slang-shaders/anti-aliasing/shaders/smaa/SMAA.frag
Jonatas Esteves a4da0992bb New port of SMAA
Adds a new port of SMAA. This includes the original sources unmodified. The original does a great job of ensuring compatibility with any shader compiler, so no need to modify it.

- Add a runtime toggle to choose edge detection technique;
- Position independent, doesn't need to be the first shader in a chain anymore.
2021-09-02 02:40:09 -03:00

711 lines
28 KiB
GLSL

/**
* Copyright (C) 2013 Jorge Jimenez (jorge@iryoku.com)
* Copyright (C) 2013 Jose I. Echevarria (joseignacioechevarria@gmail.com)
* Copyright (C) 2013 Belen Masia (bmasia@unizar.es)
* Copyright (C) 2013 Fernando Navarro (fernandn@microsoft.com)
* Copyright (C) 2013 Diego Gutierrez (diegog@unizar.es)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is furnished to
* do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software. As clarification, there
* is no requirement that the copyright notice and permission be included in
* binary distributions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
//-----------------------------------------------------------------------------
// Edge Detection Pixel Shaders (First Pass)
/**
* Luma Edge Detection
*
* IMPORTANT NOTICE: luma edge detection requires gamma-corrected colors, and
* thus 'colorTex' should be a non-sRGB texture.
*/
float2 SMAALumaEdgeDetectionPS(float2 texcoord,
float4 offset[3],
SMAATexture2D(colorTex)
#if SMAA_PREDICATION
, SMAATexture2D(predicationTex)
#endif
) {
// Calculate the threshold:
#if SMAA_PREDICATION
float2 threshold = SMAACalculatePredicatedThreshold(texcoord, offset, SMAATexturePass2D(predicationTex));
#else
float2 threshold = float2(SMAA_THRESHOLD, SMAA_THRESHOLD);
#endif
// Calculate lumas:
float3 weights = float3(0.2126, 0.7152, 0.0722);
float L = dot(SMAASamplePoint(colorTex, texcoord).rgb, weights);
float Lleft = dot(SMAASamplePoint(colorTex, offset[0].xy).rgb, weights);
float Ltop = dot(SMAASamplePoint(colorTex, offset[0].zw).rgb, weights);
// We do the usual threshold:
float4 delta;
delta.xy = abs(L - float2(Lleft, Ltop));
float2 edges = step(threshold, delta.xy);
// Then discard if there is no edge:
if (dot(edges, float2(1.0, 1.0)) == 0.0)
discard;
// Calculate right and bottom deltas:
float Lright = dot(SMAASamplePoint(colorTex, offset[1].xy).rgb, weights);
float Lbottom = dot(SMAASamplePoint(colorTex, offset[1].zw).rgb, weights);
delta.zw = abs(L - float2(Lright, Lbottom));
// Calculate the maximum delta in the direct neighborhood:
float2 maxDelta = max(delta.xy, delta.zw);
// Calculate left-left and top-top deltas:
float Lleftleft = dot(SMAASamplePoint(colorTex, offset[2].xy).rgb, weights);
float Ltoptop = dot(SMAASamplePoint(colorTex, offset[2].zw).rgb, weights);
delta.zw = abs(float2(Lleft, Ltop) - float2(Lleftleft, Ltoptop));
// Calculate the final maximum delta:
maxDelta = max(maxDelta.xy, delta.zw);
float finalDelta = max(maxDelta.x, maxDelta.y);
// Local contrast adaptation:
edges.xy *= step(finalDelta, SMAA_LOCAL_CONTRAST_ADAPTATION_FACTOR * delta.xy);
return edges;
}
/**
* Color Edge Detection
*
* IMPORTANT NOTICE: color edge detection requires gamma-corrected colors, and
* thus 'colorTex' should be a non-sRGB texture.
