dali/internal/imaging/common/image-operations.h

   1 /*
   2  * Copyright (c) 2022 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17
  18 #ifndef DALI_INTERNAL_PLATFORM_IMAGE_OPERATIONS_H
  19 #define DALI_INTERNAL_PLATFORM_IMAGE_OPERATIONS_H
  20
  21 // EXTERNAL INCLUDES
  22 #include <stdint.h>
  23
  24 // INTERNAL INCLUDES
  25 #include <dali/devel-api/adaptor-framework/pixel-buffer.h>
  26 #include <dali/integration-api/bitmap.h>
  27 #include <dali/public-api/images/image-operations.h>
  28 #include <third-party/resampler/resampler.h>
  29
  30 namespace Dali
  31 {
  32 namespace Internal
  33 {
  34 namespace Platform
  35 {
  36 /**
  37  * @brief Identify which combination of x and y dimensions matter in terminating iterative box filtering.
  38  */
  39 enum BoxDimensionTest
  40 {
  41   BoxDimensionTestEither,
  42   BoxDimensionTestBoth,
  43   BoxDimensionTestX,
  44   BoxDimensionTestY
  45 };
  46
  47 /**
  48  * @brief The integer dimensions of an image or a region of an image packed into
  49  *        16 bits per component.
  50  * @note  This can only be used for images of up to 65535 x 65535 pixels.
  51   */
  52 typedef Uint16Pair ImageDimensions;
  53
  54 /**
  55  * @brief Work out the true desired width and height, accounting for special
  56  * rules for zeros in either or both input requested dimensions.
  57  *
  58  * @param[in] rawDimensions Width and height of image before processing.
  59  * @param[in] requestedDimensions Width and height of area to scale image into. Can be zero.
  60  * @return Dimensions of area to scale image into after special rules are applied.
  61  */
  62 ImageDimensions CalculateDesiredDimensions(ImageDimensions rawDimensions, ImageDimensions requestedDimensions);
  63
  64 /**
  65  * @defgroup BitmapOperations Bitmap-to-Bitmap Image operations.
  66  * @{
  67  */
  68
  69 /**
  70  * @brief Apply requested attributes to bitmap.
  71  *
  72  * This is the top-level function which runs the on-load image post-processing
  73  * pipeline. Bitmaps enter here as loaded from the file system by the file
  74  * loaders and leave downscaled and filtered as requested by the application,
  75  * ready for use.
  76  *
  77  * @param[in] bitmap The input bitmap.
  78  * @param[in] requestedAttributes Attributes which should be applied to bitmap.
  79  * @return A bitmap which results from applying the requested attributes to the
  80  *         bitmap passed-in, or the original bitmap passed in if the attributes
  81  *         have no effect.
  82  */
  83 Dali::Devel::PixelBuffer ApplyAttributesToBitmap(Dali::Devel::PixelBuffer bitmap, ImageDimensions dimensions, FittingMode::Type fittingMode = FittingMode::DEFAULT, SamplingMode::Type samplingMode = SamplingMode::DEFAULT);
  84
  85 /**
  86  * @brief Apply downscaling to a bitmap according to requested attributes.
  87  * @note The input bitmap pixel buffer may be modified and used as scratch working space for efficiency, so it must be discarded.
  88  **/
  89 Dali::Devel::PixelBuffer DownscaleBitmap(Dali::Devel::PixelBuffer bitmap,
  90                                          ImageDimensions          desired,
  91                                          FittingMode::Type        fittingMode,
  92                                          SamplingMode::Type       samplingMode);
  93 /**@}*/
  94
  95 /**
  96  * @defgroup ImageBufferScalingAlgorithms Pixel buffer-level scaling algorithms.
  97  * @{
  98  */
  99
 100 /**
 101  * @brief Destructive in-place downscaling by a power of 2 factor.
 102  *
 103  * A box filter with a 2x2 kernel is repeatedly applied as long as the result
 104  * of the next downscaling step would not be smaller than the desired
 105  * dimensions.
