1 /*
2 * Copyright (C) 2011 LunarG, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24 /**
25 * \file texcompress_etc.c
26 * GL_OES_compressed_ETC1_RGB8_texture support.
27 */
28
29
30 #include "mfeatures.h"
31 #include "texcompress.h"
32 #include "texcompress_etc.h"
33 #include "texstore.h"
34 #include "macros.h"
35 #include "swrast/s_context.h"
36
37 GLboolean
_mesa_texstore_etc1_rgb8(TEXSTORE_PARAMS)38 _mesa_texstore_etc1_rgb8(TEXSTORE_PARAMS)
39 {
40 /* GL_ETC1_RGB8_OES is only valid in glCompressedTexImage2D */
41 ASSERT(0);
42
43 return GL_FALSE;
44 }
45
46 /* define etc1_parse_block and etc. */
47 #define UINT8_TYPE GLubyte
48 #define TAG(x) x
49 #include "texcompress_etc_tmp.h"
50 #undef TAG
51 #undef UINT8_TYPE
52
53 void
_mesa_fetch_texel_2d_f_etc1_rgb8(const struct swrast_texture_image * texImage,GLint i,GLint j,GLint k,GLfloat * texel)54 _mesa_fetch_texel_2d_f_etc1_rgb8(const struct swrast_texture_image *texImage,
55 GLint i, GLint j, GLint k, GLfloat *texel)
56 {
57 struct etc1_block block;
58 GLubyte dst[3];
59 const GLubyte *src;
60
61 src = (const GLubyte *) texImage->Map +
62 (((texImage->RowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
63
64 etc1_parse_block(&block, src);
65 etc1_fetch_texel(&block, i % 4, j % 4, dst);
66
67 texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
68 texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
69 texel[BCOMP] = UBYTE_TO_FLOAT(dst[2]);
70 texel[ACOMP] = 1.0f;
71 }
72
73 /**
74 * Decode texture data in format `MESA_FORMAT_ETC1_RGB8` to
75 * `MESA_FORMAT_ABGR8888`.
76 *
77 * The size of the source data must be a multiple of the ETC1 block size,
78 * which is 8, even if the texture image's dimensions are not aligned to 4.
79 * From the GL_OES_compressed_ETC1_RGB8_texture spec:
80 * The texture is described as a number of 4x4 pixel blocks. If the
81 * texture (or a particular mip-level) is smaller than 4 pixels in
82 * any dimension (such as a 2x2 or a 8x1 texture), the texture is
83 * found in the upper left part of the block(s), and the rest of the
84 * pixels are not used. For instance, a texture of size 4x2 will be
85 * placed in the upper half of a 4x4 block, and the lower half of the
86 * pixels in the block will not be accessed.
87 *
88 * \param src_width in pixels
89 * \param src_height in pixels
90 * \param dst_stride in bytes
91 */
92 void
_mesa_etc1_unpack_rgba8888(uint8_t * dst_row,unsigned dst_stride,const uint8_t * src_row,unsigned src_stride,unsigned src_width,unsigned src_height)93 _mesa_etc1_unpack_rgba8888(uint8_t *dst_row,
94 unsigned dst_stride,
95 const uint8_t *src_row,
96 unsigned src_stride,
97 unsigned src_width,
98 unsigned src_height)
99 {
100 etc1_unpack_rgba8888(dst_row, dst_stride,
101 src_row, src_stride,
102 src_width, src_height);
103 }
104