/**
* Copyright (C) 2011 Jorge Jimenez (jorge@iryoku.com)
* Copyright (C) 2011 Belen Masia (bmasia@unizar.es)
* Copyright (C) 2011 Jose I. Echevarria (joseignacioechevarria@gmail.com)
* Copyright (C) 2011 Fernando Navarro (fernandn@microsoft.com)
* Copyright (C) 2011 Diego Gutierrez (diegog@unizar.es)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the following disclaimer
* in the documentation and/or other materials provided with the
* distribution:
*
* "Uses SMAA. Copyright (C) 2011 by Jorge Jimenez, Jose I. Echevarria,
* Belen Masia, Fernando Navarro and Diego Gutierrez."
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
* IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and documentation are
* those of the authors and should not be interpreted as representing official
* policies, either expressed or implied, of the copyright holders.
*/
/**
* _______ ___ ___ ___ ___
* / || \/ | / \ / \
* | (---- | \ / | / ^ \ / ^ \
* \ \ | |\/| | / /_\ \ / /_\ \
* ----) | | | | | / _____ \ / _____ \
* |_______/ |__| |__| /__/ \__\ /__/ \__\
*
* E N H A N C E D
* S U B P I X E L M O R P H O L O G I C A L A N T I A L I A S I N G
*
*
http://www.iryoku.com/smaa/
*
* Hi, welcome aboard!
*
* Here you'll find instructions to get the shader up and running as fast as
* possible.
*
* The shader has three passes, chained together as follows:
*
* |input|------------------·
* v |
* [ SMAA*EdgeDetection ] |
* v |
* |edgesTex| |
* v |
* [ SMAABlendingWeightCalculation ] |
* v |
* |blendTex| |
* v |
* [ SMAANeighborhoodBlending ] <------·
* v
* |output|
*
* Note that each [pass] has its own vertex and pixel shader.
*
* You've three edge detection methods to choose from: luma, color or depth.
* They represent different quality/performance and anti-aliasing/sharpness
* tradeoffs, so our recommendation is for you to choose the one that best
* suits your particular scenario:
*
* - Depth edge detection is usually the fastest but it may miss some edges.
*
* - Luma edge detection is usually more expensive than depth edge detection,
* but catches visible edges that depth edge detection can miss.
*
* - Color edge detection is usually the most expensive one but catches
* chroma-only edges.
*
* For quickstarters: just use luma edge detection.
*
* The general advice is to not rush the integration process and ensure each
* step is done correctly (don't try to integrate SMAA T2x with predicated edge
* detection from the start!). Ok then, let's go!
*
* 1. The first step is to create two RGBA temporal framebuffers for holding
* |edgesTex| and |blendTex|.
*
* In DX10, you can use a RG framebuffer for the edges texture, but in our
* experience it yields worse performance.
*
* On the Xbox 360, you can use the same framebuffer for resolving both
* |edgesTex| and |blendTex|, as they aren't needed simultaneously.
*
* 2. Both temporal framebuffers |edgesTex| and |blendTex| must be cleared
* each frame. Do not forget to clear the alpha channel!
*
* 3. The next step is loading the two supporting precalculated textures,
* 'areaTex' and 'searchTex'. You'll find them in the 'Textures' folder as
* C++ headers, and also as regular DDS files. They'll be needed for the
* 'SMAABlendingWeightCalculation' pass.
*
* If you use the C++ headers, be sure to load them in the format specified
* inside of them.
*
* 4. In DX9, all samplers must be set to linear filtering and clamp, with the
* exception of 'searchTex', which must be set to point filtering.
*
* 5. All texture reads and buffer writes must be non-sRGB, with the exception
* of the input read and the output write of input in
* 'SMAANeighborhoodBlending' (and only in this pass!). If sRGB reads in
* this last pass are not possible, the technique will work anyway, but
* will perform antialiasing in gamma space.
*
* IMPORTANT: for best results the input read for the color/luma edge
* detection should *NOT* be sRGB.
*
* 6. Before including SMAA.h you'll have to setup the framebuffer pixel size,
* the target and any optional configuration defines. Optionally you can
* use a preset.
*
* You have three targets available:
* SMAA_HLSL_3
* SMAA_HLSL_4
* SMAA_HLSL_4_1
* SMAA_GLSL_3 *
* SMAA_GLSL_4 *
*
* * (See SMAA_ONLY_COMPILE_VS below).
*
* And four presets:
* SMAA_PRESET_LOW (%60 of the quality)
* SMAA_PRESET_MEDIUM (%80 of the quality)
* SMAA_PRESET_HIGH (%95 of the quality)
* SMAA_PRESET_ULTRA (%99 of the quality)
*
* For example:
* #define SMAA_PIXEL_SIZE float2(1.0 / 1280.0, 1.0 / 720.0)
* #define SMAA_HLSL_4 1
* #define SMAA_PRESET_HIGH 1
* #include "SMAA.h"
*
* 7. Then, you'll have to setup the passes as indicated in the scheme above.
* You can take a look into SMAA.fx, to see how we did it for our demo.
* Checkout the function wrappers, you may want to copy-paste them!
*
* 8. It's recommended to validate the produced |edgesTex| and |blendTex|.
* It's advised to not continue with the implementation until both buffers
* are verified to produce identical results to our reference demo.
*
* 9. After you get the last pass to work, it's time to optimize. You'll have
* to initialize a stencil buffer in the first pass (discard is already in
* the code), then mask execution by using it the second pass. The last
* pass should be executed in all pixels.