 106  * @param[in,out] pixels The buffer both to read from and write the result to.
 107  * @param[in]     pixelFormat The format of the image pointed at by pixels.
 108  * @param[in]     inputWidth The width of the input image.
 109  * @param[in]     inputHeight The height of the input image.
 110  * @param[in]     inputStride The stride of the input image.
 111  * @param[in]     desiredWidth The width the client is requesting.
 112  * @param[in]     desiredHeight The height the client is requesting.
 113  * @param[out]    outWidth  The resulting width after downscaling.
 114  * @param[out]    outHeight The resulting height after downscaling.
 115  * @param[out]    outStride The resulting stride after downscaling.
 116  */
 117 void DownscaleInPlacePow2(unsigned char* const pixels,
 118                           Pixel::Format        pixelFormat,
 119                           unsigned int         inputWidth,
 120                           unsigned int         inputHeight,
 121                           unsigned int         inputStride,
 122                           unsigned int         desiredWidth,
 123                           unsigned int         desiredHeight,
 124                           FittingMode::Type    fittingMode,
 125                           SamplingMode::Type   samplingMode,
 126                           unsigned&            outWidth,
 127                           unsigned&            outHeight,
 128                           unsigned&            outStride);
 129
 130 /**
 131  * @brief Destructive in-place downscaling by a power of 2 factor.
 132  *
 133  * A box filter with a 2x2 kernel is repeatedly applied as long as the result
 134  * of the next downscaling step would not be smaller than the desired
 135  * dimensions.
 136  * @param[in,out] pixels The buffer both to read from and write the result to.
 137  * @param[in]     inputWidth The width of the input image.
 138  * @param[in]     inputHeight The height of the input image.
 139  * @param[in]     inputStride The stride of the input image.
 140  * @param[in]     desiredWidth The width the client is requesting.
 141  * @param[in]     desiredHeight The height the client is requesting.
 142  * @param[out]    outWidth  The resulting width after downscaling.
 143  * @param[out]    outHeight The resulting height after downscaling.
 144  * @param[out]    outStride The resulting stride after downscaling.
 145  */
 146 void DownscaleInPlacePow2RGB888(unsigned char*   pixels,
 147                                 unsigned int     inputWidth,
 148                                 unsigned int     inputHeight,
 149                                 unsigned int     inputStride,
 150                                 unsigned int     desiredWidth,
 151                                 unsigned int     desiredHeight,
 152                                 BoxDimensionTest dimensionTest,
 153                                 unsigned int&    outWidth,
 154                                 unsigned int&    outHeight,
 155                                 unsigned int&    outStride);
 156
 157 /**
 158  * @copydoc DownscaleInPlacePow2RGB888
 159  */
 160 void DownscaleInPlacePow2RGBA8888(unsigned char*   pixels,
 161                                   unsigned int     inputWidth,
 162                                   unsigned int     inputHeight,
 163                                   unsigned int     inputStride,
 164                                   unsigned int     desiredWidth,
 165                                   unsigned int     desiredHeight,
 166                                   BoxDimensionTest dimensionTest,
 167                                   unsigned int&    outWidth,
 168                                   unsigned int&    outHeight,
 169                                   unsigned int&    outStride);
 170
 171 /**
 172  * @copydoc DownscaleInPlacePow2RGB888
 173  *
 174  * For the 2-byte packed 16 bit format RGB565.
 175  */
 176 void DownscaleInPlacePow2RGB565(unsigned char*   pixels,
 177                                 unsigned int     inputWidth,
 178                                 unsigned int     inputHeight,
 179                                 unsigned int     inputStride,
 180                                 unsigned int     desiredWidth,
 181                                 unsigned int     desiredHeight,
 182                                 BoxDimensionTest dimensionTest,
 183                                 unsigned int&    outWidth,
 184                                 unsigned int&    outHeight,
 185                                 unsigned int&    outStride);
 186
 187 /**
 188  * @copydoc DownscaleInPlacePow2RGB888
 189  *
 190  * For 2-byte formats such as lum8alpha8, but not packed 16 bit formats like RGB565.
