yuzu/src/video_core/host_shaders/opengl_smaa.glsl

1340 lines
52 KiB
GLSL

// SPDX-FileCopyrightText: 2013 Jorge Jimenez (jorge@iryoku.com)
// SPDX-FileCopyrightText: 2013 Jose I. Echevarria (joseignacioechevarria@gmail.com)
// SPDX-FileCopyrightText: 2013 Belen Masia (bmasia@unizar.es)
// SPDX-FileCopyrightText: 2013 Fernando Navarro (fernandn@microsoft.com)
// SPDX-FileCopyrightText: 2013 Diego Gutierrez (diegog@unizar.es)
// SPDX-License-Identifier: MIT
/**
* _______ ___ ___ ___ ___
* / || \/ | / \ / \
* | (---- | \ / | / ^ \ / ^ \
* \ \ | |\/| | / /_\ \ / /_\ \
* ----) | | | | | / _____ \ / _____ \
* |_______/ |__| |__| /__/ \__\ /__/ \__\
*
* 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.
*
* IMPORTANTE NOTICE: when updating, remember to update both this file and the
* precomputed textures! They may change from version to version.
*
* 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. Remember to use
* oversized triangles instead of quads to avoid overshading along the
* diagonal.
*
* 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 render targets for holding
* |edgesTex| and |blendTex|.
*
* In DX10 or DX11, you can use a RG render target for the edges texture.
* In the case of NVIDIA GPUs, using RG render targets seems to actually be
* slower.
*
* On the Xbox 360, you can use the same render target for resolving both
* |edgesTex| and |blendTex|, as they aren't needed simultaneously.
*
* 2. Both temporal render targets |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.
*
* You can also compress 'areaTex' and 'searchTex' using BC5 and BC4
* respectively, if you have that option in your content processor pipeline.
* When compressing then, you get a non-perceptible quality decrease, and a
* marginal performance increase.
*
* 4. All samplers must be set to linear filtering and clamp.
*
* After you get the technique working, remember that 64-bit inputs have
* half-rate linear filtering on GCN.
*
* If SMAA is applied to 64-bit color buffers, switching to point filtering
* when accessing them will increase the performance. Search for
* 'SMAASamplePoint' to see which textures may benefit from point
* filtering, and where (which is basically the color input in the edge
* detection and resolve passes).
*
* 5. All texture reads and buffer writes must be non-sRGB, with the exception
* of the input read and the output write 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 render target metrics,
* the target and any optional configuration defines. Optionally you can
* use a preset.
*
* You have the following targets available:
* SMAA_HLSL_3
* SMAA_HLSL_4
* SMAA_HLSL_4_1
* SMAA_GLSL_3 *
* SMAA_GLSL_4 *
*
* * (See SMAA_INCLUDE_VS and SMAA_INCLUDE_PS 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_RT_METRICS float4(1.0 / 1280.0, 1.0 / 720.0, 1280.0, 720.0)
* #define SMAA_HLSL_4
* #define SMAA_PRESET_HIGH
* #include "SMAA.h"
*
* Note that SMAA_RT_METRICS doesn't need to be a macro, it can be a
* uniform variable. The code is designed to minimize the impact of not
* using a constant value, but it is still better to hardcode it.
*
* Depending on how you encoded 'areaTex' and 'searchTex', you may have to
* add (and customize) the following defines before including SMAA.h:
* #define SMAA_AREATEX_SELECT(sample) sample.rg
* #define SMAA_SEARCHTEX_SELECT(sample) sample.r
*
* If your engine is already using porting macros, you can define
* SMAA_CUSTOM_SL, and define the porting functions by yourself.
*
* 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|.
* You can use a screenshot from your engine to compare the |edgesTex|
* and |blendTex| produced inside of the engine with the results obtained
* with the 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 (SMAA T2x):
*
* 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.
* Check out SMAA_DECODE_VELOCITY if your velocity buffer is encoded.
*
* 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
*
* | S# | Camera Jitter | subsampleIndices |
* +----+------------------+---------------------+
* | 0 | ( 0.25, -0.25) | float4(1, 1, 1, 0) |
* | 1 | (-0.25, 0.25) | float4(2, 2, 2, 0) |
*
* These jitter positions assume a bottom-to-top y axis. S# stands for the
* sample number.
*
* More information about temporal supersampling here:
* http://iryoku.com/aacourse/downloads/13-Anti-Aliasing-Methods-in-CryENGINE-3.pdf
*
* c) If you want to enable spatial multisampling (SMAA S2x):
*
* 1. The scene must be rendered using MSAA 2x. The MSAA 2x buffer must be
* created with:
* - DX10: see below (*)
* - DX10.1: D3D10_STANDARD_MULTISAMPLE_PATTERN or
* - DX11: D3D11_STANDARD_MULTISAMPLE_PATTERN
*
* This allows to ensure that the subsample order matches the table in
* @SUBSAMPLE_INDICES.