*
*
* After this point you can choose to enable predicated thresholding,
* temporal supersampling and motion blur integration:
*
* a) If you want to use predicated thresholding, take a look into
* SMAA_PREDICATION; you'll need to pass an extra texture in the edge
* detection pass.
*
* b) If you want to enable temporal supersampling:
*
* 1. The first step is to render using subpixel jitters. I won't go into
* detail, but it's as simple as moving each vertex position in the
* vertex shader, you can check how we do it in our DX10 demo.
*
* 2. Then, you must setup the temporal resolve. You may want to take a look
* into SMAAResolve for resolving 2x modes. After you get it working, you'll
* probably see ghosting everywhere. But fear not, you can enable the
* CryENGINE temporal reprojection by setting the SMAA_REPROJECTION macro.
*
* 3. The next step is to apply SMAA to each subpixel jittered frame, just as
* done for 1x.
*
* 4. At this point you should already have something usable, but for best
* results the proper area textures must be set depending on current jitter.
* For this, the parameter 'subsampleIndices' of
* 'SMAABlendingWeightCalculationPS' must be set as follows, for our T2x
* mode:
*
* @SUBSAMPLE_INDICES
*
* | jitter | subsampleIndices |
* +------------------------+------------------------|
* | float2(-0.25f, 0.25f) | int4(1, 1, 1, 0) |
* | float2( 0.25f, -0.25f) | int4(2, 2, 2, 0) |
* OR
* +------------------------+------------------------|
* | float2( 0.25f, 0.25f) | int4(2, 1, 0, 2) |
* | float2(-0.25f, -0.25f) | int4(1, 2, 0, 1) |
*
* These jitter positions assume a bottom-to-top y axis.
*
* More information about temporal supersampling here:
*
http://iryoku.com/aacourse/downloads/13-Anti-Aliasing-Methods-in-CryENGINE-3.pdf
*
* c) If motion blur is used, you may want to do the edge detection pass
* together with motion blur. This has two advantages:
*
* 1. Pixels under heavy motion can be omitted from the edge detection process.
* For these pixels we can just store "no edge", as motion blur will take
* care of them.
* 2. The center pixel tap is reused.
*
* Note that in this case depth testing should be used instead of stenciling,
* as we have to write all the pixels in the motion blur pass.
*
* That's it!
*/
//-----------------------------------------------------------------------------
// SMAA Presets
/*
#if SMAA_PRESET_LOW == 1
#define SMAA_THRESHOLD 0.15
#define SMAA_MAX_SEARCH_STEPS 4
#define SMAA_MAX_SEARCH_STEPS_DIAG 0
#define SMAA_CORNER_ROUNDING 100
#elif SMAA_PRESET_MEDIUM == 1
#define SMAA_THRESHOLD 0.1
#define SMAA_MAX_SEARCH_STEPS 8
#define SMAA_MAX_SEARCH_STEPS_DIAG 0
#define SMAA_CORNER_ROUNDING 100
#elif SMAA_PRESET_HIGH == 1
#define SMAA_THRESHOLD 0.1
#define SMAA_MAX_SEARCH_STEPS 16
#define SMAA_MAX_SEARCH_STEPS_DIAG 8
#define SMAA_CORNER_ROUNDING 25
#elif SMAA_PRESET_ULTRA == 1
#define SMAA_THRESHOLD 0.05
#define SMAA_MAX_SEARCH_STEPS 32
#define SMAA_MAX_SEARCH_STEPS_DIAG 16
#define SMAA_CORNER_ROUNDING 25
#endif
*/
//-----------------------------------------------------------------------------
// Configurable Defines
/**
* SMAA_THRESHOLD specifies the threshold or sensitivity to edges.
* Lowering this value you will be able to detect more edges at the expense of
* performance.
*
* Range: [0, 0.5]
* 0.1 is a reasonable value, and allows to catch most visible edges.
* 0.05 is a rather overkill value, that allows to catch 'em all.
*
* If temporal supersampling is used, 0.2 could be a reasonable value, as low
* contrast edges are properly filtered by just 2x.
*/
#ifndef SMAA_THRESHOLD
#define SMAA_THRESHOLD 0.05
#endif
/**
* SMAA_DEPTH_THRESHOLD specifies the threshold for depth edge detection.
*
* Range: depends on the depth range of the scene.
*/
#ifndef SMAA_DEPTH_THRESHOLD
#define SMAA_DEPTH_THRESHOLD (0.1 * SMAA_THRESHOLD)
#endif
/**
* SMAA_MAX_SEARCH_STEPS specifies the maximum steps performed in the
* horizontal/vertical pattern searches, at each side of the pixel.
*
* In number of pixels, it's actually the double. So the maximum line length
* perfectly handled by, for example 16, is 64 (by perfectly, we meant that
* longer lines won't look as good, but still antialiased).
*
* Range: [0, 98]
*/
#ifndef SMAA_MAX_SEARCH_STEPS
#define SMAA_MAX_SEARCH_STEPS 32
#endif
/**
* SMAA_MAX_SEARCH_STEPS_DIAG specifies the maximum steps performed in the
* diagonal pattern searches, at each side of the pixel. In this case we jump
* one pixel at time, instead of two.
*
* Range: [0, 20]; set it to 0 to disable diagonal processing.
*
* On high-end machines it is cheap (between a 0.8x and 0.9x slower for 16
* steps), but it can have a significant impact on older machines.