 191  */
 192 void DownscaleInPlacePow2ComponentPair(unsigned char*   pixels,
 193                                        unsigned int     inputWidth,
 194                                        unsigned int     inputHeight,
 195                                        unsigned int     inputStride,
 196                                        unsigned int     desiredWidth,
 197                                        unsigned int     desiredHeight,
 198                                        BoxDimensionTest dimensionTest,
 199                                        unsigned int&    outWidth,
 200                                        unsigned int&    outHeight,
 201                                        unsigned int&    outStride);
 202
 203 /**
 204  * @copydoc DownscaleInPlacePow2RGB888
 205  *
 206  * For single-byte formats such as lum8 or alpha8.
 207  */
 208 void DownscaleInPlacePow2SingleBytePerPixel(unsigned char*   pixels,
 209                                             unsigned int     inputWidth,
 210                                             unsigned int     inputHeight,
 211                                             unsigned int     inputStride,
 212                                             unsigned int     desiredWidth,
 213                                             unsigned int     desiredHeight,
 214                                             BoxDimensionTest dimensionTest,
 215                                             unsigned int&    outWidth,
 216                                             unsigned int&    outHeight,
 217                                             unsigned int&    outStride);
 218
 219 /**
 220  * @brief Rescales an input image into the exact output dimensions passed-in.
 221  *
 222  * Uses point sampling, equivalent to GL_NEAREST texture filter mode, for the
 223  * fastest results, at the expense of aliasing (noisy images) when downscaling.
 224  * @note inPixels is allowed to alias outPixels if this is a downscaling,
 225  * but not for upscaling.
 226  */
 227 void PointSample(const unsigned char* inPixels,
 228                  unsigned int         inputWidth,
 229                  unsigned int         inputHeight,
 230                  unsigned int         inputStride,
 231                  Pixel::Format        pixelFormat,
 232                  unsigned char*       outPixels,
 233                  unsigned int         desiredWidth,
 234                  unsigned int         desiredHeight);
 235
 236 /**
 237  * @copydoc PointSample
 238  *
 239  * Specialised for 4-byte formats like RGBA8888 and BGRA8888.
 240  */
 241 void PointSample4BPP(const unsigned char* inPixels,
 242                      unsigned int         inputWidth,
 243                      unsigned int         inputHeight,
 244                      unsigned int         inputStride,
 245                      unsigned char*       outPixels,
 246                      unsigned int         desiredWidth,
 247                      unsigned int         desiredHeight);
 248
 249 /**
 250  * @copydoc PointSample
 251  *
 252  * Specialised for 3-byte formats like RGB888 and BGR888.
 253  */
 254 void PointSample3BPP(const unsigned char* inPixels,
 255                      unsigned int         inputWidth,
 256                      unsigned int         inputHeight,
 257                      unsigned int         inputStride,
 258                      unsigned char*       outPixels,
 259                      unsigned int         desiredWidth,
 260                      unsigned int         desiredHeight);
 261
 262 /**
 263  * @copydoc PointSample
 264  *
 265  * Specialised for 2-byte formats like LA88.
 266  */
 267 void PointSample2BPP(const unsigned char* inPixels,
 268                      unsigned int         inputWidth,
 269                      unsigned int         inputHeight,
 270                      unsigned int         inputStride,
 271                      unsigned char*       outPixels,
 272                      unsigned int         desiredWidth,
 273                      unsigned int         desiredHeight);
 274
 275 /**
 276  * @copydoc PointSample
 277  *
 278  * Specialised for 1-byte formats like L8 and A8.
 279  */
 280 void PointSample1BPP(const unsigned char* inPixels,
 281                      unsigned int         inputWidth,
 282                      unsigned int         inputHeight,
 283                      unsigned int         inputStride,
 284                      unsigned char*       outPixels,
 285                      unsigned int         desiredWidth,
 286                      unsigned int         desiredHeight);
 287
 288 /**
 289  * @brief Resample input image to output image using a bilinear filter.
