"//! Decreases noise level, but introduces some bias.\n"
"uniform float uMaxRadiance = 50.f;\n"
"\n"
+ "#ifdef ADAPTIVE_SAMPLING\n"
+ "//! Wrapper over imageLoad()+imageStore() having similar syntax as imageAtomicAdd().\n"
+ "//! Modifies one component of 3Wx2H uRenderImage:\n"
+ "//! |RGL| Red, Green, Luminance\n"
+ "//! |SBH| Samples, Blue, Hit time transformed into OpenGL NDC space\n"
+ "//! Returns previous value of the component.\n"
+ "float addRenderImageComp (in ivec2 theFrag, in ivec2 theComp, in float theVal)\n"
+ "{\n"
+ " ivec2 aCoord = ivec2 (3 * theFrag.x + theComp.x,\n"
+ " 2 * theFrag.y + theComp.y);\n"
+ "#ifdef ADAPTIVE_SAMPLING_ATOMIC\n"
+ " return imageAtomicAdd (uRenderImage, aCoord, theVal);\n"
+ "#else\n"
+ " float aVal = imageLoad (uRenderImage, aCoord).x;\n"
+ " imageStore (uRenderImage, aCoord, vec4 (aVal + theVal));\n"
+ " return aVal;\n"
+ "#endif\n"
+ "}\n"
+ "#endif\n"
+ "\n"
"// =======================================================================\n"
"// function : main\n"
"// purpose :\n"
"\n"
"#ifdef ADAPTIVE_SAMPLING\n"
"\n"
+ "#ifdef ADAPTIVE_SAMPLING_ATOMIC\n"
" ivec2 aTileXY = imageLoad (uOffsetImage, aFragCoord / uTileSize).xy * uTileSize;\n"
" if (aTileXY.x < 0) { discard; }\n"
"\n"
"\n"
" aFragCoord.x = aTileXY.x + (aFragCoord.x % aRealBlockSize.x);\n"
" aFragCoord.y = aTileXY.y + (aFragCoord.y % aRealBlockSize.y);\n"
+ "#else\n"
+ " int aNbTileSamples = imageAtomicAdd (uTilesImage, aFragCoord / uTileSize, int(-1));\n"
+ " if (aNbTileSamples <= 0)\n"
+ " {\n"
+ " discard;\n"
+ " }\n"
+ "#endif\n"
"\n"
"#endif // ADAPTIVE_SAMPLING\n"
"\n"
"\n"
"#else\n"
"\n"
- " float aNbSamples = imageAtomicAdd (uRenderImage, ivec2 (3 * aFragCoord.x + 0,\n"
- " 2 * aFragCoord.y + 1), 1.0);\n"
- "\n"
+ " float aNbSamples = addRenderImageComp (aFragCoord, ivec2 (0, 1), 1.0);\n"
" vec4 aColor = PathTrace (aRay, aInvDirect, int (aNbSamples));\n"
"\n"
"#endif\n"
"#ifdef ADAPTIVE_SAMPLING\n"
"\n"
" // accumulate RGB color and depth\n"
- " imageAtomicAdd (uRenderImage, ivec2 (3 * aFragCoord.x + 0,\n"
- " 2 * aFragCoord.y + 0), aColor.r);\n"
- " imageAtomicAdd (uRenderImage, ivec2 (3 * aFragCoord.x + 1,\n"
- " 2 * aFragCoord.y + 0), aColor.g);\n"
- " imageAtomicAdd (uRenderImage, ivec2 (3 * aFragCoord.x + 1,\n"
- " 2 * aFragCoord.y + 1), aColor.b);\n"
- " imageAtomicAdd (uRenderImage, ivec2 (3 * aFragCoord.x + 2,\n"
- " 2 * aFragCoord.y + 1), aColor.w);\n"
+ " addRenderImageComp (aFragCoord, ivec2 (0, 0), aColor.r);\n"
+ " addRenderImageComp (aFragCoord, ivec2 (1, 0), aColor.g);\n"
+ " addRenderImageComp (aFragCoord, ivec2 (1, 1), aColor.b);\n"
+ " addRenderImageComp (aFragCoord, ivec2 (2, 1), aColor.w);\n"
"\n"
" if (int (aNbSamples) % 2 == 0) // accumulate luminance for even samples only\n"
" {\n"
- " imageAtomicAdd (uRenderImage, ivec2 (3 * aFragCoord.x + 2,\n"
- " 2 * aFragCoord.y + 0), dot (LUMA, aColor.rgb));\n"
+ " addRenderImageComp (aFragCoord, ivec2 (2, 0), dot (LUMA, aColor.rgb));\n"
" }\n"
"\n"
"#else\n"