SmaaBlend.glsl
   1  #version 430 core 
   2  #define SMAA_GLSL_4 1 
   3  
   4  layout (constant_id = 0) const int SMAA_PRESET_LOW = 0;
   5  layout (constant_id = 1) const int SMAA_PRESET_MEDIUM = 0;
   6  layout (constant_id = 2) const int SMAA_PRESET_HIGH = 0;
   7  layout (constant_id = 3) const int SMAA_PRESET_ULTRA = 0;
   8  layout (constant_id = 4) const float METRIC_WIDTH = 1920.0;
   9  layout (constant_id = 5) const float METRIC_HEIGHT = 1080.0;
  10  
  11  #define SMAA_RT_METRICS float4(1.0 / METRIC_WIDTH, 1.0 / METRIC_HEIGHT, METRIC_WIDTH, METRIC_HEIGHT)
  12  
  13  layout (local_size_x = 16, local_size_y = 16) in;
  14  /**
  15   * Copyright (C) 2013 Jorge Jimenez (jorge@iryoku.com)
  16   * Copyright (C) 2013 Jose I. Echevarria (joseignacioechevarria@gmail.com)
  17   * Copyright (C) 2013 Belen Masia (bmasia@unizar.es)
  18   * Copyright (C) 2013 Fernando Navarro (fernandn@microsoft.com)
  19   * Copyright (C) 2013 Diego Gutierrez (diegog@unizar.es)
  20   *
  21   * Permission is hereby granted, free of charge, to any person obtaining a copy
  22   * this software and associated documentation files (the "Software"), to deal in
  23   * the Software without restriction, including without limitation the rights to
  24   * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
  25   * of the Software, and to permit persons to whom the Software is furnished to
  26   * do so, subject to the following conditions:
  27   *
  28   * The above copyright notice and this permission notice shall be included in
  29   * all copies or substantial portions of the Software. As clarification, there
  30   * is no requirement that the copyright notice and permission be included in
  31   * binary distributions of the Software.
  32   *
  33   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  34   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  35   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  36   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  37   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  38   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  39   * SOFTWARE.
  40   */
  41  
  42  
  43  /**
  44   *                  _______  ___  ___       ___           ___
  45   *                 /       ||   \/   |     /   \         /   \
  46   *                |   (---- |  \  /  |    /  ^  \       /  ^  \
  47   *                 \   \    |  |\/|  |   /  /_\  \     /  /_\  \
  48   *              ----)   |   |  |  |  |  /  _____  \   /  _____  \
  49   *             |_______/    |__|  |__| /__/     \__\ /__/     \__\
  50   * 
  51   *                               E N H A N C E D
  52   *       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
  53   *
  54   *                         http://www.iryoku.com/smaa/
  55   *
  56   * Hi, welcome aboard!
  57   * 
  58   * Here you'll find instructions to get the shader up and running as fast as
  59   * possible.
  60   *
  61   * IMPORTANTE NOTICE: when updating, remember to update both this file and the
  62   * precomputed textures! They may change from version to version.
  63   *
  64   * The shader has three passes, chained together as follows:
  65   *
  66   *                           |input|------------------ 
  67   *                              v                     |
  68   *                    [ SMAA*EdgeDetection ]          |
  69   *                              v                     |
  70   *                          |edgesTex|                |
  71   *                              v                     |
  72   *              [ SMAABlendingWeightCalculation ]     |
  73   *                              v                     |
  74   *                          |blendTex|                |
  75   *                              v                     |
  76   *                [ SMAANeighborhoodBlending ] <------ 
  77   *                              v
  78   *                           |output|
  79   *
  80   * Note that each [pass] has its own vertex and pixel shader. Remember to use
  81   * oversized triangles instead of quads to avoid overshading along the
  82   * diagonal.
  83   *
  84   * You've three edge detection methods to choose from: luma, color or depth.
  85   * They represent different quality/performance and anti-aliasing/sharpness
  86   * tradeoffs, so our recommendation is for you to choose the one that best
  87   * suits your particular scenario:
  88   *
  89   * - Depth edge detection is usually the fastest but it may miss some edges.
  90   *
  91   * - Luma edge detection is usually more expensive than depth edge detection,
  92   *   but catches visible edges that depth edge detection can miss.
  93   *
  94   * - Color edge detection is usually the most expensive one but catches
  95   *   chroma-only edges.
  96   *
  97   * For quickstarters: just use luma edge detection.
  98   *
  99   * The general advice is to not rush the integration process and ensure each
 100   * step is done correctly (don't try to integrate SMAA T2x with predicated edge
 101   * detection from the start!). Ok then, let's go!
 102   *
 103   *  1. The first step is to create two RGBA temporal render targets for holding
 104   *     |edgesTex| and |blendTex|.
 105   *
 106   *     In DX10 or DX11, you can use a RG render target for the edges texture.
 107   *     In the case of NVIDIA GPUs, using RG render targets seems to actually be
 108   *     slower.
 109   *
 110   *     On the Xbox 360, you can use the same render target for resolving both
 111   *     |edgesTex| and |blendTex|, as they aren't needed simultaneously.
 112   *
 113   *  2. Both temporal render targets |edgesTex| and |blendTex| must be cleared
 114   *     each frame. Do not forget to clear the alpha channel!
 115   *
 116   *  3. The next step is loading the two supporting precalculated textures,
 117   *     'areaTex' and 'searchTex'. You'll find them in the 'Textures' folder as
 118   *     C++ headers, and also as regular DDS files. They'll be needed for the
 119   *     'SMAABlendingWeightCalculation' pass.
 120   *
 121   *     If you use the C++ headers, be sure to load them in the format specified
 122   *     inside of them.
 123   *
 124   *     You can also compress 'areaTex' and 'searchTex' using BC5 and BC4
 125   *     respectively, if you have that option in your content processor pipeline.
 126   *     When compressing then, you get a non-perceptible quality decrease, and a
 127   *     marginal performance increase.
 128   *
 129   *  4. All samplers must be set to linear filtering and clamp.
 130   *
 131   *     After you get the technique working, remember that 64-bit inputs have
 132   *     half-rate linear filtering on GCN.
 133   *
 134   *     If SMAA is applied to 64-bit color buffers, switching to point filtering
 135   *     when accesing them will increase the performance. Search for
 136   *     'SMAASamplePoint' to see which textures may benefit from point
 137   *     filtering, and where (which is basically the color input in the edge
 138   *     detection and resolve passes).
 139   *
 140   *  5. All texture reads and buffer writes must be non-sRGB, with the exception
 141   *     of the input read and the output write in
 142   *     'SMAANeighborhoodBlending' (and only in this pass!). If sRGB reads in
 143   *     this last pass are not possible, the technique will work anyway, but
 144   *     will perform antialiasing in gamma space.
 145   *
 146   *     IMPORTANT: for best results the input read for the color/luma edge 
 147   *     detection should *NOT* be sRGB.
 148   *
 149   *  6. Before including SMAA.h you'll have to setup the render target metrics,
 150   *     the target and any optional configuration defines. Optionally you can
 151   *     use a preset.
 152   *
 153   *     You have the following targets available: 
 154   *         SMAA_HLSL_3
 155   *         SMAA_HLSL_4
 156   *         SMAA_HLSL_4_1
 157   *         SMAA_GLSL_3 *
 158   *         SMAA_GLSL_4 *
 159   *
 160   *         * (See SMAA_INCLUDE_VS and SMAA_INCLUDE_PS below).
 161   *
 162   *     And four presets:
 163   *         SMAA_PRESET_LOW          (%60 of the quality)
 164   *         SMAA_PRESET_MEDIUM       (%80 of the quality)
 165   *         SMAA_PRESET_HIGH         (%95 of the quality)
 166   *         SMAA_PRESET_ULTRA        (%99 of the quality)
 167   *
 168   *     For example:
 169   *         #define SMAA_RT_METRICS float4(1.0 / 1280.0, 1.0 / 720.0, 1280.0, 720.0)
 170   *         #define SMAA_HLSL_4
 171   *         #define SMAA_PRESET_HIGH
 172   *         #include "SMAA.h"
 173   *
 174   *     Note that SMAA_RT_METRICS doesn't need to be a macro, it can be a
 175   *     uniform variable. The code is designed to minimize the impact of not
 176   *     using a constant value, but it is still better to hardcode it.
 177   *
 178   *     Depending on how you encoded 'areaTex' and 'searchTex', you may have to
 179   *     add (and customize) the following defines before including SMAA.h:
 180   *          #define SMAA_AREATEX_SELECT(sample) sample.rg
 181   *          #define SMAA_SEARCHTEX_SELECT(sample) sample.r
 182   *
 183   *     If your engine is already using porting macros, you can define
 184   *     SMAA_CUSTOM_SL, and define the porting functions by yourself.
 185   *
 186   *  7. Then, you'll have to setup the passes as indicated in the scheme above.
 187   *     You can take a look into SMAA.fx, to see how we did it for our demo.
