armory/raw/smaa_pass/smaa_blend_weight.frag.glsl
2016-06-13 15:07:57 +02:00

123 lines
4.4 KiB
GLSL

#version 450
#ifdef GL_ES
precision mediump float;
#endif
uniform sampler2D tex;
in vec2 texCoord;
// Blending Weight Calculation Pixel Shader (Second Pass)
float4 SMAABlendingWeightCalculationPS(float2 texcoord,
float2 pixcoord,
float4 offset[3],
SMAATexture2D(edgesTex),
SMAATexture2D(areaTex),
SMAATexture2D(searchTex),
float4 subsampleIndices) { // Just pass zero for SMAA 1x, see @SUBSAMPLE_INDICES.
float4 weights = float4(0.0, 0.0, 0.0, 0.0);
float2 e = SMAASample(edgesTex, texcoord).rg;
SMAA_BRANCH
if (e.g > 0.0) { // Edge at north
#if !defined(SMAA_DISABLE_DIAG_DETECTION)
// Diagonals have both north and west edges, so searching for them in
// one of the boundaries is enough.
weights.rg = SMAACalculateDiagWeights(SMAATexturePass2D(edgesTex), SMAATexturePass2D(areaTex), texcoord, e, subsampleIndices);
// We give priority to diagonals, so if we find a diagonal we skip
// horizontal/vertical processing.
SMAA_BRANCH
if (weights.r == -weights.g) { // weights.r + weights.g == 0.0
#endif
float2 d;
// Find the distance to the left:
float3 coords;
coords.x = SMAASearchXLeft(SMAATexturePass2D(edgesTex), SMAATexturePass2D(searchTex), offset[0].xy, offset[2].x);
coords.y = offset[1].y; // offset[1].y = texcoord.y - 0.25 * SMAA_RT_METRICS.y (@CROSSING_OFFSET)
d.x = coords.x;
// Now fetch the left crossing edges, two at a time using bilinear
// filtering. Sampling at -0.25 (see @CROSSING_OFFSET) enables to
// discern what value each edge has:
float e1 = SMAASampleLevelZero(edgesTex, coords.xy).r;
// Find the distance to the right:
coords.z = SMAASearchXRight(SMAATexturePass2D(edgesTex), SMAATexturePass2D(searchTex), offset[0].zw, offset[2].y);
d.y = coords.z;
// We want the distances to be in pixel units (doing this here allow to
// better interleave arithmetic and memory accesses):
d = abs(round(mad(SMAA_RT_METRICS.zz, d, -pixcoord.xx)));
// SMAAArea below needs a sqrt, as the areas texture is compressed
// quadratically:
float2 sqrt_d = sqrt(d);
// Fetch the right crossing edges:
float e2 = SMAASampleLevelZeroOffset(edgesTex, coords.zy, int2(1, 0)).r;
// Ok, we know how this pattern looks like, now it is time for getting
// the actual area:
weights.rg = SMAAArea(SMAATexturePass2D(areaTex), sqrt_d, e1, e2, subsampleIndices.y);
// Fix corners:
coords.y = texcoord.y;
SMAADetectHorizontalCornerPattern(SMAATexturePass2D(edgesTex), weights.rg, coords.xyzy, d);
#if !defined(SMAA_DISABLE_DIAG_DETECTION)
} else
e.r = 0.0; // Skip vertical processing.
#endif
}
SMAA_BRANCH
if (e.r > 0.0) { // Edge at west
float2 d;
// Find the distance to the top:
float3 coords;
coords.y = SMAASearchYUp(SMAATexturePass2D(edgesTex), SMAATexturePass2D(searchTex), offset[1].xy, offset[2].z);
coords.x = offset[0].x; // offset[1].x = texcoord.x - 0.25 * SMAA_RT_METRICS.x;
d.x = coords.y;
// Fetch the top crossing edges:
float e1 = SMAASampleLevelZero(edgesTex, coords.xy).g;
// Find the distance to the bottom:
coords.z = SMAASearchYDown(SMAATexturePass2D(edgesTex), SMAATexturePass2D(searchTex), offset[1].zw, offset[2].w);
d.y = coords.z;
// We want the distances to be in pixel units:
d = abs(round(mad(SMAA_RT_METRICS.ww, d, -pixcoord.yy)));
// SMAAArea below needs a sqrt, as the areas texture is compressed
// quadratically:
float2 sqrt_d = sqrt(d);
// Fetch the bottom crossing edges:
float e2 = SMAASampleLevelZeroOffset(edgesTex, coords.xz, int2(0, 1)).g;
// Get the area for this direction:
weights.ba = SMAAArea(SMAATexturePass2D(areaTex), sqrt_d, e1, e2, subsampleIndices.x);
// Fix corners:
coords.x = texcoord.x;
SMAADetectVerticalCornerPattern(SMAATexturePass2D(edgesTex), weights.ba, coords.xyxz, d);
}
return weights;
}
void main() {
// gl_FragColor = vec4(col);
}