text: /**************************************************************************
   *
   * Copyright 2010 VMware, Inc.
   * All Rights Reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sub license, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice (including the
   * next paragraph) shall be included in all copies or substantial portions
   * of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
   * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
   * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
   * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   **************************************************************************/
  
  /**
   * @file
   * Pixel format accessor functions.
   *
   * @author Jose Fonseca <jfonseca@vmware.com>
   */
  
  #include "util/format/u_format.h"
  #include "util/format/u_format_s3tc.h"
  #include "util/u_math.h"
  
  #include "pipe/p_defines.h"
  #include "pipe/p_screen.h"
  
  
  /**
   * Copy 2D rect from one place to another.
   * Position and sizes are in pixels.
   * src_stride may be negative to do vertical flip of pixels from source.
   */
  void
  util_copy_rect(ubyte * dst,
                 enum pipe_format format,
                 unsigned dst_stride,
                 unsigned dst_x,
                 unsigned dst_y,
                 unsigned width,
                 unsigned height,
                 const ubyte * src,
                 int src_stride,
                 unsigned src_x,
                 unsigned src_y)
  {
     unsigned i;
     int src_stride_pos = src_stride < 0 ? -src_stride : src_stride;
     int blocksize = util_format_get_blocksize(format);
     int blockwidth = util_format_get_blockwidth(format);
     int blockheight = util_format_get_blockheight(format);
  
     assert(blocksize > 0);
     assert(blockwidth > 0);
     assert(blockheight > 0);
  
     dst_x /= blockwidth;
     dst_y /= blockheight;
     width = (width + blockwidth - 1)/blockwidth;
     height = (height + blockheight - 1)/blockheight;
     src_x /= blockwidth;
     src_y /= blockheight;
  
     dst += dst_x * blocksize;
     src += src_x * blocksize;
     dst += dst_y * dst_stride;
     src += src_y * src_stride_pos;
     width *= blocksize;
  
     if (width == dst_stride && width == (unsigned)src_stride)
        memcpy(dst, src, height * width);
     else {
        for (i = 0; i < height; i++) {
           memcpy(dst, src, width);
           dst += dst_stride;
           src += src_stride;
        }
     }
  }
  
  
  boolean
  util_format_is_float(enum pipe_format format)
  {
     const struct util_format_description *desc = util_format_description(format);
     int i;
  
     assert(desc);
     if (!desc) {
        return FALSE;
     }
  
     i = util_format_get_first_non_void_channel(format);
     if (i < 0) {
        return FALSE;
     }
  
     return desc->channel[i].type == UTIL_FORMAT_TYPE_FLOAT ? TRUE : FALSE;
  }
  
  
  /** Test if the format contains RGB, but not alpha */
  boolean
  util_format_has_alpha(enum pipe_format format)
  {
     const struct util_format_description *desc =
        util_format_description(format);
  
     return (desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
             desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) &&
            desc->swizzle[3] != PIPE_SWIZZLE_1;
  }
  
  
  boolean
  util_format_is_luminance(enum pipe_format format)
  {
     const struct util_format_description *desc =
        util_format_description(format);
  
     if ((desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
          desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) &&
         desc->swizzle[0] == PIPE_SWIZZLE_X &&
         desc->swizzle[1] == PIPE_SWIZZLE_X &&
         desc->swizzle[2] == PIPE_SWIZZLE_X &&
         desc->swizzle[3] == PIPE_SWIZZLE_1) {
        return TRUE;
     }
     return FALSE;
  }
  
  boolean
  util_format_is_alpha(enum pipe_format format)
  {
     const struct util_format_description *desc =
        util_format_description(format);
  
     if ((desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
          desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) &&
         desc->swizzle[0] == PIPE_SWIZZLE_0 &&
         desc->swizzle[1] == PIPE_SWIZZLE_0 &&
         desc->swizzle[2] == PIPE_SWIZZLE_0 &&
         desc->swizzle[3] == PIPE_SWIZZLE_X) {
        return TRUE;
     }
     return FALSE;
  }
  
  boolean
  util_format_is_pure_integer(enum pipe_format format)
  {
     const struct util_format_description *desc = util_format_description(format);
     int i;
  
