text: /**************************************************************************
   * 
   * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   * Copyright (c) 2008-2010 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 TUNGSTEN GRAPHICS 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.
   * 
   **************************************************************************/
  
  
  /**
   * Mesa / Gallium format conversion and format selection code.
   * \author Brian Paul
   */
  
  #include "main/imports.h"
  #include "main/context.h"
  #include "main/texstore.h"
  #include "main/image.h"
  #include "main/macros.h"
  #include "main/mfeatures.h"
  
  #include "pipe/p_context.h"
  #include "pipe/p_defines.h"
  #include "pipe/p_screen.h"
  #include "util/u_format.h"
  #include "st_context.h"
  #include "st_format.h"
  
  
  static GLuint
  format_max_bits(enum pipe_format format)
  {
     GLuint size = util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 0);
  
     size = MAX2(size, util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 1));
     size = MAX2(size, util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 2));
     size = MAX2(size, util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 3));
     size = MAX2(size, util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 0));
     size = MAX2(size, util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 1));
     return size;
  }
  
  
  /**
   * Return basic GL datatype for the given gallium format.
   */
  GLenum
  st_format_datatype(enum pipe_format format)
  {
     const struct util_format_description *desc;
     int i;
  
     desc = util_format_description(format);
     assert(desc);
  
     /* Find the first non-VOID channel. */
     for (i = 0; i < 4; i++) {
         if (desc->channel[i].type != UTIL_FORMAT_TYPE_VOID) {
             break;
         }
     }
  
     if (desc->layout == UTIL_FORMAT_LAYOUT_PLAIN) {
        if (format == PIPE_FORMAT_B5G5R5A1_UNORM ||
            format == PIPE_FORMAT_B5G6R5_UNORM) {
           return GL_UNSIGNED_SHORT;
        }
        else if (format == PIPE_FORMAT_R11G11B10_FLOAT ||
                 format == PIPE_FORMAT_R9G9B9E5_FLOAT) {
           return GL_FLOAT;
        }
        else if (format == PIPE_FORMAT_Z24_UNORM_S8_USCALED ||
                 format == PIPE_FORMAT_S8_USCALED_Z24_UNORM ||
                 format == PIPE_FORMAT_Z24X8_UNORM ||
                 format == PIPE_FORMAT_X8Z24_UNORM) {
           return GL_UNSIGNED_INT_24_8;
        }
        else {
           const GLuint size = format_max_bits(format);
  
           assert(i < 4);
           if (i == 4)
              return GL_NONE;
  
           if (size == 8) {
              if (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED)
                 return GL_UNSIGNED_BYTE;
              else
                 return GL_BYTE;
           }
           else if (size == 16) {
              if (desc->channel[i].type == UTIL_FORMAT_TYPE_FLOAT)
                 return GL_HALF_FLOAT;
              if (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED)
                 return GL_UNSIGNED_SHORT;
              else
                 return GL_SHORT;
           }
           else if (size <= 32) {
              if (desc->channel[i].type == UTIL_FORMAT_TYPE_FLOAT)
                 return GL_FLOAT;
              if (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED)
                 return GL_UNSIGNED_INT;
              else
                 return GL_INT;
           }
           else {
              assert(size == 64);
              assert(desc->channel[i].type == UTIL_FORMAT_TYPE_FLOAT);
              return GL_DOUBLE;
           }
        }
     }
     else if (format == PIPE_FORMAT_UYVY) {
        return GL_UNSIGNED_SHORT;
     }
     else if (format == PIPE_FORMAT_YUYV) {
        return GL_UNSIGNED_SHORT;
     }
     else {
        /* probably a compressed format, unsupported anyway */
        return GL_NONE;
     }
  }
  
  
  /**
   * Translate Mesa format to Gallium format.
   */
  enum pipe_format
  st_mesa_format_to_pipe_format(gl_format mesaFormat)
  {
     switch (mesaFormat) {
     case MESA_FORMAT_RGBA8888:
        return PIPE_FORMAT_A8B8G8R8_UNORM;
     case MESA_FORMAT_RGBA8888_REV:
        return PIPE_FORMAT_R8G8B8A8_UNORM;
     case MESA_FORMAT_ARGB8888:
        return PIPE_FORMAT_B8G8R8A8_UNORM;
     case MESA_FORMAT_ARGB8888_REV:
        return PIPE_FORMAT_A8R8G8B8_UNORM;
     case MESA_FORMAT_XRGB8888:
        return PIPE_FORMAT_B8G8R8X8_UNORM;
     case MESA_FORMAT_XRGB8888_REV:
        return PIPE_FORMAT_X8R8G8B8_UNORM;
     case MESA_FORMAT_ARGB1555:
        return PIPE_FORMAT_B5G5R5A1_UNORM;
     case MESA_FORMAT_ARGB4444:
        return PIPE_FORMAT_B4G4R4A4_UNORM;
     case MESA_FORMAT_RGB565:
        return PIPE_FORMAT_B5G6R5_UNORM;
     case MESA_FORMAT_RGB332:
        return PIPE_FORMAT_B2G3R3_UNORM;
     case MESA_FORMAT_ARGB2101010:
        return PIPE_FORMAT_B10G10R10A2_UNORM;
     case MESA_FORMAT_AL44:
        return PIPE_FORMAT_L4A4_UNORM;
     case MESA_FORMAT_AL88:
        return PIPE_FORMAT_L8A8_UNORM;
     case MESA_FORMAT_AL1616:
        return PIPE_FORMAT_L16A16_UNORM;
     case MESA_FORMAT_A8:
        return PIPE_FORMAT_A8_UNORM;
     case MESA_FORMAT_A16:
        return PIPE_FORMAT_A16_UNORM;
     case MESA_FORMAT_L8:
        return PIPE_FORMAT_L8_UNORM;
     case MESA_FORMAT_L16:
        return PIPE_FORMAT_L16_UNORM;
     case MESA_FORMAT_I8:
        return PIPE_FORMAT_I8_UNORM;
     case MESA_FORMAT_I16:
        return PIPE_FORMAT_I16_UNORM;
     case MESA_FORMAT_Z16:
        return PIPE_FORMAT_Z16_UNORM;
     case MESA_FORMAT_Z32:
        return PIPE_FORMAT_Z32_UNORM;
     case MESA_FORMAT_Z24_S8:
        return PIPE_FORMAT_S8_USCALED_Z24_UNORM;
     case MESA_FORMAT_S8_Z24:
        return PIPE_FORMAT_Z24_UNORM_S8_USCALED;
     case MESA_FORMAT_Z24_X8:
        return PIPE_FORMAT_X8Z24_UNORM;
     case MESA_FORMAT_X8_Z24:
        return PIPE_FORMAT_Z24X8_UNORM;
     case MESA_FORMAT_S8:
        return PIPE_FORMAT_S8_USCALED;
     case MESA_FORMAT_YCBCR:
        return PIPE_FORMAT_UYVY;
  #if FEATURE_texture_s3tc
     case MESA_FORMAT_RGB_DXT1:
        return PIPE_FORMAT_DXT1_RGB;
     case MESA_FORMAT_RGBA_DXT1:
        return PIPE_FORMAT_DXT1_RGBA;
     case MESA_FORMAT_RGBA_DXT3:
        return PIPE_FORMAT_DXT3_RGBA;
     case MESA_FORMAT_RGBA_DXT5:
        return PIPE_FORMAT_DXT5_RGBA;
  #if FEATURE_EXT_texture_sRGB
     case MESA_FORMAT_SRGB_DXT1:
        return PIPE_FORMAT_DXT1_SRGB;
     case MESA_FORMAT_SRGBA_DXT1:
        return PIPE_FORMAT_DXT1_SRGBA;
     case MESA_FORMAT_SRGBA_DXT3:
        return PIPE_FORMAT_DXT3_SRGBA;
     case MESA_FORMAT_SRGBA_DXT5:
        return PIPE_FORMAT_DXT5_SRGBA;
  #endif
  #endif
  #if FEATURE_EXT_texture_sRGB
     case MESA_FORMAT_SLA8:
        return PIPE_FORMAT_L8A8_SRGB;
     case MESA_FORMAT_SL8:
        return PIPE_FORMAT_L8_SRGB;
     case MESA_FORMAT_SRGB8:
        return PIPE_FORMAT_R8G8B8_SRGB;
     case MESA_FORMAT_SRGBA8:
        return PIPE_FORMAT_A8B8G8R8_SRGB;
     case MESA_FORMAT_SARGB8:
        return PIPE_FORMAT_B8G8R8A8_SRGB;
  #endif
     case MESA_FORMAT_RGBA_FLOAT32:
        return PIPE_FORMAT_R32G32B32A32_FLOAT;
     case MESA_FORMAT_RGBA_FLOAT16:
        return PIPE_FORMAT_R16G16B16A16_FLOAT;
     case MESA_FORMAT_RGB_FLOAT32:
        return PIPE_FORMAT_R32G32B32_FLOAT;
     case MESA_FORMAT_RGB_FLOAT16:
        return PIPE_FORMAT_R16G16B16_FLOAT;
     case MESA_FORMAT_LUMINANCE_ALPHA_FLOAT32:
        return PIPE_FORMAT_L32A32_FLOAT;
     case MESA_FORMAT_LUMINANCE_ALPHA_FLOAT16:
        return PIPE_FORMAT_L16A16_FLOAT;
     case MESA_FORMAT_LUMINANCE_FLOAT32:
        return PIPE_FORMAT_L32_FLOAT;
     case MESA_FORMAT_LUMINANCE_FLOAT16:
        return PIPE_FORMAT_L16_FLOAT;
     case MESA_FORMAT_ALPHA_FLOAT32:
        return PIPE_FORMAT_A32_FLOAT;
     case MESA_FORMAT_ALPHA_FLOAT16:
        return PIPE_FORMAT_A16_FLOAT;
     case MESA_FORMAT_INTENSITY_FLOAT32:
        return PIPE_FORMAT_I32_FLOAT;
     case MESA_FORMAT_INTENSITY_FLOAT16:
        return PIPE_FORMAT_I16_FLOAT;
     case MESA_FORMAT_R_FLOAT32:
        return PIPE_FORMAT_R32_FLOAT;
     case MESA_FORMAT_R_FLOAT16:
        return PIPE_FORMAT_R16_FLOAT;
     case MESA_FORMAT_RG_FLOAT32:
        return PIPE_FORMAT_R32G32_FLOAT;
     case MESA_FORMAT_RG_FLOAT16:
        return PIPE_FORMAT_R16G16_FLOAT;
  