 290  *
 291  * Each output pixel is formed of a weighted sum of a 2x2 block of four input
 292  * pixels
 293  * @pre inPixels must not alias outPixels. The input image should be a totally
 294  * separate buffer from the input one.
 295  */
 296 void LinearSample(const unsigned char* __restrict__ inPixels,
 297                   ImageDimensions inDimensions,
 298                   unsigned int    inStride,
 299                   Pixel::Format   pixelFormat,
 300                   unsigned char* __restrict__ outPixels,
 301                   ImageDimensions outDimensions);
 302
 303 /**
 304  * @copydoc LinearSample
 305  *
 306  * Specialised for one byte per pixel formats.
 307  */
 308 void LinearSample1BPP(const unsigned char* __restrict__ inPixels,
 309                       ImageDimensions inputDimensions,
 310                       unsigned int    inputStride,
 311                       unsigned char* __restrict__ outPixels,
 312                       ImageDimensions desiredDimensions);
 313
 314 /**
 315  * @copydoc LinearSample
 316  *
 317  * Specialised for two byte per pixel formats.
 318  */
 319 void LinearSample2BPP(const unsigned char* __restrict__ inPixels,
 320                       ImageDimensions inputDimensions,
 321                       unsigned int    inputStride,
 322                       unsigned char* __restrict__ outPixels,
 323                       ImageDimensions desiredDimensions);
 324
 325 /**
 326  * @copydoc LinearSample
 327  *
 328  * Specialised for RGB565 16 bit pixel format.
 329  */
 330 void LinearSampleRGB565(const unsigned char* __restrict__ inPixels,
 331                         ImageDimensions inputDimensions,
 332                         unsigned int    inputStride,
 333                         unsigned char* __restrict__ outPixels,
 334                         ImageDimensions desiredDimensions);
 335
 336 /**
 337  * @copydoc LinearSample
 338  *
 339  * Specialised for three byte per pixel formats like RGB888.
 340  */
 341 void LinearSample3BPP(const unsigned char* __restrict__ inPixels,
 342                       ImageDimensions inputDimensions,
 343                       unsigned int    inputStride,
 344                       unsigned char* __restrict__ outPixels,
 345                       ImageDimensions desiredDimensions);
 346
 347 /**
 348  * @copydoc LinearSample
 349  *
 350  * Specialised for four byte per pixel formats like RGBA8888.
 351  * @note, If used on RGBA8888, the A component will be blended independently.
 352  */
 353 void LinearSample4BPP(const unsigned char* __restrict__ inPixels,
 354                       ImageDimensions inputDimensions,
 355                       unsigned int    inputStride,
 356                       unsigned char* __restrict__ outPixels,
 357                       ImageDimensions desiredDimensions);
 358
 359 /**
 360  * @brief Resamples the input image with the Lanczos algorithm.
 361  *
 362  * @pre @p inPixels must not alias @p outPixels. The input image should be a totally
 363  * separate buffer from the output buffer.
 364  *
 365  * @param[in] inPixels Pointer to the input image buffer.
 366  * @param[in] inputDimensions The input dimensions of the image.
 367  * @param[in] inputStride The input stride of the image.
 368  * @param[out] outPixels Pointer to the output image buffer.
 369  * @param[in] desiredDimensions The output dimensions of the image.
 370  */
 371 void LanczosSample4BPP(const unsigned char* __restrict__ inPixels,
 372                        ImageDimensions inputDimensions,
 373                        unsigned int    inputStride,
 374                        unsigned char* __restrict__ outPixels,
 375                        ImageDimensions desiredDimensions);
 376
 377 /**
 378  * @brief Resamples the input image with the Lanczos algorithm.
 379  *
 380  * @pre @p inPixels must not alias @p outPixels. The input image should be a totally
 381  * separate buffer from the output buffer.
 382  *
 383  * @param[in] inPixels Pointer to the input image buffer.
 384  * @param[in] inputDimensions The input dimensions of the image.
