nuclear@0: /* vi:set filetype=glsl ts=4 sw=4: */
nuclear@0: #version 120
nuclear@0: #extension GL_ARB_gpu_shader5 : enable
nuclear@0: 
nuclear@0: #define M_PI	3.1415926
nuclear@0: 
nuclear@0: #define INIT_EVERYTHING
nuclear@0: #define USE_XFORM
nuclear@0: #define OBJ_LINE_WIDTH	16.0
nuclear@0: 
nuclear@0: struct Ray {
nuclear@0: 	vec3 origin, dir;
nuclear@0: };
nuclear@0: 
nuclear@0: struct Material {
nuclear@0: 	vec3 diffuse, specular;
nuclear@0: 	float shininess;
nuclear@0: 	vec4 megatex_rect;
nuclear@0: 	float reflectivity;
nuclear@0: };
nuclear@0: 
nuclear@0: struct HitPoint {
nuclear@0: 	float dist;
nuclear@0: 	vec3 pos, normal;
nuclear@0: 	vec2 texcoord;
nuclear@0: 	struct Material mat;
nuclear@0: };
nuclear@0: 
nuclear@0: struct Sphere {
nuclear@0: 	float index;
nuclear@0: 	vec3 pos;
nuclear@0: 	float radius;
nuclear@0: 	struct Material mat;
nuclear@0: };
nuclear@0: 
nuclear@0: struct Plane {
nuclear@0: 	float index;
nuclear@0: 	vec3 normal;
nuclear@0: 	float dist;
nuclear@0: 	struct Material mat;
nuclear@0: };
nuclear@0: 
nuclear@0: struct Box {
nuclear@0: 	float index;
nuclear@0: 	vec3 min, max;
nuclear@0: 	struct Material mat;
nuclear@0: };
nuclear@0: 
nuclear@0: struct Light {
nuclear@0: 	vec3 pos, color;
nuclear@0: };
nuclear@0: 
nuclear@0: vec3 shade(in Ray ray, in HitPoint hit);
nuclear@0: bool find_intersection(in Ray ray, out HitPoint hit);
nuclear@0: bool sphere_intersect(in Sphere sph, in Ray ray, out HitPoint pt);
nuclear@0: bool plane_intersect(in Plane plane, in Ray ray, out HitPoint pt);
nuclear@0: bool box_intersect(in Box box, in Ray ray, out HitPoint pt);
nuclear@0: vec3 transform(in vec3 v, in mat4 inv_xform);
nuclear@0: Ray transform(in Ray ray, in mat4 xform, in mat4 inv_xform);
nuclear@0: Ray get_primary_ray();
nuclear@0: 
nuclear@0: Sphere read_sphere(in float idx);
nuclear@0: Plane read_plane(in float idx);
nuclear@0: Box read_box(in float idx);
nuclear@0: Material read_material(in sampler2D tex, in float ty);
nuclear@0: void read_xform(in float idx, out mat4 xform, out mat4 inv_xform);
nuclear@0: 
nuclear@0: uniform sampler2D tex_raydir;
nuclear@0: uniform sampler2D tex_spheres, tex_planes, tex_boxes;
nuclear@0: uniform sampler2D tex_megatex;
nuclear@0: uniform sampler2D tex_xforms;
nuclear@0: uniform samplerCube tex_env;
nuclear@0: uniform vec2 fog;
nuclear@0: 
nuclear@0: uniform Light lights[8];
nuclear@0: uniform int num_lights;
nuclear@0: 
nuclear@0: int num_spheres, num_planes, num_boxes;
nuclear@0: float sph_tex_sz, plane_tex_sz, box_tex_sz, xform_tex_sz;
nuclear@0: 
nuclear@0: #ifdef INIT_EVERYTHING
nuclear@0: Material default_material;
nuclear@0: #endif
nuclear@0: 
nuclear@0: void main()
nuclear@0: {
nuclear@0: #ifdef INIT_EVERYTHING
nuclear@0: 	default_material.diffuse = default_material.specular = vec3(0.0, 0.0, 0.0);
nuclear@0: 	default_material.shininess = 1.0;
nuclear@0: 	default_material.reflectivity = 0.0;
nuclear@0: 	default_material.megatex_rect = vec4(0.0, 0.0, 0.0, 0.0);