*/
float2 SMAAColorEdgeDetectionPS(float2 texcoord,
float4 offset[3],
SMAATexture2D(colorTex)
#if SMAA_PREDICATION
, SMAATexture2D(predicationTex)
#endif
) {
// Calculate the threshold:
#if SMAA_PREDICATION
float2 threshold = SMAACalculatePredicatedThreshold(texcoord, offset, predicationTex);
#else
float2 threshold = float2(SMAA_THRESHOLD, SMAA_THRESHOLD);
#endif
// Calculate color deltas:
float4 delta;
float3 C = SMAASamplePoint(colorTex, texcoord).rgb;
float3 Cleft = SMAASamplePoint(colorTex, offset[0].xy).rgb;
float3 t = abs(C - Cleft);
delta.x = max(max(t.r, t.g), t.b);
float3 Ctop = SMAASamplePoint(colorTex, offset[0].zw).rgb;
t = abs(C - Ctop);
delta.y = max(max(t.r, t.g), t.b);
// We do the usual threshold:
float2 edges = step(threshold, delta.xy);
// Then discard if there is no edge:
if (dot(edges, float2(1.0, 1.0)) == 0.0)
discard;
// Calculate right and bottom deltas:
float3 Cright = SMAASamplePoint(colorTex, offset[1].xy).rgb;
t = abs(C - Cright);
delta.z = max(max(t.r, t.g), t.b);
float3 Cbottom = SMAASamplePoint(colorTex, offset[1].zw).rgb;
t = abs(C - Cbottom);
delta.w = max(max(t.r, t.g), t.b);
// Calculate the maximum delta in the direct neighborhood:
float2 maxDelta = max(delta.xy, delta.zw);
// Calculate left-left and top-top deltas:
float3 Cleftleft = SMAASamplePoint(colorTex, offset[2].xy).rgb;
t = abs(C - Cleftleft);
delta.z = max(max(t.r, t.g), t.b);
float3 Ctoptop = SMAASamplePoint(colorTex, offset[2].zw).rgb;
t = abs(C - Ctoptop);
delta.w = max(max(t.r, t.g), t.b);
// Calculate the final maximum delta:
maxDelta = max(maxDelta.xy, delta.zw);
float finalDelta = max(maxDelta.x, maxDelta.y);
// Local contrast adaptation:
edges.xy *= step(finalDelta, SMAA_LOCAL_CONTRAST_ADAPTATION_FACTOR * delta.xy);
return edges;
}
/**
* Depth Edge Detection
*/
float2 SMAADepthEdgeDetectionPS(float2 texcoord,
float4 offset[3],
SMAATexture2D(depthTex)) {
float3 neighbours = SMAAGatherNeighbours(texcoord, offset, SMAATexturePass2D(depthTex));
float2 delta = abs(neighbours.xx - float2(neighbours.y, neighbours.z));
float2 edges = step(SMAA_DEPTH_THRESHOLD, delta);
if (dot(edges, float2(1.0, 1.0)) == 0.0)
discard;
return edges;
}
//-----------------------------------------------------------------------------
// Diagonal Search Functions
#if !defined(SMAA_DISABLE_DIAG_DETECTION)
/**
* Allows to decode two binary values from a bilinear-filtered access.
*/
float2 SMAADecodeDiagBilinearAccess(float2 e) {
// Bilinear access for fetching 'e' have a 0.25 offset, and we are
// interested in the R and G edges:
//
// +---G---+-------+
// | x o R x |
// +-------+-------+
//
// Then, if one of these edge is enabled:
// Red: (0.75 * X + 0.25 * 1) => 0.25 or 1.0
// Green: (0.75 * 1 + 0.25 * X) => 0.75 or 1.0
//
// This function will unpack the values (mad + mul + round):
// wolframalpha.com: round(x * abs(5 * x - 5 * 0.75)) plot 0 to 1
e.r = e.r * abs(5.0 * e.r - 5.0 * 0.75);
return round(e);
}
float4 SMAADecodeDiagBilinearAccess(float4 e) {
e.rb = e.rb * abs(5.0 * e.rb - 5.0 * 0.75);
return round(e);
}
/**
* These functions allows to perform diagonal pattern searches.