 188   *     Checkout the function wrappers, you may want to copy-paste them!
 189   *
 190   *  8. It's recommended to validate the produced |edgesTex| and |blendTex|.
 191   *     You can use a screenshot from your engine to compare the |edgesTex|
 192   *     and |blendTex| produced inside of the engine with the results obtained
 193   *     with the reference demo.
 194   *
 195   *  9. After you get the last pass to work, it's time to optimize. You'll have
 196   *     to initialize a stencil buffer in the first pass (discard is already in
 197   *     the code), then mask execution by using it the second pass. The last
 198   *     pass should be executed in all pixels.
 199   *
 200   *
 201   * After this point you can choose to enable predicated thresholding,
 202   * temporal supersampling and motion blur integration:
 203   *
 204   * a) If you want to use predicated thresholding, take a look into
 205   *    SMAA_PREDICATION; you'll need to pass an extra texture in the edge
 206   *    detection pass.
 207   *
 208   * b) If you want to enable temporal supersampling (SMAA T2x):
 209   *
 210   * 1. The first step is to render using subpixel jitters. I won't go into
 211   *    detail, but it's as simple as moving each vertex position in the
 212   *    vertex shader, you can check how we do it in our DX10 demo.
 213   *
 214   * 2. Then, you must setup the temporal resolve. You may want to take a look
 215   *    into SMAAResolve for resolving 2x modes. After you get it working, you'll
 216   *    probably see ghosting everywhere. But fear not, you can enable the
 217   *    CryENGINE temporal reprojection by setting the SMAA_REPROJECTION macro.
 218   *    Check out SMAA_DECODE_VELOCITY if your velocity buffer is encoded.
 219   *
 220   * 3. The next step is to apply SMAA to each subpixel jittered frame, just as
 221   *    done for 1x.
 222   *
 223   * 4. At this point you should already have something usable, but for best
 224   *    results the proper area textures must be set depending on current jitter.
 225   *    For this, the parameter 'subsampleIndices' of
 226   *    'SMAABlendingWeightCalculationPS' must be set as follows, for our T2x
 227   *    mode:
 228   *
 229   *    @SUBSAMPLE_INDICES
 230   *
 231   *    | S# |  Camera Jitter   |  subsampleIndices    |
 232   *    +----+------------------+---------------------+
 233   *    |  0 |  ( 0.25, -0.25)  |  float4(1, 1, 1, 0)  |
 234   *    |  1 |  (-0.25,  0.25)  |  float4(2, 2, 2, 0)  |
 235   *
 236   *    These jitter positions assume a bottom-to-top y axis. S# stands for the
 237   *    sample number.
 238   *
 239   * More information about temporal supersampling here:
 240   *    http://iryoku.com/aacourse/downloads/13-Anti-Aliasing-Methods-in-CryENGINE-3.pdf
 241   *
 242   * c) If you want to enable spatial multisampling (SMAA S2x):
 243   *
 244   * 1. The scene must be rendered using MSAA 2x. The MSAA 2x buffer must be
 245   *    created with:
 246   *      - DX10:     see below (*)
 247   *      - DX10.1:   D3D10_STANDARD_MULTISAMPLE_PATTERN or
 248   *      - DX11:     D3D11_STANDARD_MULTISAMPLE_PATTERN
 249   *
 250   *    This allows to ensure that the subsample order matches the table in
 251   *    @SUBSAMPLE_INDICES.
 252   *
 253   *    (*) In the case of DX10, we refer the reader to:
 254   *      - SMAA::detectMSAAOrder and
 255   *      - SMAA::msaaReorder
 256   *
 257   *    These functions allow to match the standard multisample patterns by
 258   *    detecting the subsample order for a specific GPU, and reordering
 259   *    them appropriately.
 260   *
 261   * 2. A shader must be run to output each subsample into a separate buffer
 262   *    (DX10 is required). You can use SMAASeparate for this purpose, or just do
 263   *    it in an existing pass (for example, in the tone mapping pass, which has
 264   *    the advantage of feeding tone mapped subsamples to SMAA, which will yield
 265   *    better results).
 266   *
 267   * 3. The full SMAA 1x pipeline must be run for each separated buffer, storing
 268   *    the results in the final buffer. The second run should alpha blend with
 269   *    the existing final buffer using a blending factor of 0.5.
 270   *    'subsampleIndices' must be adjusted as in the SMAA T2x case (see point
 271   *    b).
 272   *
 273   * d) If you want to enable temporal supersampling on top of SMAA S2x
 274   *    (which actually is SMAA 4x):
 275   *
 276   * 1. SMAA 4x consists on temporally jittering SMAA S2x, so the first step is
 277   *    to calculate SMAA S2x for current frame. In this case, 'subsampleIndices'
 278   *    must be set as follows:
 279   *
 280   *    | F# | S# |   Camera Jitter    |    Net Jitter     |   subsampleIndices   |
 281   *    +----+----+--------------------+-------------------+----------------------+
 282   *    |  0 |  0 |  ( 0.125,  0.125)  |  ( 0.375, -0.125) |  float4(5, 3, 1, 3)  |
 283   *    |  0 |  1 |  ( 0.125,  0.125)  |  (-0.125,  0.375) |  float4(4, 6, 2, 3)  |
 284   *    +----+----+--------------------+-------------------+----------------------+
 285   *    |  1 |  2 |  (-0.125, -0.125)  |  ( 0.125, -0.375) |  float4(3, 5, 1, 4)  |
 286   *    |  1 |  3 |  (-0.125, -0.125)  |  (-0.375,  0.125) |  float4(6, 4, 2, 4)  |
 287   *
 288   *    These jitter positions assume a bottom-to-top y axis. F# stands for the
 289   *    frame number. S# stands for the sample number.
 290   *
 291   * 2. After calculating SMAA S2x for current frame (with the new subsample
 292   *    indices), previous frame must be reprojected as in SMAA T2x mode (see
 293   *    point b).
 294   *
 295   * e) If motion blur is used, you may want to do the edge detection pass
 296   *    together with motion blur. This has two advantages:
 297   *
 298   * 1. Pixels under heavy motion can be omitted from the edge detection process.
 299   *    For these pixels we can just store "no edge", as motion blur will take
 300   *    care of them.
 301   * 2. The center pixel tap is reused.
 302   *
 303   * Note that in this case depth testing should be used instead of stenciling,
 304   * as we have to write all the pixels in the motion blur pass.
 305   *
 306   * That's it!
 307   */
 308  
 309  //-----------------------------------------------------------------------------
 310  // SMAA Presets
 311  
 312  /**
 313   * Note that if you use one of these presets, the following configuration
 314   * macros will be ignored if set in the "Configurable Defines" section.
 315   */
 316  
 317  #if defined(SMAA_PRESET_LOW)
 318  #define SMAA_THRESHOLD 0.15
 319  #define SMAA_MAX_SEARCH_STEPS 4
 320  #define SMAA_DISABLE_DIAG_DETECTION
 321  #define SMAA_DISABLE_CORNER_DETECTION
 322  #elif defined(SMAA_PRESET_MEDIUM)
 323  #define SMAA_THRESHOLD 0.1
 324  #define SMAA_MAX_SEARCH_STEPS 8
 325  #define SMAA_DISABLE_DIAG_DETECTION
 326  #define SMAA_DISABLE_CORNER_DETECTION
 327  #elif defined(SMAA_PRESET_HIGH)
 328  #define SMAA_THRESHOLD 0.1
 329  #define SMAA_MAX_SEARCH_STEPS 16
 330  #define SMAA_MAX_SEARCH_STEPS_DIAG 8
 331  #define SMAA_CORNER_ROUNDING 25
 332  #elif defined(SMAA_PRESET_ULTRA)
 333  #define SMAA_THRESHOLD 0.05
 334  #define SMAA_MAX_SEARCH_STEPS 32
 335  #define SMAA_MAX_SEARCH_STEPS_DIAG 16
 336  #define SMAA_CORNER_ROUNDING 25
 337  #endif
 338  
 339  //-----------------------------------------------------------------------------
 340  // Configurable Defines
 341  
 342  /**
 343   * SMAA_THRESHOLD specifies the threshold or sensitivity to edges.
 344   * Lowering this value you will be able to detect more edges at the expense of
 345   * performance. 
 346   *
 347   * Range: [0, 0.5]
 348   *   0.1 is a reasonable value, and allows to catch most visible edges.
 349   *   0.05 is a rather overkill value, that allows to catch 'em all.
 350   *
 351   *   If temporal supersampling is used, 0.2 could be a reasonable value, as low
 352   *   contrast edges are properly filtered by just 2x.
 353   */
 354  #ifndef SMAA_THRESHOLD
 355  #define SMAA_THRESHOLD 0.1
 356  #endif
 357  
 358  /**
 359   * SMAA_DEPTH_THRESHOLD specifies the threshold for depth edge detection.
 360   * 
 361   * Range: depends on the depth range of the scene.