*
* (*) In the case of DX10, we refer the reader to:
* - SMAA::detectMSAAOrder and
* - SMAA::msaaReorder
*
* These functions allow to match the standard multisample patterns by
* detecting the subsample order for a specific GPU, and reordering
* them appropriately.
*
* 2. A shader must be run to output each subsample into a separate buffer
* (DX10 is required). You can use SMAASeparate for this purpose, or just do
* it in an existing pass (for example, in the tone mapping pass, which has
* the advantage of feeding tone mapped subsamples to SMAA, which will yield
* better results).
*
* 3. The full SMAA 1x pipeline must be run for each separated buffer, storing
* the results in the final buffer. The second run should alpha blend with
* the existing final buffer using a blending factor of 0.5.
* 'subsampleIndices' must be adjusted as in the SMAA T2x case (see point
* b).
*
* d) If you want to enable temporal supersampling on top of SMAA S2x
* (which actually is SMAA 4x):
*
* 1. SMAA 4x consists on temporally jittering SMAA S2x, so the first step is
* to calculate SMAA S2x for current frame. In this case, 'subsampleIndices'
* must be set as follows:
*
* | F# | S# | Camera Jitter | Net Jitter | subsampleIndices |
* +----+----+--------------------+-------------------+----------------------+
* | 0 | 0 | ( 0.125, 0.125) | ( 0.375, -0.125) | float4(5, 3, 1, 3) |
* | 0 | 1 | ( 0.125, 0.125) | (-0.125, 0.375) | float4(4, 6, 2, 3) |
* +----+----+--------------------+-------------------+----------------------+
* | 1 | 2 | (-0.125, -0.125) | ( 0.125, -0.375) | float4(3, 5, 1, 4) |
* | 1 | 3 | (-0.125, -0.125) | (-0.375, 0.125) | float4(6, 4, 2, 4) |
*
* These jitter positions assume a bottom-to-top y axis. F# stands for the
* frame number. S# stands for the sample number.
*
* 2. After calculating SMAA S2x for current frame (with the new subsample
* indices), previous frame must be reprojected as in SMAA T2x mode (see
* point b).
*
* e) 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
/**
* Note that if you use one of these presets, the following configuration
* macros will be ignored if set in the "Configurable Defines" section.
*/
#if defined(SMAA_PRESET_LOW)
#define SMAA_THRESHOLD 0.15
#define SMAA_MAX_SEARCH_STEPS 4
#define SMAA_DISABLE_DIAG_DETECTION
#define SMAA_DISABLE_CORNER_DETECTION
#elif defined(SMAA_PRESET_MEDIUM)
#define SMAA_THRESHOLD 0.1
#define SMAA_MAX_SEARCH_STEPS 8
#define SMAA_DISABLE_DIAG_DETECTION
#define SMAA_DISABLE_CORNER_DETECTION
#elif defined(SMAA_PRESET_HIGH)
#define SMAA_THRESHOLD 0.1
#define SMAA_MAX_SEARCH_STEPS 16
#define SMAA_MAX_SEARCH_STEPS_DIAG 8
#define SMAA_CORNER_ROUNDING 25
#elif defined(SMAA_PRESET_ULTRA)
#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 0.1
#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, 112]
*/
#ifndef SMAA_MAX_SEARCH_STEPS
#define SMAA_MAX_SEARCH_STEPS 16
#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]
*
* 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.
*
* Define SMAA_DISABLE_DIAG_DETECTION to disable diagonal processing.
*/
#ifndef SMAA_MAX_SEARCH_STEPS_DIAG
#define SMAA_MAX_SEARCH_STEPS_DIAG 8
#endif
/**
* SMAA_CORNER_ROUNDING specifies how much sharp corners will be rounded.
*
* Range: [0, 100]
*
* Define SMAA_DISABLE_CORNER_DETECTION to disable corner processing.
*/
#ifndef SMAA_CORNER_ROUNDING
#define SMAA_CORNER_ROUNDING 25
#endif
/**
* If there is an neighbor edge that has SMAA_LOCAL_CONTRAST_FACTOR times
* bigger contrast than current edge, current edge will be 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
* perceptually contrast in the other neighbors.