     case MESA_FORMAT_R8:
        return PIPE_FORMAT_R8_UNORM;
     case MESA_FORMAT_R16:
        return PIPE_FORMAT_R16_UNORM;
     case MESA_FORMAT_RG88:
        return PIPE_FORMAT_R8G8_UNORM;
     case MESA_FORMAT_RG1616:
        return PIPE_FORMAT_R16G16_UNORM;
     case MESA_FORMAT_RGBA_16:
        return PIPE_FORMAT_R16G16B16A16_UNORM;
  
     /* signed int formats */
     case MESA_FORMAT_RGBA_INT8:
        return PIPE_FORMAT_R8G8B8A8_SSCALED;
     case MESA_FORMAT_RGBA_INT16:
        return PIPE_FORMAT_R16G16B16A16_SSCALED;
     case MESA_FORMAT_RGBA_INT32:
        return PIPE_FORMAT_R32G32B32A32_SSCALED;
  
     /* unsigned int formats */
     case MESA_FORMAT_RGBA_UINT8:
        return PIPE_FORMAT_R8G8B8A8_USCALED;
     case MESA_FORMAT_RGBA_UINT16:
        return PIPE_FORMAT_R16G16B16A16_USCALED;
     case MESA_FORMAT_RGBA_UINT32:
        return PIPE_FORMAT_R32G32B32A32_USCALED;
  
     case MESA_FORMAT_RED_RGTC1:
        return PIPE_FORMAT_RGTC1_UNORM;
     case MESA_FORMAT_SIGNED_RED_RGTC1:
        return PIPE_FORMAT_RGTC1_SNORM;
     case MESA_FORMAT_RG_RGTC2:
        return PIPE_FORMAT_RGTC2_UNORM;
     case MESA_FORMAT_SIGNED_RG_RGTC2:
        return PIPE_FORMAT_RGTC2_SNORM;
  
     case MESA_FORMAT_L_LATC1:
        return PIPE_FORMAT_LATC1_UNORM;
     case MESA_FORMAT_SIGNED_L_LATC1:
        return PIPE_FORMAT_LATC1_SNORM;
     case MESA_FORMAT_LA_LATC2:
        return PIPE_FORMAT_LATC2_UNORM;
     case MESA_FORMAT_SIGNED_LA_LATC2:
        return PIPE_FORMAT_LATC2_SNORM;
  
     /* signed normalized formats */
     case MESA_FORMAT_SIGNED_R8:
        return PIPE_FORMAT_R8_SNORM;
     case MESA_FORMAT_SIGNED_RG88_REV:
        return PIPE_FORMAT_R8G8_SNORM;
     case MESA_FORMAT_SIGNED_RGBA8888_REV:
        return PIPE_FORMAT_R8G8B8A8_SNORM;
  
     case MESA_FORMAT_SIGNED_A8:
        return PIPE_FORMAT_A8_SNORM;
     case MESA_FORMAT_SIGNED_L8:
        return PIPE_FORMAT_L8_SNORM;
     case MESA_FORMAT_SIGNED_AL88:
        return PIPE_FORMAT_L8A8_SNORM;
     case MESA_FORMAT_SIGNED_I8:
        return PIPE_FORMAT_I8_SNORM;
  
     case MESA_FORMAT_SIGNED_R16:
        return PIPE_FORMAT_R16_SNORM;
     case MESA_FORMAT_SIGNED_GR1616:
        return PIPE_FORMAT_R16G16_SNORM;
     case MESA_FORMAT_SIGNED_RGBA_16:
        return PIPE_FORMAT_R16G16B16A16_SNORM;
  
     case MESA_FORMAT_SIGNED_A16:
        return PIPE_FORMAT_A16_SNORM;
     case MESA_FORMAT_SIGNED_L16:
        return PIPE_FORMAT_L16_SNORM;
     case MESA_FORMAT_SIGNED_AL1616:
        return PIPE_FORMAT_L16A16_SNORM;
     case MESA_FORMAT_SIGNED_I16:
        return PIPE_FORMAT_I16_SNORM;
  
     case MESA_FORMAT_RGB9_E5_FLOAT:
        return PIPE_FORMAT_R9G9B9E5_FLOAT;
     case MESA_FORMAT_R11_G11_B10_FLOAT:
        return PIPE_FORMAT_R11G11B10_FLOAT;
  