 362   */
 363  #ifndef SMAA_DEPTH_THRESHOLD
 364  #define SMAA_DEPTH_THRESHOLD (0.1 * SMAA_THRESHOLD)
 365  #endif
 366  
 367  /**
 368   * SMAA_MAX_SEARCH_STEPS specifies the maximum steps performed in the
 369   * horizontal/vertical pattern searches, at each side of the pixel.
 370   *
 371   * In number of pixels, it's actually the double. So the maximum line length
 372   * perfectly handled by, for example 16, is 64 (by perfectly, we meant that
 373   * longer lines won't look as good, but still antialiased).
 374   *
 375   * Range: [0, 112]
 376   */
 377  #ifndef SMAA_MAX_SEARCH_STEPS
 378  #define SMAA_MAX_SEARCH_STEPS 16
 379  #endif
 380  
 381  /**
 382   * SMAA_MAX_SEARCH_STEPS_DIAG specifies the maximum steps performed in the
 383   * diagonal pattern searches, at each side of the pixel. In this case we jump
 384   * one pixel at time, instead of two.
 385   *
 386   * Range: [0, 20]
 387   *
 388   * On high-end machines it is cheap (between a 0.8x and 0.9x slower for 16 
 389   * steps), but it can have a significant impact on older machines.
 390   *
 391   * Define SMAA_DISABLE_DIAG_DETECTION to disable diagonal processing.
 392   */
 393  #ifndef SMAA_MAX_SEARCH_STEPS_DIAG
 394  #define SMAA_MAX_SEARCH_STEPS_DIAG 8
 395  #endif
 396  
 397  /**
 398   * SMAA_CORNER_ROUNDING specifies how much sharp corners will be rounded.
 399   *
 400   * Range: [0, 100]
 401   *
 402   * Define SMAA_DISABLE_CORNER_DETECTION to disable corner processing.
 403   */
 404  #ifndef SMAA_CORNER_ROUNDING
 405  #define SMAA_CORNER_ROUNDING 25
 406  #endif
 407  
 408  /**
 409   * If there is an neighbor edge that has SMAA_LOCAL_CONTRAST_FACTOR times
 410   * bigger contrast than current edge, current edge will be discarded.
 411   *
 412   * This allows to eliminate spurious crossing edges, and is based on the fact
 413   * that, if there is too much contrast in a direction, that will hide
 414   * perceptually contrast in the other neighbors.
 415   */
 416  #ifndef SMAA_LOCAL_CONTRAST_ADAPTATION_FACTOR
 417  #define SMAA_LOCAL_CONTRAST_ADAPTATION_FACTOR 2.0
 418  #endif
 419  
 420  /**
 421   * Predicated thresholding allows to better preserve texture details and to
 422   * improve performance, by decreasing the number of detected edges using an
 423   * additional buffer like the light accumulation buffer, object ids or even the
 424   * depth buffer (the depth buffer usage may be limited to indoor or short range
 425   * scenes).
 426   *
 427   * It locally decreases the luma or color threshold if an edge is found in an
 428   * additional buffer (so the global threshold can be higher).
 429   *
 430   * This method was developed by Playstation EDGE MLAA team, and used in 
 431   * Killzone 3, by using the light accumulation buffer. More information here:
 432   *     http://iryoku.com/aacourse/downloads/06-MLAA-on-PS3.pptx 
 433   */
 434  #ifndef SMAA_PREDICATION
 435  #define SMAA_PREDICATION 0
 436  #endif
 437  
 438  /**
 439   * Threshold to be used in the additional predication buffer. 
 440   *
 441   * Range: depends on the input, so you'll have to find the magic number that
 442   * works for you.
 443   */
 444  #ifndef SMAA_PREDICATION_THRESHOLD
 445  #define SMAA_PREDICATION_THRESHOLD 0.01
 446  #endif
 447  
 448  /**
 449   * How much to scale the global threshold used for luma or color edge
 450   * detection when using predication.
 451   *
 452   * Range: [1, 5]
 453   */
 454  #ifndef SMAA_PREDICATION_SCALE
 455  #define SMAA_PREDICATION_SCALE 2.0
 456  #endif
 457  
 458  /**
 459   * How much to locally decrease the threshold.
 460   *
 461   * Range: [0, 1]
 462   */
 463  #ifndef SMAA_PREDICATION_STRENGTH
 464  #define SMAA_PREDICATION_STRENGTH 0.4
 465  #endif
 466  
 467  /**
 468   * Temporal reprojection allows to remove ghosting artifacts when using
 469   * temporal supersampling. We use the CryEngine 3 method which also introduces
 470   * velocity weighting. This feature is of extreme importance for totally
 471   * removing ghosting. More information here:
 472   *    http://iryoku.com/aacourse/downloads/13-Anti-Aliasing-Methods-in-CryENGINE-3.pdf
 473   *
 474   * Note that you'll need to setup a velocity buffer for enabling reprojection.
 475   * For static geometry, saving the previous depth buffer is a viable
 476   * alternative.
 477   */
 478  #ifndef SMAA_REPROJECTION
 479  #define SMAA_REPROJECTION 0
 480  #endif
 481  
 482  /**
 483   * SMAA_REPROJECTION_WEIGHT_SCALE controls the velocity weighting. It allows to
 484   * remove ghosting trails behind the moving object, which are not removed by
 485   * just using reprojection. Using low values will exhibit ghosting, while using
 486   * high values will disable temporal supersampling under motion.
 487   *
 488   * Behind the scenes, velocity weighting removes temporal supersampling when
 489   * the velocity of the subsamples differs (meaning they are different objects).
 490   *
 491   * Range: [0, 80]
 492   */
 493  #ifndef SMAA_REPROJECTION_WEIGHT_SCALE
 494  #define SMAA_REPROJECTION_WEIGHT_SCALE 30.0
 495  #endif
 496  
 497  /**
 498   * On some compilers, discard cannot be used in vertex shaders. Thus, they need
 499   * to be compiled separately.
 500   */
 501  #ifndef SMAA_INCLUDE_VS
 502  #define SMAA_INCLUDE_VS 1
 503  #endif
 504  #ifndef SMAA_INCLUDE_PS
 505  #define SMAA_INCLUDE_PS 1
 506  #endif
 507  
 508  //-----------------------------------------------------------------------------
 509  // Texture Access Defines
 510  
 511  #ifndef SMAA_AREATEX_SELECT
 512  #if defined(SMAA_HLSL_3)
 513  #define SMAA_AREATEX_SELECT(sample) sample.ra
 514  #else
 515  #define SMAA_AREATEX_SELECT(sample) sample.rg
 516  #endif
 517  #endif
 518  
 519  #ifndef SMAA_SEARCHTEX_SELECT
 520  #define SMAA_SEARCHTEX_SELECT(sample) sample.r
 521  #endif
 522  
 523  #ifndef SMAA_DECODE_VELOCITY
 524  #define SMAA_DECODE_VELOCITY(sample) sample.rg
 525  #endif
 526  
 527  //-----------------------------------------------------------------------------
 528  // Non-Configurable Defines
 529  
 530  #define SMAA_AREATEX_MAX_DISTANCE 16
 531  #define SMAA_AREATEX_MAX_DISTANCE_DIAG 20
 532  #define SMAA_AREATEX_PIXEL_SIZE (1.0 / float2(160.0, 560.0))
 533  #define SMAA_AREATEX_SUBTEX_SIZE (1.0 / 7.0)
 534  #define SMAA_SEARCHTEX_SIZE float2(66.0, 33.0)
 535  #define SMAA_SEARCHTEX_PACKED_SIZE float2(64.0, 16.0)
 536  #define SMAA_CORNER_ROUNDING_NORM (float(SMAA_CORNER_ROUNDING) / 100.0)
 537  
 538  //-----------------------------------------------------------------------------
 539  // Porting Functions
 540  
 541  #if defined(SMAA_HLSL_3)
 542  #define SMAATexture2D(tex) sampler2D tex
 543  #define SMAATexturePass2D(tex) tex
 544  #define SMAASampleLevelZero(tex, coord) tex2Dlod(tex, float4(coord, 0.0, 0.0))
 545  #define SMAASampleLevelZeroPoint(tex, coord) tex2Dlod(tex, float4(coord, 0.0, 0.0))