     /* Find the first non-void channel. */
     i = util_format_get_first_non_void_channel(format);
     if (i == -1)
        return FALSE;
  
     return desc->channel[i].pure_integer ? TRUE : FALSE;
  }
  
  boolean
  util_format_is_pure_sint(enum pipe_format format)
  {
     const struct util_format_description *desc = util_format_description(format);
     int i;
  
     i = util_format_get_first_non_void_channel(format);
     if (i == -1)
        return FALSE;
  
     return (desc->channel[i].type == UTIL_FORMAT_TYPE_SIGNED && desc->channel[i].pure_integer) ? TRUE : FALSE;
  }
  
  boolean
  util_format_is_pure_uint(enum pipe_format format)
  {
     const struct util_format_description *desc = util_format_description(format);
     int i;
  
     i = util_format_get_first_non_void_channel(format);
     if (i == -1)
        return FALSE;
  
     return (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED && desc->channel[i].pure_integer) ? TRUE : FALSE;
  }
  
  /**
   * Returns true if the format contains normalized signed channels.
   */
  boolean
  util_format_is_snorm(enum pipe_format format)
  {
     const struct util_format_description *desc = util_format_description(format);
  
     return desc->is_snorm;
  }
  
  /**
   * Returns true if the format contains normalized unsigned channels.
   */
  boolean
  util_format_is_unorm(enum pipe_format format)
  {
     const struct util_format_description *desc = util_format_description(format);
  
     return desc->is_unorm;
  }
  
  boolean
  util_format_is_snorm8(enum pipe_format format)
  {
     const struct util_format_description *desc = util_format_description(format);
     int i;
  
     if (desc->is_mixed)
        return FALSE;
  
     i = util_format_get_first_non_void_channel(format);
     if (i == -1)
        return FALSE;
  
     return desc->channel[i].type == UTIL_FORMAT_TYPE_SIGNED &&
            !desc->channel[i].pure_integer &&
            desc->channel[i].normalized &&
            desc->channel[i].size == 8;
  }
  
  boolean
  util_format_is_luminance_alpha(enum pipe_format format)
  {
     const struct util_format_description *desc =
        util_format_description(format);
  
     if ((desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
          desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) &&
         desc->swizzle[0] == PIPE_SWIZZLE_X &&
         desc->swizzle[1] == PIPE_SWIZZLE_X &&
         desc->swizzle[2] == PIPE_SWIZZLE_X &&
         desc->swizzle[3] == PIPE_SWIZZLE_Y) {
        return TRUE;
     }
     return FALSE;
  }
  
  
  boolean
  util_format_is_intensity(enum pipe_format format)
  {
     const struct util_format_description *desc =
        util_format_description(format);
  
     if ((desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
          desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) &&
         desc->swizzle[0] == PIPE_SWIZZLE_X &&
         desc->swizzle[1] == PIPE_SWIZZLE_X &&
         desc->swizzle[2] == PIPE_SWIZZLE_X &&
         desc->swizzle[3] == PIPE_SWIZZLE_X) {
        return TRUE;
     }
     return FALSE;
  }
  
  boolean
  util_format_is_subsampled_422(enum pipe_format format)
  {
     const struct util_format_description *desc =
        util_format_description(format);
  
     return desc->layout == UTIL_FORMAT_LAYOUT_SUBSAMPLED &&
        desc->block.width == 2 &&
        desc->block.height == 1 &&
        desc->block.bits == 32;
  }
  
  /**
   * Calculates the MRD for the depth format. MRD is used in depth bias
   * for UNORM and unbound depth buffers. When the depth buffer is floating
   * point, the depth bias calculation does not use the MRD. However, the
   * default MRD will be 1.0 / ((1 << 24) - 1).
   */
  double
  util_get_depth_format_mrd(const struct util_format_description *desc)
  {
     /*
      * Depth buffer formats without a depth component OR scenarios
      * without a bound depth buffer default to D24.
      */
     double mrd = 1.0 / ((1 << 24) - 1);
     unsigned depth_channel;
  
     assert(desc);
  