 385  * @param[in] inputStride The input stride of the image.
 386  * @param[out] outPixels Pointer to the output image buffer.
 387  * @param[in] desiredDimensions The output dimensions of the image.
 388  */
 389 void LanczosSample1BPP(const unsigned char* __restrict__ inPixels,
 390                        ImageDimensions inputDimensions,
 391                        unsigned int    inputStride,
 392                        unsigned char* __restrict__ outPixels,
 393                        ImageDimensions desiredDimensions);
 394
 395 /**
 396  * @brief Resamples the input image with the Lanczos algorithm.
 397  *
 398  * @pre @p inPixels must not alias @p outPixels. The input image should be a totally
 399  * separate buffer from the output buffer.
 400  *
 401  * @param[in] inPixels Pointer to the input image buffer.
 402  * @param[in] inputDimensions The input dimensions of the image.
 403  * @param[in] inputStride The input stride of the image.
 404  * @param[out] outPixels Pointer to the output image buffer.
 405  * @param[in] desiredDimensions The output dimensions of the image.
 406  */
 407 void Resample(const unsigned char* __restrict__ inPixels,
 408               ImageDimensions inputDimensions,
 409               unsigned int    inputStride,
 410               unsigned char* __restrict__ outPixels,
 411               ImageDimensions   desiredDimensions,
 412               Resampler::Filter filterType,
 413               int               numChannels,
 414               bool              hasAlpha);
 415
 416 /**
 417  * @brief Rotates the input image with an implementation of the 'Rotate by Shear' algorithm.
 418  *
 419  * @pre @p pixelsIn must not alias @p pixelsOut. The input image should be a totally
 420  * separate buffer from the output buffer.
 421  *
 422  * @note This function allocates memory in @p pixelsOut which has to be released by calling @e free()
 423  *
 424  * @param[in] pixelsIn The input buffer.
 425  * @param[in] widthIn The width of the input buffer.
 426  * @param[in] heightIn The height of the input buffer.
 427  * @param[in] strideIn The stride of the input buffer.
 428  * @param[in] pixelSize The size of the pixel.
 429  * @param[in] radians The rotation angle in radians.
 430  * @param[out] pixelsOut The rotated output buffer.
 431  * @param[out] widthOut The width of the output buffer.
 432  * @param[out] heightOut The height of the output buffer.
 433  */
 434 void RotateByShear(const uint8_t* const pixelsIn,
 435                    unsigned int         widthIn,
 436                    unsigned int         heightIn,
 437                    unsigned int         strideIn,
 438                    unsigned int         pixelSize,
 439                    float                radians,
 440                    uint8_t*&            pixelsOut,
 441                    unsigned int&        widthOut,
 442                    unsigned int&        heightOut);
 443
 444 /**
 445  * @brief Applies to the input image a horizontal shear transformation.
 446  *
 447  * @pre @p pixelsIn must not alias @p pixelsOut. The input image should be a totally
 448  * separate buffer from the output buffer.
 449  * @pre The maximun/minimum shear angle is +/-45 degrees (PI/4 around 0.79 radians).
 450  *
 451  * @note This function allocates memory in @p pixelsOut which has to be released by calling @e free()
 452  *
 453  * @param[in] pixelsIn The input buffer.
 454  * @param[in] widthIn The width of the input buffer.
 455  * @param[in] heightIn The height of the input buffer.
 456  * @param[in] strideIn The stride of the input buffer.
 457  * @param[in] pixelSize The size of the pixel.
 458  * @param[in] radians The shear angle in radians.
 459  * @param[out] pixelsOut The rotated output buffer.
 460  * @param[out] widthOut The width of the output buffer.
 461  * @param[out] heightOut The height of the output buffer.