 546  #define SMAASampleLevelZeroOffset(tex, coord, offset) tex2Dlod(tex, float4(coord + offset * SMAA_RT_METRICS.xy, 0.0, 0.0))
 547  #define SMAASample(tex, coord) tex2D(tex, coord)
 548  #define SMAASamplePoint(tex, coord) tex2D(tex, coord)
 549  #define SMAASampleOffset(tex, coord, offset) tex2D(tex, coord + offset * SMAA_RT_METRICS.xy)
 550  #define SMAA_FLATTEN [flatten]
 551  #define SMAA_BRANCH [branch]
 552  #endif
 553  #if defined(SMAA_HLSL_4) || defined(SMAA_HLSL_4_1)
 554  SamplerState LinearSampler { Filter = MIN_MAG_LINEAR_MIP_POINT; AddressU = Clamp; AddressV = Clamp; };
 555  SamplerState PointSampler { Filter = MIN_MAG_MIP_POINT; AddressU = Clamp; AddressV = Clamp; };
 556  #define SMAATexture2D(tex) Texture2D tex
 557  #define SMAATexturePass2D(tex) tex
 558  #define SMAASampleLevelZero(tex, coord) tex.SampleLevel(LinearSampler, coord, 0)
 559  #define SMAASampleLevelZeroPoint(tex, coord) tex.SampleLevel(PointSampler, coord, 0)
 560  #define SMAASampleLevelZeroOffset(tex, coord, offset) tex.SampleLevel(LinearSampler, coord, 0, offset)
 561  #define SMAASample(tex, coord) tex.Sample(LinearSampler, coord)
 562  #define SMAASamplePoint(tex, coord) tex.Sample(PointSampler, coord)
 563  #define SMAASampleOffset(tex, coord, offset) tex.Sample(LinearSampler, coord, offset)
 564  #define SMAA_FLATTEN [flatten]
 565  #define SMAA_BRANCH [branch]
 566  #define SMAATexture2DMS2(tex) Texture2DMS<float4, 2> tex
 567  #define SMAALoad(tex, pos, sample) tex.Load(pos, sample)
 568  #if defined(SMAA_HLSL_4_1)
 569  #define SMAAGather(tex, coord) tex.Gather(LinearSampler, coord, 0)
 570  #endif
 571  #endif
 572  #if defined(SMAA_GLSL_3) || defined(SMAA_GLSL_4)
 573  #define SMAATexture2D(tex) sampler2D tex
 574  #define SMAATexturePass2D(tex) tex
 575  #define SMAASampleLevelZero(tex, coord) textureLod(tex, coord, 0.0)
 576  #define SMAASampleLevelZeroPoint(tex, coord) textureLod(tex, coord, 0.0)
 577  #define SMAASampleLevelZeroOffset(tex, coord, offset) textureLodOffset(tex, coord, 0.0, offset)
 578  #define SMAASample(tex, coord) texture(tex, coord)
 579  #define SMAASamplePoint(tex, coord) texture(tex, coord)
 580  #define SMAASampleOffset(tex, coord, offset) texture(tex, coord, offset)
 581  #define SMAA_FLATTEN
 582  #define SMAA_BRANCH
 583  #define lerp(a, b, t) mix(a, b, t)
 584  #define saturate(a) clamp(a, 0.0, 1.0)
 585  #if defined(SMAA_GLSL_4)
 586  #define mad(a, b, c) fma(a, b, c)
 587  #define SMAAGather(tex, coord) textureGather(tex, coord)
 588  #else
 589  #define mad(a, b, c) (a * b + c)
 590  #endif
 591  #define float2 vec2
 592  #define float3 vec3
 593  #define float4 vec4
 594  #define int2 ivec2
 595  #define int3 ivec3
 596  #define int4 ivec4
 597  #define bool2 bvec2
 598  #define bool3 bvec3
 599  #define bool4 bvec4
 600  #endif
 601  
 602  #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)
 603  #error you must define the shading language: SMAA_HLSL_*, SMAA_GLSL_* or SMAA_CUSTOM_SL
 604  #endif
 605  
 606  //-----------------------------------------------------------------------------
 607  // Misc functions
 608  
 609  /**
 610   * Gathers current pixel, and the top-left neighbors.
 611   */
 612  float3 SMAAGatherNeighbours(float2 texcoord,
 613                              float4 offset[3],
 614                              SMAATexture2D(tex)) {
 615      #ifdef SMAAGather
 616      return SMAAGather(tex, texcoord + SMAA_RT_METRICS.xy * float2(-0.5, -0.5)).grb;
 617      #else
 618      float P = SMAASamplePoint(tex, texcoord).r;
 619      float Pleft = SMAASamplePoint(tex, offset[0].xy).r;
 620      float Ptop  = SMAASamplePoint(tex, offset[0].zw).r;
 621      return float3(P, Pleft, Ptop);
 622      #endif
 623  }
 624  
 625  /**
 626   * Adjusts the threshold by means of predication.
 627   */
 628  float2 SMAACalculatePredicatedThreshold(float2 texcoord,
 629                                          float4 offset[3],
 630                                          SMAATexture2D(predicationTex)) {
 631      float3 neighbours = SMAAGatherNeighbours(texcoord, offset, SMAATexturePass2D(predicationTex));
 632      float2 delta = abs(neighbours.xx - neighbours.yz);
 633      float2 edges = step(SMAA_PREDICATION_THRESHOLD, delta);
 634      return SMAA_PREDICATION_SCALE * SMAA_THRESHOLD * (1.0 - SMAA_PREDICATION_STRENGTH * edges);
 635  }
 636  
 637  /**
 638   * Conditional move:
 639   */
 640  void SMAAMovc(bool2 cond, inout float2 variable, float2 value) {
 641      SMAA_FLATTEN if (cond.x) variable.x = value.x;
 642      SMAA_FLATTEN if (cond.y) variable.y = value.y;
 643  }
 644  
 645  void SMAAMovc(bool4 cond, inout float4 variable, float4 value) {
 646      SMAAMovc(cond.xy, variable.xy, value.xy);
 647      SMAAMovc(cond.zw, variable.zw, value.zw);
 648  }
 649  
 650  
 651  #if SMAA_INCLUDE_VS
 652  //-----------------------------------------------------------------------------
 653  // Vertex Shaders
 654  
 655  /**
 656   * Edge Detection Vertex Shader
 657   */
 658  void SMAAEdgeDetectionVS(float2 texcoord,
 659                           out float4 offset[3]) {
 660      offset[0] = mad(SMAA_RT_METRICS.xyxy, float4(-1.0, 0.0, 0.0, -1.0), texcoord.xyxy);
 661      offset[1] = mad(SMAA_RT_METRICS.xyxy, float4( 1.0, 0.0, 0.0,  1.0), texcoord.xyxy);
 662      offset[2] = mad(SMAA_RT_METRICS.xyxy, float4(-2.0, 0.0, 0.0, -2.0), texcoord.xyxy);
 663  }
 664  
 665  /**
 666   * Blend Weight Calculation Vertex Shader
 667   */
 668  void SMAABlendingWeightCalculationVS(float2 texcoord,
 669                                       out float2 pixcoord,
 670                                       out float4 offset[3]) {
 671      pixcoord = texcoord * SMAA_RT_METRICS.zw;
 672  
 673      // We will use these offsets for the searches later on (see @PSEUDO_GATHER4):
 674      offset[0] = mad(SMAA_RT_METRICS.xyxy, float4(-0.25, -0.125,  1.25, -0.125), texcoord.xyxy);
 675      offset[1] = mad(SMAA_RT_METRICS.xyxy, float4(-0.125, -0.25, -0.125,  1.25), texcoord.xyxy);
 676  
 677      // And these for the searches, they indicate the ends of the loops:
 678      offset[2] = mad(SMAA_RT_METRICS.xxyy,
 679                      float4(-2.0, 2.0, -2.0, 2.0) * float(SMAA_MAX_SEARCH_STEPS),
 680                      float4(offset[0].xz, offset[1].yw));
 681  }
 682  
 683  /**
 684   * Neighborhood Blending Vertex Shader
 685   */
 686  void SMAANeighborhoodBlendingVS(float2 texcoord,
 687                                  out float4 offset) {
 688      offset = mad(SMAA_RT_METRICS.xyxy, float4( 1.0, 0.0, 0.0,  1.0), texcoord.xyxy);
 689  }
 690  #endif // SMAA_INCLUDE_VS
 691  
 692  #if SMAA_INCLUDE_PS
 693  //-----------------------------------------------------------------------------
 694  // Edge Detection Pixel Shaders (First Pass)
 695  
 696  /**
 697   * Luma Edge Detection
 698   *
 699   * IMPORTANT NOTICE: luma edge detection requires gamma-corrected colors, and
 700   * thus 'colorTex' should be a non-sRGB texture.