     default:
        assert(0);
        return PIPE_FORMAT_NONE;
     }
  }
  
  
  /**
   * Translate Gallium format to Mesa format.
   */
  gl_format
  st_pipe_format_to_mesa_format(enum pipe_format format)
  {
     switch (format) {
     case PIPE_FORMAT_A8B8G8R8_UNORM:
        return MESA_FORMAT_RGBA8888;
     case PIPE_FORMAT_R8G8B8A8_UNORM:
        return MESA_FORMAT_RGBA8888_REV;
     case PIPE_FORMAT_B8G8R8A8_UNORM:
        return MESA_FORMAT_ARGB8888;
     case PIPE_FORMAT_A8R8G8B8_UNORM:
        return MESA_FORMAT_ARGB8888_REV;
     case PIPE_FORMAT_B8G8R8X8_UNORM:
        return MESA_FORMAT_XRGB8888;
     case PIPE_FORMAT_X8R8G8B8_UNORM:
        return MESA_FORMAT_XRGB8888_REV;
     case PIPE_FORMAT_B5G5R5A1_UNORM:
        return MESA_FORMAT_ARGB1555;
     case PIPE_FORMAT_B4G4R4A4_UNORM:
        return MESA_FORMAT_ARGB4444;
     case PIPE_FORMAT_B5G6R5_UNORM:
        return MESA_FORMAT_RGB565;
     case PIPE_FORMAT_B2G3R3_UNORM:
        return MESA_FORMAT_RGB332;
     case PIPE_FORMAT_B10G10R10A2_UNORM:
        return MESA_FORMAT_ARGB2101010;
     case PIPE_FORMAT_L4A4_UNORM:
        return MESA_FORMAT_AL44;
     case PIPE_FORMAT_L8A8_UNORM:
        return MESA_FORMAT_AL88;
     case PIPE_FORMAT_L16A16_UNORM:
        return MESA_FORMAT_AL1616;
     case PIPE_FORMAT_A8_UNORM:
        return MESA_FORMAT_A8;
     case PIPE_FORMAT_A16_UNORM:
        return MESA_FORMAT_A16;
     case PIPE_FORMAT_L8_UNORM:
        return MESA_FORMAT_L8;
     case PIPE_FORMAT_L16_UNORM:
        return MESA_FORMAT_L16;
     case PIPE_FORMAT_I8_UNORM:
        return MESA_FORMAT_I8;
     case PIPE_FORMAT_I16_UNORM:
        return MESA_FORMAT_I16;
     case PIPE_FORMAT_S8_USCALED:
        return MESA_FORMAT_S8;
  
     case PIPE_FORMAT_R16G16B16A16_UNORM:
        return MESA_FORMAT_RGBA_16;
  
     case PIPE_FORMAT_Z16_UNORM:
        return MESA_FORMAT_Z16;
     case PIPE_FORMAT_Z32_UNORM:
        return MESA_FORMAT_Z32;
     case PIPE_FORMAT_S8_USCALED_Z24_UNORM:
        return MESA_FORMAT_Z24_S8;
     case PIPE_FORMAT_X8Z24_UNORM:
        return MESA_FORMAT_Z24_X8;
     case PIPE_FORMAT_Z24X8_UNORM:
        return MESA_FORMAT_X8_Z24;
     case PIPE_FORMAT_Z24_UNORM_S8_USCALED:
        return MESA_FORMAT_S8_Z24;
  
     case PIPE_FORMAT_UYVY:
        return MESA_FORMAT_YCBCR;
     case PIPE_FORMAT_YUYV:
        return MESA_FORMAT_YCBCR_REV;
  
  #if FEATURE_texture_s3tc
     case PIPE_FORMAT_DXT1_RGB:
        return MESA_FORMAT_RGB_DXT1;
     case PIPE_FORMAT_DXT1_RGBA:
        return MESA_FORMAT_RGBA_DXT1;
     case PIPE_FORMAT_DXT3_RGBA:
        return MESA_FORMAT_RGBA_DXT3;
     case PIPE_FORMAT_DXT5_RGBA:
        return MESA_FORMAT_RGBA_DXT5;
  #if FEATURE_EXT_texture_sRGB
     case PIPE_FORMAT_DXT1_SRGB:
        return MESA_FORMAT_SRGB_DXT1;
     case PIPE_FORMAT_DXT1_SRGBA:
        return MESA_FORMAT_SRGBA_DXT1;
     case PIPE_FORMAT_DXT3_SRGBA:
        return MESA_FORMAT_SRGBA_DXT3;
     case PIPE_FORMAT_DXT5_SRGBA:
        return MESA_FORMAT_SRGBA_DXT5;
  #endif
  #endif
  
  #if FEATURE_EXT_texture_sRGB
     case PIPE_FORMAT_L8A8_SRGB:
        return MESA_FORMAT_SLA8;
     case PIPE_FORMAT_L8_SRGB:
        return MESA_FORMAT_SL8;
     case PIPE_FORMAT_R8G8B8_SRGB:
        return MESA_FORMAT_SRGB8;
     case PIPE_FORMAT_A8B8G8R8_SRGB:
        return MESA_FORMAT_SRGBA8;
     case PIPE_FORMAT_B8G8R8A8_SRGB:
        return MESA_FORMAT_SARGB8;
  #endif
     case PIPE_FORMAT_R32G32B32A32_FLOAT:
        return MESA_FORMAT_RGBA_FLOAT32;
     case PIPE_FORMAT_R16G16B16A16_FLOAT:
        return MESA_FORMAT_RGBA_FLOAT16;
     case PIPE_FORMAT_R32G32B32_FLOAT:
        return MESA_FORMAT_RGB_FLOAT32;
     case PIPE_FORMAT_R16G16B16_FLOAT:
        return MESA_FORMAT_RGB_FLOAT16;
     case PIPE_FORMAT_L32A32_FLOAT:
        return MESA_FORMAT_LUMINANCE_ALPHA_FLOAT32;
     case PIPE_FORMAT_L16A16_FLOAT:
        return MESA_FORMAT_LUMINANCE_ALPHA_FLOAT16;
     case PIPE_FORMAT_L32_FLOAT:
        return MESA_FORMAT_LUMINANCE_FLOAT32;
     case PIPE_FORMAT_L16_FLOAT:
        return MESA_FORMAT_LUMINANCE_FLOAT16;
     case PIPE_FORMAT_A32_FLOAT:
        return MESA_FORMAT_ALPHA_FLOAT32;
     case PIPE_FORMAT_A16_FLOAT:
        return MESA_FORMAT_ALPHA_FLOAT16;
     case PIPE_FORMAT_I32_FLOAT:
        return MESA_FORMAT_INTENSITY_FLOAT32;
     case PIPE_FORMAT_I16_FLOAT:
        return MESA_FORMAT_INTENSITY_FLOAT16;
     case PIPE_FORMAT_R32_FLOAT:
        return MESA_FORMAT_R_FLOAT32;
     case PIPE_FORMAT_R16_FLOAT:
        return MESA_FORMAT_R_FLOAT16;
     case PIPE_FORMAT_R32G32_FLOAT:
        return MESA_FORMAT_RG_FLOAT32;
     case PIPE_FORMAT_R16G16_FLOAT:
        return MESA_FORMAT_RG_FLOAT16;
  
     case PIPE_FORMAT_R8_UNORM:
        return MESA_FORMAT_R8;
     case PIPE_FORMAT_R16_UNORM:
        return MESA_FORMAT_R16;
     case PIPE_FORMAT_R8G8_UNORM:
        return MESA_FORMAT_RG88;
     case PIPE_FORMAT_R16G16_UNORM:
        return MESA_FORMAT_RG1616;
  
     /* signed int formats */
     case PIPE_FORMAT_R8G8B8A8_SSCALED:
        return MESA_FORMAT_RGBA_INT8;
     case PIPE_FORMAT_R16G16B16A16_SSCALED:
        return MESA_FORMAT_RGBA_INT16;
     case PIPE_FORMAT_R32G32B32A32_SSCALED:
        return MESA_FORMAT_RGBA_INT32;
  
     /* unsigned int formats */
     case PIPE_FORMAT_R8G8B8A8_USCALED:
        return MESA_FORMAT_RGBA_UINT8;
     case PIPE_FORMAT_R16G16B16A16_USCALED:
        return MESA_FORMAT_RGBA_UINT16;
     case PIPE_FORMAT_R32G32B32A32_USCALED:
        return MESA_FORMAT_RGBA_UINT32;
  
     case PIPE_FORMAT_RGTC1_UNORM:
        return MESA_FORMAT_RED_RGTC1;
     case PIPE_FORMAT_RGTC1_SNORM:
        return MESA_FORMAT_SIGNED_RED_RGTC1;
     case PIPE_FORMAT_RGTC2_UNORM:
        return MESA_FORMAT_RG_RGTC2;
     case PIPE_FORMAT_RGTC2_SNORM:
        return MESA_FORMAT_SIGNED_RG_RGTC2;
  
     case PIPE_FORMAT_LATC1_UNORM:
        return MESA_FORMAT_L_LATC1;
     case PIPE_FORMAT_LATC1_SNORM:
        return MESA_FORMAT_SIGNED_L_LATC1;
     case PIPE_FORMAT_LATC2_UNORM:
        return MESA_FORMAT_LA_LATC2;
     case PIPE_FORMAT_LATC2_SNORM:
        return MESA_FORMAT_SIGNED_LA_LATC2;
  
