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 "u_math.h"
  #include "u_memory.h"
  #include "u_format.h"
  #include "u_format_s3tc.h"
  #include "u_surface.h"
  
  #include "pipe/p_defines.h"
  
  boolean util_format_s3tc_enabled = FALSE;
  
  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 == -1) {
        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] != UTIL_FORMAT_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] == UTIL_FORMAT_SWIZZLE_X &&
         desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_X &&
         desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_X &&
         desc->swizzle[3] == UTIL_FORMAT_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] == UTIL_FORMAT_SWIZZLE_0 &&
         desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_0 &&
         desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_0 &&
         desc->swizzle[3] == UTIL_FORMAT_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 all non-void channels are normalized signed.
   */
  boolean
  util_format_is_snorm(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;
  }
  
  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] == UTIL_FORMAT_SWIZZLE_X &&
         desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_X &&
         desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_X &&
         desc->swizzle[3] == UTIL_FORMAT_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] == UTIL_FORMAT_SWIZZLE_X &&
         desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_X &&
         desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_X &&
         desc->swizzle[3] == UTIL_FORMAT_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;
  }
  
  boolean
  util_format_is_supported(enum pipe_format format, unsigned bind)
  {
     if (util_format_is_s3tc(format) && !util_format_s3tc_enabled) {
        return FALSE;
     }
  
  #ifndef TEXTURE_FLOAT_ENABLED
     if ((bind & PIPE_BIND_RENDER_TARGET) &&
         format != PIPE_FORMAT_R9G9B9E5_FLOAT &&
         format != PIPE_FORMAT_R11G11B10_FLOAT &&
         util_format_is_float(format)) {
        return FALSE;
     }
  #endif
  
     return TRUE;
  }
  
  
  /**
   * 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;
  }
  
  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 util_format_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_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;
        }
     }
  }
  
  
  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] <= UTIL_FORMAT_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_RED:   dst->ui[c] = src->ui[0]; break;
           case PIPE_SWIZZLE_GREEN: dst->ui[c] = src->ui[1]; break;
           case PIPE_SWIZZLE_BLUE:  dst->ui[c] = src->ui[2]; break;
           case PIPE_SWIZZLE_ALPHA: dst->ui[c] = src->ui[3]; break;
           default:
              dst->ui[c] = (swz[c] == PIPE_SWIZZLE_ONE) ? 1 : 0;
              break;
           }
        }
     } else {
        for (c = 0; c < 4; ++c) {
           switch (swz[c]) {
           case PIPE_SWIZZLE_RED:   dst->f[c] = src->f[0]; break;
           case PIPE_SWIZZLE_GREEN: dst->f[c] = src->f[1]; break;
           case PIPE_SWIZZLE_BLUE:  dst->f[c] = src->f[2]; break;
           case PIPE_SWIZZLE_ALPHA: dst->f[c] = src->f[3]; break;
           default:
              dst->f[c] = (swz[c] == PIPE_SWIZZLE_ONE) ? 1.0f : 0.0f;
              break;
           }
        }
     }
  }
  
  void util_format_swizzle_4f(float *dst, const float *src,
                              const unsigned char swz[4])
  {
     unsigned i;
  
     for (i = 0; i < 4; i++) {
        if (swz[i] <= UTIL_FORMAT_SWIZZLE_W)
           dst[i] = src[swz[i]];
        else if (swz[i] == UTIL_FORMAT_SWIZZLE_0)
           dst[i] = 0;
        else if (swz[i] == UTIL_FORMAT_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 UTIL_FORMAT_SWIZZLE_X:
           dst[0] = src[i];
           break;
        case UTIL_FORMAT_SWIZZLE_Y:
           dst[1] = src[i];
           break;
        case UTIL_FORMAT_SWIZZLE_Z:
           dst[2] = src[i];
           break;
        case UTIL_FORMAT_SWIZZLE_W:
           dst[3] = src[i];
           break;
        }
     }
  }
  