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