     /* signed normalized formats */
     case PIPE_FORMAT_R8_SNORM:
        return MESA_FORMAT_SIGNED_R8;
     case PIPE_FORMAT_R8G8_SNORM:
        return MESA_FORMAT_SIGNED_RG88_REV;
     case PIPE_FORMAT_R8G8B8A8_SNORM:
        return MESA_FORMAT_SIGNED_RGBA8888_REV;
  
     case PIPE_FORMAT_A8_SNORM:
        return MESA_FORMAT_SIGNED_A8;
     case PIPE_FORMAT_L8_SNORM:
        return MESA_FORMAT_SIGNED_L8;
     case PIPE_FORMAT_L8A8_SNORM:
        return MESA_FORMAT_SIGNED_AL88;
     case PIPE_FORMAT_I8_SNORM:
        return MESA_FORMAT_SIGNED_I8;
  
     case PIPE_FORMAT_R16_SNORM:
        return MESA_FORMAT_SIGNED_R16;
     case PIPE_FORMAT_R16G16_SNORM:
        return MESA_FORMAT_SIGNED_GR1616;
     case PIPE_FORMAT_R16G16B16A16_SNORM:
        return MESA_FORMAT_SIGNED_RGBA_16;
  
     case PIPE_FORMAT_A16_SNORM:
        return MESA_FORMAT_SIGNED_A16;
     case PIPE_FORMAT_L16_SNORM:
        return MESA_FORMAT_SIGNED_L16;
     case PIPE_FORMAT_L16A16_SNORM:
        return MESA_FORMAT_SIGNED_AL1616;
     case PIPE_FORMAT_I16_SNORM:
        return MESA_FORMAT_SIGNED_I16;
  
     case PIPE_FORMAT_R9G9B9E5_FLOAT:
        return MESA_FORMAT_RGB9_E5_FLOAT;
     case PIPE_FORMAT_R11G11B10_FLOAT:
        return MESA_FORMAT_R11_G11_B10_FLOAT;
  
     default:
        assert(0);
        return MESA_FORMAT_NONE;
     }
  }
  
  
  /**
   * Map GL texture formats to Gallium pipe formats.
   */
  struct format_mapping
  {
     GLenum glFormats[18];       /**< list of GLenum formats, 0-terminated */
     enum pipe_format pipeFormats[10]; /**< list of pipe formats, 0-terminated */
  };
  
  
  #define DEFAULT_RGBA_FORMATS \
        PIPE_FORMAT_B8G8R8A8_UNORM, \
        PIPE_FORMAT_A8R8G8B8_UNORM, \
        PIPE_FORMAT_A8B8G8R8_UNORM, \
        PIPE_FORMAT_B5G6R5_UNORM, \
        0
  
  #define DEFAULT_RGB_FORMATS \
        PIPE_FORMAT_B8G8R8X8_UNORM, \
        PIPE_FORMAT_X8R8G8B8_UNORM, \
        PIPE_FORMAT_X8B8G8R8_UNORM, \
        PIPE_FORMAT_B8G8R8A8_UNORM, \
        PIPE_FORMAT_A8R8G8B8_UNORM, \
        PIPE_FORMAT_A8B8G8R8_UNORM, \
        PIPE_FORMAT_B5G6R5_UNORM, \
        0
  
  #define DEFAULT_SRGBA_FORMATS \
        PIPE_FORMAT_B8G8R8A8_SRGB, \
        PIPE_FORMAT_A8R8G8B8_SRGB, \
        PIPE_FORMAT_A8B8G8R8_SRGB, \
        0
  
  #define DEFAULT_DEPTH_FORMATS \
        PIPE_FORMAT_Z24X8_UNORM, \
        PIPE_FORMAT_X8Z24_UNORM, \
        PIPE_FORMAT_Z16_UNORM, \
        PIPE_FORMAT_Z24_UNORM_S8_USCALED, \
        PIPE_FORMAT_S8_USCALED_Z24_UNORM, \
        0
  
  /**
   * This table maps OpenGL texture format enums to Gallium pipe_format enums.
   * Multiple GL enums might map to multiple pipe_formats.
   * The first pipe format in the list that's supported is the one that's chosen.
   */
  static const struct format_mapping format_map[] = {
     /* Basic RGB, RGBA formats */
     {
        { GL_RGB10, GL_RGB10_A2, 0 },
        { PIPE_FORMAT_B10G10R10A2_UNORM, DEFAULT_RGBA_FORMATS }
     },
     {
        { 4, GL_RGBA, GL_RGBA8, 0 },
        { PIPE_FORMAT_R8G8B8A8_UNORM, DEFAULT_RGBA_FORMATS }
     },
     {
        { GL_BGRA, 0 },
        { PIPE_FORMAT_B8G8R8A8_UNORM, DEFAULT_RGBA_FORMATS }
     },
     {
        { 3, GL_RGB, GL_RGB8, 0 },
        { DEFAULT_RGB_FORMATS }
     },
     {
        { GL_RGB12, GL_RGB16, GL_RGBA12, GL_RGBA16, 0 },
        { PIPE_FORMAT_R16G16B16A16_UNORM, DEFAULT_RGBA_FORMATS }
     },
     {
        { GL_RGBA4, GL_RGBA2, 0 },
        { PIPE_FORMAT_B4G4R4A4_UNORM, DEFAULT_RGBA_FORMATS }
     },
     {
        { GL_RGB5_A1, 0 },
        { PIPE_FORMAT_B5G5R5A1_UNORM, DEFAULT_RGBA_FORMATS }
     },
     {
        { GL_R3_G3_B2, 0 },
        { PIPE_FORMAT_B2G3R3_UNORM, PIPE_FORMAT_B5G6R5_UNORM,
          PIPE_FORMAT_B5G5R5A1_UNORM, DEFAULT_RGBA_FORMATS }
     },
     {
        { GL_RGB5, GL_RGB4 },
        { PIPE_FORMAT_B5G6R5_UNORM, PIPE_FORMAT_B5G5R5A1_UNORM,
          DEFAULT_RGBA_FORMATS }
     },
  
     /* basic Alpha formats */
     {
        { GL_ALPHA12, GL_ALPHA16, 0 },
        { PIPE_FORMAT_A16_UNORM, PIPE_FORMAT_A8_UNORM,
          DEFAULT_RGBA_FORMATS }
     },
     {
        { GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_COMPRESSED_ALPHA, 0 },
        { PIPE_FORMAT_A8_UNORM, DEFAULT_RGBA_FORMATS }
     },
  
     /* basic Luminance formats */
     {
        { GL_LUMINANCE12, GL_LUMINANCE16, 0 },
        { PIPE_FORMAT_L16_UNORM, PIPE_FORMAT_L8_UNORM, DEFAULT_RGB_FORMATS }
     },
     {
        { 1, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8, 0 },
        { PIPE_FORMAT_L8_UNORM, DEFAULT_RGB_FORMATS }
     },
  
     /* basic Luminance/Alpha formats */
     {
        { GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12,
          GL_LUMINANCE16_ALPHA16, 0},
        { PIPE_FORMAT_L16A16_UNORM, PIPE_FORMAT_L8A8_UNORM,
          DEFAULT_RGBA_FORMATS }
     },
     {
        { 2, GL_LUMINANCE_ALPHA, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8, 0 },
        { PIPE_FORMAT_L8A8_UNORM, DEFAULT_RGBA_FORMATS }
     },
     {
        { GL_LUMINANCE4_ALPHA4, 0 },
        { PIPE_FORMAT_L4A4_UNORM, PIPE_FORMAT_L8A8_UNORM,
          DEFAULT_RGBA_FORMATS }
     },
  