*/
#ifndef SMAA_MAX_SEARCH_STEPS_DIAG
#define SMAA_MAX_SEARCH_STEPS_DIAG 16
#endif
/**
* SMAA_CORNER_ROUNDING specifies how much sharp corners will be rounded.
*
* Range: [0, 100]; set it to 100 to disable corner detection.
*/
#ifndef SMAA_CORNER_ROUNDING
#define SMAA_CORNER_ROUNDING 25
#endif
/**
* Predicated thresholding allows to better preserve texture details and to
* improve performance, by decreasing the number of detected edges using an
* additional buffer like the light accumulation buffer, object ids or even the
* depth buffer (the depth buffer usage may be limited to indoor or short range
* scenes).
*
* It locally decreases the luma or color threshold if an edge is found in an
* additional buffer (so the global threshold can be higher).
*
* This method was developed by Playstation EDGE MLAA team, and used in
* Killzone 3, by using the light accumulation buffer. More information here:
*
http://iryoku.com/aacourse/downloads/06-MLAA-on-PS3.pptx
*/
#ifndef SMAA_PREDICATION
#define SMAA_PREDICATION 0
#endif
/**
* Threshold to be used in the additional predication buffer.
*
* Range: depends on the input, so you'll have to find the magic number that
* works for you.
*/
#ifndef SMAA_PREDICATION_THRESHOLD
#define SMAA_PREDICATION_THRESHOLD 0.01
#endif
/**
* How much to scale the global threshold used for luma or color edge
* detection when using predication.
*
* Range: [1, 5]
*/
#ifndef SMAA_PREDICATION_SCALE
#define SMAA_PREDICATION_SCALE 2.0
#endif
/**
* How much to locally decrease the threshold.
*
* Range: [0, 1]
*/
#ifndef SMAA_PREDICATION_STRENGTH
#define SMAA_PREDICATION_STRENGTH 0.4
#endif
/**
* Temporal reprojection allows to remove ghosting artifacts when using
* temporal supersampling. We use the CryEngine 3 method which also introduces
* velocity weighting. This feature is of extreme importance for totally
* removing ghosting. More information here:
*
http://iryoku.com/aacourse/downloads/13-Anti-Aliasing-Methods-in-CryENGINE-3.pdf
*
* Note that you'll need to setup a velocity buffer for enabling reprojection.
* For static geometry, saving the previous depth buffer is a viable
* alternative.
*/
#ifndef SMAA_REPROJECTION
#define SMAA_REPROJECTION 0
#endif
/**
* SMAA_REPROJECTION_WEIGHT_SCALE controls the velocity weighting. It allows to
* remove ghosting trails behind the moving object, which are not removed by
* just using reprojection. Using low values will exhibit ghosting, while using
* high values will disable temporal supersampling under motion.
*
* Behind the scenes, velocity weighting removes temporal supersampling when
* the velocity of the subsamples differs (meaning they are different objects).
*
* Range: [0, 80]
*/
#define SMAA_REPROJECTION_WEIGHT_SCALE 30.0
/**
* In the last pass we leverage bilinear filtering to avoid some lerps.
* However, bilinear filtering is done in gamma space in DX9, under DX9
* hardware (but not in DX9 code running on DX10 hardware), which gives
* inaccurate results.
*
* So, if you are in DX9, under DX9 hardware, and do you want accurate linear
* blending, you must set this flag to 1.
*
* It's ignored when using SMAA_HLSL_4, and of course, only has sense when
* using sRGB read and writes on the last pass.
*/
#ifndef SMAA_DIRECTX9_LINEAR_BLEND
#define SMAA_DIRECTX9_LINEAR_BLEND 0
#endif
/**
* On ATI compilers, discard cannot be used in vertex shaders. Thus, they need
* to be compiled separately. These macros allow to easily accomplish it.
*/
#ifndef SMAA_ONLY_COMPILE_VS
#define SMAA_ONLY_COMPILE_VS 0
#endif
#ifndef SMAA_ONLY_COMPILE_PS
#define SMAA_ONLY_COMPILE_PS 0
#endif
//-----------------------------------------------------------------------------
// Non-Configurable Defines
#ifndef SMAA_AREATEX_MAX_DISTANCE
#define SMAA_AREATEX_MAX_DISTANCE 16
#endif
#ifndef SMAA_AREATEX_MAX_DISTANCE_DIAG
#define SMAA_AREATEX_MAX_DISTANCE_DIAG 20
#endif
#define SMAA_AREATEX_PIXEL_SIZE (1.0 / float2(160.0, 240.0))
#define SMAA_AREATEX_SUBTEX_SIZE (1.0 / 3.0)
//-----------------------------------------------------------------------------
// Porting Functions
#if SMAA_HLSL_3 == 1
#define SMAATexture2D sampler2D
#define SMAASampleLevelZero(tex, coord) tex2Dlod(tex, float4(coord, 0.0, 0.0))
#define SMAASampleLevelZeroPoint(tex, coord) tex2Dlod(tex, float4(coord, 0.0, 0.0))
#define SMAASample(tex, coord) tex2D(tex, coord)
#define SMAASamplePoint(tex, coord) tex2D(tex, coord)
#define SMAASampleLevelZeroOffset(tex, coord, offset) tex2Dlod(tex, float4(coord + offset * SMAA_PIXEL_SIZE, 0.0, 0.0))
#define SMAASampleOffset(tex, coord, offset) tex2D(tex, coord + offset * SMAA_PIXEL_SIZE)
#define SMAALerp(a, b, t) lerp(a, b, t)
#define SMAASaturate(a) saturate(a)
#define SMAAMad(a, b, c) mad(a, b, c)
#define SMAA_FLATTEN [flatten]
#define SMAA_BRANCH [branch]
#endif
#if SMAA_HLSL_4 == 1 || SMAA_HLSL_4_1 == 1