 701   */
 702  float2 SMAALumaEdgeDetectionPS(float2 texcoord,
 703                                 float4 offset[3],
 704                                 SMAATexture2D(colorTex)
 705                                 #if SMAA_PREDICATION
 706                                 , SMAATexture2D(predicationTex)
 707                                 #endif
 708                                 ) {
 709      // Calculate the threshold:
 710      #if SMAA_PREDICATION
 711      float2 threshold = SMAACalculatePredicatedThreshold(texcoord, offset, SMAATexturePass2D(predicationTex));
 712      #else
 713      float2 threshold = float2(SMAA_THRESHOLD, SMAA_THRESHOLD);
 714      #endif
 715  
 716      // Calculate lumas:
 717      float3 weights = float3(0.2126, 0.7152, 0.0722);
 718      float L = dot(SMAASamplePoint(colorTex, texcoord).rgb, weights);
 719  
 720      float Lleft = dot(SMAASamplePoint(colorTex, offset[0].xy).rgb, weights);
 721      float Ltop  = dot(SMAASamplePoint(colorTex, offset[0].zw).rgb, weights);
 722  
 723      // We do the usual threshold:
 724      float4 delta;
 725      delta.xy = abs(L - float2(Lleft, Ltop));
 726      float2 edges = step(threshold, delta.xy);
 727  
 728      // Then discard if there is no edge:
 729      if (dot(edges, float2(1.0, 1.0)) == 0.0)
 730          return float2(-2.0, -2.0);
 731  
 732      // Calculate right and bottom deltas:
 733      float Lright = dot(SMAASamplePoint(colorTex, offset[1].xy).rgb, weights);
 734      float Lbottom  = dot(SMAASamplePoint(colorTex, offset[1].zw).rgb, weights);
 735      delta.zw = abs(L - float2(Lright, Lbottom));
 736  
 737      // Calculate the maximum delta in the direct neighborhood:
 738      float2 maxDelta = max(delta.xy, delta.zw);
 739  
 740      // Calculate left-left and top-top deltas:
 741      float Lleftleft = dot(SMAASamplePoint(colorTex, offset[2].xy).rgb, weights);
 742      float Ltoptop = dot(SMAASamplePoint(colorTex, offset[2].zw).rgb, weights);
 743      delta.zw = abs(float2(Lleft, Ltop) - float2(Lleftleft, Ltoptop));
 744  
 745      // Calculate the final maximum delta:
 746      maxDelta = max(maxDelta.xy, delta.zw);
 747      float finalDelta = max(maxDelta.x, maxDelta.y);
 748  
 749      // Local contrast adaptation:
 750      edges.xy *= step(finalDelta, SMAA_LOCAL_CONTRAST_ADAPTATION_FACTOR * delta.xy);
 751  
 752      return edges;
 753  }
 754  
 755  /**
 756   * Color Edge Detection
 757   *
 758   * IMPORTANT NOTICE: color edge detection requires gamma-corrected colors, and
 759   * thus 'colorTex' should be a non-sRGB texture.
 760   */
 761  float2 SMAAColorEdgeDetectionPS(float2 texcoord,
 762                                  float4 offset[3],
 763                                  SMAATexture2D(colorTex)
 764                                  #if SMAA_PREDICATION
 765                                  , SMAATexture2D(predicationTex)
 766                                  #endif
 767                                  ) {
 768      // Calculate the threshold:
 769      #if SMAA_PREDICATION
 770      float2 threshold = SMAACalculatePredicatedThreshold(texcoord, offset, predicationTex);
 771      #else
 772      float2 threshold = float2(SMAA_THRESHOLD, SMAA_THRESHOLD);
 773      #endif
 774  
 775      // Calculate color deltas:
 776      float4 delta;
 777      float3 C = SMAASamplePoint(colorTex, texcoord).rgb;
 778  
 779      float3 Cleft = SMAASamplePoint(colorTex, offset[0].xy).rgb;
 780      float3 t = abs(C - Cleft);
 781      delta.x = max(max(t.r, t.g), t.b);
 782  
 783      float3 Ctop  = SMAASamplePoint(colorTex, offset[0].zw).rgb;
 784      t = abs(C - Ctop);
 785      delta.y = max(max(t.r, t.g), t.b);
 786  
 787      // We do the usual threshold:
 788      float2 edges = step(threshold, delta.xy);
 789  
 790      // Then discard if there is no edge:
 791      if (dot(edges, float2(1.0, 1.0)) == 0.0)
 792          return float2(-2.0, -2.0);
 793  
 794      // Calculate right and bottom deltas:
 795      float3 Cright = SMAASamplePoint(colorTex, offset[1].xy).rgb;
 796      t = abs(C - Cright);
 797      delta.z = max(max(t.r, t.g), t.b);
 798  
 799      float3 Cbottom  = SMAASamplePoint(colorTex, offset[1].zw).rgb;
 800      t = abs(C - Cbottom);
 801      delta.w = max(max(t.r, t.g), t.b);
 802  
 803      // Calculate the maximum delta in the direct neighborhood:
 804      float2 maxDelta = max(delta.xy, delta.zw);
 805  
 806      // Calculate left-left and top-top deltas:
 807      float3 Cleftleft  = SMAASamplePoint(colorTex, offset[2].xy).rgb;
 808      t = abs(C - Cleftleft);
 809      delta.z = max(max(t.r, t.g), t.b);
 810  
 811      float3 Ctoptop = SMAASamplePoint(colorTex, offset[2].zw).rgb;
 812      t = abs(C - Ctoptop);
 813      delta.w = max(max(t.r, t.g), t.b);
 814  
 815      // Calculate the final maximum delta:
 816      maxDelta = max(maxDelta.xy, delta.zw);
 817      float finalDelta = max(maxDelta.x, maxDelta.y);
 818  
 819      // Local contrast adaptation:
 820      edges.xy *= step(finalDelta, SMAA_LOCAL_CONTRAST_ADAPTATION_FACTOR * delta.xy);
 821  
 822      return edges;
 823  }
 824  
 825  /**
 826   * Depth Edge Detection
 827   */
 828  float2 SMAADepthEdgeDetectionPS(float2 texcoord,
 829                                  float4 offset[3],
 830                                  SMAATexture2D(depthTex)) {
 831      float3 neighbours = SMAAGatherNeighbours(texcoord, offset, SMAATexturePass2D(depthTex));
 832      float2 delta = abs(neighbours.xx - float2(neighbours.y, neighbours.z));
 833      float2 edges = step(SMAA_DEPTH_THRESHOLD, delta);
 834  
 835      if (dot(edges, float2(1.0, 1.0)) == 0.0)
 836          return float2(-2.0, -2.0);
 837  
 838      return edges;
 839  }
 840  
 841  //-----------------------------------------------------------------------------
 842  // Diagonal Search Functions
 843  
 844  #if !defined(SMAA_DISABLE_DIAG_DETECTION)
 845  
 846  /**
 847   * Allows to decode two binary values from a bilinear-filtered access.
 848   */
 849  float2 SMAADecodeDiagBilinearAccess(float2 e) {
 850      // Bilinear access for fetching 'e' have a 0.25 offset, and we are
 851      // interested in the R and G edges:
 852      //
 853      // +---G---+-------+
 854      // |   x o R   x   |
 855      // +-------+-------+
 856      //
 857      // Then, if one of these edge is enabled:
 858      //   Red:   (0.75 * X + 0.25 * 1) => 0.25 or 1.0
 859      //   Green: (0.75 * 1 + 0.25 * X) => 0.75 or 1.0
 860      //
 861      // This function will unpack the values (mad + mul + round):
 862      // wolframalpha.com: round(x * abs(5 * x - 5 * 0.75)) plot 0 to 1
 863      e.r = e.r * abs(5.0 * e.r - 5.0 * 0.75);
 864      return round(e);
 865  }
 866  
 867  float4 SMAADecodeDiagBilinearAccess(float4 e) {
 868      e.rb = e.rb * abs(5.0 * e.rb - 5.0 * 0.75);
 869      return round(e);
 870  }
 871  
 872  /**
 873   * These functions allows to perform diagonal pattern searches.
 874   */
 875  float2 SMAASearchDiag1(SMAATexture2D(edgesTex), float2 texcoord, float2 dir, out float2 e) {
 876      float4 coord = float4(texcoord, -1.0, 1.0);
 877      float3 t = float3(SMAA_RT_METRICS.xy, 1.0);
 878      while (coord.z < float(SMAA_MAX_SEARCH_STEPS_DIAG - 1) &&
 879             coord.w > 0.9) {
 880          coord.xyz = mad(t, float3(dir, 1.0), coord.xyz);
 881          e = SMAASampleLevelZero(edgesTex, coord.xy).rg;
 882          coord.w = dot(e, float2(0.5, 0.5));
 883      }
 884      return coord.zw;
 885  }
 886  
 887  float2 SMAASearchDiag2(SMAATexture2D(edgesTex), float2 texcoord, float2 dir, out float2 e) {
 888      float4 coord = float4(texcoord, -1.0, 1.0);
 889      coord.x += 0.25 * SMAA_RT_METRICS.x; // See @SearchDiag2Optimization
 890      float3 t = float3(SMAA_RT_METRICS.xy, 1.0);
 891      while (coord.z < float(SMAA_MAX_SEARCH_STEPS_DIAG - 1) &&
 892             coord.w > 0.9) {
 893          coord.xyz = mad(t, float3(dir, 1.0), coord.xyz);
 894  
 895          // @SearchDiag2Optimization
 896          // Fetch both edges at once using bilinear filtering:
 897          e = SMAASampleLevelZero(edgesTex, coord.xy).rg;
 898          e = SMAADecodeDiagBilinearAccess(e);
 899  
 900          // Non-optimized version:
 901          // e.g = SMAASampleLevelZero(edgesTex, coord.xy).g;
 902          // e.r = SMAASampleLevelZeroOffset(edgesTex, coord.xy, int2(1, 0)).r;
 903  
 904          coord.w = dot(e, float2(0.5, 0.5));
 905      }
 906      return coord.zw;
 907  }
 908  
 909  /** 
 910   * Similar to SMAAArea, this calculates the area corresponding to a certain
 911   * diagonal distance and crossing edges 'e'.