     /* basic Intensity formats */
     {
        { GL_INTENSITY12, GL_INTENSITY16, 0 },
        { PIPE_FORMAT_I16_UNORM, PIPE_FORMAT_I8_UNORM, DEFAULT_RGBA_FORMATS }
     },
     {
        { GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8,
          GL_COMPRESSED_INTENSITY, 0 },
        { PIPE_FORMAT_I8_UNORM, DEFAULT_RGBA_FORMATS }
     },
  
     /* YCbCr */
     {
        { GL_YCBCR_MESA, 0 },
        { PIPE_FORMAT_UYVY, PIPE_FORMAT_YUYV, 0 }
     },
  
     /* compressed formats */ /* XXX PIPE_BIND_SAMPLER_VIEW only */
     {
        { GL_COMPRESSED_RGB, 0 },
        { PIPE_FORMAT_DXT1_RGB, DEFAULT_RGB_FORMATS }
     },
     {
        { GL_COMPRESSED_RGBA, 0 },
        { PIPE_FORMAT_DXT5_RGBA, DEFAULT_RGBA_FORMATS }
     },
     {
        { GL_RGB_S3TC, GL_RGB4_S3TC, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 0 },
        { PIPE_FORMAT_DXT1_RGB, 0 }
     },
     {
        { GL_COMPRESSED_RGBA_S3TC_DXT1_EXT, 0 },
        { PIPE_FORMAT_DXT1_RGBA, 0 }
     },
     {
        { GL_RGBA_S3TC, GL_RGBA4_S3TC, GL_COMPRESSED_RGBA_S3TC_DXT3_EXT, 0 },
        { PIPE_FORMAT_DXT3_RGBA, 0 }
     },
     {
        { GL_COMPRESSED_RGBA_S3TC_DXT5_EXT, 0 },
        { PIPE_FORMAT_DXT5_RGBA, 0 }
     },
  
  #if 0
     {
        { GL_COMPRESSED_RGB_FXT1_3DFX, 0 },
        { PIPE_FORMAT_RGB_FXT1, 0 }
     },
     {
        { GL_COMPRESSED_RGBA_FXT1_3DFX, 0 },
        { PIPE_FORMAT_RGBA_FXT1, 0 }
     },
  #endif
  
     /* Depth formats */
     {
        { GL_DEPTH_COMPONENT16, 0 },
        { PIPE_FORMAT_Z16_UNORM, DEFAULT_DEPTH_FORMATS }
     },
     {
        { GL_DEPTH_COMPONENT24, 0 },
        { PIPE_FORMAT_Z24X8_UNORM, PIPE_FORMAT_X8Z24_UNORM,
          DEFAULT_DEPTH_FORMATS }
     },
     {
        { GL_DEPTH_COMPONENT32, 0 },
        { PIPE_FORMAT_Z32_UNORM, DEFAULT_DEPTH_FORMATS }
     },
     {
        { GL_DEPTH_COMPONENT, 0 },
        { DEFAULT_DEPTH_FORMATS }
     },
  
     /* stencil formats */
     {
        { GL_STENCIL_INDEX, GL_STENCIL_INDEX1_EXT, GL_STENCIL_INDEX4_EXT,
          GL_STENCIL_INDEX8_EXT, GL_STENCIL_INDEX16_EXT, 0 },
        {
           PIPE_FORMAT_S8_USCALED, PIPE_FORMAT_Z24_UNORM_S8_USCALED,
           PIPE_FORMAT_S8_USCALED_Z24_UNORM, 0
        }
     },
  
     /* Depth / Stencil formats */
     {
        { GL_DEPTH_STENCIL_EXT, GL_DEPTH24_STENCIL8_EXT, 0 },
        { PIPE_FORMAT_Z24_UNORM_S8_USCALED, PIPE_FORMAT_S8_USCALED_Z24_UNORM, 0 }
     },
  
     /* sRGB formats */
     {
        { GL_SRGB_EXT, GL_SRGB8_EXT, GL_SRGB_ALPHA_EXT, GL_SRGB8_ALPHA8_EXT, 0 },
        { DEFAULT_SRGBA_FORMATS }
     },
     {
        { GL_COMPRESSED_SRGB_EXT, GL_COMPRESSED_SRGB_S3TC_DXT1_EXT, 0 },
        { PIPE_FORMAT_DXT1_SRGB, DEFAULT_SRGBA_FORMATS }
     },
     {
        { GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT, 0 },
        { PIPE_FORMAT_DXT1_SRGBA, 0 }
     },
     {
        { GL_COMPRESSED_SRGB_ALPHA_EXT,
          GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT, 0 },
        { PIPE_FORMAT_DXT3_SRGBA, DEFAULT_SRGBA_FORMATS }
     },
     {
        { GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT, 0 },
        { PIPE_FORMAT_DXT5_SRGBA, 0 }
     },
     {
        { GL_SLUMINANCE_ALPHA_EXT, GL_SLUMINANCE8_ALPHA8_EXT,
          GL_COMPRESSED_SLUMINANCE_EXT, GL_COMPRESSED_SLUMINANCE_ALPHA_EXT, 0 },
        { PIPE_FORMAT_L8A8_SRGB, DEFAULT_SRGBA_FORMATS }
     },
     {
        { GL_SLUMINANCE_EXT, GL_SLUMINANCE8_EXT, 0 },
        { PIPE_FORMAT_L8_SRGB, DEFAULT_SRGBA_FORMATS }
     },
  
     /* 16-bit float formats */
     {
        { GL_RGBA16F_ARB, 0 },
        { PIPE_FORMAT_R16G16B16A16_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT, 0 }
     },
     {
        { GL_RGB16F_ARB, 0 },
        { PIPE_FORMAT_R16G16B16_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT,
          PIPE_FORMAT_R32G32B32_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT, 0 }
     },
     {
        { GL_LUMINANCE_ALPHA16F_ARB, 0 },
        { PIPE_FORMAT_L16A16_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT,
          PIPE_FORMAT_L32A32_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT, 0 }
     },
     {
        { GL_ALPHA16F_ARB, 0 },
        { PIPE_FORMAT_A16_FLOAT, PIPE_FORMAT_L16A16_FLOAT,
          PIPE_FORMAT_A32_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT,
          PIPE_FORMAT_L32A32_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT, 0 }
     },
     {
        { GL_INTENSITY16F_ARB, 0 },
        { PIPE_FORMAT_I16_FLOAT, PIPE_FORMAT_L16A16_FLOAT,
          PIPE_FORMAT_I32_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT,
          PIPE_FORMAT_L32A32_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT, 0 }
     },
     {
        { GL_LUMINANCE16F_ARB, 0 },
        { PIPE_FORMAT_L16_FLOAT, PIPE_FORMAT_L16A16_FLOAT,
          PIPE_FORMAT_L32_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT,
          PIPE_FORMAT_L32A32_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT, 0 }
     },
     {
        { GL_R16F, 0 },
        { PIPE_FORMAT_R16_FLOAT, PIPE_FORMAT_R16G16_FLOAT,
          PIPE_FORMAT_R32_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT,
          PIPE_FORMAT_R32G32_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT, 0 }
     },
     {
        { GL_RG16F, 0 },
        { PIPE_FORMAT_R16G16_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT,
          PIPE_FORMAT_R32G32_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT, 0 }
     },
  