SamplerState LinearSampler { Filter = MIN_MAG_LINEAR_MIP_POINT; AddressU = Clamp; AddressV = Clamp; };
SamplerState PointSampler { Filter = MIN_MAG_MIP_POINT; AddressU = Clamp; AddressV = Clamp; };
#define SMAATexture2D Texture2D
#define SMAASampleLevelZero(tex, coord) tex.SampleLevel(LinearSampler, coord, 0)
#define SMAASampleLevelZeroPoint(tex, coord) tex.SampleLevel(PointSampler, coord, 0)
#define SMAASample(tex, coord) SMAASampleLevelZero(tex, coord)
#define SMAASamplePoint(tex, coord) SMAASampleLevelZeroPoint(tex, coord)
#define SMAASampleLevelZeroOffset(tex, coord, offset) tex.SampleLevel(LinearSampler, coord, 0, offset)
#define SMAASampleOffset(tex, coord, offset) SMAASampleLevelZeroOffset(tex, coord, offset)
#define SMAALerp(a, b, t) lerp(a, b, t)
#define SMAASaturate(a) saturate(a)
#define SMAAMad(a, b, c) mad(a, b, c)
#define SMAA_FLATTEN [flatten]
#define SMAA_BRANCH [branch]
#endif
#if SMAA_HLSL_4_1 == 1
#define SMAAGather(tex, coord) tex.Gather(LinearSampler, coord, 0)
#endif
#if SMAA_GLSL_3 == 1 || SMAA_GLSL_4 == 1
#define SMAATexture2D sampler2D
#define SMAASampleLevelZero(tex, coord) textureLod(tex, coord, 0.0)
#define SMAASampleLevelZeroPoint(tex, coord) textureLod(tex, coord, 0.0)
#define SMAASample(tex, coord) texture(tex, coord)
#define SMAASamplePoint(tex, coord) texture(tex, coord)
#define SMAASampleLevelZeroOffset(tex, coord, offset) textureLodOffset(tex, coord, 0.0, offset)
#define SMAASampleOffset(tex, coord, offset) texture(tex, coord, offset)
#define SMAALerp(a, b, t) mix(a, b, t)
#define SMAASaturate(a) clamp(a, 0.0, 1.0)
#define SMAA_FLATTEN
#define SMAA_BRANCH
#define float2 vec2
#define float3 vec3
#define float4 vec4
#define int2 ivec2
#define int3 ivec3
#define int4 ivec4
#endif
#if SMAA_GLSL_3 == 1
#define SMAAMad(a, b, c) (a * b + c)
#endif
#if SMAA_GLSL_4 == 1
#define SMAAMad(a, b, c) fma(a, b, c)
#define SMAAGather(tex, coord) textureGather(tex, coord)
#endif
//-----------------------------------------------------------------------------
// Misc functions
/**
* Gathers current pixel, and the top-left neighbors.
*/
float3 SMAAGatherNeighbours(float2 texcoord,
float4 offset[3],
SMAATexture2D tex) {
#if SMAA_HLSL_4_1 == 1
return SMAAGather(tex, texcoord + SMAA_PIXEL_SIZE * float2(-0.5, -0.5)).grb;
#else
float P = SMAASample(tex, texcoord).r;
float Pleft = SMAASample(tex, offset[0].xy).r;
float Ptop = SMAASample(tex, offset[0].zw).r;
return float3(P, Pleft, Ptop);
#endif
}
/**
* Adjusts the threshold by means of predication.
*/
float2 SMAACalculatePredicatedThreshold(float2 texcoord,
float4 offset[3],
SMAATexture2D colorTex,
SMAATexture2D predicationTex) {
float3 neighbours = SMAAGatherNeighbours(texcoord, offset, predicationTex);
float2 delta = abs(neighbours.xx - float2(neighbours.y, neighbours.z));
float2 edges = step(SMAA_PREDICATION_THRESHOLD, delta);
return SMAA_PREDICATION_SCALE * SMAA_THRESHOLD * (1.0 - SMAA_PREDICATION_STRENGTH * edges);
}
#if SMAA_ONLY_COMPILE_PS == 0
//-----------------------------------------------------------------------------
// Vertex Shaders
/**
* Edge Detection Vertex Shader
*/
void SMAAEdgeDetectionVS(float4 position,
out float4 svPosition,
inout float2 texcoord,
out float4 offset[3]) {
svPosition = position;
offset[0] = texcoord.xyxy + SMAA_PIXEL_SIZE.xyxy * float4(-1.0, 0.0, 0.0, -1.0);
offset[1] = texcoord.xyxy + SMAA_PIXEL_SIZE.xyxy * float4( 1.0, 0.0, 0.0, 1.0);
offset[2] = texcoord.xyxy + SMAA_PIXEL_SIZE.xyxy * float4(-2.0, 0.0, 0.0, -2.0);
}
/**
* Blend Weight Calculation Vertex Shader
*/
void SMAABlendWeightCalculationVS(float4 position,
out float4 svPosition,
inout float2 texcoord,
out float2 pixcoord,
out float4 offset[3]) {
svPosition = position;
pixcoord = texcoord / SMAA_PIXEL_SIZE;
// We will use these offsets for the searches later on (see @PSEUDO_GATHER4):
offset[0] = texcoord.xyxy + SMAA_PIXEL_SIZE.xyxy * float4(-0.25, -0.125, 1.25, -0.125);
offset[1] = texcoord.xyxy + SMAA_PIXEL_SIZE.xyxy * float4(-0.125, -0.25, -0.125, 1.25);
// And these for the searches, they indicate the ends of the loops:
offset[2] = float4(offset[0].xz, offset[1].yw) +
float4(-2.0, 2.0, -2.0, 2.0) *
SMAA_PIXEL_SIZE.xxyy * float(SMAA_MAX_SEARCH_STEPS);
}
/**
* Neighborhood Blending Vertex Shader
*/
void SMAANeighborhoodBlendingVS(float4 position,
out float4 svPosition,
inout float2 texcoord,
out float4 offset[2]) {
svPosition = position;
offset[0] = texcoord.xyxy + SMAA_PIXEL_SIZE.xyxy * float4(-1.0, 0.0, 0.0, -1.0);
offset[1] = texcoord.xyxy + SMAA_PIXEL_SIZE.xyxy * float4( 1.0, 0.0, 0.0, 1.0);
}
/**
* Resolve Vertex Shader
*/
void SMAAResolveVS(float4 position,
out float4 svPosition,
inout float2 texcoord) {
svPosition = position;
}
#endif // SMAA_ONLY_COMPILE_PS == 0
#if SMAA_ONLY_COMPILE_VS == 0
//-----------------------------------------------------------------------------
// 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.