     /*
      * Some depth formats do not store the depth component in the first
      * channel, detect the format and adjust the depth channel. Get the
      * swizzled depth component channel.
      */
     depth_channel = desc->swizzle[0];
  
     if (desc->channel[depth_channel].type == UTIL_FORMAT_TYPE_UNSIGNED &&
         desc->channel[depth_channel].normalized) {
        int depth_bits;
  
        depth_bits = desc->channel[depth_channel].size;
        mrd = 1.0 / ((1ULL << depth_bits) - 1);
     }
  
     return mrd;
  }
  
  
  void
  util_format_read_4(enum pipe_format format,
                     void *dst, unsigned dst_stride,
                     const void *src, unsigned src_stride,
                     unsigned x, unsigned y, unsigned w, unsigned h)
  {
     const struct util_format_description *format_desc;
     const uint8_t *src_row;
  
     format_desc = util_format_description(format);
  
     assert(x % format_desc->block.width == 0);
     assert(y % format_desc->block.height == 0);
  
     src_row = (const uint8_t *)src + y*src_stride + x*(format_desc->block.bits/8);
  
     format_desc->unpack_rgba(dst, dst_stride, src_row, src_stride, w, h);
  }
  
  
  void
  util_format_write_4(enum pipe_format format,
                       const void *src, unsigned src_stride,
                       void *dst, unsigned dst_stride,
                       unsigned x, unsigned y, unsigned w, unsigned h)
  {
     const struct util_format_description *format_desc;
     uint8_t *dst_row;
  
     format_desc = util_format_description(format);
  
     assert(x % format_desc->block.width == 0);
     assert(y % format_desc->block.height == 0);
  
     dst_row = (uint8_t *)dst + y*dst_stride + x*(format_desc->block.bits/8);
  
     if (util_format_is_pure_uint(format))
        format_desc->pack_rgba_uint(dst_row, dst_stride, src, src_stride, w, h);
     else if (util_format_is_pure_sint(format))
        format_desc->pack_rgba_sint(dst_row, dst_stride, src, src_stride, w, h);
     else
        format_desc->pack_rgba_float(dst_row, dst_stride, src, src_stride, w, h);
  }
  
  
  void
  util_format_read_4ub(enum pipe_format format, uint8_t *dst, unsigned dst_stride, const void *src, unsigned src_stride, unsigned x, unsigned y, unsigned w, unsigned h)
  {
     const struct util_format_description *format_desc;
     const uint8_t *src_row;
     uint8_t *dst_row;
  
     format_desc = util_format_description(format);
  
     assert(x % format_desc->block.width == 0);
     assert(y % format_desc->block.height == 0);
  
     src_row = (const uint8_t *)src + y*src_stride + x*(format_desc->block.bits/8);
     dst_row = dst;
  
     format_desc->unpack_rgba_8unorm(dst_row, dst_stride, src_row, src_stride, w, h);
  }
  
  
  void
  util_format_write_4ub(enum pipe_format format, const uint8_t *src, unsigned src_stride, void *dst, unsigned dst_stride, unsigned x, unsigned y, unsigned w, unsigned h)
  {
     const struct util_format_description *format_desc;
     uint8_t *dst_row;
     const uint8_t *src_row;
  
     format_desc = util_format_description(format);
  
     assert(x % format_desc->block.width == 0);
     assert(y % format_desc->block.height == 0);
  
     dst_row = (uint8_t *)dst + y*dst_stride + x*(format_desc->block.bits/8);
     src_row = src;
  
     format_desc->pack_rgba_8unorm(dst_row, dst_stride, src_row, src_stride, w, h);
  }
  
  /**
   * Check if we can safely memcopy from the source format to the dest format.
   * This basically covers the cases of a "used" channel copied to a typeless
   * channel, plus some 1-channel cases.
   * Examples of compatible copy formats include:
   *    b8g8r8a8_unorm -> b8g8r8x8_unorm
   *    a8r8g8b8_unorm -> x8r8g8b8_unorm
   *    b5g5r5a1_unorm -> b5g5r5x1_unorm
   *    b4g4r4a4_unorm -> b4g4r4x4_unorm
   *    l8_unorm -> r8_unorm
   *    i8_unorm -> l8_unorm
   *    i8_unorm -> a8_unorm
   *    i8_unorm -> r8_unorm
   *    l16_unorm -> r16_unorm
   *    z24_unorm_s8_uint -> z24x8_unorm
   *    s8_uint_z24_unorm -> x8z24_unorm
   *    r8g8b8a8_unorm -> r8g8b8x8_unorm
   *    a8b8g8r8_srgb -> x8b8g8r8_srgb
   *    b8g8r8a8_srgb -> b8g8r8x8_srgb
   *    a8r8g8b8_srgb -> x8r8g8b8_srgb
   *    a8b8g8r8_unorm -> x8b8g8r8_unorm
   *    r10g10b10a2_uscaled -> r10g10b10x2_uscaled
   *    r10sg10sb10sa2u_norm -> r10g10b10x2_snorm
   */
  boolean
  util_is_format_compatible(const struct util_format_description *src_desc,
                            const struct util_format_description *dst_desc)
  {
     unsigned chan;
  