 912   */
 913  float2 SMAAAreaDiag(SMAATexture2D(areaTex), float2 dist, float2 e, float offset) {
 914      float2 texcoord = mad(float2(SMAA_AREATEX_MAX_DISTANCE_DIAG, SMAA_AREATEX_MAX_DISTANCE_DIAG), e, dist);
 915  
 916      // We do a scale and bias for mapping to texel space:
 917      texcoord = mad(SMAA_AREATEX_PIXEL_SIZE, texcoord, 0.5 * SMAA_AREATEX_PIXEL_SIZE);
 918  
 919      // Diagonal areas are on the second half of the texture:
 920      texcoord.x += 0.5;
 921  
 922      // Move to proper place, according to the subpixel offset:
 923      texcoord.y += SMAA_AREATEX_SUBTEX_SIZE * offset;
 924  
 925      // Do it!
 926      return SMAA_AREATEX_SELECT(SMAASampleLevelZero(areaTex, texcoord));
 927  }
 928  
 929  /**
 930   * This searches for diagonal patterns and returns the corresponding weights.
 931   */
 932  float2 SMAACalculateDiagWeights(SMAATexture2D(edgesTex), SMAATexture2D(areaTex), float2 texcoord, float2 e, float4 subsampleIndices) {
 933      float2 weights = float2(0.0, 0.0);
 934  
 935      // Search for the line ends:
 936      float4 d;
 937      float2 end;
 938      if (e.r > 0.0) {
 939          d.xz = SMAASearchDiag1(SMAATexturePass2D(edgesTex), texcoord, float2(-1.0,  1.0), end);
 940          d.x += float(end.y > 0.9);
 941      } else
 942          d.xz = float2(0.0, 0.0);
 943      d.yw = SMAASearchDiag1(SMAATexturePass2D(edgesTex), texcoord, float2(1.0, -1.0), end);
 944  
 945      SMAA_BRANCH
 946      if (d.x + d.y > 2.0) { // d.x + d.y + 1 > 3
 947          // Fetch the crossing edges:
 948          float4 coords = mad(float4(-d.x + 0.25, d.x, d.y, -d.y - 0.25), SMAA_RT_METRICS.xyxy, texcoord.xyxy);
 949          float4 c;
 950          c.xy = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2(-1,  0)).rg;
 951          c.zw = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2( 1,  0)).rg;
 952          c.yxwz = SMAADecodeDiagBilinearAccess(c.xyzw);
 953  
 954          // Non-optimized version:
 955          // float4 coords = mad(float4(-d.x, d.x, d.y, -d.y), SMAA_RT_METRICS.xyxy, texcoord.xyxy);
 956          // float4 c;
 957          // c.x = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2(-1,  0)).g;
 958          // c.y = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2( 0,  0)).r;
 959          // c.z = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2( 1,  0)).g;
 960          // c.w = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2( 1, -1)).r;
 961  
 962          // Merge crossing edges at each side into a single value:
 963          float2 cc = mad(float2(2.0, 2.0), c.xz, c.yw);
 964  
 965          // Remove the crossing edge if we didn't found the end of the line:
 966          SMAAMovc(bool2(step(0.9, d.zw)), cc, float2(0.0, 0.0));
 967  
 968          // Fetch the areas for this line:
 969          weights += SMAAAreaDiag(SMAATexturePass2D(areaTex), d.xy, cc, subsampleIndices.z);
 970      }
 971  
 972      // Search for the line ends:
 973      d.xz = SMAASearchDiag2(SMAATexturePass2D(edgesTex), texcoord, float2(-1.0, -1.0), end);
 974      if (SMAASampleLevelZeroOffset(edgesTex, texcoord, int2(1, 0)).r > 0.0) {
 975          d.yw = SMAASearchDiag2(SMAATexturePass2D(edgesTex), texcoord, float2(1.0, 1.0), end);
 976          d.y += float(end.y > 0.9);
 977      } else
 978          d.yw = float2(0.0, 0.0);
 979  
 980      SMAA_BRANCH
 981      if (d.x + d.y > 2.0) { // d.x + d.y + 1 > 3
 982          // Fetch the crossing edges:
 983          float4 coords = mad(float4(-d.x, -d.x, d.y, d.y), SMAA_RT_METRICS.xyxy, texcoord.xyxy);
 984          float4 c;
 985          c.x  = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2(-1,  0)).g;
 986          c.y  = SMAASampleLevelZeroOffset(edgesTex, coords.xy, int2( 0, -1)).r;
 987          c.zw = SMAASampleLevelZeroOffset(edgesTex, coords.zw, int2( 1,  0)).gr;
 988          float2 cc = mad(float2(2.0, 2.0), c.xz, c.yw);
 989  
 990          // Remove the crossing edge if we didn't found the end of the line:
 991          SMAAMovc(bool2(step(0.9, d.zw)), cc, float2(0.0, 0.0));
 992  
 993          // Fetch the areas for this line:
 994          weights += SMAAAreaDiag(SMAATexturePass2D(areaTex), d.xy, cc, subsampleIndices.w).gr;
 995      }
 996  
 997      return weights;
 998  }
 999  #endif
1000  
1001  //-----------------------------------------------------------------------------
1002  // Horizontal/Vertical Search Functions
1003  
1004  /**
1005   * This allows to determine how much length should we add in the last step
1006   * of the searches. It takes the bilinearly interpolated edge (see 
1007   * @PSEUDO_GATHER4), and adds 0, 1 or 2, depending on which edges and
1008   * crossing edges are active.
1009   */
1010  float SMAASearchLength(SMAATexture2D(searchTex), float2 e, float offset) {
1011      // The texture is flipped vertically, with left and right cases taking half
1012      // of the space horizontally:
1013      float2 scale = SMAA_SEARCHTEX_SIZE * float2(0.5, -1.0);
1014      float2 bias = SMAA_SEARCHTEX_SIZE * float2(offset, 1.0);
1015  
1016      // Scale and bias to access texel centers:
1017      scale += float2(-1.0,  1.0);
1018      bias  += float2( 0.5, -0.5);
1019  
1020      // Convert from pixel coordinates to texcoords:
1021      // (We use SMAA_SEARCHTEX_PACKED_SIZE because the texture is cropped)
1022      scale *= 1.0 / SMAA_SEARCHTEX_PACKED_SIZE;
1023      bias *= 1.0 / SMAA_SEARCHTEX_PACKED_SIZE;
1024  
1025      // Lookup the search texture:
1026      return SMAA_SEARCHTEX_SELECT(SMAASampleLevelZero(searchTex, mad(scale, e, bias)));
1027  }
1028  
1029  /**
1030   * Horizontal/vertical search functions for the 2nd pass.
1031   */
1032  float SMAASearchXLeft(SMAATexture2D(edgesTex), SMAATexture2D(searchTex), float2 texcoord, float end) {
1033      /**
1034       * @PSEUDO_GATHER4
1035       * This texcoord has been offset by (-0.25, -0.125) in the vertex shader to
1036       * sample between edge, thus fetching four edges in a row.
1037       * Sampling with different offsets in each direction allows to disambiguate
1038       * which edges are active from the four fetched ones.
1039       */
1040      float2 e = float2(0.0, 1.0);
1041      while (texcoord.x > end && 
1042             e.g > 0.8281 && // Is there some edge not activated?
1043             e.r == 0.0) { // Or is there a crossing edge that breaks the line?
1044          e = SMAASampleLevelZero(edgesTex, texcoord).rg;
1045          texcoord = mad(-float2(2.0, 0.0), SMAA_RT_METRICS.xy, texcoord);
1046      }
1047  
1048      float offset = mad(-(255.0 / 127.0), SMAASearchLength(SMAATexturePass2D(searchTex), e, 0.0), 3.25);
1049      return mad(SMAA_RT_METRICS.x, offset, texcoord.x);
1050  
1051      // Non-optimized version:
1052      // We correct the previous (-0.25, -0.125) offset we applied:
1053      // texcoord.x += 0.25 * SMAA_RT_METRICS.x;
1054  
1055      // The searches are bias by 1, so adjust the coords accordingly:
1056      // texcoord.x += SMAA_RT_METRICS.x;
1057  
1058      // Disambiguate the length added by the last step:
1059      // texcoord.x += 2.0 * SMAA_RT_METRICS.x; // Undo last step
1060      // texcoord.x -= SMAA_RT_METRICS.x * (255.0 / 127.0) * SMAASearchLength(SMAATexturePass2D(searchTex), e, 0.0);
1061      // return mad(SMAA_RT_METRICS.x, offset, texcoord.x);
1062  }
1063  
1064  float SMAASearchXRight(SMAATexture2D(edgesTex), SMAATexture2D(searchTex), float2 texcoord, float end) {
1065      float2 e = float2(0.0, 1.0);
1066      while (texcoord.x < end && 
1067             e.g > 0.8281 && // Is there some edge not activated?
