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
43static 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 */
66static GLuint
67get_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 */
78static void
79paletted_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
107unsigned
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 */
147void
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}
211