     if (src_desc->format == dst_desc->format) {
        return TRUE;
     }
  
     if (src_desc->layout != UTIL_FORMAT_LAYOUT_PLAIN ||
         dst_desc->layout != UTIL_FORMAT_LAYOUT_PLAIN) {
        return FALSE;
     }
  
     if (src_desc->block.bits != dst_desc->block.bits ||
         src_desc->nr_channels != dst_desc->nr_channels ||
         src_desc->colorspace != dst_desc->colorspace) {
        return FALSE;
     }
  
     for (chan = 0; chan < 4; ++chan) {
        if (src_desc->channel[chan].size !=
            dst_desc->channel[chan].size) {
           return FALSE;
        }
     }
  
     for (chan = 0; chan < 4; ++chan) {
        enum pipe_swizzle swizzle = dst_desc->swizzle[chan];
  
        if (swizzle < 4) {
           if (src_desc->swizzle[chan] != swizzle) {
              return FALSE;
           }
           if ((src_desc->channel[swizzle].type !=
                dst_desc->channel[swizzle].type) ||
               (src_desc->channel[swizzle].normalized !=
                dst_desc->channel[swizzle].normalized)) {
              return FALSE;
           }
        }
     }
  
     return TRUE;
  }
  
  
  boolean
  util_format_fits_8unorm(const struct util_format_description *format_desc)
  {
     unsigned chan;
  
     /*
      * After linearized sRGB values require more than 8bits.
      */
  
     if (format_desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) {
        return FALSE;
     }
  
     switch (format_desc->layout) {
  
     case UTIL_FORMAT_LAYOUT_S3TC:
        /*
         * These are straight forward.
         */
        return TRUE;
     case UTIL_FORMAT_LAYOUT_RGTC:
        if (format_desc->format == PIPE_FORMAT_RGTC1_SNORM ||
            format_desc->format == PIPE_FORMAT_RGTC2_SNORM ||
            format_desc->format == PIPE_FORMAT_LATC1_SNORM ||
            format_desc->format == PIPE_FORMAT_LATC2_SNORM)
           return FALSE;
        return TRUE;
     case UTIL_FORMAT_LAYOUT_BPTC:
        if (format_desc->format == PIPE_FORMAT_BPTC_RGBA_UNORM)
           return TRUE;
        return FALSE;
  
     case UTIL_FORMAT_LAYOUT_ETC:
        if (format_desc->format == PIPE_FORMAT_ETC1_RGB8)
           return TRUE;
        return FALSE;
  
     case UTIL_FORMAT_LAYOUT_PLAIN:
        /*
         * For these we can find a generic rule.
         */
  
        for (chan = 0; chan < format_desc->nr_channels; ++chan) {
           switch (format_desc->channel[chan].type) {
           case UTIL_FORMAT_TYPE_VOID:
              break;
           case UTIL_FORMAT_TYPE_UNSIGNED:
              if (!format_desc->channel[chan].normalized ||
                  format_desc->channel[chan].size > 8) {
                 return FALSE;
              }
              break;
           default:
              return FALSE;
           }
        }
        return TRUE;
  
     default:
        /*
         * Handle all others on a case by case basis.
         */
  
        switch (format_desc->format) {
        case PIPE_FORMAT_R1_UNORM:
        case PIPE_FORMAT_UYVY:
        case PIPE_FORMAT_YUYV:
        case PIPE_FORMAT_R8G8_B8G8_UNORM:
        case PIPE_FORMAT_G8R8_G8B8_UNORM:
           return TRUE;
  
        default:
           return FALSE;
        }
     }
  }
  
  
  boolean
  util_format_translate(enum pipe_format dst_format,
                        void *dst, unsigned dst_stride,
                        unsigned dst_x, unsigned dst_y,
                        enum pipe_format src_format,
                        const void *src, unsigned src_stride,
                        unsigned src_x, unsigned src_y,
                        unsigned width, unsigned height)
  {
     const struct util_format_description *dst_format_desc;
     const struct util_format_description *src_format_desc;
     uint8_t *dst_row;
     const uint8_t *src_row;
     unsigned x_step, y_step;
     unsigned dst_step;
     unsigned src_step;
  