1068             e.r == 0.0) { // Or is there a crossing edge that breaks the line?
1069          e = SMAASampleLevelZero(edgesTex, texcoord).rg;
1070          texcoord = mad(float2(2.0, 0.0), SMAA_RT_METRICS.xy, texcoord);
1071      }
1072      float offset = mad(-(255.0 / 127.0), SMAASearchLength(SMAATexturePass2D(searchTex), e, 0.5), 3.25);
1073      return mad(-SMAA_RT_METRICS.x, offset, texcoord.x);
1074  }
1075  
1076  float SMAASearchYUp(SMAATexture2D(edgesTex), SMAATexture2D(searchTex), float2 texcoord, float end) {
1077      float2 e = float2(1.0, 0.0);
1078      while (texcoord.y > end && 
1079             e.r > 0.8281 && // Is there some edge not activated?
1080             e.g == 0.0) { // Or is there a crossing edge that breaks the line?
1081          e = SMAASampleLevelZero(edgesTex, texcoord).rg;
1082          texcoord = mad(-float2(0.0, 2.0), SMAA_RT_METRICS.xy, texcoord);
1083      }
1084      float offset = mad(-(255.0 / 127.0), SMAASearchLength(SMAATexturePass2D(searchTex), e.gr, 0.0), 3.25);
1085      return mad(SMAA_RT_METRICS.y, offset, texcoord.y);
1086  }
1087  
1088  float SMAASearchYDown(SMAATexture2D(edgesTex), SMAATexture2D(searchTex), float2 texcoord, float end) {
1089      float2 e = float2(1.0, 0.0);
1090      while (texcoord.y < end && 
1091             e.r > 0.8281 && // Is there some edge not activated?
1092             e.g == 0.0) { // Or is there a crossing edge that breaks the line?
1093          e = SMAASampleLevelZero(edgesTex, texcoord).rg;
1094          texcoord = mad(float2(0.0, 2.0), SMAA_RT_METRICS.xy, texcoord);
1095      }
1096      float offset = mad(-(255.0 / 127.0), SMAASearchLength(SMAATexturePass2D(searchTex), e.gr, 0.5), 3.25);
1097      return mad(-SMAA_RT_METRICS.y, offset, texcoord.y);
1098  }
1099  
1100  /** 
1101   * Ok, we have the distance and both crossing edges. So, what are the areas
1102   * at each side of current edge?
1103   */
1104  float2 SMAAArea(SMAATexture2D(areaTex), float2 dist, float e1, float e2, float offset) {
1105      // Rounding prevents precision errors of bilinear filtering:
1106      float2 texcoord = mad(float2(SMAA_AREATEX_MAX_DISTANCE, SMAA_AREATEX_MAX_DISTANCE), round(4.0 * float2(e1, e2)), dist);
1107      
1108      // We do a scale and bias for mapping to texel space:
1109      texcoord = mad(SMAA_AREATEX_PIXEL_SIZE, texcoord, 0.5 * SMAA_AREATEX_PIXEL_SIZE);
1110  
1111      // Move to proper place, according to the subpixel offset:
1112      texcoord.y = mad(SMAA_AREATEX_SUBTEX_SIZE, offset, texcoord.y);
1113  
1114      // Do it!
1115      return SMAA_AREATEX_SELECT(SMAASampleLevelZero(areaTex, texcoord));
1116  }
1117  
1118  //-----------------------------------------------------------------------------
1119  // Corner Detection Functions
1120  
1121  void SMAADetectHorizontalCornerPattern(SMAATexture2D(edgesTex), inout float2 weights, float4 texcoord, float2 d) {
1122      #if !defined(SMAA_DISABLE_CORNER_DETECTION)
1123      float2 leftRight = step(d.xy, d.yx);
1124      float2 rounding = (1.0 - SMAA_CORNER_ROUNDING_NORM) * leftRight;
1125  
1126      rounding /= leftRight.x + leftRight.y; // Reduce blending for pixels in the center of a line.
1127  
1128      float2 factor = float2(1.0, 1.0);
1129      factor.x -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, int2(0,  1)).r;
1130      factor.x -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, int2(1,  1)).r;
1131      factor.y -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, int2(0, -2)).r;
1132      factor.y -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, int2(1, -2)).r;
1133  
1134      weights *= saturate(factor);
1135      #endif
1136  }
1137  
1138  void SMAADetectVerticalCornerPattern(SMAATexture2D(edgesTex), inout float2 weights, float4 texcoord, float2 d) {
1139      #if !defined(SMAA_DISABLE_CORNER_DETECTION)
1140      float2 leftRight = step(d.xy, d.yx);
1141      float2 rounding = (1.0 - SMAA_CORNER_ROUNDING_NORM) * leftRight;
1142  
1143      rounding /= leftRight.x + leftRight.y;
1144  
1145      float2 factor = float2(1.0, 1.0);
1146      factor.x -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, int2( 1, 0)).g;
1147      factor.x -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, int2( 1, 1)).g;
1148      factor.y -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, int2(-2, 0)).g;
1149      factor.y -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, int2(-2, 1)).g;
1150  
1151      weights *= saturate(factor);
1152      #endif
1153  }
1154  
1155  //-----------------------------------------------------------------------------
1156  // Blending Weight Calculation Pixel Shader (Second Pass)
1157  
1158  float4 SMAABlendingWeightCalculationPS(float2 texcoord,
1159                                         float2 pixcoord,
1160                                         float4 offset[3],
1161                                         SMAATexture2D(edgesTex),
1162                                         SMAATexture2D(areaTex),
1163                                         SMAATexture2D(searchTex),
1164                                         float4 subsampleIndices) { // Just pass zero for SMAA 1x, see @SUBSAMPLE_INDICES.
1165      float4 weights = float4(0.0, 0.0, 0.0, 0.0);
1166  
1167      float2 e = SMAASample(edgesTex, texcoord).rg;
1168  
1169      SMAA_BRANCH
1170      if (e.g > 0.0) { // Edge at north
1171          #if !defined(SMAA_DISABLE_DIAG_DETECTION)
1172          // Diagonals have both north and west edges, so searching for them in
1173          // one of the boundaries is enough.
1174          weights.rg = SMAACalculateDiagWeights(SMAATexturePass2D(edgesTex), SMAATexturePass2D(areaTex), texcoord, e, subsampleIndices);
1175  
1176          // We give priority to diagonals, so if we find a diagonal we skip 
1177          // horizontal/vertical processing.
1178          SMAA_BRANCH
1179          if (weights.r == -weights.g) { // weights.r + weights.g == 0.0
1180          #endif
1181  
1182          float2 d;
1183  
1184          // Find the distance to the left:
1185          float3 coords;
1186          coords.x = SMAASearchXLeft(SMAATexturePass2D(edgesTex), SMAATexturePass2D(searchTex), offset[0].xy, offset[2].x);
1187          coords.y = offset[1].y; // offset[1].y = texcoord.y - 0.25 * SMAA_RT_METRICS.y (@CROSSING_OFFSET)
1188          d.x = coords.x;
1189  
1190          // Now fetch the left crossing edges, two at a time using bilinear
1191          // filtering. Sampling at -0.25 (see @CROSSING_OFFSET) enables to
1192          // discern what value each edge has:
1193          float e1 = SMAASampleLevelZero(edgesTex, coords.xy).r;
1194  
1195          // Find the distance to the right:
1196          coords.z = SMAASearchXRight(SMAATexturePass2D(edgesTex), SMAATexturePass2D(searchTex), offset[0].zw, offset[2].y);
1197          d.y = coords.z;
1198  
1199          // We want the distances to be in pixel units (doing this here allow to
1200          // better interleave arithmetic and memory accesses):
1201          d = abs(round(mad(SMAA_RT_METRICS.zz, d, -pixcoord.xx)));
1202  
1203          // SMAAArea below needs a sqrt, as the areas texture is compressed
1204          // quadratically:
1205          float2 sqrt_d = sqrt(d);
1206  
1207          // Fetch the right crossing edges:
1208          float e2 = SMAASampleLevelZeroOffset(edgesTex, coords.zy, int2(1, 0)).r;
1209  
1210          // Ok, we know how this pattern looks like, now it is time for getting
1211          // the actual area:
1212          weights.rg = SMAAArea(SMAATexturePass2D(areaTex), sqrt_d, e1, e2, subsampleIndices.y);
1213  
1214          // Fix corners:
1215          coords.y = texcoord.y;
1216          SMAADetectHorizontalCornerPattern(SMAATexturePass2D(edgesTex), weights.rg, coords.xyzy, d);
1217  
1218          #if !defined(SMAA_DISABLE_DIAG_DETECTION)
1219          } else
1220              e.r = 0.0; // Skip vertical processing.