     /* 32-bit float formats */
     {
        { GL_RGBA32F_ARB, 0 },
        { PIPE_FORMAT_R32G32B32A32_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT, 0 }
     },
     {
        { GL_RGB32F_ARB, 0 },
        { PIPE_FORMAT_R32G32B32_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT,
          PIPE_FORMAT_R16G16B16A16_FLOAT, 0 }
     },
     {
        { GL_LUMINANCE_ALPHA32F_ARB, 0 },
        { PIPE_FORMAT_L32A32_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT,
          PIPE_FORMAT_L16A16_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT, 0 }
     },
     {
        { GL_ALPHA32F_ARB, 0 },
        { PIPE_FORMAT_A32_FLOAT, PIPE_FORMAT_L32A32_FLOAT,
          PIPE_FORMAT_R32G32B32A32_FLOAT, PIPE_FORMAT_A16_FLOAT,
          PIPE_FORMAT_L16A16_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT, 0 }
     },
     {
        { GL_INTENSITY32F_ARB, 0 },
        { PIPE_FORMAT_I32_FLOAT, PIPE_FORMAT_L32A32_FLOAT,
          PIPE_FORMAT_R32G32B32A32_FLOAT, PIPE_FORMAT_I16_FLOAT,
          PIPE_FORMAT_L16A16_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT, 0 }
     },
     {
        { GL_LUMINANCE32F_ARB, 0 },
        { PIPE_FORMAT_L32_FLOAT, PIPE_FORMAT_L32A32_FLOAT,
          PIPE_FORMAT_R32G32B32A32_FLOAT, PIPE_FORMAT_L16_FLOAT,
          PIPE_FORMAT_L16A16_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT, 0 }
     },
     {
        { GL_R32F, 0 },
        { PIPE_FORMAT_R32_FLOAT, PIPE_FORMAT_R32G32_FLOAT,
          PIPE_FORMAT_R32G32B32A32_FLOAT, PIPE_FORMAT_R16_FLOAT,
          PIPE_FORMAT_R16G16_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT, 0 }
     },
     {
        { GL_RG32F, 0 },
        { PIPE_FORMAT_R32G32_FLOAT, PIPE_FORMAT_R32G32B32A32_FLOAT,
          PIPE_FORMAT_R16G16_FLOAT, PIPE_FORMAT_R16G16B16A16_FLOAT, 0 }
     },
  
     /* R, RG formats */
     {
        { GL_RED, GL_R8, 0 },
        { PIPE_FORMAT_R8_UNORM, 0 }
     },
     {
        { GL_RG, GL_RG8, 0 },
        { PIPE_FORMAT_R8G8_UNORM, 0 }
     },
     {
        { GL_R16, 0 },
        { PIPE_FORMAT_R16_UNORM, 0 }
     },
     {
        { GL_RG16, 0 },
        { PIPE_FORMAT_R16G16_UNORM, 0 }
     },
  
     /* compressed R, RG formats */
     {
        { GL_COMPRESSED_RED, GL_COMPRESSED_RED_RGTC1, 0 },
        { PIPE_FORMAT_RGTC1_UNORM, PIPE_FORMAT_R8_UNORM, 0 }
     },
     {
        { GL_COMPRESSED_SIGNED_RED_RGTC1, 0 },
        { PIPE_FORMAT_RGTC1_SNORM, 0 }
     },
     {
        { GL_COMPRESSED_RG, GL_COMPRESSED_RG_RGTC2, 0 },
        { PIPE_FORMAT_RGTC2_UNORM, PIPE_FORMAT_R8G8_UNORM, 0 }
     },
     {
        { GL_COMPRESSED_SIGNED_RG_RGTC2, 0 },
        { PIPE_FORMAT_RGTC2_SNORM, 0 }
     },
     {
        { GL_COMPRESSED_LUMINANCE, GL_COMPRESSED_LUMINANCE_LATC1_EXT, 0 },
        { PIPE_FORMAT_LATC1_UNORM, PIPE_FORMAT_L8_UNORM, 0 }
     },
     {
        { GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT, 0 },
        { PIPE_FORMAT_LATC1_SNORM, 0 }
     },
     {
        { GL_COMPRESSED_LUMINANCE_ALPHA, GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT,
          GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI, 0 },
        { PIPE_FORMAT_LATC2_UNORM, PIPE_FORMAT_L8A8_UNORM, 0 }
     },
     {
        { GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT, 0 },
        { PIPE_FORMAT_LATC2_SNORM, 0 }
     },
  
     /* signed/unsigned integer formats.
      * XXX Mesa only has formats for RGBA signed/unsigned integer formats.
      * If/when new formats are added this code should be updated.
      */
     {
        { GL_RED_INTEGER_EXT,
          GL_GREEN_INTEGER_EXT,
          GL_BLUE_INTEGER_EXT,
          GL_ALPHA_INTEGER_EXT,
          GL_RGB_INTEGER_EXT,
          GL_RGBA_INTEGER_EXT,
          GL_BGR_INTEGER_EXT,
          GL_BGRA_INTEGER_EXT,
          GL_LUMINANCE_INTEGER_EXT,
          GL_LUMINANCE_ALPHA_INTEGER_EXT,
          GL_RGBA8I_EXT,
          GL_RGB8I_EXT,
          GL_ALPHA8I_EXT,
          GL_INTENSITY8I_EXT,
          GL_LUMINANCE8I_EXT,
          GL_LUMINANCE_ALPHA8I_EXT, 0 },
        { PIPE_FORMAT_R8G8B8A8_SSCALED, 0 }
     },
     {
        {
           GL_RGBA16I_EXT,
           GL_RGB16I_EXT,
           GL_ALPHA16I_EXT,
           GL_INTENSITY16I_EXT,
           GL_LUMINANCE16I_EXT,
           GL_LUMINANCE_ALPHA16I_EXT, 0 },
        { PIPE_FORMAT_R16G16B16A16_SSCALED, 0 },
     },
     {
        {
           GL_RGBA32I_EXT,
           GL_RGB32I_EXT,
           GL_ALPHA32I_EXT,
           GL_INTENSITY32I_EXT,
           GL_LUMINANCE32I_EXT,
           GL_LUMINANCE_ALPHA32I_EXT, 0 },
        { PIPE_FORMAT_R32G32B32A32_SSCALED, 0 }
     },
     {
        {
           GL_RGBA8UI_EXT,
           GL_RGB8UI_EXT,
           GL_ALPHA8UI_EXT,
           GL_INTENSITY8UI_EXT,
           GL_LUMINANCE8UI_EXT,
           GL_LUMINANCE_ALPHA8UI_EXT, 0 },
        { PIPE_FORMAT_R8G8B8A8_USCALED, 0 }
     },
     {
        {
           GL_RGBA16UI_EXT,
           GL_RGB16UI_EXT,
           GL_ALPHA16UI_EXT,
           GL_INTENSITY16UI_EXT,
           GL_LUMINANCE16UI_EXT,
           GL_LUMINANCE_ALPHA16UI_EXT, 0 },
        { PIPE_FORMAT_R16G16B16A16_USCALED, 0 }
     },
     {
        {
           GL_RGBA32UI_EXT,
           GL_RGB32UI_EXT,
           GL_ALPHA32UI_EXT,
           GL_INTENSITY32UI_EXT,
           GL_LUMINANCE32UI_EXT,
           GL_LUMINANCE_ALPHA32UI_EXT, 0 },
        { PIPE_FORMAT_R32G32B32A32_USCALED, 0 }
     },
  