     dst_format_desc = util_format_description(dst_format);
     src_format_desc = util_format_description(src_format);
  
     if (util_is_format_compatible(src_format_desc, dst_format_desc)) {
        /*
         * Trivial case.
         */
  
        util_copy_rect(dst, dst_format, dst_stride,  dst_x, dst_y,
                       width, height, src, (int)src_stride,
                       src_x, src_y);
        return TRUE;
     }
  
     assert(dst_x % dst_format_desc->block.width == 0);
     assert(dst_y % dst_format_desc->block.height == 0);
     assert(src_x % src_format_desc->block.width == 0);
     assert(src_y % src_format_desc->block.height == 0);
  
     dst_row = (uint8_t *)dst + dst_y*dst_stride + dst_x*(dst_format_desc->block.bits/8);
     src_row = (const uint8_t *)src + src_y*src_stride + src_x*(src_format_desc->block.bits/8);
  
     /*
      * This works because all pixel formats have pixel blocks with power of two
      * sizes.
      */
  
     y_step = MAX2(dst_format_desc->block.height, src_format_desc->block.height);
     x_step = MAX2(dst_format_desc->block.width, src_format_desc->block.width);
     assert(y_step % dst_format_desc->block.height == 0);
     assert(y_step % src_format_desc->block.height == 0);
  
     dst_step = y_step / dst_format_desc->block.height * dst_stride;
     src_step = y_step / src_format_desc->block.height * src_stride;
  
     /*
      * TODO: double formats will loose precision
      * TODO: Add a special case for formats that are mere swizzles of each other
      */
  
     if (src_format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS ||
         dst_format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS) {
        float *tmp_z = NULL;
        uint8_t *tmp_s = NULL;
  
        assert(x_step == 1);
        assert(y_step == 1);
  
        if (src_format_desc->unpack_z_float &&
            dst_format_desc->pack_z_float) {
           tmp_z = malloc(width * sizeof *tmp_z);
        }
  
        if (src_format_desc->unpack_s_8uint &&
            dst_format_desc->pack_s_8uint) {
           tmp_s = malloc(width * sizeof *tmp_s);
        }
  
        while (height--) {
           if (tmp_z) {
              util_format_unpack_z_float(src_format, tmp_z, src_row, width);
              util_format_pack_z_float(dst_format, dst_row, tmp_z, width);
           }
  
           if (tmp_s) {
              util_format_unpack_s_8uint(src_format, tmp_s, src_row, width);
              util_format_pack_s_8uint(dst_format, dst_row, tmp_s, width);
           }
  
           dst_row += dst_step;
           src_row += src_step;
        }
  
        free(tmp_s);
  
        free(tmp_z);
  
        return TRUE;
     }
  
     if (util_format_fits_8unorm(src_format_desc) ||
         util_format_fits_8unorm(dst_format_desc)) {
        unsigned tmp_stride;
        uint8_t *tmp_row;
  
        if (!src_format_desc->unpack_rgba_8unorm ||
            !dst_format_desc->pack_rgba_8unorm) {
           return FALSE;
        }
  
        tmp_stride = MAX2(width, x_step) * 4 * sizeof *tmp_row;
        tmp_row = malloc(y_step * tmp_stride);
        if (!tmp_row)
           return FALSE;
  
        while (height >= y_step) {
           src_format_desc->unpack_rgba_8unorm(tmp_row, tmp_stride, src_row, src_stride, width, y_step);
           dst_format_desc->pack_rgba_8unorm(dst_row, dst_stride, tmp_row, tmp_stride, width, y_step);
  
           dst_row += dst_step;
           src_row += src_step;
           height -= y_step;
        }
  
        if (height) {
           src_format_desc->unpack_rgba_8unorm(tmp_row, tmp_stride, src_row, src_stride, width, height);
           dst_format_desc->pack_rgba_8unorm(dst_row, dst_stride, tmp_row, tmp_stride, width, height);
        }
  
        free(tmp_row);
     }
     else if (util_format_is_pure_sint(src_format) ||
              util_format_is_pure_sint(dst_format)) {
        unsigned tmp_stride;
        int *tmp_row;
  
        if (util_format_is_pure_sint(src_format) !=
            util_format_is_pure_sint(dst_format)) {
           return FALSE;
        }
  
        tmp_stride = MAX2(width, x_step) * 4 * sizeof *tmp_row;
        tmp_row = malloc(y_step * tmp_stride);
        if (!tmp_row)
           return FALSE;
  