*/
#ifndef SMAA_LOCAL_CONTRAST_ADAPTATION_FACTOR
#define SMAA_LOCAL_CONTRAST_ADAPTATION_FACTOR 2.0
#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]
*/
#ifndef SMAA_REPROJECTION_WEIGHT_SCALE
#define SMAA_REPROJECTION_WEIGHT_SCALE 30.0
#endif
/**
* On some compilers, discard cannot be used in vertex shaders. Thus, they need
* to be compiled separately.
*/
#ifndef SMAA_INCLUDE_VS
#define SMAA_INCLUDE_VS 1
#endif
#ifndef SMAA_INCLUDE_PS
#define SMAA_INCLUDE_PS 1
#endif
//-----------------------------------------------------------------------------
// Texture Access Defines
#ifndef SMAA_AREATEX_SELECT
#if defined(SMAA_HLSL_3)
#define SMAA_AREATEX_SELECT(sample) sample.ra
#else
#define SMAA_AREATEX_SELECT(sample) sample.rg
#endif
#endif
#ifndef SMAA_SEARCHTEX_SELECT
#define SMAA_SEARCHTEX_SELECT(sample) sample.r
#endif
#ifndef SMAA_DECODE_VELOCITY
#define SMAA_DECODE_VELOCITY(sample) sample.rg
#endif
//-----------------------------------------------------------------------------
// Non-Configurable Defines
#define SMAA_AREATEX_MAX_DISTANCE 16
#define SMAA_AREATEX_MAX_DISTANCE_DIAG 20
#define SMAA_AREATEX_PIXEL_SIZE (1.0 / float2(160.0, 560.0))
#define SMAA_AREATEX_SUBTEX_SIZE (1.0 / 7.0)
#define SMAA_SEARCHTEX_SIZE float2(66.0, 33.0)
#define SMAA_SEARCHTEX_PACKED_SIZE float2(64.0, 16.0)
#define SMAA_CORNER_ROUNDING_NORM (float(SMAA_CORNER_ROUNDING) / 100.0)
//-----------------------------------------------------------------------------
// Porting Functions
#if defined(SMAA_HLSL_3)
#define SMAATexture2D(tex) sampler2D tex
#define SMAATexturePass2D(tex) tex
#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 SMAASampleLevelZeroOffset(tex, coord, offset) tex2Dlod(tex, float4(coord + offset * SMAA_RT_METRICS.xy, 0.0, 0.0))
#define SMAASample(tex, coord) tex2D(tex, coord)
#define SMAASamplePoint(tex, coord) tex2D(tex, coord)
#define SMAASampleOffset(tex, coord, offset) tex2D(tex, coord + offset * SMAA_RT_METRICS.xy)
#define SMAA_FLATTEN [flatten]
#define SMAA_BRANCH [branch]
#endif
#if defined(SMAA_HLSL_4) || defined(SMAA_HLSL_4_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(tex) Texture2D tex
#define SMAATexturePass2D(tex) tex
#define SMAASampleLevelZero(tex, coord) tex.SampleLevel(LinearSampler, coord, 0)
#define SMAASampleLevelZeroPoint(tex, coord) tex.SampleLevel(PointSampler, coord, 0)
#define SMAASampleLevelZeroOffset(tex, coord, offset) tex.SampleLevel(LinearSampler, coord, 0, offset)
#define SMAASample(tex, coord) tex.Sample(LinearSampler, coord)
#define SMAASamplePoint(tex, coord) tex.Sample(PointSampler, coord)
#define SMAASampleOffset(tex, coord, offset) tex.Sample(LinearSampler, coord, offset)
#define SMAA_FLATTEN [flatten]
#define SMAA_BRANCH [branch]
#define SMAATexture2DMS2(tex) Texture2DMS<float4, 2> tex
#define SMAALoad(tex, pos, sample) tex.Load(pos, sample)
#if defined(SMAA_HLSL_4_1)
#define SMAAGather(tex, coord) tex.Gather(LinearSampler, coord, 0)
#endif
#endif
#if defined(SMAA_GLSL_3) || defined(SMAA_GLSL_4)
#define SMAATexture2D(tex) sampler2D tex
#define SMAATexturePass2D(tex) tex
#define SMAASampleLevelZero(tex, coord) textureLod(tex, coord, 0.0)
#define SMAASampleLevelZeroPoint(tex, coord) textureLod(tex, coord, 0.0)
#define SMAASampleLevelZeroOffset(tex, coord, offset) textureLodOffset(tex, coord, 0.0, offset)
#define SMAASample(tex, coord) texture(tex, coord)
#define SMAASamplePoint(tex, coord) texture(tex, coord)
#define SMAASampleOffset(tex, coord, offset) texture(tex, coord, offset)
#define SMAA_FLATTEN
#define SMAA_BRANCH
#define lerp(a, b, t) mix(a, b, t)
#define saturate(a) clamp(a, 0.0, 1.0)
#if defined(SMAA_GLSL_4)
#define mad(a, b, c) fma(a, b, c)
#define SMAAGather(tex, coord) textureGather(tex, coord)
#else
#define mad(a, b, c) (a * b + c)
#endif
#define float2 vec2
#define float3 vec3
#define float4 vec4
#define int2 ivec2
#define int3 ivec3
#define int4 ivec4
#define bool2 bvec2
#define bool3 bvec3
#define bool4 bvec4
#endif
#if !defined(SMAA_HLSL_3) && !defined(SMAA_HLSL_4) && !defined(SMAA_HLSL_4_1) && !defined(SMAA_GLSL_3) && !defined(SMAA_GLSL_4) && !defined(SMAA_CUSTOM_SL)
#error you must define the shading language: SMAA_HLSL_*, SMAA_GLSL_* or SMAA_CUSTOM_SL
#endif
//-----------------------------------------------------------------------------
// Misc functions
/**
* Gathers current pixel, and the top-left neighbors.