*/
float2 SMAASearchDiag1(SMAATexture2D(edgesTex), float2 texcoord, float2 dir, out float2 e) {
float4 coord = float4(texcoord, -1.0, 1.0);
float3 t = float3(SMAA_RT_METRICS.xy, 1.0);
while (coord.z < float(SMAA_MAX_SEARCH_STEPS_DIAG - 1) &&
coord.w > 0.9) {
coord.xyz = mad(t, float3(dir, 1.0), coord.xyz);
e = SMAASampleLevelZero(edgesTex, coord.xy).rg;
coord.w = dot(e, float2(0.5, 0.5));
}
return coord.zw;
}
float2 SMAASearchDiag2(SMAATexture2D(edgesTex), float2 texcoord, float2 dir, out float2 e) {
float4 coord = float4(texcoord, -1.0, 1.0);
coord.x += 0.25 * SMAA_RT_METRICS.x; // See @SearchDiag2Optimization
float3 t = float3(SMAA_RT_METRICS.xy, 1.0);
while (coord.z < float(SMAA_MAX_SEARCH_STEPS_DIAG - 1) &&
coord.w > 0.9) {
coord.xyz = mad(t, float3(dir, 1.0), coord.xyz);
// @SearchDiag2Optimization
// Fetch both edges at once using bilinear filtering:
e = SMAASampleLevelZero(edgesTex, coord.xy).rg;
e = SMAADecodeDiagBilinearAccess(e);
// Non-optimized version:
// e.g = SMAASampleLevelZero(edgesTex, coord.xy).g;
// e.r = SMAASampleLevelZeroOffset(edgesTex, coord.xy, int2(1, 0)).r;
coord.w = dot(e, float2(0.5, 0.5));
}
return coord.zw;
}
/**
* Similar to SMAAArea, this calculates the area corresponding to a certain
* diagonal distance and crossing edges 'e'.
*/
float2 SMAAAreaDiag(SMAATexture2D(areaTex), float2 dist, float2 e, float offset) {
float2 texcoord = mad(float2(SMAA_AREATEX_MAX_DISTANCE_DIAG, SMAA_AREATEX_MAX_DISTANCE_DIAG), e, dist);
// We do a scale and bias for mapping to texel space:
texcoord = mad(SMAA_AREATEX_PIXEL_SIZE, texcoord, 0.5 * SMAA_AREATEX_PIXEL_SIZE);
// Diagonal areas are on the second half of the texture:
texcoord.x += 0.5;
// Move to proper place, according to the subpixel offset:
texcoord.y += SMAA_AREATEX_SUBTEX_SIZE * offset;
// Do it!
return SMAA_AREATEX_SELECT(SMAASampleLevelZero(areaTex, texcoord));
}
/**
* This searches for diagonal patterns and returns the corresponding weights.
*/
float2 SMAACalculateDiagWeights(SMAATexture2D(edgesTex), SMAATexture2D(areaTex), float2 texcoord, float2 e, float4 subsampleIndices) {
float2 weights = float2(0.0, 0.0);
// Search for the line ends:
float4 d;
float2 end;
if (e.r > 0.0) {
d.xz = SMAASearchDiag1(SMAATexturePass2D(edgesTex), texcoord, float2(-1.0, 1.0), end);
d.x += float(end.y > 0.9);
} else
d.xz = float2(0.0, 0.0);
d.yw = SMAASearchDiag1(SMAATexturePass2D(edgesTex), texcoord, float2(1.0, -1.0), end);
SMAA_BRANCH
if (d.x + d.y > 2.0) { // d.x + d.y + 1 > 3
// Fetch the crossing edges:
float4 coords = mad(float4(-d.x + 0.25, d.x, d.y, -d.y - 0.25), SMAA_RT_METRICS.xyxy, texcoord.xyxy);
float4 c;
c.xy = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2(-1, 0)).rg;
c.zw = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2( 1, 0)).rg;
c.yxwz = SMAADecodeDiagBilinearAccess(c.xyzw);
// Non-optimized version:
// float4 coords = mad(float4(-d.x, d.x, d.y, -d.y), SMAA_RT_METRICS.xyxy, texcoord.xyxy);
// float4 c;
// c.x = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2(-1, 0)).g;
// c.y = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2( 0, 0)).r;
// c.z = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2( 1, 0)).g;
// c.w = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2( 1, -1)).r;
// Merge crossing edges at each side into a single value:
float2 cc = mad(float2(2.0, 2.0), c.xz, c.yw);
// Remove the crossing edge if we didn't found the end of the line:
SMAAMovc(bool2(step(0.9, d.zw)), cc, float2(0.0, 0.0));
// Fetch the areas for this line:
weights += SMAAAreaDiag(SMAATexturePass2D(areaTex), d.xy, cc, subsampleIndices.z);
}
// Search for the line ends:
d.xz = SMAASearchDiag2(SMAATexturePass2D(edgesTex), texcoord, float2(-1.0, -1.0), end);
if (SMAASampleLevelZeroOffset(edgesTex, texcoord, int2(1, 0)).r > 0.0) {
d.yw = SMAASearchDiag2(SMAATexturePass2D(edgesTex), texcoord, float2(1.0, 1.0), end);
d.y += float(end.y > 0.9);
} else
d.yw = float2(0.0, 0.0);
SMAA_BRANCH
if (d.x + d.y > 2.0) { // d.x + d.y + 1 > 3
// Fetch the crossing edges:
float4 coords = mad(float4(-d.x, -d.x, d.y, d.y), SMAA_RT_METRICS.xyxy, texcoord.xyxy);
float4 c;
c.x = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2(-1, 0)).g;
c.y = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2( 0, -1)).r;
c.zw = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2( 1, 0)).gr;
float2 cc = mad(float2(2.0, 2.0), c.xz, c.yw);
// Remove the crossing edge if we didn't found the end of the line:
SMAAMovc(bool2(step(0.9, d.zw)), cc, float2(0.0, 0.0));
// Fetch the areas for this line:
weights += SMAAAreaDiag(SMAATexturePass2D(areaTex), d.xy, cc, subsampleIndices.w).gr;
}
return weights;
}
#endif
//-----------------------------------------------------------------------------
// Horizontal/Vertical Search Functions
/**
* This allows to determine how much length should we add in the last step
* of the searches. It takes the bilinearly interpolated edge (see
* @PSEUDO_GATHER4), and adds 0, 1 or 2, depending on which edges and
* crossing edges are active.