     /* signed normalized formats */
     {
        { GL_RED_SNORM, GL_R8_SNORM, 0 },
        { PIPE_FORMAT_R8_SNORM, PIPE_FORMAT_R8G8_SNORM,
          PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_R16_SNORM, 0 },
        { PIPE_FORMAT_R16_SNORM,
          PIPE_FORMAT_R16G16_SNORM,
          PIPE_FORMAT_R16G16B16A16_SNORM,
          PIPE_FORMAT_R8_SNORM,
          PIPE_FORMAT_R8G8_SNORM,
          PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_RG_SNORM, GL_RG8_SNORM, 0 },
        { PIPE_FORMAT_R8G8_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_RG16_SNORM, 0 },
        { PIPE_FORMAT_R16G16_SNORM, PIPE_FORMAT_R16G16B16A16_SNORM,
          PIPE_FORMAT_R8G8_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_RGB_SNORM, GL_RGB8_SNORM, GL_RGBA_SNORM, GL_RGBA8_SNORM, 0 },
        { PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_RGB16_SNORM, GL_RGBA16_SNORM, 0 },
        { PIPE_FORMAT_R16G16B16A16_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_ALPHA_SNORM, GL_ALPHA8_SNORM, 0 },
        { PIPE_FORMAT_A8_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_ALPHA16_SNORM, 0 },
        { PIPE_FORMAT_A16_SNORM, PIPE_FORMAT_R16G16B16A16_SNORM,
          PIPE_FORMAT_A8_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_LUMINANCE_SNORM, GL_LUMINANCE8_SNORM, 0 },
        { PIPE_FORMAT_L8_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_LUMINANCE16_SNORM, 0 },
        { PIPE_FORMAT_L16_SNORM, PIPE_FORMAT_R16G16B16A16_SNORM,
          PIPE_FORMAT_L8_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_LUMINANCE_ALPHA_SNORM, GL_LUMINANCE8_ALPHA8_SNORM, 0 },
        { PIPE_FORMAT_L8A8_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_LUMINANCE16_ALPHA16_SNORM, 0 },
        { PIPE_FORMAT_L16A16_SNORM, PIPE_FORMAT_R16G16B16A16_SNORM,
          PIPE_FORMAT_L8A8_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_INTENSITY_SNORM, GL_INTENSITY8_SNORM, 0 },
        { PIPE_FORMAT_I8_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_INTENSITY16_SNORM, 0 },
        { PIPE_FORMAT_I16_SNORM, PIPE_FORMAT_R16G16B16A16_SNORM,
          PIPE_FORMAT_I8_SNORM, PIPE_FORMAT_R8G8B8A8_SNORM, 0 }
     },
     {
        { GL_RGB9_E5, 0 },
        { PIPE_FORMAT_R9G9B9E5_FLOAT, 0 }
     },
     {
        { GL_R11F_G11F_B10F, 0 },
        { PIPE_FORMAT_R11G11B10_FLOAT, 0 }
     }
  };
  
  
  /**
   * Return first supported format from the given list.
   */
  static enum pipe_format
  find_supported_format(struct pipe_screen *screen,
                        const enum pipe_format formats[],
                        enum pipe_texture_target target,
                        unsigned sample_count,
                        unsigned tex_usage)
  {
     uint i;
     for (i = 0; formats[i]; i++) {
        if (screen->is_format_supported(screen, formats[i], target,
                                        sample_count, tex_usage)) {
           return formats[i];
        }
     }
     return PIPE_FORMAT_NONE;
  }
  
  struct exact_format_mapping
  {
     GLenum format;
     GLenum type;
     enum pipe_format pformat;
  };
  
  static const struct exact_format_mapping rgba8888_tbl[] =
  {
     { GL_RGBA,     GL_UNSIGNED_INT_8_8_8_8,        PIPE_FORMAT_A8B8G8R8_UNORM },
     { GL_ABGR_EXT, GL_UNSIGNED_INT_8_8_8_8_REV,    PIPE_FORMAT_A8B8G8R8_UNORM },
     { GL_RGBA,     GL_UNSIGNED_INT_8_8_8_8_REV,    PIPE_FORMAT_R8G8B8A8_UNORM },
     { GL_ABGR_EXT, GL_UNSIGNED_INT_8_8_8_8,        PIPE_FORMAT_R8G8B8A8_UNORM },
     { GL_BGRA,     GL_UNSIGNED_INT_8_8_8_8,        PIPE_FORMAT_A8R8G8B8_UNORM },
     { GL_BGRA,     GL_UNSIGNED_INT_8_8_8_8_REV,    PIPE_FORMAT_B8G8R8A8_UNORM },
     { GL_RGBA,     GL_UNSIGNED_BYTE,               PIPE_FORMAT_R8G8B8A8_UNORM },
     { GL_ABGR_EXT, GL_UNSIGNED_BYTE,               PIPE_FORMAT_A8B8G8R8_UNORM },
     { GL_BGRA,     GL_UNSIGNED_BYTE,               PIPE_FORMAT_B8G8R8A8_UNORM },
     { 0,           0,                              0                          }
  };
  
  static const struct exact_format_mapping rgbx8888_tbl[] =
  {
     { GL_BGRA,     GL_UNSIGNED_INT_8_8_8_8,        PIPE_FORMAT_X8R8G8B8_UNORM },
     { GL_BGRA,     GL_UNSIGNED_INT_8_8_8_8_REV,    PIPE_FORMAT_B8G8R8X8_UNORM },
     { GL_BGRA,     GL_UNSIGNED_BYTE,               PIPE_FORMAT_B8G8R8X8_UNORM },
     /* No Mesa formats for these Gallium formats:
     { GL_RGBA,     GL_UNSIGNED_INT_8_8_8_8,        PIPE_FORMAT_X8B8G8R8_UNORM },
     { GL_ABGR_EXT, GL_UNSIGNED_INT_8_8_8_8_REV,    PIPE_FORMAT_X8B8G8R8_UNORM },
     { GL_RGBA,     GL_UNSIGNED_INT_8_8_8_8_REV,    PIPE_FORMAT_R8G8B8X8_UNORM },
     { GL_ABGR_EXT, GL_UNSIGNED_INT_8_8_8_8,        PIPE_FORMAT_R8G8B8X8_UNORM },
     { GL_RGBA,     GL_UNSIGNED_BYTE,               PIPE_FORMAT_R8G8B8X8_UNORM },
     { GL_ABGR_EXT, GL_UNSIGNED_BYTE,               PIPE_FORMAT_X8B8G8R8_UNORM },
     */
     { 0,           0,                              0                          }
  };
  
  static const struct exact_format_mapping rgba1010102_tbl[] =
  {
     { GL_BGRA,     GL_UNSIGNED_INT_2_10_10_10_REV, PIPE_FORMAT_B10G10R10A2_UNORM },
     /* No Mesa formats for these Gallium formats:
     { GL_RGBA,     GL_UNSIGNED_INT_2_10_10_10_REV, PIPE_FORMAT_R10G10B10A2_UNORM },
     { GL_ABGR_EXT, GL_UNSIGNED_INT_10_10_10_2,     PIPE_FORMAT_R10G10B10A2_UNORM },
     { GL_ABGR_EXT, GL_UNSIGNED_INT,                PIPE_FORMAT_R10G10B10A2_UNORM },
     */
     { 0,           0,                              0                             }
  };
  
  /**
   * If there is an exact pipe_format match for {internalFormat, format, type}
   * return that, otherwise return PIPE_FORMAT_NONE so we can do fuzzy matching.
   */
  static enum pipe_format
  find_exact_format(GLint internalFormat, GLenum format, GLenum type)
  {
     uint i;
     const struct exact_format_mapping* tbl;
  
     if (format == GL_NONE || type == GL_NONE)
        return PIPE_FORMAT_NONE;
  
     switch (internalFormat) {
     case 4:
     case GL_RGBA:
     case GL_RGBA8:
        tbl = rgba8888_tbl;
        break;
     case 3:
     case GL_RGB:
     case GL_RGB8:
        tbl = rgbx8888_tbl;
        break;
     case GL_RGB10_A2:
        tbl = rgba1010102_tbl;
        break;
     default:
        return PIPE_FORMAT_NONE;
     }
  
     for (i = 0; tbl[i].format; i++)
        if (tbl[i].format == format && tbl[i].type == type)
           return tbl[i].pformat;
  
     return PIPE_FORMAT_NONE;
  }
  
  /**
   * Given an OpenGL internalFormat value for a texture or surface, return
   * the best matching PIPE_FORMAT_x, or PIPE_FORMAT_NONE if there's no match.
   * This is called during glTexImage2D, for example.
   *
   * The bindings parameter typically has PIPE_BIND_SAMPLER_VIEW set, plus
   * either PIPE_BINDING_RENDER_TARGET or PIPE_BINDING_DEPTH_STENCIL if
   * we want render-to-texture ability.
   *
   * \param internalFormat  the user value passed to glTexImage2D
   * \param target  one of PIPE_TEXTURE_x
   * \param bindings  bitmask of PIPE_BIND_x flags.
   */
  enum pipe_format
  st_choose_format(struct pipe_screen *screen, GLenum internalFormat,
                   GLenum format, GLenum type,
                   enum pipe_texture_target target, unsigned sample_count,
                   unsigned bindings)
  {
     GET_CURRENT_CONTEXT(ctx); /* XXX this should be a function parameter */
     int i, j;
     enum pipe_format pf;
  
