compsize.c revision cdc920a0 
1/*
2 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
3 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice including the dates of first publication and
13 * either this permission notice or a reference to
14 * http://oss.sgi.com/projects/FreeB/
15 * shall be included in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
21 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
22 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 *
25 * Except as contained in this notice, the name of Silicon Graphics, Inc.
26 * shall not be used in advertising or otherwise to promote the sale, use or
27 * other dealings in this Software without prior written authorization from
28 * Silicon Graphics, Inc.
29 */
30
31#include <GL/gl.h>
32#include "glxclient.h"
33
34/*
35** Return the number of elements per group of a specified format
36*/
37GLint
38__glElementsPerGroup(GLenum format, GLenum type)
39{
40   /*
41    ** To make row length computation valid for image extraction,
42    ** packed pixel types assume elements per group equals one.
43    */
44   switch (type) {
45   case GL_UNSIGNED_BYTE_3_3_2:
46   case GL_UNSIGNED_BYTE_2_3_3_REV:
47   case GL_UNSIGNED_SHORT_5_6_5:
48   case GL_UNSIGNED_SHORT_5_6_5_REV:
49   case GL_UNSIGNED_SHORT_4_4_4_4:
50   case GL_UNSIGNED_SHORT_4_4_4_4_REV:
51   case GL_UNSIGNED_SHORT_5_5_5_1:
52   case GL_UNSIGNED_SHORT_1_5_5_5_REV:
53   case GL_UNSIGNED_SHORT_8_8_APPLE:
54   case GL_UNSIGNED_SHORT_8_8_REV_APPLE:
55   case GL_UNSIGNED_SHORT_15_1_MESA:
56   case GL_UNSIGNED_SHORT_1_15_REV_MESA:
57   case GL_UNSIGNED_INT_8_8_8_8:
58   case GL_UNSIGNED_INT_8_8_8_8_REV:
59   case GL_UNSIGNED_INT_10_10_10_2:
60   case GL_UNSIGNED_INT_2_10_10_10_REV:
61   case GL_UNSIGNED_INT_24_8_NV:
62   case GL_UNSIGNED_INT_24_8_MESA:
63   case GL_UNSIGNED_INT_8_24_REV_MESA:
64      return 1;
65   default:
66      break;
67   }
68
69   switch (format) {
70   case GL_RGB:
71   case GL_BGR:
72      return 3;
73   case GL_422_EXT:
74   case GL_422_REV_EXT:
75   case GL_422_AVERAGE_EXT:
76   case GL_422_REV_AVERAGE_EXT:
77   case GL_YCBCR_422_APPLE:
78   case GL_LUMINANCE_ALPHA:
79      return 2;
80   case GL_RGBA:
81   case GL_BGRA:
82   case GL_ABGR_EXT:
83      return 4;
84   case GL_COLOR_INDEX:
85   case GL_STENCIL_INDEX:
86   case GL_DEPTH_COMPONENT:
87   case GL_RED:
88   case GL_GREEN:
89   case GL_BLUE:
90   case GL_ALPHA:
91   case GL_LUMINANCE:
92   case GL_INTENSITY:
93      return 1;
94   default:
95      return 0;
96   }
97}
98
99/*
100** Return the number of bytes per element, based on the element type (other
101** than GL_BITMAP).
102*/
103GLint
104__glBytesPerElement(GLenum type)
105{
106   switch (type) {
107   case GL_UNSIGNED_SHORT:
108   case GL_SHORT:
109   case GL_UNSIGNED_SHORT_5_6_5:
110   case GL_UNSIGNED_SHORT_5_6_5_REV:
111   case GL_UNSIGNED_SHORT_4_4_4_4:
112   case GL_UNSIGNED_SHORT_4_4_4_4_REV:
113   case GL_UNSIGNED_SHORT_5_5_5_1:
114   case GL_UNSIGNED_SHORT_1_5_5_5_REV:
115   case GL_UNSIGNED_SHORT_8_8_APPLE:
116   case GL_UNSIGNED_SHORT_8_8_REV_APPLE:
117   case GL_UNSIGNED_SHORT_15_1_MESA:
118   case GL_UNSIGNED_SHORT_1_15_REV_MESA:
119      return 2;
120   case GL_UNSIGNED_BYTE:
121   case GL_BYTE:
122   case GL_UNSIGNED_BYTE_3_3_2:
123   case GL_UNSIGNED_BYTE_2_3_3_REV:
124      return 1;
125   case GL_INT:
126   case GL_UNSIGNED_INT:
127   case GL_FLOAT:
128   case GL_UNSIGNED_INT_8_8_8_8:
129   case GL_UNSIGNED_INT_8_8_8_8_REV:
130   case GL_UNSIGNED_INT_10_10_10_2:
131   case GL_UNSIGNED_INT_2_10_10_10_REV:
132   case GL_UNSIGNED_INT_24_8_NV:
133   case GL_UNSIGNED_INT_24_8_MESA:
134   case GL_UNSIGNED_INT_8_24_REV_MESA:
135      return 4;
136   default:
137      return 0;
138   }
139}
140
141/*
142** Compute memory required for internal packed array of data of given type
143** and format.
144*/
145GLint
146__glImageSize(GLsizei width, GLsizei height, GLsizei depth,
147              GLenum format, GLenum type, GLenum target)
148{
149   int bytes_per_row;
150   int components;
151
152   switch (target) {
153   case GL_PROXY_TEXTURE_1D:
154   case GL_PROXY_TEXTURE_2D:
155   case GL_PROXY_TEXTURE_3D:
156   case GL_PROXY_TEXTURE_4D_SGIS:
157   case GL_PROXY_TEXTURE_CUBE_MAP:
158   case GL_PROXY_TEXTURE_RECTANGLE_ARB:
159   case GL_PROXY_HISTOGRAM:
160   case GL_PROXY_COLOR_TABLE:
161   case GL_PROXY_TEXTURE_COLOR_TABLE_SGI:
162   case GL_PROXY_POST_CONVOLUTION_COLOR_TABLE:
163   case GL_PROXY_POST_COLOR_MATRIX_COLOR_TABLE:
164   case GL_PROXY_POST_IMAGE_TRANSFORM_COLOR_TABLE_HP:
165      return 0;
166   }
167
168   if (width < 0 || height < 0 || depth < 0) {
169      return 0;
170   }
171
172   /*
173    ** Zero is returned if either format or type are invalid.
174    */
175   components = __glElementsPerGroup(format, type);
176   if (type == GL_BITMAP) {
177      if (format == GL_COLOR_INDEX || format == GL_STENCIL_INDEX) {
178         bytes_per_row = (width + 7) >> 3;
179      }
180      else {
181         return 0;
182      }
183   }
184   else {
185      bytes_per_row = __glBytesPerElement(type) * width;
186   }
187
188   return bytes_per_row * height * depth * components;
189}
190