nuclear@0: #endif
nuclear@0: 
nuclear@0: 	Ray ray = get_primary_ray();
nuclear@0: 
nuclear@0: 	/* read the various descriptors specifying dimensions and counts for
nuclear@0: 	 * all the relevant data textures
nuclear@0: 	 */
nuclear@0: 	vec4 desc = texture2D(tex_spheres, vec2(0.0, 0.0));
nuclear@0: 	num_spheres = int(desc.x);
nuclear@0: 	sph_tex_sz = desc.y;
nuclear@0: 
nuclear@0: 	desc = texture2D(tex_planes, vec2(0.0, 0.0));
nuclear@0: 	num_planes = int(desc.x);
nuclear@0: 	plane_tex_sz = desc.y;
nuclear@0: 
nuclear@0: 	desc = texture2D(tex_boxes, vec2(0.0, 0.0));
nuclear@0: 	num_boxes = int(desc.x);
nuclear@0: 	box_tex_sz = desc.y;
nuclear@0: 
nuclear@0: 	xform_tex_sz = texture2D(tex_xforms, vec2(0.0, 0.0)).x;
nuclear@0: 
nuclear@0: 
nuclear@0: 	HitPoint hit;
nuclear@0: #ifdef INIT_EVERYTHING
nuclear@0: 	hit.dist = 0.0;
nuclear@0: 	hit.pos = hit.normal = vec3(0.0, 0.0, 0.0);
nuclear@0: #endif
nuclear@0: 
nuclear@0: 	vec3 color = vec3(0.0, 0.0, 0.0);
nuclear@0: 	float energy = 1.0;
nuclear@0: 
nuclear@0: 	int iter = 0;
nuclear@0: 	while(energy > 0.01 && iter++ < 4) {
nuclear@0: 		vec3 envcol = textureCube(tex_env, ray.dir).xyz;
nuclear@0: 
nuclear@0: 		if(find_intersection(ray, hit)) {
nuclear@0: 			float fog_t = clamp((hit.dist - fog.x) / (fog.y - fog.x), 0.0, 1.0);
nuclear@0: 			color += mix(shade(ray, hit), envcol, fog_t) * energy;
nuclear@0: 			energy *= hit.mat.reflectivity * (1.0 - fog_t);
nuclear@0: 			ray.origin = hit.pos;
nuclear@0: 			ray.dir = reflect(ray.dir, hit.normal);
nuclear@0: 		} else {
nuclear@0: 			color += envcol * energy;
nuclear@0: 			energy = 0.0;
nuclear@0: 			iter = 100;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	gl_FragColor.xyz = color;
nuclear@0: 	gl_FragColor.w = 1.0;
nuclear@0: }
nuclear@0: 
nuclear@0: vec3 shade(in Ray ray, in HitPoint hit)
nuclear@0: {
nuclear@0: 	vec3 normal = faceforward(hit.normal, ray.dir, hit.normal);
nuclear@0: 
nuclear@0: 	vec3 vdir = normalize(ray.dir);
nuclear@0: 	vec3 vref = reflect(vdir, normal);
nuclear@0: 
nuclear@0: 	/* if there's no texture rect.zw will be (0, 0, 0, 0) so this will map onto
nuclear@0: 	 * the top-left 1x1 null texture which is all white (having no effect)
nuclear@0: 	 */
nuclear@0: 	vec2 tc = mod(hit.texcoord, vec2(1.0, 1.0)) * hit.mat.megatex_rect.zw + hit.mat.megatex_rect.xy;
nuclear@0: 
nuclear@0: 	vec3 diffuse_color = hit.mat.diffuse * texture2D(tex_megatex, tc).xyz;
nuclear@0: 
nuclear@0: 	vec3 color = vec3(0.0, 0.0, 0.0);
nuclear@0: 	for(int i=0; i<num_lights; i++) {
nuclear@0: 		Ray shadow_ray;
nuclear@0: 		shadow_ray.origin = hit.pos;
nuclear@0: 		shadow_ray.dir = lights[i].pos - hit.pos;
nuclear@0: 
nuclear@0: 		HitPoint shadow_hit;
nuclear@0: 		if(!find_intersection(shadow_ray, shadow_hit) || shadow_hit.dist > 1.0) {
nuclear@0: 			vec3 ldir = normalize(shadow_ray.dir);
nuclear@0: 
nuclear@0: 			float diffuse = max(dot(ldir, normal), 0.0);