*/
float4 SMAALumaEdgeDetectionPS(float2 texcoord,
float4 offset[3],
SMAATexture2D colorTex
#if SMAA_PREDICATION == 1
, SMAATexture2D predicationTex
#endif
) {
// Calculate the threshold:
#if SMAA_PREDICATION == 1
float2 threshold = SMAACalculatePredicatedThreshold(texcoord, offset, colorTex, predicationTex);
#else
float2 threshold = float2(SMAA_THRESHOLD, SMAA_THRESHOLD);
#endif
// Calculate lumas:
float3 weights = float3(0.2126, 0.7152, 0.0722);
float L = dot(SMAASample(colorTex, texcoord).rgb, weights);
float Lleft = dot(SMAASample(colorTex, offset[0].xy).rgb, weights);
float Ltop = dot(SMAASample(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(SMAASample(colorTex, offset[1].xy).rgb, weights);
float Lbottom = dot(SMAASample(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);
maxDelta = max(maxDelta.xx, maxDelta.yy);
// Calculate left-left and top-top deltas:
float Lleftleft = dot(SMAASample(colorTex, offset[2].xy).rgb, weights);
float Ltoptop = dot(SMAASample(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);
/**
* Each edge with a delta in luma of less than 50% of the maximum luma
* surrounding this pixel is discarded. This allows to eliminate spurious
* crossing edges, and is based on the fact that, if there is too much
* contrast in a direction, that will hide contrast in the other
* neighbors.
* This is done after the discard intentionally as this situation doesn't
* happen too frequently (but it's important to do as it prevents some
* edges from going undetected).
*/
edges.xy *= step(0.5 * maxDelta, delta.xy);
return float4(edges, 0.0, 0.0);
}
/**
* Color Edge Detection
*
* IMPORTANT NOTICE: color edge detection requires gamma-corrected colors, and
* thus 'colorTex' should be a non-sRGB texture.
*/
float4 SMAAColorEdgeDetectionPS(float2 texcoord,
float4 offset[3],
SMAATexture2D colorTex
#if SMAA_PREDICATION == 1
, SMAATexture2D predicationTex
#endif
) {
// Calculate the threshold:
#if SMAA_PREDICATION == 1
float2 threshold = SMAACalculatePredicatedThreshold(texcoord, offset, colorTex, predicationTex);
#else
float2 threshold = float2(SMAA_THRESHOLD, SMAA_THRESHOLD);
#endif
// Calculate color deltas:
float4 delta;
float3 C = SMAASample(colorTex, texcoord).rgb;
float3 Cleft = SMAASample(colorTex, offset[0].xy).rgb;
float3 t = abs(C - Cleft);
delta.x = max(max(t.r, t.g), t.b);
float3 Ctop = SMAASample(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 = SMAASample(colorTex, offset[1].xy).rgb;
t = abs(C - Cright);
delta.z = max(max(t.r, t.g), t.b);
float3 Cbottom = SMAASample(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:
float maxDelta = max(max(max(delta.x, delta.y), delta.z), delta.w);
// Calculate left-left and top-top deltas:
float3 Cleftleft = SMAASample(colorTex, offset[2].xy).rgb;
t = abs(C - Cleftleft);
delta.z = max(max(t.r, t.g), t.b);
float3 Ctoptop = SMAASample(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(max(maxDelta, delta.z), delta.w);
// Local contrast adaptation in action:
edges.xy *= step(0.5 * maxDelta, delta.xy);
return float4(edges, 0.0, 0.0);
}
/**
* Depth Edge Detection
*/
float4 SMAADepthEdgeDetectionPS(float2 texcoord,
float4 offset[3],
SMAATexture2D depthTex) {
float3 neighbours = SMAAGatherNeighbours(texcoord, offset, 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 float4(edges, 0.0, 0.0);
}
//-----------------------------------------------------------------------------
// Diagonal Search Functions
#if SMAA_MAX_SEARCH_STEPS_DIAG > 0 || SMAA_FORCE_DIAGONAL_DETECTION == 1
/**
* These functions allows to perform diagonal pattern searches.
