_dist = dist.y;
   1.407 +			pt.normal = sign(local_pt.y) * vec3(0.0, 1.0, 0.0);
   1.408 +			pt.texcoord = pt.pos.xz;
   1.409 +		}
   1.410 +		if(dist.z < min_dist) {
   1.411 +			pt.normal = sign(local_pt.y) * vec3(0.0, 0.0, 1.0);
   1.412 +			pt.texcoord = pt.pos.xy;
   1.413 +		}
   1.414 +
   1.415 +
   1.416 +#ifdef USE_XFORM
   1.417 +		pt.pos = (xform * vec4(pt.pos, 1.0)).xyz;
   1.418 +		pt.normal = normalize(transform(pt.normal, xform));
   1.419 +#endif
   1.420 +		return true;
   1.421 +	}
   1.422 +	return false;
   1.423 +}
   1.424 +
   1.425 +vec3 transform(in vec3 v, in mat4 xform)
   1.426 +{
   1.427 +	return mat3(xform) * v;
   1.428 +}
   1.429 +
   1.430 +Ray transform(in Ray ray, in mat4 xform, in mat4 inv_xform)
   1.431 +{
   1.432 +	Ray res;
   1.433 +	res.origin = (xform * vec4(ray.origin, 1.0)).xyz;
   1.434 +	res.dir = transform(ray.dir, xform);
   1.435 +	return res;
   1.436 +}
   1.437 +
   1.438 +Ray get_primary_ray()
   1.439 +{
   1.440 +	Ray ray;
   1.441 +	ray.origin = (gl_ModelViewMatrix * vec4(0.0, 0.0, 0.0, 1.0)).xyz;
   1.442 +	vec3 dir = texture2D(tex_raydir, gl_TexCoord[0].st).xyz;
   1.443 +	ray.dir = normalize(gl_NormalMatrix * dir);
   1.444 +	return ray;
   1.445 +}
   1.446 +
   1.447 +#define ITEM(x)	((float(x) + 0.5) / OBJ_LINE_WIDTH)
   1.448 +
   1.449 +Sphere read_sphere(in float idx)
   1.450 +{
   1.451 +	Sphere sph;
   1.452 +	// +1 because the first scanline is the descriptor
   1.453 +	float ty = (idx + 1.0) / sph_tex_sz;
   1.454 +
   1.455 +	sph.index = texture2D(tex_spheres, vec2(ITEM(0), ty)).x;
   1.456 +
   1.457 +	vec4 texel = texture2D(tex_spheres, vec2(ITEM(1), ty));
   1.458 +	sph.pos = texel.xyz;
   1.459 +	sph.radius = texel.w;
   1.460 +
   1.461 +	sph.mat = read_material(tex_spheres, ty);
   1.462 +	return sph;
   1.463 +}
   1.464 +
   1.465 +Plane read_plane(in float idx)
   1.466 +{
   1.467 +	Plane plane;
   1.468 +	// +1 (see above)
   1.469 +	float ty = (idx + 1.0) / plane_tex_sz;
   1.470 +
   1.471 +	plane.index = texture2D(tex_planes, vec2(ITEM(0), ty)).x;
   1.472 +
   1.473 +	vec4 texel = texture2D(tex_planes, vec2(ITEM(1), ty));
   1.474 +	plane.normal = texel.xyz;
   1.475 +	plane.dist = texel.w;
   1.476 +
   1.477 +	plane.mat = read_material(tex_planes, ty);
   1.478 +	return plane;
   1.479 +}
   1.480 +
   1.481 +Box read_box(in float idx)
   1.482 +{
   1.483 +	Box box;
   1.484 +	float ty = (idx + 1.0) / box_tex_sz;
   1.485 +
   1.486 +	box.index = texture2D(tex_boxes, vec2(ITEM(0), ty)).x;
   1.487 +
   1.488 +	box.min = texture2D(tex_boxes, vec2(ITEM(1), ty)).xyz;
   1.489 +	box.max = texture2D(tex_boxes, vec2(ITEM(2), ty)).xyz;
   1.490 +
   1.491 +	box.mat = read_material(tex_boxes, ty);
   1.492 +	return box;
   1.493 +}
   1.494 +
   1.495 +void read_xform(in float idx, out mat4 xform, out mat4 inv_xform)
   1.496 +{
   1.497 +	float ty = (idx + 1.0) / xform_tex_sz;
   1.498 +
   1.499 +	for(int i=0; i<4; i++) {
   1.500 +		xform[i] = texture2D(tex_xforms, vec2(ITEM(i), ty));
   1.501 +	}
   1.502 +	inv_xform = inverse(xform);
   1.503 +	/*for(int i=0; i<4; i++) {
   1.504 +		inv_xform[i] = texture2D(tex_xforms, vec2(ITEM(float(i) + 4.0), ty));
   1.505 +	}*/
   1.506 +}
   1.507 +
   1.508 +#define MAT_START	4
   1.509 +Material read_material(in sampler2D tex, in float ty)
   1.510 +{
   1.511 +	Material mat;
   1.512 +
   1.513 +	vec4 texel = texture2D(tex, vec2(ITEM(MAT_START), ty));
   1.514 +	mat.diffuse = texel.xyz;
   1.515 +
   1.516 +	texel = texture2D(tex, vec2(ITEM(MAT_START + 1), ty));
   1.517 +	mat.specular = texel.xyz;
   1.518 +	mat.shininess = texel.w;
   1.519 +
   1.520 +	texel = texture2D(tex, vec2(ITEM(MAT_START + 2), ty));
   1.521 +	mat.reflectivity = texel.x;
   1.522 +
   1.523 +	mat.megatex_rect = texture2D(tex, vec2(ITEM(MAT_START + 3), ty));
   1.524 +
   1.525 +	return mat;
   1.526 +}