nuclear@0: 			float specular = pow(max(dot(ldir, vref), 0.0), hit.mat.shininess);
nuclear@0: 
nuclear@0: 			color += (diffuse_color * diffuse + hit.mat.specular * specular) * lights[i].color;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	return color;
nuclear@0: }
nuclear@0: 
nuclear@0: bool find_intersection(in Ray ray, out HitPoint hit)
nuclear@0: {
nuclear@0: 	hit.dist = 100000.0;
nuclear@0: #ifdef INIT_EVERYTHING
nuclear@0: 	hit.pos = hit.normal = vec3(0.0, 0.0, 0.0);
nuclear@0: 	hit.mat = default_material;
nuclear@0: 	hit.texcoord = vec2(0.0, 0.0);
nuclear@0: #endif
nuclear@0: 	bool found = false;
nuclear@0: 
nuclear@0: 	for(int i=0; i<num_spheres; i++) {
nuclear@0: 		Sphere sph = read_sphere(i);
nuclear@0: 
nuclear@0: 		HitPoint tmphit;
nuclear@0: 		if(sphere_intersect(sph, ray, tmphit) && tmphit.dist < hit.dist) {
nuclear@0: 			hit = tmphit;
nuclear@0: 			found = true;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	for(int i=0; i<num_planes; i++) {
nuclear@0: 		Plane plane = read_plane(i);
nuclear@0: 
nuclear@0: 		HitPoint tmphit;
nuclear@0: 		if(plane_intersect(plane, ray, tmphit) && tmphit.dist < hit.dist) {
nuclear@0: 			hit = tmphit;
nuclear@0: 			found = true;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	for(int i=0; i<num_boxes; i++) {
nuclear@0: 		Box box = read_box(i);
nuclear@0: 
nuclear@0: 		HitPoint tmphit;
nuclear@0: 		if(box_intersect(box, ray, tmphit) && tmphit.dist < hit.dist) {
nuclear@0: 			hit = tmphit;
nuclear@0: 			found = true;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	return found;
nuclear@0: }
nuclear@0: 
nuclear@0: #define EPSILON	1e-4
nuclear@0: #define SQ(x)	((x) * (x))
nuclear@0: 
nuclear@0: bool sphere_intersect(in Sphere sph, in Ray inray, out HitPoint pt)
nuclear@0: {
nuclear@0: #ifdef USE_XFORM
nuclear@0: 	mat4 xform, inv_xform;
nuclear@0: 	read_xform(sph.index, xform, inv_xform);
nuclear@0: 
nuclear@0: 	Ray ray = transform(inray, inv_xform, xform);
nuclear@0: #else
nuclear@0: 	Ray ray = inray;
nuclear@0: #endif
nuclear@0: 
nuclear@0: #ifdef INIT_EVERYTHING
nuclear@0: 	pt.dist = 0.0;
nuclear@0: 	pt.pos = pt.normal = vec3(0.0, 0.0, 0.0);
nuclear@0: 	pt.mat = default_material;
nuclear@0: 	pt.texcoord = vec2(0.0, 0.0);
nuclear@0: #endif
nuclear@0: 
nuclear@0: 	float a = dot(ray.dir, ray.dir);
nuclear@0: 	float b = dot(ray.dir, ray.origin - sph.pos) * 2.0;
nuclear@0: 	float c = dot(ray.origin, ray.origin) + dot(sph.pos, sph.pos) -
nuclear@0: 		2.0 * dot(ray.origin, sph.pos) - sph.radius * sph.radius;
nuclear@0: 
nuclear@0: 	float discr = b * b - 4.0 * a * c;
nuclear@0: 	if(discr < EPSILON)
nuclear@0: 		return false;
nuclear@0: 
nuclear@0: 	float sqrt_discr = sqrt(discr);
nuclear@0: 	float t0 = (-b + sqrt_discr) / (2.0 * a);
nuclear@0: 	float t1 = (-b - sqrt_discr) / (2.0 * a);
nuclear@0: 
nuclear@0: 	if(t0 < EPSILON)
nuclear@0: 		t0 = t1;
nuclear@0: 	if(t1 < EPSILON)
nuclear@0: 		t1 = t0;
nuclear@0: 
nuclear@0: 	float t = min(t0, t1);
nuclear@0: 	if(t < EPSILON)
