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 
38 #include "pixelstore.h"
39 #include "texcompress_cpal.h"
40 #include "teximage.h"
41 #include "api_exec_decl.h"
42 
43 
44 static const struct cpal_format_info {
45    GLenum cpal_format;
46    GLenum format;
47    GLenum type;
48    GLuint palette_size;
49    GLuint size;
50 } formats[] = {
51    { GL_PALETTE4_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,           16, 3 },
52    { GL_PALETTE4_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,           16, 4 },
53    { GL_PALETTE4_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,    16, 2 },
54    { GL_PALETTE4_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4,  16, 2 },
55    { GL_PALETTE4_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1,  16, 2 },
56    { GL_PALETTE8_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,          256, 3 },
57    { GL_PALETTE8_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,          256, 4 },
58    { GL_PALETTE8_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,   256, 2 },
59    { GL_PALETTE8_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 256, 2 },
60    { GL_PALETTE8_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, 256, 2 }
61 };
62 
63 
64 /**
65  * Get a color/entry from the palette.
66  */
67 static GLuint
get_palette_entry(const struct cpal_format_info * info,const GLubyte * palette,GLuint index,GLubyte * pixel)68 get_palette_entry(const struct cpal_format_info *info, const GLubyte *palette,
69                   GLuint index, GLubyte *pixel)
70 {
71    memcpy(pixel, palette + info->size * index, info->size);
72    return info->size;
73 }
74 
75 
76 /**
77  * Convert paletted texture to color texture.
78  */
79 static void
paletted_to_color(const struct cpal_format_info * info,const GLubyte * palette,const void * indices,GLuint num_pixels,GLubyte * image)80 paletted_to_color(const struct cpal_format_info *info, const GLubyte *palette,
81                   const void *indices, GLuint num_pixels, GLubyte *image)
82 {
83    GLubyte *pix = image;
84    GLuint remain, i;
85 
86    if (info->palette_size == 16) {
87       /* 4 bits per index */
88       const GLubyte *ind = (const GLubyte *) indices;
89 
90       /* two pixels per iteration */
91       remain = num_pixels % 2;
92       for (i = 0; i < num_pixels / 2; i++) {
93          pix += get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
94          pix += get_palette_entry(info, palette, ind[i] & 0xf, pix);
95       }
96       if (remain) {
97          get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
98       }
99    }
100    else {
101       /* 8 bits per index */
102       const GLubyte *ind = (const GLubyte *) indices;
103       for (i = 0; i < num_pixels; i++)
104          pix += get_palette_entry(info, palette, ind[i], pix);
105    }
106 }
107 
108 unsigned
_mesa_cpal_compressed_size(int level,GLenum internalFormat,unsigned width,unsigned height)109 _mesa_cpal_compressed_size(int level, GLenum internalFormat,
110 			   unsigned width, unsigned height)
111 {
112    const struct cpal_format_info *info;
113    const int num_levels = -level + 1;
114    int lvl;
115    unsigned w, h, expect_size;
116 
117    if (internalFormat < GL_PALETTE4_RGB8_OES
118        || internalFormat > GL_PALETTE8_RGB5_A1_OES) {
119       return 0;
120    }
121 
122    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
123    assert(info->cpal_format == internalFormat);
124 
125    expect_size = info->palette_size * info->size;
126    for (lvl = 0; lvl < num_levels; lvl++) {
127       w = width >> lvl;
128       if (!w)
129          w = 1;
130       h = height >> lvl;
131       if (!h)
132          h = 1;
133 
134       if (info->palette_size == 16)
135          expect_size += (w * h  + 1) / 2;
136       else
137          expect_size += w * h;
138    }
139 
140    return expect_size;
141 }
142 
143 
144 /**
145  * Convert a call to glCompressedTexImage2D() where internalFormat is a
146  *  compressed palette format into a regular GLubyte/RGBA glTexImage2D() call.
147  */
148 void
_mesa_cpal_compressed_teximage2d(GLenum target,GLint level,GLenum internalFormat,GLsizei width,GLsizei height,GLsizei imageSize,const void * palette)149 _mesa_cpal_compressed_teximage2d(GLenum target, GLint level,
150 				 GLenum internalFormat,
151 				 GLsizei width, GLsizei height,
152 				 GLsizei imageSize, const void *palette)
153 {
154    const struct cpal_format_info *info;
155    GLint lvl, num_levels;
156    const GLubyte *indices;
157    GLint saved_align, align;
158    GET_CURRENT_CONTEXT(ctx);
159 
160    /* By this point, the internalFormat should have been validated.
161     */
162    assert(internalFormat >= GL_PALETTE4_RGB8_OES
163 	  && internalFormat <= GL_PALETTE8_RGB5_A1_OES);
164 
165    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
166 
167    num_levels = -level + 1;
168 
169    /* first image follows the palette */
170    indices = (const GLubyte *) palette + info->palette_size * info->size;
171 
172    saved_align = ctx->Unpack.Alignment;
173    align = saved_align;
174 
175    for (lvl = 0; lvl < num_levels; lvl++) {
176       GLsizei w, h;
177       GLuint num_texels;
178       GLubyte *image = NULL;
179 
180       w = width >> lvl;
181       if (!w)
182          w = 1;
183       h = height >> lvl;
184       if (!h)
185          h = 1;
186       num_texels = w * h;
187       if (w * info->size % align) {
188          _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, 1);
189          align = 1;
190       }
191 
192       /* allocate and fill dest image buffer */
193       if (palette) {
194          image = malloc(num_texels * info->size);
195          paletted_to_color(info, palette, indices, num_texels, image);
196       }
197 
198       _mesa_TexImage2D(target, lvl, info->format, w, h, 0,
199                        info->format, info->type, image);
200       free(image);
201 
202       /* advance index pointer to point to next src mipmap */
203       if (info->palette_size == 16)
204          indices += (num_texels + 1) / 2;
205       else
206          indices += num_texels;
207    }
208 
209    if (saved_align != align)
210       _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, saved_align);
211 }
212