*/
float SMAASearchLength(SMAATexture2D(searchTex), float2 e, float offset) {
// The texture is flipped vertically, with left and right cases taking half
// of the space horizontally:
float2 scale = SMAA_SEARCHTEX_SIZE * float2(0.5, -1.0);
float2 bias = SMAA_SEARCHTEX_SIZE * float2(offset, 1.0);
// Scale and bias to access texel centers:
scale += float2(-1.0, 1.0);
bias += float2( 0.5, -0.5);
// Convert from pixel coordinates to texcoords:
// (We use SMAA_SEARCHTEX_PACKED_SIZE because the texture is cropped)
scale *= 1.0 / SMAA_SEARCHTEX_PACKED_SIZE;
bias *= 1.0 / SMAA_SEARCHTEX_PACKED_SIZE;
// Lookup the search texture:
return SMAA_SEARCHTEX_SELECT(SMAASampleLevelZero(searchTex, mad(scale, e, bias)));
}
/**
* Horizontal/vertical search functions for the 2nd pass.
*/
float SMAASearchXLeft(SMAATexture2D(edgesTex), SMAATexture2D(searchTex), float2 texcoord, float end) {
/**
* @PSEUDO_GATHER4
* This texcoord has been offset by (-0.25, -0.125) in the vertex shader to
* sample between edge, thus fetching four edges in a row.
* Sampling with different offsets in each direction allows to disambiguate
* which edges are active from the four fetched ones.
*/
float2 e = float2(0.0, 1.0);
while (texcoord.x > end &&
e.g > 0.8281 && // Is there some edge not activated?
e.r == 0.0) { // Or is there a crossing edge that breaks the line?
e = SMAASampleLevelZero(edgesTex, texcoord).rg;
texcoord = mad(-float2(2.0, 0.0), SMAA_RT_METRICS.xy, texcoord);
}
float offset = mad(-(255.0 / 127.0), SMAASearchLength(SMAATexturePass2D(searchTex), e, 0.0), 3.25);
return mad(SMAA_RT_METRICS.x, offset, texcoord.x);
// Non-optimized version:
// We correct the previous (-0.25, -0.125) offset we applied:
// texcoord.x += 0.25 * SMAA_RT_METRICS.x;
// The searches are bias by 1, so adjust the coords accordingly:
// texcoord.x += SMAA_RT_METRICS.x;
// Disambiguate the length added by the last step:
// texcoord.x += 2.0 * SMAA_RT_METRICS.x; // Undo last step
// texcoord.x -= SMAA_RT_METRICS.x * (255.0 / 127.0) * SMAASearchLength(SMAATexturePass2D(searchTex), e, 0.0);
// return mad(SMAA_RT_METRICS.x, offset, texcoord.x);
}
float SMAASearchXRight(SMAATexture2D(edgesTex), SMAATexture2D(searchTex), float2 texcoord, float end) {
float2 e = float2(0.0, 1.0);
while (texcoord.x < end &&
e.g > 0.8281 && // Is there some edge not activated?
e.r == 0.0) { // Or is there a crossing edge that breaks the line?