     /* can't render to compressed formats at this time */
     if (_mesa_is_compressed_format(ctx, internalFormat)
         && (bindings & ~PIPE_BIND_SAMPLER_VIEW)) {
        return PIPE_FORMAT_NONE;
     }
  
     /* search for exact matches */
     pf = find_exact_format(internalFormat, format, type);
     if (pf != PIPE_FORMAT_NONE &&
         screen->is_format_supported(screen, pf,
                                     target, sample_count, bindings))
        return pf;
  
     /* search table for internalFormat */
     for (i = 0; i < Elements(format_map); i++) {
        const struct format_mapping *mapping = &format_map[i];
        for (j = 0; mapping->glFormats[j]; j++) {
           if (mapping->glFormats[j] == internalFormat) {
              /* Found the desired internal format.  Find first pipe format
               * which is supported by the driver.
               */
              return find_supported_format(screen, mapping->pipeFormats,
                                           target, sample_count, bindings);
           }
        }
     }
  
     _mesa_problem(NULL, "unhandled format!\n");
     return PIPE_FORMAT_NONE;
  }
  
  
  /**
   * Called by FBO code to choose a PIPE_FORMAT_ for drawing surfaces.
   */
  enum pipe_format
  st_choose_renderbuffer_format(struct pipe_screen *screen,
                                GLenum internalFormat, unsigned sample_count)
  {
     uint usage;
     if (_mesa_is_depth_or_stencil_format(internalFormat))
        usage = PIPE_BIND_DEPTH_STENCIL;
     else
        usage = PIPE_BIND_RENDER_TARGET;
     return st_choose_format(screen, internalFormat, GL_NONE, GL_NONE, PIPE_TEXTURE_2D,
                             sample_count, usage);
  }
  
  
  gl_format
  st_ChooseTextureFormat_renderable(struct gl_context *ctx, GLint internalFormat,
  				  GLenum format, GLenum type, GLboolean renderable)
  {
     struct pipe_screen *screen = st_context(ctx)->pipe->screen;
     enum pipe_format pFormat;
     uint bindings;
  
     (void) format;
     (void) type;
  
     /* GL textures may wind up being render targets, but we don't know
      * that in advance.  Specify potential render target flags now.
      */
     bindings = PIPE_BIND_SAMPLER_VIEW;
     if (renderable) {
        if (_mesa_is_depth_or_stencil_format(internalFormat))
  	 bindings |= PIPE_BIND_DEPTH_STENCIL;
        else
  	 bindings |= PIPE_BIND_RENDER_TARGET;
     }
  
     pFormat = st_choose_format(screen, internalFormat, format, type,
                                PIPE_TEXTURE_2D, 0, bindings);
  
     if (pFormat == PIPE_FORMAT_NONE) {
        /* try choosing format again, this time without render target bindings */
        pFormat = st_choose_format(screen, internalFormat, format, type,
                                   PIPE_TEXTURE_2D, 0, PIPE_BIND_SAMPLER_VIEW);
     }
  
     if (pFormat == PIPE_FORMAT_NONE) {
        /* no luck at all */
        return MESA_FORMAT_NONE;
     }
  
     return st_pipe_format_to_mesa_format(pFormat);
  }
  
  
  /**
   * Called via ctx->Driver.ChooseTextureFormat().
   */
  gl_format
  st_ChooseTextureFormat(struct gl_context *ctx, GLint internalFormat,
                         GLenum format, GLenum type)
  {
     boolean want_renderable =
        internalFormat == 3 || internalFormat == 4 ||
        internalFormat == GL_RGB || internalFormat == GL_RGBA ||
        internalFormat == GL_RGB8 || internalFormat == GL_RGBA8 ||
        internalFormat == GL_BGRA;
  
     return st_ChooseTextureFormat_renderable(ctx, internalFormat,
  					    format, type, want_renderable);
  }
  
  /**
   * Test if a gallium format is equivalent to a GL format/type.
   */
  GLboolean
  st_equal_formats(enum pipe_format pFormat, GLenum format, GLenum type)
  {
     switch (pFormat) {
     case PIPE_FORMAT_A8B8G8R8_UNORM:
        return format == GL_RGBA && type == GL_UNSIGNED_BYTE;
     case PIPE_FORMAT_A8R8G8B8_UNORM:
        return format == GL_BGRA && type == GL_UNSIGNED_BYTE;
     case PIPE_FORMAT_B5G6R5_UNORM:
        return format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5;
     /* XXX more combos... */
     default:
        return GL_FALSE;
     }
  }
  
  GLboolean
  st_sampler_compat_formats(enum pipe_format format1, enum pipe_format format2)
  {
     if (format1 == format2)
        return GL_TRUE;
  
     if (format1 == PIPE_FORMAT_B8G8R8A8_UNORM &&
         format2 == PIPE_FORMAT_B8G8R8X8_UNORM)
        return GL_TRUE;
  
     if (format1 == PIPE_FORMAT_B8G8R8X8_UNORM &&
         format2 == PIPE_FORMAT_B8G8R8A8_UNORM)
        return GL_TRUE;
  
     if (format1 == PIPE_FORMAT_A8B8G8R8_UNORM &&
         format2 == PIPE_FORMAT_X8B8G8R8_UNORM)
        return GL_TRUE;
  
     if (format1 == PIPE_FORMAT_X8B8G8R8_UNORM &&
         format2 == PIPE_FORMAT_A8B8G8R8_UNORM)
        return GL_TRUE;
  
     if (format1 == PIPE_FORMAT_A8R8G8B8_UNORM &&
         format2 == PIPE_FORMAT_X8R8G8B8_UNORM)
        return GL_TRUE;
  
     if (format1 == PIPE_FORMAT_X8R8G8B8_UNORM &&
         format2 == PIPE_FORMAT_A8R8G8B8_UNORM)
        return GL_TRUE;
  
     return GL_FALSE;
  }
  
  
  
  /**
   * This is used for translating texture border color and the clear
   * color.  For example, the clear color is interpreted according to
   * the renderbuffer's base format.  For example, if clearing a
   * GL_LUMINANCE buffer, ClearColor[0] = luminance and ClearColor[1] =
   * alpha.  Similarly for texture border colors.
   */
  void
  st_translate_color(const GLfloat colorIn[4], GLenum baseFormat,
                     GLfloat colorOut[4])
  {
     switch (baseFormat) {
     case GL_RED:
        colorOut[0] = colorIn[0];
        colorOut[1] = 0.0F;
        colorOut[2] = 0.0F;
        colorOut[3] = 1.0F;
        break;
     case GL_RG:
        colorOut[0] = colorIn[0];
        colorOut[1] = colorIn[1];
        colorOut[2] = 0.0F;
        colorOut[3] = 1.0F;
        break;
     case GL_RGB:
        colorOut[0] = colorIn[0];
        colorOut[1] = colorIn[1];
        colorOut[2] = colorIn[2];
        colorOut[3] = 1.0F;
        break;
     case GL_ALPHA:
        colorOut[0] = colorOut[1] = colorOut[2] = 0.0;
        colorOut[3] = colorIn[3];
        break;
     case GL_LUMINANCE:
        colorOut[0] = colorOut[1] = colorOut[2] = colorIn[0];
        colorOut[3] = 1.0;
        break;
     case GL_LUMINANCE_ALPHA:
        colorOut[0] = colorOut[1] = colorOut[2] = colorIn[0];
        colorOut[3] = colorIn[3];
        break;
     case GL_INTENSITY:
        colorOut[0] = colorOut[1] = colorOut[2] = colorOut[3] = colorIn[0];
        break;
     default:
        COPY_4V(colorOut, colorIn);
     }
  }
  