nuclear@0: 		return false;
nuclear@0: 
nuclear@0: 	// fill the HitPoint structure
nuclear@0: 	pt.dist = t;
nuclear@0: 	pt.pos = ray.origin + ray.dir * t;
nuclear@0: 	pt.normal = (pt.pos - sph.pos) / sph.radius;
nuclear@0: 	pt.mat = sph.mat;
nuclear@0: 
nuclear@0: 	pt.texcoord.x = 0.5 * atan(pt.normal.z, pt.normal.x) / M_PI + 0.5;
nuclear@0: 	pt.texcoord.y = acos(pt.normal.y) / M_PI;
nuclear@0: 
nuclear@0: #ifdef USE_XFORM
nuclear@0: 	pt.pos = (xform * vec4(pt.pos, 1.0)).xyz;
nuclear@0: 	pt.normal = normalize(transform(pt.normal, xform));
nuclear@0: #endif
nuclear@0: 	return true;
nuclear@0: }
nuclear@0: 
nuclear@0: bool plane_intersect(in Plane plane, in Ray inray, out HitPoint pt)
nuclear@0: {
nuclear@0: #ifdef USE_XFORM
nuclear@0: 	mat4 xform, inv_xform;
nuclear@0: 	read_xform(plane.index, xform, inv_xform);
nuclear@0: 
nuclear@0: 	Ray ray = transform(inray, inv_xform, xform);
nuclear@0: #else
nuclear@0: 	Ray ray = inray;
nuclear@0: #endif
nuclear@0: 
nuclear@0: #ifdef INIT_EVERYTHING
nuclear@0: 	pt.dist = 0.0;
nuclear@0: 	pt.pos = pt.normal = vec3(0.0, 0.0, 0.0);
nuclear@0: 	pt.mat = default_material;
nuclear@0: 	pt.texcoord = vec2(0.0, 0.0);
nuclear@0: #endif
nuclear@0: 
nuclear@0: 	float ndotdir = dot(plane.normal, ray.dir);
nuclear@0: 	if(abs(ndotdir) < EPSILON) {
nuclear@0: 		return false;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	vec3 planept = plane.normal * plane.dist;
nuclear@0: 	vec3 pptdir = planept - ray.origin;
nuclear@0: 
nuclear@0: 	float t = dot(plane.normal, pptdir) / ndotdir;
nuclear@0: 	if(t < EPSILON) {
nuclear@0: 		return false;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	pt.dist = t;
nuclear@0: 	pt.pos = ray.origin + ray.dir * t;
nuclear@0: 	pt.normal = plane.normal;
nuclear@0: 	pt.mat = plane.mat;
nuclear@0: 	pt.texcoord.x = pt.pos.x;
nuclear@0: 	pt.texcoord.y = pt.pos.z;
nuclear@0: 
nuclear@0: #ifdef USE_XFORM
nuclear@0: 	pt.pos = (xform * vec4(pt.pos, 1.0)).xyz;
nuclear@0: 	pt.normal = normalize(transform(pt.normal, xform));
nuclear@0: #endif
nuclear@0: 	return true;
nuclear@0: }
nuclear@0: 
nuclear@0: bool box_intersect(in Box box, in Ray inray, out HitPoint pt)
nuclear@0: {
nuclear@0: #ifdef USE_XFORM
nuclear@0: 	mat4 xform, inv_xform;
nuclear@0: 	read_xform(box.index, xform, inv_xform);
nuclear@0: 
nuclear@0: 	Ray ray = transform(inray, inv_xform, xform);
nuclear@0: #else
nuclear@0: 	Ray ray = inray;
nuclear@0: #endif
nuclear@0: 
nuclear@0: #ifdef INIT_EVERYTHING
nuclear@0: 	pt.dist = 0.0;
nuclear@0: 	pt.pos = pt.normal = vec3(0.0, 0.0, 0.0);
nuclear@0: 	pt.mat = default_material;
nuclear@0: 	pt.texcoord = vec2(0.0, 0.0);
nuclear@0: #endif
nuclear@0: 
nuclear@0: 	vec3 param[2];
nuclear@0: 	param[0] = box.min;
nuclear@0: 	param[1] = box.max;
nuclear@0: 
nuclear@0: 	vec3 inv_dir = 1.0 / ray.dir;
nuclear@0: 	int sgn[3];
nuclear@0: 	sgn[0] = inv_dir.x < 0.0 ? 1 : 0;
nuclear@0: 	sgn[1] = inv_dir.y < 0.0 ? 1 : 0;
nuclear@0: 	sgn[2] = inv_dir.z < 0.0 ? 1 : 0;
nuclear@0: 