e = SMAASampleLevelZero(edgesTex, texcoord).rg;
texcoord = mad(float2(2.0, 0.0), SMAA_RT_METRICS.xy, texcoord);
}
float offset = mad(-(255.0 / 127.0), SMAASearchLength(SMAATexturePass2D(searchTex), e, 0.5), 3.25);
return mad(-SMAA_RT_METRICS.x, offset, texcoord.x);
}
float SMAASearchYUp(SMAATexture2D(edgesTex), SMAATexture2D(searchTex), float2 texcoord, float end) {
float2 e = float2(1.0, 0.0);
while (texcoord.y > end &&
e.r > 0.8281 && // Is there some edge not activated?
e.g == 0.0) { // Or is there a crossing edge that breaks the line?
e = SMAASampleLevelZero(edgesTex, texcoord).rg;
texcoord = mad(-float2(0.0, 2.0), SMAA_RT_METRICS.xy, texcoord);
}
float offset = mad(-(255.0 / 127.0), SMAASearchLength(SMAATexturePass2D(searchTex), e.gr, 0.0), 3.25);
return mad(SMAA_RT_METRICS.y, offset, texcoord.y);
}
float SMAASearchYDown(SMAATexture2D(edgesTex), SMAATexture2D(searchTex), float2 texcoord, float end) {
float2 e = float2(1.0, 0.0);
while (texcoord.y < end &&
e.r > 0.8281 && // Is there some edge not activated?
e.g == 0.0) { // Or is there a crossing edge that breaks the line?
e = SMAASampleLevelZero(edgesTex, texcoord).rg;
texcoord = mad(float2(0.0, 2.0), SMAA_RT_METRICS.xy, texcoord);
}
float offset = mad(-(255.0 / 127.0), SMAASearchLength(SMAATexturePass2D(searchTex), e.gr, 0.5), 3.25);
return mad(-SMAA_RT_METRICS.y, offset, texcoord.y);
}
/**
* Ok, we have the distance and both crossing edges. So, what are the areas
* at each side of current edge?
*/
float2 SMAAArea(SMAATexture2D(areaTex), float2 dist, float e1, float e2, float offset) {
// Rounding prevents precision errors of bilinear filtering:
float2 texcoord = mad(float2(SMAA_AREATEX_MAX_DISTANCE, SMAA_AREATEX_MAX_DISTANCE), round(4.0 * float2(e1, e2)), dist);
// We do a scale and bias for mapping to texel space:
texcoord = mad(SMAA_AREATEX_PIXEL_SIZE, texcoord, 0.5 * SMAA_AREATEX_PIXEL_SIZE);
// Move to proper place, according to the subpixel offset:
texcoord.y = mad(SMAA_AREATEX_SUBTEX_SIZE, offset, texcoord.y);
// Do it!
return SMAA_AREATEX_SELECT(SMAASampleLevelZero(areaTex, texcoord));
}
//-----------------------------------------------------------------------------
// Corner Detection Functions
void SMAADetectHorizontalCornerPattern(SMAATexture2D(edgesTex), inout float2 weights, float4 texcoord, float2 d) {
#if !defined(SMAA_DISABLE_CORNER_DETECTION)
float2 leftRight = step(d.xy, d.yx);
float2 rounding = (1.0 - SMAA_CORNER_ROUNDING_NORM) * leftRight;
rounding /= leftRight.x + leftRight.y; // Reduce blending for pixels in the center of a line.
float2 factor = float2(1.0, 1.0);
factor.x -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, int2(0, 1)).r;
factor.x -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, int2(1, 1)).r;
factor.y -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, int2(0, -2)).r;
factor.y -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, int2(1, -2)).r;
weights *= saturate(factor);
#endif
}
void SMAADetectVerticalCornerPattern(SMAATexture2D(edgesTex), inout float2 weights, float4 texcoord, float2 d) {
#if !defined(SMAA_DISABLE_CORNER_DETECTION)
float2 leftRight = step(d.xy, d.yx);
float2 rounding = (1.0 - SMAA_CORNER_ROUNDING_NORM) * leftRight;
rounding /= leftRight.x + leftRight.y;
float2 factor = float2(1.0, 1.0);
factor.x -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, int2( 1, 0)).g;
factor.x -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, int2( 1, 1)).g;
factor.y -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, int2(-2, 0)).g;
factor.y -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, int2(-2, 1)).g;
weights *= saturate(factor);
#endif
}
//-----------------------------------------------------------------------------
// 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;
}
//-----------------------------------------------------------------------------
// Neighborhood Blending Pixel Shader (Third Pass)
float4 SMAANeighborhoodBlendingPS(float2 texcoord,
float4 offset,
SMAATexture2D(colorTex),
SMAATexture2D(blendTex)
#if SMAA_REPROJECTION
, SMAATexture2D(velocityTex)
#endif
) {
// Fetch the blending weights for current pixel:
float4 a;
a.x = SMAASample(blendTex, offset.xy).a; // Right
a.y = SMAASample(blendTex, offset.zw).g; // Top
a.wz = SMAASample(blendTex, texcoord).xz; // Bottom / Left
// Is there any blending weight with a value greater than 0.0?