*/
float SMAASearchDiag1(SMAATexture2D edgesTex, float2 texcoord, float2 dir, float c) {
texcoord += dir * SMAA_PIXEL_SIZE;
float2 e = float2(0.0, 0.0);
float i;
for (i = 0.0; i < float(SMAA_MAX_SEARCH_STEPS_DIAG); i++) {
e.rg = SMAASampleLevelZero(edgesTex, texcoord).rg;
SMAA_FLATTEN if (dot(e, float2(1.0, 1.0)) < 1.9) break;
texcoord += dir * SMAA_PIXEL_SIZE;
}
return i + float(e.g > 0.9) * c;
}
float SMAASearchDiag2(SMAATexture2D edgesTex, float2 texcoord, float2 dir, float c) {
texcoord += dir * SMAA_PIXEL_SIZE;
float2 e = float2(0.0, 0.0);
float i;
for (i = 0.0; i < float(SMAA_MAX_SEARCH_STEPS_DIAG); i++) {
e.g = SMAASampleLevelZero(edgesTex, texcoord).g;
e.r = SMAASampleLevelZeroOffset(edgesTex, texcoord, int2(1, 0)).r;
SMAA_FLATTEN if (dot(e, float2(1.0, 1.0)) < 1.9) break;
texcoord += dir * SMAA_PIXEL_SIZE;
}
return i + float(e.g > 0.9) * c;
}
/**
* 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 = float(SMAA_AREATEX_MAX_DISTANCE_DIAG) * e + dist;
// We do a scale and bias for mapping to texel space:
texcoord = 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!
#if SMAA_HLSL_3 == 1
return SMAASampleLevelZero(areaTex, texcoord).ra;
#else
return SMAASampleLevelZero(areaTex, texcoord).rg;
#endif
}
/**
* This searches for diagonal patterns and returns the corresponding weights.
*/
float2 SMAACalculateDiagWeights(SMAATexture2D edgesTex, SMAATexture2D areaTex, float2 texcoord, float2 e, int4 subsampleIndices) {
float2 weights = float2(0.0, 0.0);
float2 d;
d.x = e.r > 0.0? SMAASearchDiag1(edgesTex, texcoord, float2(-1.0, 1.0), 1.0) : 0.0;
d.y = SMAASearchDiag1(edgesTex, texcoord, float2(1.0, -1.0), 0.0);
SMAA_BRANCH
if (d.r + d.g > 2.0) { // d.r + d.g + 1 > 3
float4 coords = SMAAMad(float4(-d.r, d.r, d.g, -d.g), SMAA_PIXEL_SIZE.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;
float2 e = 2.0 * c.xz + c.yw;
float t = float(SMAA_MAX_SEARCH_STEPS_DIAG) - 1.0;
e *= step(d.rg, float2(t, t));
weights += SMAAAreaDiag(areaTex, d, e, float(subsampleIndices.z));
}
d.x = SMAASearchDiag2(edgesTex, texcoord, float2(-1.0, -1.0), 0.0);
float right = SMAASampleLevelZeroOffset(edgesTex, texcoord, int2(1, 0)).r;
d.y = right > 0.0? SMAASearchDiag2(edgesTex, texcoord, float2(1.0, 1.0), 1.0) : 0.0;
SMAA_BRANCH
if (d.r + d.g > 2.0) { // d.r + d.g + 1 > 3
float4 coords = SMAAMad(float4(-d.r, -d.r, d.g, d.g), SMAA_PIXEL_SIZE.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 e = 2.0 * c.xz + c.yw;
float t = float(SMAA_MAX_SEARCH_STEPS_DIAG) - 1.0;
e *= step(d.rg, float2(t, t));
weights += SMAAAreaDiag(areaTex, d, e, float(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 bias, float scale) {
// Not required if searchTex accesses are set to point:
// float2 SEARCH_TEX_PIXEL_SIZE = 1.0 / float2(66.0, 33.0);
// e = float2(bias, 0.0) + 0.5 * SEARCH_TEX_PIXEL_SIZE +
// e * float2(scale, 1.0) * float2(64.0, 32.0) * SEARCH_TEX_PIXEL_SIZE;
e.r = bias + e.r * scale;
return 255.0 * SMAASampleLevelZeroPoint(searchTex, e).r;
}
/**
* 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 -= float2(2.0, 0.0) * SMAA_PIXEL_SIZE;
}
// We correct the previous (-0.25, -0.125) offset we applied:
texcoord.x += 0.25 * SMAA_PIXEL_SIZE.x;
// The searches are bias by 1, so adjust the coords accordingly:
texcoord.x += SMAA_PIXEL_SIZE.x;
// Disambiguate the length added by the last step:
texcoord.x += 2.0 * SMAA_PIXEL_SIZE.x; // Undo last step
texcoord.x -= SMAA_PIXEL_SIZE.x * SMAASearchLength(searchTex, e, 0.0, 0.5);
return 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 += float2(2.0, 0.0) * SMAA_PIXEL_SIZE;
}
texcoord.x -= 0.25 * SMAA_PIXEL_SIZE.x;
texcoord.x -= SMAA_PIXEL_SIZE.x;
texcoord.x -= 2.0 * SMAA_PIXEL_SIZE.x;
texcoord.x += SMAA_PIXEL_SIZE.x * SMAASearchLength(searchTex, e, 0.5, 0.5);
return 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 -= float2(0.0, 2.0) * SMAA_PIXEL_SIZE;
}
texcoord.y += 0.25 * SMAA_PIXEL_SIZE.y;
texcoord.y += SMAA_PIXEL_SIZE.y;
texcoord.y += 2.0 * SMAA_PIXEL_SIZE.y;
texcoord.y -= SMAA_PIXEL_SIZE.y * SMAASearchLength(searchTex, e.gr, 0.0, 0.5);
return 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 += float2(0.0, 2.0) * SMAA_PIXEL_SIZE;
}
texcoord.y -= 0.25 * SMAA_PIXEL_SIZE.y;
texcoord.y -= SMAA_PIXEL_SIZE.y;
texcoord.y -= 2.0 * SMAA_PIXEL_SIZE.y;
texcoord.y += SMAA_PIXEL_SIZE.y * SMAASearchLength(searchTex, e.gr, 0.5, 0.5);
return 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 = float(SMAA_AREATEX_MAX_DISTANCE) * round(4.0 * float2(e1, e2)) + dist;
// We do a scale and bias for mapping to texel space:
texcoord = SMAA_AREATEX_PIXEL_SIZE * texcoord + (0.5 * SMAA_AREATEX_PIXEL_SIZE);
// Move to proper place, according to the subpixel offset:
texcoord.y += SMAA_AREATEX_SUBTEX_SIZE * offset;
// Do it!