        while (height >= y_step) {
           src_format_desc->unpack_rgba(tmp_row, tmp_stride, src_row, src_stride, width, y_step);
           dst_format_desc->pack_rgba_sint(dst_row, dst_stride, tmp_row, tmp_stride, width, y_step);
  
           dst_row += dst_step;
           src_row += src_step;
           height -= y_step;
        }
  
        if (height) {
           src_format_desc->unpack_rgba(tmp_row, tmp_stride, src_row, src_stride, width, height);
           dst_format_desc->pack_rgba_sint(dst_row, dst_stride, tmp_row, tmp_stride, width, height);
        }
  
        free(tmp_row);
     }
     else if (util_format_is_pure_uint(src_format) ||
              util_format_is_pure_uint(dst_format)) {
        unsigned tmp_stride;
        unsigned int *tmp_row;
  
        if (!src_format_desc->unpack_rgba ||
            !dst_format_desc->pack_rgba_uint) {
           return FALSE;
        }
  
        tmp_stride = MAX2(width, x_step) * 4 * sizeof *tmp_row;
        tmp_row = malloc(y_step * tmp_stride);
        if (!tmp_row)
           return FALSE;
  
        while (height >= y_step) {
           src_format_desc->unpack_rgba(tmp_row, tmp_stride, src_row, src_stride, width, y_step);
           dst_format_desc->pack_rgba_uint(dst_row, dst_stride, tmp_row, tmp_stride, width, y_step);
  
           dst_row += dst_step;
           src_row += src_step;
           height -= y_step;
        }
  
        if (height) {
           src_format_desc->unpack_rgba(tmp_row, tmp_stride, src_row, src_stride, width, height);
           dst_format_desc->pack_rgba_uint(dst_row, dst_stride, tmp_row, tmp_stride, width, height);
        }
  
        free(tmp_row);
     }
     else {
        unsigned tmp_stride;
        float *tmp_row;
  
        if (!src_format_desc->unpack_rgba ||
            !dst_format_desc->pack_rgba_float) {
           return FALSE;
        }
  
        tmp_stride = MAX2(width, x_step) * 4 * sizeof *tmp_row;
        tmp_row = malloc(y_step * tmp_stride);
        if (!tmp_row)
           return FALSE;
  
        while (height >= y_step) {
           src_format_desc->unpack_rgba(tmp_row, tmp_stride, src_row, src_stride, width, y_step);
           dst_format_desc->pack_rgba_float(dst_row, dst_stride, tmp_row, tmp_stride, width, y_step);
  
           dst_row += dst_step;
           src_row += src_step;
           height -= y_step;
        }
  
        if (height) {
           src_format_desc->unpack_rgba(tmp_row, tmp_stride, src_row, src_stride, width, height);
           dst_format_desc->pack_rgba_float(dst_row, dst_stride, tmp_row, tmp_stride, width, height);
        }
  
        free(tmp_row);
     }
     return TRUE;
  }
  
  boolean
  util_format_translate_3d(enum pipe_format dst_format,
                           void *dst, unsigned dst_stride,
                           unsigned dst_slice_stride,
                           unsigned dst_x, unsigned dst_y,
                           unsigned dst_z,
                           enum pipe_format src_format,
                           const void *src, unsigned src_stride,
                           unsigned src_slice_stride,
                           unsigned src_x, unsigned src_y,
                           unsigned src_z, unsigned width,
                           unsigned height, unsigned depth)
  {
     uint8_t *dst_layer;
     const uint8_t *src_layer;
     unsigned z;
     dst_layer = dst;
     src_layer = src;
     dst_layer += dst_z * dst_slice_stride;
     src_layer += src_z * src_slice_stride;
     for (z = 0; z < depth; ++z) {
        if (!util_format_translate(dst_format, dst_layer, dst_stride,
                                   dst_x, dst_y,
                                   src_format, src_layer, src_stride,
                                   src_x, src_y,
                                   width, height))
            return FALSE;
  
        dst_layer += dst_slice_stride;
        src_layer += src_slice_stride;
     }
     return TRUE;
  }
  
  void util_format_compose_swizzles(const unsigned char swz1[4],
                                    const unsigned char swz2[4],
                                    unsigned char dst[4])
  {
     unsigned i;
  