1221          #endif
1222      }
1223  
1224      SMAA_BRANCH
1225      if (e.r > 0.0) { // Edge at west
1226          float2 d;
1227  
1228          // Find the distance to the top:
1229          float3 coords;
1230          coords.y = SMAASearchYUp(SMAATexturePass2D(edgesTex), SMAATexturePass2D(searchTex), offset[1].xy, offset[2].z);
1231          coords.x = offset[0].x; // offset[1].x = texcoord.x - 0.25 * SMAA_RT_METRICS.x;
1232          d.x = coords.y;
1233  
1234          // Fetch the top crossing edges:
1235          float e1 = SMAASampleLevelZero(edgesTex, coords.xy).g;
1236  
1237          // Find the distance to the bottom:
1238          coords.z = SMAASearchYDown(SMAATexturePass2D(edgesTex), SMAATexturePass2D(searchTex), offset[1].zw, offset[2].w);
1239          d.y = coords.z;
1240  
1241          // We want the distances to be in pixel units:
1242          d = abs(round(mad(SMAA_RT_METRICS.ww, d, -pixcoord.yy)));
1243  
1244          // SMAAArea below needs a sqrt, as the areas texture is compressed 
1245          // quadratically:
1246          float2 sqrt_d = sqrt(d);
1247  
1248          // Fetch the bottom crossing edges:
1249          float e2 = SMAASampleLevelZeroOffset(edgesTex, coords.xz, int2(0, 1)).g;
1250  
1251          // Get the area for this direction:
1252          weights.ba = SMAAArea(SMAATexturePass2D(areaTex), sqrt_d, e1, e2, subsampleIndices.x);
1253  
1254          // Fix corners:
1255          coords.x = texcoord.x;
1256          SMAADetectVerticalCornerPattern(SMAATexturePass2D(edgesTex), weights.ba, coords.xyxz, d);
1257      }
1258  
1259      return weights;
1260  }
1261  
1262  //-----------------------------------------------------------------------------
1263  // Neighborhood Blending Pixel Shader (Third Pass)
1264  
1265  float4 SMAANeighborhoodBlendingPS(float2 texcoord,
1266                                    float4 offset,
1267                                    SMAATexture2D(colorTex),
1268                                    SMAATexture2D(blendTex)
1269                                    #if SMAA_REPROJECTION
1270                                    , SMAATexture2D(velocityTex)
1271                                    #endif
1272                                    ) {
1273      // Fetch the blending weights for current pixel:
1274      float4 a;
1275      a.x = SMAASample(blendTex, offset.xy).a; // Right
1276      a.y = SMAASample(blendTex, offset.zw).g; // Top
1277      a.wz = SMAASample(blendTex, texcoord).xz; // Bottom / Left
1278  
1279      // Is there any blending weight with a value greater than 0.0?
1280      SMAA_BRANCH
1281      if (dot(a, float4(1.0, 1.0, 1.0, 1.0)) < 1e-5) {
1282          float4 color = SMAASampleLevelZero(colorTex, texcoord);
1283  
1284          #if SMAA_REPROJECTION
1285          float2 velocity = SMAA_DECODE_VELOCITY(SMAASampleLevelZero(velocityTex, texcoord));
1286  
1287          // Pack velocity into the alpha channel:
1288          color.a = sqrt(5.0 * length(velocity));
1289          #endif
1290  
1291          return color;
1292      } else {
1293          bool h = max(a.x, a.z) > max(a.y, a.w); // max(horizontal) > max(vertical)
1294  
1295          // Calculate the blending offsets:
1296          float4 blendingOffset = float4(0.0, a.y, 0.0, a.w);
1297          float2 blendingWeight = a.yw;
1298          SMAAMovc(bool4(h, h, h, h), blendingOffset, float4(a.x, 0.0, a.z, 0.0));
1299          SMAAMovc(bool2(h, h), blendingWeight, a.xz);
1300          blendingWeight /= dot(blendingWeight, float2(1.0, 1.0));
1301  
1302          // Calculate the texture coordinates:
1303          float4 blendingCoord = mad(blendingOffset, float4(SMAA_RT_METRICS.xy, -SMAA_RT_METRICS.xy), texcoord.xyxy);
1304  
1305          // We exploit bilinear filtering to mix current pixel with the chosen
1306          // neighbor:
1307          float4 color = blendingWeight.x * SMAASampleLevelZero(colorTex, blendingCoord.xy);
1308          color += blendingWeight.y * SMAASampleLevelZero(colorTex, blendingCoord.zw);
1309  
1310          #if SMAA_REPROJECTION
1311          // Antialias velocity for proper reprojection in a later stage:
1312          float2 velocity = blendingWeight.x * SMAA_DECODE_VELOCITY(SMAASampleLevelZero(velocityTex, blendingCoord.xy));
1313          velocity += blendingWeight.y * SMAA_DECODE_VELOCITY(SMAASampleLevelZero(velocityTex, blendingCoord.zw));
1314  
1315          // Pack velocity into the alpha channel:
1316          color.a = sqrt(5.0 * length(velocity));
1317          #endif
1318  
1319          return color;
1320      }
1321  }
1322  
1323  //-----------------------------------------------------------------------------
1324  // Temporal Resolve Pixel Shader (Optional Pass)
1325  
1326  float4 SMAAResolvePS(float2 texcoord,
1327                       SMAATexture2D(currentColorTex),
1328                       SMAATexture2D(previousColorTex)
1329                       #if SMAA_REPROJECTION
1330                       , SMAATexture2D(velocityTex)
1331                       #endif
1332                       ) {
1333      #if SMAA_REPROJECTION
1334      // Velocity is assumed to be calculated for motion blur, so we need to
1335      // inverse it for reprojection:
1336      float2 velocity = -SMAA_DECODE_VELOCITY(SMAASamplePoint(velocityTex, texcoord).rg);
1337  
1338      // Fetch current pixel:
1339      float4 current = SMAASamplePoint(currentColorTex, texcoord);
1340  
1341      // Reproject current coordinates and fetch previous pixel:
1342      float4 previous = SMAASamplePoint(previousColorTex, texcoord + velocity);
1343  
1344      // Attenuate the previous pixel if the velocity is different:
1345      float delta = abs(current.a * current.a - previous.a * previous.a) / 5.0;
1346      float weight = 0.5 * saturate(1.0 - sqrt(delta) * SMAA_REPROJECTION_WEIGHT_SCALE);
1347  
1348      // Blend the pixels according to the calculated weight:
1349      return lerp(current, previous, weight);
1350      #else
1351      // Just blend the pixels:
1352      float4 current = SMAASamplePoint(currentColorTex, texcoord);
1353      float4 previous = SMAASamplePoint(previousColorTex, texcoord);
1354      return lerp(current, previous, 0.5);
1355      #endif
1356  }
1357  
1358  //-----------------------------------------------------------------------------
1359  // Separate Multisamples Pixel Shader (Optional Pass)
1360  
1361  #ifdef SMAALoad
1362  void SMAASeparatePS(float4 position,
1363                      float2 texcoord,
1364                      out float4 target0,
1365                      out float4 target1,
1366                      SMAATexture2DMS2(colorTexMS)) {
1367      int2 pos = int2(position.xy);
1368      target0 = SMAALoad(colorTexMS, pos, 0);
1369      target1 = SMAALoad(colorTexMS, pos, 1);
1370  }
1371  #endif
1372  
1373  //-----------------------------------------------------------------------------
1374  #endif // SMAA_INCLUDE_PS
1375  
1376  layout(rgba8, binding = 0, set = 3) uniform image2D imgOutput;
1377  
1378  layout(binding = 1, set = 2) uniform sampler2D inputImg;
1379  layout(binding = 3, set = 2) uniform sampler2D samplerArea;
1380  layout(binding = 4, set = 2) uniform sampler2D samplerSearch;
1381  layout( binding = 2 ) uniform invResolution
1382  {
1383      vec2 invResolution_data;
1384  };
1385  
1386  void main() {
1387    ivec2 loc = ivec2(gl_GlobalInvocationID.x * 4, gl_GlobalInvocationID.y * 4);
1388    for(int i = 0; i < 4; i++)
1389    {
1390        for(int j = 0; j < 4; j++)
1391        {
1392          ivec2 texelCoord = ivec2(loc.x + i, loc.y + j);
1393          vec2 coord = (texelCoord + vec2(0.5)) / invResolution_data;
1394          vec2 pixCoord;
1395          vec4 offset[3];
1396  
1397          SMAABlendingWeightCalculationVS( coord, pixCoord, offset);
1398  
1399          vec4 oColor = SMAABlendingWeightCalculationPS(coord, pixCoord, offset, inputImg, samplerArea, samplerSearch, ivec4(0));
1400  
1401          imageStore(imgOutput,  texelCoord, oColor);
1402      }
1403    }
1404  }