#if SMAA_HLSL_3 == 1
return SMAASampleLevelZero(areaTex, texcoord).ra;
#else
return SMAASampleLevelZero(areaTex, texcoord).rg;
#endif
}
//-----------------------------------------------------------------------------
// Corner Detection Functions
void SMAADetectHorizontalCornerPattern(SMAATexture2D edgesTex, inout float2 weights, float2 texcoord, float2 d) {
#if SMAA_CORNER_ROUNDING < 100 || SMAA_FORCE_CORNER_DETECTION == 1
float4 coords = SMAAMad(float4(d.x, 0.0, d.y, 0.0),
SMAA_PIXEL_SIZE.xyxy, texcoord.xyxy);
float2 e;
e.r = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2(0.0, 1.0)).r;
bool left = abs(d.x) < abs(d.y);
e.g = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2(0.0, -2.0)).r;
if (left) weights *= SMAASaturate(float(SMAA_CORNER_ROUNDING) / 100.0 + 1.0 - e);
e.r = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2(1.0, 1.0)).r;
e.g = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2(1.0, -2.0)).r;
if (!left) weights *= SMAASaturate(float(SMAA_CORNER_ROUNDING) / 100.0 + 1.0 - e);
#endif
}
void SMAADetectVerticalCornerPattern(SMAATexture2D edgesTex, inout float2 weights, float2 texcoord, float2 d) {
#if SMAA_CORNER_ROUNDING < 100 || SMAA_FORCE_CORNER_DETECTION == 1
float4 coords = SMAAMad(float4(0.0, d.x, 0.0, d.y),
SMAA_PIXEL_SIZE.xyxy, texcoord.xyxy);
float2 e;
e.r = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2( 1.0, 0.0)).g;
bool left = abs(d.x) < abs(d.y);
e.g = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2(-2.0, 0.0)).g;
if (left) weights *= SMAASaturate(float(SMAA_CORNER_ROUNDING) / 100.0 + 1.0 - e);
e.r = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2( 1.0, 1.0)).g;
e.g = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2(-2.0, 1.0)).g;
if (!left) weights *= SMAASaturate(float(SMAA_CORNER_ROUNDING) / 100.0 + 1.0 - e);
#endif
}
//-----------------------------------------------------------------------------
// Blending Weight Calculation Pixel Shader (Second Pass)
float4 SMAABlendingWeightCalculationPS(float2 texcoord,
float2 pixcoord,
float4 offset[3],
SMAATexture2D edgesTex,
SMAATexture2D areaTex,
SMAATexture2D searchTex,
int4 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 SMAA_MAX_SEARCH_STEPS_DIAG > 0 || SMAA_FORCE_DIAGONAL_DETECTION == 1
// Diagonals have both north and west edges, so searching for them in
// one of the boundaries is enough.
weights.rg = SMAACalculateDiagWeights(edgesTex, areaTex, texcoord, e, subsampleIndices);
// We give priority to diagonals, so if we find a diagonal we skip
// horizontal/vertical processing.
