123 lines
3.2 KiB
GLSL
123 lines
3.2 KiB
GLSL
#version 430
|
|
|
|
#include sphere.glsl
|
|
|
|
// TODO: do i actually need explicit location descriptors?
|
|
layout (location = 1) uniform vec4 _t;
|
|
|
|
layout (location = 2) uniform vec3 _w; // view space axes
|
|
layout (location = 3) uniform vec3 _u;
|
|
layout (location = 4) uniform vec3 _v;
|
|
|
|
layout (location = 5) uniform mat4 _cameraInverseProjection;
|
|
layout (location = 6) uniform vec3 _camh;
|
|
layout (location = 7) uniform vec3 _camv;
|
|
layout (location = 8) uniform vec3 _camll;
|
|
layout (location = 9) uniform vec3 _cpos;
|
|
layout (location = 10) uniform vec3 _tpos; // target
|
|
|
|
const int SPHERES = 250; // 253 is the maximum?? TODO: use uniform buffer objects
|
|
layout (location = 12) uniform int _activeSpheres;
|
|
layout (location = 13) uniform Sphere _spheres[SPHERES];
|
|
|
|
layout(local_size_x = 1, local_size_y = 1) in; // size of local work group - 1 pixel
|
|
layout(rgba32f, binding = 0) uniform image2D img_output; // rgba32f defines internal format, image2d for random write to output texture
|
|
|
|
const float INF = 20.0;
|
|
const float PI = 3.14159;
|
|
|
|
struct Ray
|
|
{
|
|
vec3 origin;
|
|
vec3 direction;
|
|
};
|
|
|
|
struct RayHit
|
|
{
|
|
vec3 position;
|
|
float distance;
|
|
vec3 normal;
|
|
vec3 albedo;
|
|
};
|
|
|
|
void intersectSphere(Ray ray, inout RayHit bestHit, Sphere sphere)
|
|
{
|
|
vec3 c = sphere.cr.xyz;
|
|
float r = sphere.cr.w;
|
|
|
|
vec3 d = ray.origin-c;
|
|
float p1 = -dot(ray.direction,d);
|
|
float p2sqr = p1*p1-dot(d,d)+r*r;
|
|
|
|
if (p2sqr < 0) return;
|
|
|
|
float p2 = sqrt(p2sqr);
|
|
float t = p1-p2 > 0 ? p1-p2 : p1+p2;
|
|
if (t > 0 && t < bestHit.distance)
|
|
{
|
|
bestHit.distance = t;
|
|
bestHit.position = ray.origin + t*ray.direction;
|
|
bestHit.normal = normalize(bestHit.position-c);
|
|
bestHit.albedo = sphere.albedo;
|
|
}
|
|
}
|
|
|
|
Ray createCameraRay(vec2 uv)
|
|
{
|
|
// transform -1..1 -> 0..1
|
|
uv = uv*0.5+0.5;
|
|
//uv.x=1-uv.x;
|
|
|
|
vec3 target = vec3(0,0,0);
|
|
|
|
vec3 dir;
|
|
dir = uv.x*_camh + uv.y*_camv;
|
|
dir = _camll + uv.x*_camh + uv.y*_camv;
|
|
dir = normalize(dir);
|
|
|
|
float max_x = 5.0;
|
|
float max_y = 5.0;
|
|
|
|
Ray ray;
|
|
ray.origin = _cpos;
|
|
ray.direction = dir;
|
|
|
|
return ray;
|
|
};
|
|
|
|
void main()
|
|
{
|
|
// base pixel colour for the image
|
|
vec4 pixel = vec4(0.0, 0.0, 0.0, 1.0);
|
|
// get index in global work group ie xy position
|
|
ivec2 pixel_coords = ivec2(gl_GlobalInvocationID.xy);
|
|
|
|
// set up ray based on pixel position, project it forward with an orthographic projection
|
|
ivec2 dims = imageSize(img_output); // fetch image dimensions
|
|
vec2 uv;
|
|
uv.x = (float(pixel_coords.x * 2 - dims.x) / dims.x) * dims.x/dims.y; // account for aspect ratio
|
|
uv.y = (float(pixel_coords.y * 2 - dims.y) / dims.y);
|
|
|
|
Ray ray = createCameraRay(uv);
|
|
|
|
RayHit hit;
|
|
hit.position = vec3(0.0,0.0,0.0);
|
|
hit.distance = INF;
|
|
hit.normal = vec3(0.0,0.0,0.0);
|
|
hit.albedo = vec3(0.0,0.0,0.0);
|
|
|
|
for (int i = 0; i < _activeSpheres; i++)
|
|
{
|
|
intersectSphere(ray, hit, _spheres[i]);
|
|
}
|
|
|
|
// TODO: write depth to texture
|
|
float depth = hit.distance/INF;
|
|
|
|
pixel = vec4(hit.albedo,1.0);
|
|
pixel *= (1.0-depth);
|
|
|
|
// output to a specific pixel in the image
|
|
imageStore(img_output, pixel_coords, pixel);
|
|
}
|