src/mesa/main/texcompress_cpal.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright 2008 VMware, Inc.
   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 OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * Code to convert compressed/paletted texture images to ordinary images.
  27  * See the GL_OES_compressed_paletted_texture spec at
  28  * http://khronos.org/registry/gles/extensions/OES/OES_compressed_paletted_texture.txt
  29  *
  30  * XXX this makes it impossible to add hardware support...
  31  */
  32
  33
  34 #include "glheader.h"
  35 #include "context.h"
  36 #include "mtypes.h"
  37 #include "imports.h"
  38 #include "pixelstore.h"
  39 #include "texcompress_cpal.h"
  40 #include "teximage.h"
  41
  42
  43 static const struct cpal_format_info {
  44    GLenum cpal_format;
  45    GLenum format;
  46    GLenum type;
  47    GLuint palette_size;
  48    GLuint size;
  49 } formats[] = {
  50    { GL_PALETTE4_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,           16, 3 },
  51    { GL_PALETTE4_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,           16, 4 },
  52    { GL_PALETTE4_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,    16, 2 },
  53    { GL_PALETTE4_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4,  16, 2 },
  54    { GL_PALETTE4_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1,  16, 2 },
  55    { GL_PALETTE8_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,          256, 3 },
  56    { GL_PALETTE8_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,          256, 4 },
  57    { GL_PALETTE8_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,   256, 2 },
  58    { GL_PALETTE8_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 256, 2 },
  59    { GL_PALETTE8_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, 256, 2 }
  60 };
  61
  62
  63 /**
  64  * Get a color/entry from the palette.
  65  */
  66 static GLuint
  67 get_palette_entry(const struct cpal_format_info *info, const GLubyte *palette,
  68                   GLuint index, GLubyte *pixel)
  69 {
  70    memcpy(pixel, palette + info->size * index, info->size);
  71    return info->size;
  72 }
  73
  74
  75 /**
  76  * Convert paletted texture to color texture.
  77  */
  78 static void
  79 paletted_to_color(const struct cpal_format_info *info, const GLubyte *palette,
  80                   const void *indices, GLuint num_pixels, GLubyte *image)
  81 {
  82    GLubyte *pix = image;
  83    GLuint remain, i;
  84
  85    if (info->palette_size == 16) {
  86       /* 4 bits per index */
  87       const GLubyte *ind = (const GLubyte *) indices;
  88
  89       /* two pixels per iteration */
  90       remain = num_pixels % 2;
  91       for (i = 0; i < num_pixels / 2; i++) {
  92          pix += get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
  93          pix += get_palette_entry(info, palette, ind[i] & 0xf, pix);
  94       }
  95       if (remain) {
  96          get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
  97       }
  98    }
  99    else {
 100       /* 8 bits per index */
 101       const GLubyte *ind = (const GLubyte *) indices;
 102       for (i = 0; i < num_pixels; i++)
 103          pix += get_palette_entry(info, palette, ind[i], pix);
 104    }
 105 }
 106
 107 unsigned
 108 _mesa_cpal_compressed_size(int level, GLenum internalFormat,
 109                            unsigned width, unsigned height)
 110 {
 111    const struct cpal_format_info *info;
 112    const int num_levels = -level + 1;
 113    int lvl;
 114    unsigned w, h, expect_size;
 115
 116    if (internalFormat < GL_PALETTE4_RGB8_OES
 117        || internalFormat > GL_PALETTE8_RGB5_A1_OES) {
 118       return 0;
 119    }
 120
 121    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 122    assert(info->cpal_format == internalFormat);
 123
 124    expect_size = info->palette_size * info->size;
 125    for (lvl = 0; lvl < num_levels; lvl++) {
 126       w = width >> lvl;
 127       if (!w)
 128          w = 1;
 129       h = height >> lvl;
 130       if (!h)
 131          h = 1;
 132
 133       if (info->palette_size == 16)
 134          expect_size += (w * h  + 1) / 2;
 135       else
 136          expect_size += w * h;
 137    }
 138
 139    return expect_size;
 140 }
 141
 142
 143 /**
 144  * Convert a call to glCompressedTexImage2D() where internalFormat is a
 145  *  compressed palette format into a regular GLubyte/RGBA glTexImage2D() call.
 146  */
 147 void
 148 _mesa_cpal_compressed_teximage2d(GLenum target, GLint level,
 149                                  GLenum internalFormat,
 150                                  GLsizei width, GLsizei height,
 151                                  GLsizei imageSize, const void *palette)
 152 {
 153    const struct cpal_format_info *info;
 154    GLint lvl, num_levels;
 155    const GLubyte *indices;
 156    GLint saved_align, align;
 157    GET_CURRENT_CONTEXT(ctx);
 158
 159    /* By this point, the internalFormat should have been validated.
 160     */
 161    assert(internalFormat >= GL_PALETTE4_RGB8_OES
 162           && internalFormat <= GL_PALETTE8_RGB5_A1_OES);
 163
 164    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 165
 166    num_levels = -level + 1;
 167
 168    /* first image follows the palette */
 169    indices = (const GLubyte *) palette + info->palette_size * info->size;
 170
 171    saved_align = ctx->Unpack.Alignment;
 172    align = saved_align;
 173
 174    for (lvl = 0; lvl < num_levels; lvl++) {
 175       GLsizei w, h;
 176       GLuint num_texels;
 177       GLubyte *image = NULL;
 178
 179       w = width >> lvl;
 180       if (!w)
 181          w = 1;
 182       h = height >> lvl;
 183       if (!h)
 184          h = 1;
 185       num_texels = w * h;
 186       if (w * info->size % align) {
 187          _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, 1);
 188          align = 1;
 189       }
 190
 191       /* allocate and fill dest image buffer */
 192       if (palette) {
 193          image = malloc(num_texels * info->size);
 194          paletted_to_color(info, palette, indices, num_texels, image);
 195       }
 196
 197       _mesa_TexImage2D(target, lvl, info->format, w, h, 0,
 198                        info->format, info->type, image);
 199       free(image);
 200
 201       /* advance index pointer to point to next src mipmap */
 202       if (info->palette_size == 16)
 203          indices += (num_texels + 1) / 2;
 204       else
 205          indices += num_texels;
 206    }
 207
 208    if (saved_align != align)
 209       _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, saved_align);
 210 }