 462  */
 463 void HorizontalShear(const uint8_t* const pixelsIn,
 464                      unsigned int         widthIn,
 465                      unsigned int         heightIn,
 466                      unsigned int         strideIn,
 467                      unsigned int         pixelSize,
 468                      float                radians,
 469                      uint8_t*&            pixelsOut,
 470                      unsigned int&        widthOut,
 471                      unsigned int&        heightOut);
 472
 473 /**@}*/
 474
 475 /**
 476  * @defgroup ScalingAlgorithmFragments Composable subunits of the scaling algorithms.
 477  * @{
 478  */
 479
 480 /**
 481  * @brief Average adjacent pairs of pixels, overwriting the input array.
 482  * @param[in,out] pixels The array of pixels to work on.
 483  * @param[i]      width  The number of pixels in the array passed-in.
 484  */
 485 void HalveScanlineInPlaceRGB888(unsigned char* pixels, unsigned int width);
 486
 487 /**
 488  * @copydoc HalveScanlineInPlaceRGB888
 489  */
 490 void HalveScanlineInPlaceRGBA8888(unsigned char* pixels, unsigned int width);
 491
 492 /**
 493  * @copydoc HalveScanlineInPlaceRGB888
 494  */
 495 void HalveScanlineInPlaceRGB565(unsigned char* pixels, unsigned int width);
 496
 497 /**
 498  * @copydoc HalveScanlineInPlaceRGB888
 499  */
 500 void HalveScanlineInPlace2Bytes(unsigned char* pixels, unsigned int width);
 501
 502 /**
 503  * @copydoc HalveScanlineInPlaceRGB888
 504  */
 505 void HalveScanlineInPlace1Byte(unsigned char* pixels, unsigned int width);
 506
 507 /**
 508  * @brief Average pixels at corresponding offsets in two scanlines.
 509  *
 510  * outputScanline is allowed to alias scanline1.
 511  * @param[in] scanline1 First scanline of pixels to average.
 512  * @param[in] scanline2 Second scanline of pixels to average.
 513  * @param[out] outputScanline Destination for the averaged pixels.
 514  * @param[in] width The widths of all the scanlines passed-in.
 515  */
 516 void AverageScanlines1(const unsigned char* scanline1,
 517                        const unsigned char* scanline2,
 518                        unsigned char*       outputScanline,
 519                        /** Image width in pixels (1 byte == 1 pixel: e.g. lum8 or alpha8).*/
 520                        unsigned int width);
 521
 522 /**
 523  * @copydoc AverageScanlines1
 524  */
 525 void AverageScanlines2(const unsigned char* scanline1,
 526                        const unsigned char* scanline2,
 527                        unsigned char*       outputScanline,
 528                        /** Image width in pixels (2 bytes == 1 pixel: e.g. lum8alpha8).*/
 529                        unsigned int width);
 530
 531 /**
 532  * @copydoc AverageScanlines1
 533  */
 534 void AverageScanlines3(const unsigned char* scanline1,
 535                        const unsigned char* scanline2,
 536                        unsigned char*       outputScanline,
 537                        /** Image width in pixels (3 bytes == 1 pixel: e.g. RGB888).*/
 538                        unsigned int width);
 539
 540 /**
 541  * @copydoc AverageScanlines1
 542  */
 543 void AverageScanlinesRGBA8888(const unsigned char* scanline1,
 544                               const unsigned char* scanline2,
 545                               unsigned char*       outputScanline,
 546                               unsigned int         width);
 547
 548 /**
 549  * @copydoc AverageScanlines1
 550  */
 551 void AverageScanlinesRGB565(const unsigned char* scanline1,
 552                             const unsigned char* scanline2,
 553                             unsigned char*       outputScanline,
 554                             unsigned int         width);
 555 /**@}*/
 556
 557 /**
 558  * @defgroup TestableInlines Inline functions exposed in header to allow unit testing.
 559  * @{
 560  */
 561
 562 /**
 563  * @brief Average two integer arguments.
 564  * @return The average of two uint arguments.
 565  * @param[in] a First component to average.
 566  * @param[in] b Second component to average.
 567  **/
 568 inline unsigned int AverageComponent(unsigned int a, unsigned int b)
 569 {
 570   unsigned int avg = (a + b) >> 1u;
 571   return avg;
 572 }
 573
 574 /**
 575  * @brief Average a pair of RGBA8888 pixels.
