src/mesa/main/texcompress_cpal.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  20  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * Code to convert compressed/paletted texture images to ordinary images.
  26  * See the GL_OES_compressed_paletted_texture spec at
  27  * http://khronos.org/registry/gles/extensions/OES/OES_compressed_paletted_texture.txt
  28  *
  29  * XXX this makes it impossible to add hardware support...
  30  */
  31
  32
  33 #include "glheader.h"
  34 #include "compiler.h" /* for ASSERT */
  35 #include "context.h"
  36 #include "mfeatures.h"
  37 #include "mtypes.h"
  38 #include "imports.h"
  39 #include "pixelstore.h"
  40 #include "texcompress_cpal.h"
  41 #include "teximage.h"
  42
  43 #if FEATURE_ES
  44
  45
  46 static const struct cpal_format_info {
  47    GLenum cpal_format;
  48    GLenum format;
  49    GLenum type;
  50    GLuint palette_size;
  51    GLuint size;
  52 } formats[] = {
  53    { GL_PALETTE4_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,           16, 3 },
  54    { GL_PALETTE4_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,           16, 4 },
  55    { GL_PALETTE4_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,    16, 2 },
  56    { GL_PALETTE4_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4,  16, 2 },
  57    { GL_PALETTE4_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1,  16, 2 },
  58    { GL_PALETTE8_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,          256, 3 },
  59    { GL_PALETTE8_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,          256, 4 },
  60    { GL_PALETTE8_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,   256, 2 },
  61    { GL_PALETTE8_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 256, 2 },
  62    { GL_PALETTE8_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, 256, 2 }
  63 };
  64
  65
  66 /**
  67  * Get a color/entry from the palette.
  68  */
  69 static GLuint
  70 get_palette_entry(const struct cpal_format_info *info, const GLubyte *palette,
  71                   GLuint index, GLubyte *pixel)
  72 {
  73    memcpy(pixel, palette + info->size * index, info->size);
  74    return info->size;
  75 }
  76
  77
  78 /**
  79  * Convert paletted texture to color texture.
  80  */
  81 static void
  82 paletted_to_color(const struct cpal_format_info *info, const GLubyte *palette,
  83                   const void *indices, GLuint num_pixels, GLubyte *image)
  84 {
  85    GLubyte *pix = image;
  86    GLuint remain, i;
  87
  88    if (info->palette_size == 16) {
  89       /* 4 bits per index */
  90       const GLubyte *ind = (const GLubyte *) indices;
  91
  92       /* two pixels per iteration */
  93       remain = num_pixels % 2;
  94       for (i = 0; i < num_pixels / 2; i++) {
  95          pix += get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
  96          pix += get_palette_entry(info, palette, ind[i] & 0xf, pix);
  97       }
  98       if (remain) {
  99          get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
 100       }
 101    }
 102    else {
 103       /* 8 bits per index */
 104       const GLubyte *ind = (const GLubyte *) indices;
 105       for (i = 0; i < num_pixels; i++)
 106          pix += get_palette_entry(info, palette, ind[i], pix);
 107    }
 108 }
 109
 110 unsigned
 111 _mesa_cpal_compressed_size(int level, GLenum internalFormat,
 112                            unsigned width, unsigned height)
 113 {
 114    const struct cpal_format_info *info;
 115    const int num_levels = -level + 1;
 116    int lvl;
 117    unsigned w, h, expect_size;
 118
 119    if (internalFormat < GL_PALETTE4_RGB8_OES
 120        || internalFormat > GL_PALETTE8_RGB5_A1_OES) {
 121       return 0;
 122    }
 123
 124    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 125    ASSERT(info->cpal_format == internalFormat);
 126
 127    expect_size = info->palette_size * info->size;
 128    for (lvl = 0; lvl < num_levels; lvl++) {
 129       w = width >> lvl;
 130       if (!w)
 131          w = 1;
 132       h = height >> lvl;
 133       if (!h)
 134          h = 1;
 135
 136       if (info->palette_size == 16)
 137          expect_size += (w * h  + 1) / 2;
 138       else
 139          expect_size += w * h;
 140    }
 141
 142    return expect_size;
 143 }
 144
 145 void
 146 _mesa_cpal_compressed_format_type(GLenum internalFormat, GLenum *format,
 147                                   GLenum *type)
 148 {
 149    const struct cpal_format_info *info;
 150
 151    if (internalFormat < GL_PALETTE4_RGB8_OES
 152        || internalFormat > GL_PALETTE8_RGB5_A1_OES) {
 153       return;
 154    }
 155
 156    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 157    *format = info->format;
 158    *type = info->type;
 159 }
 160
 161 /**
 162  * Convert a call to glCompressedTexImage2D() where internalFormat is a
 163  *  compressed palette format into a regular GLubyte/RGBA glTexImage2D() call.
 164  */
 165 void
 166 _mesa_cpal_compressed_teximage2d(GLenum target, GLint level,
 167                                  GLenum internalFormat,
 168                                  GLsizei width, GLsizei height,
 169                                  GLsizei imageSize, const void *palette)
 170 {
 171    const struct cpal_format_info *info;
 172    GLint lvl, num_levels;
 173    const GLubyte *indices;
 174    GLint saved_align, align;
 175    GET_CURRENT_CONTEXT(ctx);
 176
 177    /* By this point, the internalFormat should have been validated.
 178     */
 179    assert(internalFormat >= GL_PALETTE4_RGB8_OES
 180           && internalFormat <= GL_PALETTE8_RGB5_A1_OES);
 181
 182    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 183
 184    num_levels = -level + 1;
 185
 186    /* first image follows the palette */
 187    indices = (const GLubyte *) palette + info->palette_size * info->size;
 188
 189    saved_align = ctx->Unpack.Alignment;
 190    align = saved_align;
 191
 192    for (lvl = 0; lvl < num_levels; lvl++) {
 193       GLsizei w, h;
 194       GLuint num_texels;
 195       GLubyte *image = NULL;
 196
 197       w = width >> lvl;
 198       if (!w)
 199          w = 1;
 200       h = height >> lvl;
 201       if (!h)
 202          h = 1;
 203       num_texels = w * h;
 204       if (w * info->size % align) {
 205          _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, 1);
 206          align = 1;
 207       }
 208
 209       /* allocate and fill dest image buffer */
 210       if (palette) {
 211          image = malloc(num_texels * info->size);
 212          paletted_to_color(info, palette, indices, num_texels, image);
 213       }
 214
 215       _mesa_TexImage2D(target, lvl, info->format, w, h, 0,
 216                        info->format, info->type, image);
 217       if (image)
 218          free(image);
 219
 220       /* advance index pointer to point to next src mipmap */
 221       if (info->palette_size == 16)
 222          indices += (num_texels + 1) / 2;
 223       else
 224          indices += num_texels;
 225    }
 226
 227    if (saved_align != align)
 228       _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, saved_align);
 229 }
 230
 231 #endif