store first hit albedo

shader/include/constants.glsl

@@ -1,5 +1,4 @@
-const float INF = 17.0;
+const float INF = 50.0;
 const float PI = 3.14159;
 const float E = 2.71828;
-const int SAMPLES = 1;
-const int BOUNCES = 8;
+const int BOUNCES = 4;

shader/root/rt.glsl

@@ -4,10 +4,13 @@ layout(local_size_x = 1, local_size_y = 1) in;                  // size of local
 
 // gbuffer?
 layout(rgba32f, binding = 2) readonly uniform image2D _g0;
+layout(rgba32f, binding = 3) readonly uniform image2D _g1;
 
 // final output
 layout(rgba32f, binding = 0) uniform image2D img_output;        // rgba32f defines internal format, image2d for random write to output texture
 
+uniform vec3 _skyColor = vec3(0.68,0.85,0.9);
+
 // TODO: some of these depend on each other!! need be be in this order for now c:
 #include func.glsl
 #include constants.glsl
@@ -30,7 +33,7 @@ vec3 shade(inout Ray ray, RayHit hit)
     }
 
     // sky color
-    return vec3(0.68,0.85,0.9);
+    return _skyColor;
 }
 
 void main()
@@ -43,10 +46,15 @@ void main()
 
     vec2 uv = pixelUv(pixelCoords, dims);
 
+    vec4 g[2];
+
     // load data from first pass
-    vec4 d = imageLoad(_g0, ivec2(gl_GlobalInvocationID.xy));
-    float depth = d.w;
-    vec3 normal = d.xyz*2.0-1.0; // unpack normal packaged into texture
+    g[0] = imageLoad(_g0, ivec2(gl_GlobalInvocationID.xy));
+    float depth = g[0].w;
+    vec3 normal = g[0].xyz*2.0-1.0; // unpack normal packaged into texture
+
+    g[1] = imageLoad(_g1, ivec2(gl_GlobalInvocationID.xy));
+    vec3 albedo = g[1].xyz;
 
     // create a ray from the uv
     Ray ray = createCameraRay(uv);
@@ -54,13 +62,14 @@ void main()
     firstHit.position = ray.origin+ray.direction*depth;
     firstHit.distance = depth;
     firstHit.normal = normal;
-    firstHit.albedo = vec3(1.0,1.0,1.0);
+    firstHit.albedo = albedo;
 
-    // do a trace using precomputed depth and surface normal values
-    //RayHit hit = trace(ray);
+    int sky = depth >= INF ? 1 : 0;
+    int bounces = (1-sky) * BOUNCES; 
+    pixel.xyz = mix(pixel.xyz, _skyColor, sky);
 
     // trace the rays path around the scene
-    for (int j = 1; j < BOUNCES; j++)
+    for (int j = 0; j < bounces; j++)
     {
         RayHit hit = trace(ray);
 
@@ -69,10 +78,11 @@ void main()
         if (length(ray.energy) < 0.001) break;
     }
 
-
     //pixel.xyz = mix(pixel.xyz, normal, 1.0-depth);
     pixel.xyz = mix(pixel.xyz, vec3(1.0), depth);
 
+    //pixel.xyz = mix(firstHit.albedo, pixel.xyz, depth);
+
     //pixel.a = 1.0;
 
     //pixel.xyz = texture(_g0, uv).xyz;

shader/root/rtpre.glsl

@@ -5,7 +5,8 @@
 // local work group
 layout(local_size_x = 1, local_size_y = 1) in;
 
-layout (rgba32f, binding = 2) uniform image2D g0_output;
+layout (rgba32f, binding = 2) writeonly uniform image2D g0_output;
+layout (rgba32f, binding = 3) writeonly uniform image2D g1_output;
 
 #include func.glsl
 #include constants.glsl
@@ -35,7 +36,7 @@ void main()
 
     // n roughly correlates to steepness of log curve
     // TODO: what does this mean in mathematical terms??
-    float n = 1.0;
+    float n = 4;
     float f = INF;
     float z = hit.distance;
     
@@ -44,11 +45,15 @@ void main()
     //depth = z/f;
 
     // logarithmic depth
-    depth = log(z*pow(E,n)/f)/n;
+    depth = max(0,log(z*pow(E,n)/f)/n);
 
     // pack normal into texture
     pixel.xyz = hit.normal*0.5+0.5;
     pixel.w = depth;
 
     imageStore(g0_output, pixelCoords, pixel);
+
+    pixel.xyz = hit.albedo;
+    pixel.w = 0;
+    imageStore(g1_output, pixelCoords, pixel); 
 }

src/gfx.c

@@ -200,7 +200,8 @@ int createTextures(int width, int height, struct Shaders shaders, struct Texture
     // create a texture for the compute shader to write to
     textures->target = createWriteOnlyTexture(width, height);
 
-    textures->g0 = createTexture(width, height);
+    textures->g0 = createTextureUnit(width, height, 2);
+    textures->g1 = createTextureUnit(width, height, 3);
 
     return 0;
 }
@@ -256,11 +257,10 @@ GLuint createWriteOnlyTexture(int width, int height)
 }
 
 // creates an empty texture in GL_TEXTURE2 unit
-GLuint createTexture(int width, int height)
+GLuint createTextureUnit(int width, int height, int unit)
 {
     GLuint texture;
     glGenTextures(1, &texture);
-    //glActiveTexture(GL_TEXTURE0);
     glBindTexture(GL_TEXTURE_2D, texture);
 
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
@@ -268,7 +268,7 @@ GLuint createTexture(int width, int height)
 
     // an empty image
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_FLOAT, NULL);
-    glBindImageTexture(2, texture, 0, GL_FALSE, 0, GL_READ_WRITE, GL_RGBA32F);
+    glBindImageTexture(unit, texture, 0, GL_FALSE, 0, GL_READ_WRITE, GL_RGBA32F);
 
     return texture;
 }

src/gfx.h

@@ -25,13 +25,19 @@ struct Textures
     // noise texture to help with randomness
     GLuint noise;
 
+    // TODO: replace these with an actual array!
     // additional view space information
     //
-    // x    depth
-    // y    -
-    // z    -
-    // w    -
+    // x    surface normal x
+    // y    surface normal y
+    // z    surface normal z
+    // w    depth
     GLuint g0;  
+    // x    albedo x
+    // y    albedo y
+    // z    albedo z
+    // w    -
+    GLuint g1;
 };
 
 SDL_Window* gfxInit(int width, int height);
@@ -42,7 +48,7 @@ GLuint compileComputeShaderProgram(const char* csPath);
 
 int createTextures(int width, int height, struct Shaders shaders, struct Textures* textures);
 GLuint createNoiseTexture(int width, int height);
-GLuint createTexture(int width, int height);
+GLuint createTextureUnit(int width, int height, int unit);
 GLuint createWriteOnlyTexture(int width, int height);
 GLuint compileShader(const char* path, GLenum type);
 

src/main.c

@@ -36,6 +36,7 @@ int main()
 {
     initialise();
 
+    float start = now();
     int frames;
     for (frames = 0; !checkQuit(); frames++)
     {
@@ -77,8 +78,8 @@ int main()
         SDL_GL_SwapWindow(window);
     }
 
-    float elapsed = now();
-    printf("%d frames in %f seconds (avg: %f fps)\n", 
+    float elapsed = now()-start;
+    printf("%d frames in %fs [%f fps]\n", 
             frames, 
             elapsed, 
             (float)frames/elapsed);