*/
float3 SMAAGatherNeighbours(float2 texcoord,
float4 offset[3],
SMAATexture2D(tex)) {
#ifdef SMAAGather
return SMAAGather(tex, texcoord + SMAA_RT_METRICS.xy * float2(-0.5, -0.5)).grb;
#else
float P = SMAASamplePoint(tex, texcoord).r;
float Pleft = SMAASamplePoint(tex, offset[0].xy).r;
float Ptop = SMAASamplePoint(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(predicationTex)) {
float3 neighbours = SMAAGatherNeighbours(texcoord, offset, SMAATexturePass2D(predicationTex));
float2 delta = abs(neighbours.xx - neighbours.yz);
float2 edges = step(SMAA_PREDICATION_THRESHOLD, delta);
return SMAA_PREDICATION_SCALE * SMAA_THRESHOLD * (1.0 - SMAA_PREDICATION_STRENGTH * edges);
}
/**
* Conditional move:
*/
void SMAAMovc(bool2 cond, inout float2 variable, float2 value) {
SMAA_FLATTEN if (cond.x) variable.x = value.x;
SMAA_FLATTEN if (cond.y) variable.y = value.y;
}
void SMAAMovc(bool4 cond, inout float4 variable, float4 value) {
SMAAMovc(cond.xy, variable.xy, value.xy);
SMAAMovc(cond.zw, variable.zw, value.zw);
}
#if SMAA_INCLUDE_VS
//-----------------------------------------------------------------------------
// Vertex Shaders
/**
* Edge Detection Vertex Shader
*/
void SMAAEdgeDetectionVS(float2 texcoord,
out float4 offset[3]) {
offset[0] = mad(SMAA_RT_METRICS.xyxy, float4(-1.0, 0.0, 0.0, -1.0), texcoord.xyxy);
offset[1] = mad(SMAA_RT_METRICS.xyxy, float4( 1.0, 0.0, 0.0, 1.0), texcoord.xyxy);
offset[2] = mad(SMAA_RT_METRICS.xyxy, float4(-2.0, 0.0, 0.0, -2.0), texcoord.xyxy);
}
/**
* Blend Weight Calculation Vertex Shader
*/
void SMAABlendingWeightCalculationVS(float2 texcoord,
out float2 pixcoord,
out float4 offset[3]) {
pixcoord = texcoord * SMAA_RT_METRICS.zw;
// We will use these offsets for the searches later on (see @PSEUDO_GATHER4):
offset[0] = mad(SMAA_RT_METRICS.xyxy, float4(-0.25, -0.125, 1.25, -0.125), texcoord.xyxy);
offset[1] = mad(SMAA_RT_METRICS.xyxy, float4(-0.125, -0.25, -0.125, 1.25), texcoord.xyxy);
// And these for the searches, they indicate the ends of the loops:
offset[2] = mad(SMAA_RT_METRICS.xxyy,
float4(-2.0, 2.0, -2.0, 2.0) * float(SMAA_MAX_SEARCH_STEPS),
float4(offset[0].xz, offset[1].yw));
}
/**
* Neighborhood Blending Vertex Shader
*/
void SMAANeighborhoodBlendingVS(float2 texcoord,
out float4 offset) {
offset = mad(SMAA_RT_METRICS.xyxy, float4( 1.0, 0.0, 0.0, 1.0), texcoord.xyxy);
}
#endif // SMAA_INCLUDE_VS
#if SMAA_INCLUDE_PS
//-----------------------------------------------------------------------------
// 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
//-----------------------------------------------------------------------------
#endif // SMAA_INCLUDE_PS