     for (i = 0; i < 4; i++) {
        dst[i] = swz2[i] <= PIPE_SWIZZLE_W ?
                 swz1[swz2[i]] : swz2[i];
     }
  }
  
  void util_format_apply_color_swizzle(union pipe_color_union *dst,
                                       const union pipe_color_union *src,
                                       const unsigned char swz[4],
                                       const boolean is_integer)
  {
     unsigned c;
  
     if (is_integer) {
        for (c = 0; c < 4; ++c) {
           switch (swz[c]) {
           case PIPE_SWIZZLE_X:   dst->ui[c] = src->ui[0]; break;
           case PIPE_SWIZZLE_Y: dst->ui[c] = src->ui[1]; break;
           case PIPE_SWIZZLE_Z:  dst->ui[c] = src->ui[2]; break;
           case PIPE_SWIZZLE_W: dst->ui[c] = src->ui[3]; break;
           default:
              dst->ui[c] = (swz[c] == PIPE_SWIZZLE_1) ? 1 : 0;
              break;
           }
        }
     } else {
        for (c = 0; c < 4; ++c) {
           switch (swz[c]) {
           case PIPE_SWIZZLE_X:   dst->f[c] = src->f[0]; break;
           case PIPE_SWIZZLE_Y: dst->f[c] = src->f[1]; break;
           case PIPE_SWIZZLE_Z:  dst->f[c] = src->f[2]; break;
           case PIPE_SWIZZLE_W: dst->f[c] = src->f[3]; break;
           default:
              dst->f[c] = (swz[c] == PIPE_SWIZZLE_1) ? 1.0f : 0.0f;
              break;
           }
        }
     }
  }
  
  void pipe_swizzle_4f(float *dst, const float *src,
                              const unsigned char swz[4])
  {
     unsigned i;
  
     for (i = 0; i < 4; i++) {
        if (swz[i] <= PIPE_SWIZZLE_W)
           dst[i] = src[swz[i]];
        else if (swz[i] == PIPE_SWIZZLE_0)
           dst[i] = 0;
        else if (swz[i] == PIPE_SWIZZLE_1)
           dst[i] = 1;
     }
  }
  
  void util_format_unswizzle_4f(float *dst, const float *src,
                                const unsigned char swz[4])
  {
     unsigned i;
  
     for (i = 0; i < 4; i++) {
        switch (swz[i]) {
        case PIPE_SWIZZLE_X:
           dst[0] = src[i];
           break;
        case PIPE_SWIZZLE_Y:
           dst[1] = src[i];
           break;
        case PIPE_SWIZZLE_Z:
           dst[2] = src[i];
           break;
        case PIPE_SWIZZLE_W:
           dst[3] = src[i];
           break;
        }
     }
  }
  
  enum pipe_format
  util_format_snorm8_to_sint8(enum pipe_format format)
  {
     switch (format) {
     case PIPE_FORMAT_R8_SNORM:
        return PIPE_FORMAT_R8_SINT;
     case PIPE_FORMAT_R8G8_SNORM:
        return PIPE_FORMAT_R8G8_SINT;
     case PIPE_FORMAT_R8G8B8_SNORM:
        return PIPE_FORMAT_R8G8B8_SINT;
     case PIPE_FORMAT_R8G8B8A8_SNORM:
        return PIPE_FORMAT_R8G8B8A8_SINT;
  
     case PIPE_FORMAT_A8_SNORM:
        return PIPE_FORMAT_A8_SINT;
     case PIPE_FORMAT_L8_SNORM:
        return PIPE_FORMAT_L8_SINT;
     case PIPE_FORMAT_L8A8_SNORM:
        return PIPE_FORMAT_L8A8_SINT;
     case PIPE_FORMAT_I8_SNORM:
        return PIPE_FORMAT_I8_SINT;
  
     case PIPE_FORMAT_R8G8B8X8_SNORM:
        return PIPE_FORMAT_R8G8B8X8_SINT;
     case PIPE_FORMAT_R8A8_SNORM:
        return PIPE_FORMAT_R8A8_SINT;
     case PIPE_FORMAT_G8R8_SNORM:
        return PIPE_FORMAT_G8R8_SINT;
     case PIPE_FORMAT_A8B8G8R8_SNORM:
        return PIPE_FORMAT_A8B8G8R8_SINT;
     case PIPE_FORMAT_X8B8G8R8_SNORM:
        return PIPE_FORMAT_X8B8G8R8_SINT;
  
     default:
        return format;
     }
  }
  