SMAA_BRANCH
if (dot(weights.rg, float2(1.0, 1.0)) == 0.0) {
#endif
float2 d;
// Find the distance to the left:
float2 coords;
coords.x = SMAASearchXLeft(edgesTex, searchTex, offset[0].xy, offset[2].x);
coords.y = offset[1].y; // offset[1].y = texcoord.y - 0.25 * SMAA_PIXEL_SIZE.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).r;
// Find the distance to the right:
coords.x = SMAASearchXRight(edgesTex, searchTex, offset[0].zw, offset[2].y);
d.y = coords.x;
// We want the distances to be in pixel units (doing this here allow to
// better interleave arithmetic and memory accesses):
d = d / SMAA_PIXEL_SIZE.x - pixcoord.x;
// SMAAArea below needs a sqrt, as the areas texture is compressed
// quadratically:
float2 sqrt_d = sqrt(abs(d));
// Fetch the right crossing edges:
float e2 = SMAASampleLevelZeroOffset(edgesTex, coords, int2(1, 0)).r;
// Ok, we know how this pattern looks like, now it is time for getting
// the actual area:
weights.rg = SMAAArea(areaTex, sqrt_d, e1, e2, float(subsampleIndices.y));
// Fix corners:
SMAADetectHorizontalCornerPattern(edgesTex, weights.rg, texcoord, d);
#if SMAA_MAX_SEARCH_STEPS_DIAG > 0 || SMAA_FORCE_DIAGONAL_DETECTION == 1
} 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:
float2 coords;
coords.y = SMAASearchYUp(edgesTex, searchTex, offset[1].xy, offset[2].z);
coords.x = offset[0].x; // offset[1].x = texcoord.x - 0.25 * SMAA_PIXEL_SIZE.x;
d.x = coords.y;
// Fetch the top crossing edges:
float e1 = SMAASampleLevelZero(edgesTex, coords).g;
// Find the distance to the bottom:
coords.y = SMAASearchYDown(edgesTex, searchTex, offset[1].zw, offset[2].w);
d.y = coords.y;
// We want the distances to be in pixel units:
d = d / SMAA_PIXEL_SIZE.y - pixcoord.y;
// SMAAArea below needs a sqrt, as the areas texture is compressed
// quadratically:
float2 sqrt_d = sqrt(abs(d));
// Fetch the bottom crossing edges:
float e2 = SMAASampleLevelZeroOffset(edgesTex, coords, int2(0, 1)).g;
// Get the area for this direction:
weights.ba = SMAAArea(areaTex, sqrt_d, e1, e2, float(subsampleIndices.x));
// Fix corners:
SMAADetectVerticalCornerPattern(edgesTex, weights.ba, texcoord, d);
}
return weights;
}
//-----------------------------------------------------------------------------
// Neighborhood Blending Pixel Shader (Third Pass)
float4 SMAANeighborhoodBlendingPS(float2 texcoord,
float4 offset[2],
SMAATexture2D colorTex,
SMAATexture2D blendTex) {
// Fetch the blending weights for current pixel:
float4 a;
a.xz = SMAASample(blendTex, texcoord).xz;
a.y = SMAASample(blendTex, offset[1].zw).g;
a.w = SMAASample(blendTex, offset[1].xy).a;
// 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)
return SMAASampleLevelZero(colorTex, texcoord);
else {
float4 color = float4(0.0, 0.0, 0.0, 0.0);
// Up to 4 lines can be crossing a pixel (one through each edge). We
// favor blending by choosing the line with the maximum weight for each
// direction:
float2 offset;
offset.x = a.a > a.b? a.a : -a.b; // left vs. right
offset.y = a.g > a.r? a.g : -a.r; // top vs. bottom
// Then we go in the direction that has the maximum weight:
if (abs(offset.x) > abs(offset.y)) // horizontal vs. vertical
offset.y = 0.0;
else
offset.x = 0.0;
#if SMAA_REPROJECTION == 1
// Fetch the opposite color and lerp by hand:
float4 C = SMAASampleLevelZero(colorTex, texcoord);
texcoord += sign(offset) * SMAA_PIXEL_SIZE;
float4 Cop = SMAASampleLevelZero(colorTex, texcoord);
float s = abs(offset.x) > abs(offset.y)? abs(offset.x) : abs(offset.y);
// Unpack the velocity values:
C.a *= C.a;
Cop.a *= Cop.a;
// Lerp the colors:
float4 Caa = SMAALerp(C, Cop, s);
// Unpack velocity and return the resulting value:
Caa.a = sqrt(Caa.a);
return Caa;
#else
#if SMAA_HLSL_4 == 1 || SMAA_DIRECTX9_LINEAR_BLEND == 0
// We exploit bilinear filtering to mix current pixel with the chosen
// neighbor:
texcoord += offset * SMAA_PIXEL_SIZE;
return SMAASampleLevelZero(colorTex, texcoord);
#else
// Fetch the opposite color and lerp by hand:
float4 C = SMAASampleLevelZero(colorTex, texcoord);
texcoord += sign(offset) * SMAA_PIXEL_SIZE;
float4 Cop = SMAASampleLevelZero(colorTex, texcoord);
float s = abs(offset.x) > abs(offset.y)? abs(offset.x) : abs(offset.y);
return SMAALerp(C, Cop, s);
#endif
#endif
}
}
//-----------------------------------------------------------------------------
// Temporal Resolve Pixel Shader (Optional Fourth Pass)
float4 SMAAResolvePS(float2 texcoord,
SMAATexture2D colorTexCurr,
SMAATexture2D colorTexPrev
#if SMAA_REPROJECTION == 1
, SMAATexture2D velocityTex
#endif
) {
#if SMAA_REPROJECTION == 1
// Velocity is calculated from previous to current position, so we need to
// inverse it:
float2 velocity = -SMAASample(velocityTex, texcoord).rg;
// Fetch current pixel:
float4 current = SMAASample(colorTexCurr, texcoord);
// Reproject current coordinates and fetch previous pixel:
float4 previous = SMAASample(colorTexPrev, 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 * SMAASaturate(1.0 - (sqrt(delta) * SMAA_REPROJECTION_WEIGHT_SCALE));
// Blend the pixels according to the calculated weight:
return SMAALerp(current, previous, weight);
#else
// Just blend the pixels:
float4 current = SMAASample(colorTexCurr, texcoord);
float4 previous = SMAASample(colorTexPrev, texcoord);
return SMAALerp(current, previous, 0.5);
#endif
}
//-----------------------------------------------------------------------------
#endif // SMAA_ONLY_COMPILE_VS == 0