 576  * @return The average of two RGBA8888 pixels.
 577  * @param[in] a First pixel to average.
 578  * @param[in] b Second pixel to average
 579  **/
 580 inline uint32_t AveragePixelRGBA8888(uint32_t a, uint32_t b)
 581 {
 582   /**
 583    * @code
 584    * const unsigned int avg =
 585    *   (AverageComponent((a & 0xff000000) >> 1u, (b & 0xff000000) >> 1u) << 1u) & 0xff000000) +
 586    *   (AverageComponent(a & 0x00ff0000, b & 0x00ff0000) & 0x00ff0000) +
 587    *   (AverageComponent(a & 0x0000ff00, b & 0x0000ff00) & 0x0000ff00) +
 588    *   (AverageComponent(a & 0x000000ff, b & 0x000000ff);
 589    * return avg;
 590    * @endcode
 591    */
 592   return (((a ^ b) & 0xfefefefeu) >> 1) + (a & b);
 593   ///@ToDo: Optimise for ARM using the single ARMV6 instruction: UHADD8  R4, R0, R5. This is not Neon. It runs in the normal integer pipeline so there is no downside like a stall moving between integer and copro.
 594 }
 595
 596 /**
 597  * @brief Average a pair of RGB565 pixels.
 598  * @param a[in] Low 16 bits hold a color value as RGB565 to average with parameter b.
 599  * @param b[in] Low 16 bits hold a color value as RGB565 to average with parameter a.
 600  * @return The average color of the two RGB565 pixels passed in, in the low 16 bits of the returned value.
 601  **/
 602 inline uint32_t AveragePixelRGB565(uint32_t a, uint32_t b)
 603 {
 604   /**
 605    * @code
 606    * const unsigned int avg =
 607    *   (AverageComponent(a & 0xf800, b & 0xf800) & 0xf800) +
 608    *   (AverageComponent(a & 0x7e0, b & 0x7e0) & 0x7e0) +
 609    *   (AverageComponent(a & 0x1f, b & 0x1f));
 610    * return avg;
 611    * @endcode
 612    */
 613   return (((a ^ b) & 0xf7deu) >> 1) + (a & b);
 614 }
 615
 616 /** @return The weighted blend of two integers as a 16.16 fixed-point number, given a 0.16 fixed-point blending factor. */
 617 inline unsigned int WeightedBlendIntToFixed1616(unsigned int a, unsigned int b, unsigned int fractBlend)
 618 {
 619   DALI_ASSERT_DEBUG(fractBlend <= 65535u && "Factor should be in 0.16 fixed-point.");
 620   /**
 621    * @code
 622    * const unsigned int weightedAFixed = a * (65535u - fractBlend);
 623    * const unsigned int weightedBFixed = b * fractBlend;
 624    * const unsigned     blended        = (weightedAFixed + weightedBFixed);
 625    * @endcode
 626    */
 627   const unsigned int blended = (a << 16) - a + (static_cast<int32_t>(b) - static_cast<int32_t>(a)) * fractBlend;
 628   return blended;
 629 }
 630
 631 /** @brief Blend two 16.16 inputs to give a 16.32 output. */
 632 inline uint64_t WeightedBlendFixed1616ToFixed1632(unsigned int a, unsigned int b, unsigned int fractBlend)
 633 {
 634   DALI_ASSERT_DEBUG(fractBlend <= 65535u && "Factor should be in 0.16 fixed-point.");
 635   /**
 636    * @code
 637    * // Blend while promoting intermediates to 16.32 fixed point:
 638    * const uint64_t weightedAFixed = uint64_t(a) * (65535u - fractBlend);
 639    * const uint64_t weightedBFixed = uint64_t(b) * fractBlend;
 640    * const uint64_t blended        = (weightedAFixed + weightedBFixed);
 641    * @endcode
 642    */
 643   const uint64_t blended = (static_cast<uint64_t>(a) << 16) - a + (static_cast<int64_t>(b) - static_cast<int64_t>(a)) * fractBlend;
 644   return blended;
 645 }
 646
 647 /**
 648  * @brief Blend 4 taps into one value using horizontal and vertical weights.