SMAA_BRANCH
if (dot(a, float4(1.0, 1.0, 1.0, 1.0)) < 1e-5) {
float4 color = SMAASampleLevelZero(colorTex, texcoord);
#if SMAA_REPROJECTION
float2 velocity = SMAA_DECODE_VELOCITY(SMAASampleLevelZero(velocityTex, texcoord));
// Pack velocity into the alpha channel:
color.a = sqrt(5.0 * length(velocity));
#endif
return color;
} else {
bool h = max(a.x, a.z) > max(a.y, a.w); // max(horizontal) > max(vertical)
// Calculate the blending offsets:
float4 blendingOffset = float4(0.0, a.y, 0.0, a.w);
float2 blendingWeight = a.yw;
SMAAMovc(bool4(h, h, h, h), blendingOffset, float4(a.x, 0.0, a.z, 0.0));
SMAAMovc(bool2(h, h), blendingWeight, a.xz);
blendingWeight /= dot(blendingWeight, float2(1.0, 1.0));
// Calculate the texture coordinates:
float4 blendingCoord = mad(blendingOffset, float4(SMAA_RT_METRICS.xy, -SMAA_RT_METRICS.xy), texcoord.xyxy);
// We exploit bilinear filtering to mix current pixel with the chosen
// neighbor:
float4 color = blendingWeight.x * SMAASampleLevelZero(colorTex, blendingCoord.xy);
color += blendingWeight.y * SMAASampleLevelZero(colorTex, blendingCoord.zw);
#if SMAA_REPROJECTION
// Antialias velocity for proper reprojection in a later stage:
float2 velocity = blendingWeight.x * SMAA_DECODE_VELOCITY(SMAASampleLevelZero(velocityTex, blendingCoord.xy));
velocity += blendingWeight.y * SMAA_DECODE_VELOCITY(SMAASampleLevelZero(velocityTex, blendingCoord.zw));
// Pack velocity into the alpha channel:
color.a = sqrt(5.0 * length(velocity));
#endif
return color;
}
}
//-----------------------------------------------------------------------------
// Temporal Resolve Pixel Shader (Optional Pass)
float4 SMAAResolvePS(float2 texcoord,
SMAATexture2D(currentColorTex),
SMAATexture2D(previousColorTex)
#if SMAA_REPROJECTION
, SMAATexture2D(velocityTex)
#endif
) {
#if SMAA_REPROJECTION
// Velocity is assumed to be calculated for motion blur, so we need to
// inverse it for reprojection:
float2 velocity = -SMAA_DECODE_VELOCITY(SMAASamplePoint(velocityTex, texcoord).rg);
// Fetch current pixel:
float4 current = SMAASamplePoint(currentColorTex, texcoord);
// Reproject current coordinates and fetch previous pixel:
float4 previous = SMAASamplePoint(previousColorTex, texcoord + velocity);
// Attenuate the previous pixel if the velocity is different:
float delta = abs(current.a * current.a - previous.a * previous.a) / 5.0;
float weight = 0.5 * saturate(1.0 - sqrt(delta) * SMAA_REPROJECTION_WEIGHT_SCALE);
// Blend the pixels according to the calculated weight:
return lerp(current, previous, weight);
#else
// Just blend the pixels:
float4 current = SMAASamplePoint(currentColorTex, texcoord);
float4 previous = SMAASamplePoint(previousColorTex, texcoord);
return lerp(current, previous, 0.5);
#endif
}
//-----------------------------------------------------------------------------
// Separate Multisamples Pixel Shader (Optional Pass)
#ifdef SMAALoad
void SMAASeparatePS(float4 position,
float2 texcoord,
out float4 target0,
out float4 target1,
SMAATexture2DMS2(colorTexMS)) {
int2 pos = int2(position.xy);
target0 = SMAALoad(colorTexMS, pos, 0);
target1 = SMAALoad(colorTexMS, pos, 1);
}
#endif
//-----------------------------------------------------------------------------