nuclear@0: 	float tmin = (param[sgn[0]].x - ray.origin.x) * inv_dir.x;
nuclear@0: 	float tmax = (param[1 - sgn[0]].x - ray.origin.x) * inv_dir.x;
nuclear@0: 	float tymin = (param[sgn[1]].y - ray.origin.y) * inv_dir.y;
nuclear@0: 	float tymax = (param[1 - sgn[1]].y - ray.origin.y) * inv_dir.y;
nuclear@0: 
nuclear@0: 	pt.normal = vec3(ray.origin.x > 0.0 ? 1.0 : -1.0, 0.0, 0.0);
nuclear@0: 
nuclear@0: 	if(tmin > tymax || tymin > tmax) {
nuclear@0: 		return false;
nuclear@0: 	}
nuclear@0: 	if(tymin > tmin) {
nuclear@0: 		pt.normal = vec3(0.0, ray.origin.y > 0.0 ? 1.0 : -1.0, 0.0);
nuclear@0: 		tmin = tymin;
nuclear@0: 	}
nuclear@0: 	if(tymax < tmax) {
nuclear@0: 		tmax = tymax;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	float tzmin = (param[sgn[2]].z - ray.origin.z) * inv_dir.z;
nuclear@0: 	float tzmax = (param[1 - sgn[2]].z - ray.origin.z) * inv_dir.z;
nuclear@0: 
nuclear@0: 	if(tmin > tzmax || tzmin > tmax) {
nuclear@0: 		return false;
nuclear@0: 	}
nuclear@0: 	if(tzmin > tmin) {
nuclear@0: 		pt.normal = vec3(0.0, 0.0, ray.origin.z > 0.0 ? 1.0 : -1.0);
nuclear@0: 		tmin = tzmin;
nuclear@0: 	}
nuclear@0: 	if(tzmax < tmax) {
nuclear@0: 		tmax = tzmax;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	float t = tmin < EPSILON ? tmax : tmin;
nuclear@0: 	if(t >= 1e-4) {
nuclear@0: 		pt.dist = t;
nuclear@0: 		pt.pos = ray.origin + ray.dir * t;
nuclear@0: 		pt.mat = box.mat;
nuclear@0: 
nuclear@0: 		float min_dist = 10000.0;
nuclear@0: 
nuclear@0: 		vec3 offs = box.min + (box.max - box.min) / 2.0;
nuclear@0: 		vec3 local_pt = pt.pos - offs;
nuclear@0: 
nuclear@0: 		vec3 dist = abs((box.max - offs) - abs(local_pt));
nuclear@0: 		if(dist.x < min_dist) {
nuclear@0: 			min_dist = dist.x;
nuclear@0: 			pt.normal = sign(local_pt.x) * vec3(1.0, 0.0, 0.0);
nuclear@0: 			pt.texcoord = pt.pos.zy;
nuclear@0: 		}
nuclear@0: 		if(dist.y < min_dist) {
nuclear@0: 			min_dist = dist.y;
nuclear@0: 			pt.normal = sign(local_pt.y) * vec3(0.0, 1.0, 0.0);
nuclear@0: 			pt.texcoord = pt.pos.xz;
nuclear@0: 		}
nuclear@0: 		if(dist.z < min_dist) {
nuclear@0: 			pt.normal = sign(local_pt.y) * vec3(0.0, 0.0, 1.0);
nuclear@0: 			pt.texcoord = pt.pos.xy;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 
nuclear@0: #ifdef USE_XFORM
nuclear@0: 		pt.pos = (xform * vec4(pt.pos, 1.0)).xyz;
nuclear@0: 		pt.normal = normalize(transform(pt.normal, xform));
nuclear@0: #endif
nuclear@0: 		return true;
nuclear@0: 	}
nuclear@0: 	return false;
nuclear@0: }
nuclear@0: 
nuclear@0: vec3 transform(in vec3 v, in mat4 xform)
nuclear@0: {
nuclear@0: 	return mat3(xform) * v;
nuclear@0: }
nuclear@0: 
nuclear@0: Ray transform(in Ray ray, in mat4 xform, in mat4 inv_xform)
nuclear@0: {
nuclear@0: 	Ray res;
nuclear@0: 	res.origin = (xform * vec4(ray.origin, 1.0)).xyz;
nuclear@0: 	res.dir = transform(ray.dir, xform);
nuclear@0: 	return res;
nuclear@0: }
nuclear@0: 
nuclear@0: Ray get_primary_ray()
nuclear@0: {
nuclear@0: 	Ray ray;