 649  */
 650 inline unsigned int BilinearFilter1Component(unsigned int tl, unsigned int tr, unsigned int bl, unsigned int br, unsigned int fractBlendHorizontal, unsigned int fractBlendVertical)
 651 {
 652   DALI_ASSERT_DEBUG(fractBlendHorizontal <= 65535u && "Factor should be in 0.16 fixed-point.");
 653   DALI_ASSERT_DEBUG(fractBlendVertical <= 65535u && "Factor should be in 0.16 fixed-point.");
 654
 655   /**
 656    * @code
 657    * const unsigned int topBlend   = WeightedBlendIntToFixed1616(tl, tr, fractBlendHorizontal);
 658    * const unsigned int botBlend   = WeightedBlendIntToFixed1616(bl, br, fractBlendHorizontal);
 659    * const uint64_t     blended2x2 = WeightedBlendFixed1616ToFixed1632(topBlend, botBlend, fractBlendVertical);
 660    * const unsigned int rounded    = (blended2x2 + (1u << 31u)) >> 32u;
 661    * @endcode
 662    */
 663
 664   /**
 665    * Hard-coding optimize!
 666    *
 667    * Let p = 65536, s.t we can optimze it as << 16.
 668    * Let x = fractBlendHorizontal, y = fractBlendVertical.
 669    * topBlend = (tl*p - tl - tl*x + tr*x)
 670    * botBlend = (bl*p - bl - bl*x + br*x)
 671    * blended2x2 = topBlend*p - topBlend - topBlend*y + botBlend*y
 672    *
 673    * And now we can split all values.
 674    * tl*p*p - tl*p - tl*x*p + tr*x*p  -  tl*p + tl + tl*x - tr*x  -  tl*y*p + tl*y + tl*x*y - tr*x*y  +  bl*y*p - bl*y - bl*x*y + br*x*y;
 675    * --> (collect by p, x, and y)
 676    * (tl)*p*p + (-2tl + (-tl + tr)*x + (-tl+bl)*y)*p + tl + (tl - tr)*x + (tl - bl)*y + (tl - tr - bl + br)*x*y
 677    *
 678    * A = (tl - tr) * x;
 679    * B = (tl - bl) * y;
 680    * C = (tl - tr - bl + br) * x * y;
 681    * D = (2*tl + A + B)
 682    * -->
 683    * (tl << 32) - (D << 16) + tl + A + B + C
 684    *
 685    * Becareful of overflow and negative value.
 686    */
 687   const int32_t A = (static_cast<int32_t>(tl) - static_cast<int32_t>(tr)) * static_cast<int32_t>(fractBlendHorizontal);
 688   const int32_t B = (static_cast<int32_t>(tl) - static_cast<int32_t>(bl)) * static_cast<int32_t>(fractBlendVertical);
 689   const int64_t C = (static_cast<int64_t>(tl) - static_cast<int64_t>(tr) - static_cast<int64_t>(bl) + static_cast<int64_t>(br)) * static_cast<int64_t>(fractBlendHorizontal) * static_cast<int64_t>(fractBlendVertical);
 690   const int64_t D = ((static_cast<int64_t>(tl) << 1) + A + B);
 691
 692   const uint64_t     blended2x2 = (static_cast<int64_t>(tl) << 32u) - (D << 16u) + tl + A + B + C;
 693   const unsigned int rounded    = (blended2x2 + (1u << 31u)) >> 32u;
 694   return rounded;
 695 }
 696
 697 /**@}*/
 698
 699 } /* namespace Platform */
 700 } /* namespace Internal */
 701 } /* namespace Dali */
 702
 703 #endif /* DALI_INTERNAL_PLATFORM_IMAGE_OPERATIONS_H */