nuclear@0: 	ray.origin = (gl_ModelViewMatrix * vec4(0.0, 0.0, 0.0, 1.0)).xyz;
nuclear@0: 	vec3 dir = texture2D(tex_raydir, gl_TexCoord[0].st).xyz;
nuclear@0: 	ray.dir = normalize(gl_NormalMatrix * dir);
nuclear@0: 	return ray;
nuclear@0: }
nuclear@0: 
nuclear@0: #define ITEM(x)	((float(x) + 0.5) / OBJ_LINE_WIDTH)
nuclear@0: 
nuclear@0: Sphere read_sphere(in float idx)
nuclear@0: {
nuclear@0: 	Sphere sph;
nuclear@0: 	// +1 because the first scanline is the descriptor
nuclear@0: 	float ty = (idx + 1.0) / sph_tex_sz;
nuclear@0: 
nuclear@0: 	sph.index = texture2D(tex_spheres, vec2(ITEM(0), ty)).x;
nuclear@0: 
nuclear@0: 	vec4 texel = texture2D(tex_spheres, vec2(ITEM(1), ty));
nuclear@0: 	sph.pos = texel.xyz;
nuclear@0: 	sph.radius = texel.w;
nuclear@0: 
nuclear@0: 	sph.mat = read_material(tex_spheres, ty);
nuclear@0: 	return sph;
nuclear@0: }
nuclear@0: 
nuclear@0: Plane read_plane(in float idx)
nuclear@0: {
nuclear@0: 	Plane plane;
nuclear@0: 	// +1 (see above)
nuclear@0: 	float ty = (idx + 1.0) / plane_tex_sz;
nuclear@0: 
nuclear@0: 	plane.index = texture2D(tex_planes, vec2(ITEM(0), ty)).x;
nuclear@0: 
nuclear@0: 	vec4 texel = texture2D(tex_planes, vec2(ITEM(1), ty));
nuclear@0: 	plane.normal = texel.xyz;
nuclear@0: 	plane.dist = texel.w;
nuclear@0: 
nuclear@0: 	plane.mat = read_material(tex_planes, ty);
nuclear@0: 	return plane;
nuclear@0: }
nuclear@0: 
nuclear@0: Box read_box(in float idx)
nuclear@0: {
nuclear@0: 	Box box;
nuclear@0: 	float ty = (idx + 1.0) / box_tex_sz;
nuclear@0: 
nuclear@0: 	box.index = texture2D(tex_boxes, vec2(ITEM(0), ty)).x;
nuclear@0: 
nuclear@0: 	box.min = texture2D(tex_boxes, vec2(ITEM(1), ty)).xyz;
nuclear@0: 	box.max = texture2D(tex_boxes, vec2(ITEM(2), ty)).xyz;
nuclear@0: 
nuclear@0: 	box.mat = read_material(tex_boxes, ty);
nuclear@0: 	return box;
nuclear@0: }
nuclear@0: 
nuclear@0: void read_xform(in float idx, out mat4 xform, out mat4 inv_xform)
nuclear@0: {
nuclear@0: 	float ty = (idx + 1.0) / xform_tex_sz;
nuclear@0: 
nuclear@0: 	for(int i=0; i<4; i++) {
nuclear@0: 		xform[i] = texture2D(tex_xforms, vec2(ITEM(i), ty));
nuclear@0: 	}
nuclear@0: 	inv_xform = inverse(xform);
nuclear@0: 	/*for(int i=0; i<4; i++) {
nuclear@0: 		inv_xform[i] = texture2D(tex_xforms, vec2(ITEM(float(i) + 4.0), ty));
nuclear@0: 	}*/
nuclear@0: }
nuclear@0: 
nuclear@0: #define MAT_START	4
nuclear@0: Material read_material(in sampler2D tex, in float ty)
nuclear@0: {
nuclear@0: 	Material mat;
nuclear@0: 
nuclear@0: 	vec4 texel = texture2D(tex, vec2(ITEM(MAT_START), ty));
nuclear@0: 	mat.diffuse = texel.xyz;
nuclear@0: 
nuclear@0: 	texel = texture2D(tex, vec2(ITEM(MAT_START + 1), ty));
nuclear@0: 	mat.specular = texel.xyz;
nuclear@0: 	mat.shininess = texel.w;
nuclear@0: 
nuclear@0: 	texel = texture2D(tex, vec2(ITEM(MAT_START + 2), ty));
nuclear@0: 	mat.reflectivity = texel.x;
nuclear@0: 
nuclear@0: 	mat.megatex_rect = texture2D(tex, vec2(ITEM(MAT_START + 3), ty));
nuclear@0: 
nuclear@0: 	return mat;
nuclear@0: }