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 */
37 GLint
__glElementsPerGroup(GLenum format,GLenum type)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_INT_8_8_8_8:
56    case GL_UNSIGNED_INT_8_8_8_8_REV:
57    case GL_UNSIGNED_INT_10_10_10_2:
58    case GL_UNSIGNED_INT_2_10_10_10_REV:
59    case GL_UNSIGNED_INT_24_8_NV:
60       return 1;
61    default:
62       break;
63    }
64 
65    switch (format) {
66    case GL_RGB:
67    case GL_BGR:
68       return 3;
69    case GL_RG:
70    case GL_422_EXT:
71    case GL_422_REV_EXT:
72    case GL_422_AVERAGE_EXT:
73    case GL_422_REV_AVERAGE_EXT:
74    case GL_DEPTH_STENCIL_NV:
75    case GL_YCBCR_422_APPLE:
76    case GL_LUMINANCE_ALPHA:
77       return 2;
78    case GL_RGBA:
79    case GL_BGRA:
80    case GL_ABGR_EXT:
81       return 4;
82    case GL_COLOR_INDEX:
83    case GL_STENCIL_INDEX:
84    case GL_DEPTH_COMPONENT:
85    case GL_RED:
86    case GL_GREEN:
87    case GL_BLUE:
88    case GL_ALPHA:
89    case GL_LUMINANCE:
90    case GL_INTENSITY:
91       return 1;
92    default:
93       return 0;
94    }
95 }
96 
97 /*
98 ** Return the number of bytes per element, based on the element type (other
99 ** than GL_BITMAP).
100 */
101 GLint
__glBytesPerElement(GLenum type)102 __glBytesPerElement(GLenum type)
103 {
104    switch (type) {
105    case GL_UNSIGNED_SHORT:
106    case GL_SHORT:
107    case GL_UNSIGNED_SHORT_5_6_5:
108    case GL_UNSIGNED_SHORT_5_6_5_REV:
109    case GL_UNSIGNED_SHORT_4_4_4_4:
110    case GL_UNSIGNED_SHORT_4_4_4_4_REV:
111    case GL_UNSIGNED_SHORT_5_5_5_1:
112    case GL_UNSIGNED_SHORT_1_5_5_5_REV:
113    case GL_UNSIGNED_SHORT_8_8_APPLE:
114    case GL_UNSIGNED_SHORT_8_8_REV_APPLE:
115       return 2;
116    case GL_UNSIGNED_BYTE:
117    case GL_BYTE:
118    case GL_UNSIGNED_BYTE_3_3_2:
119    case GL_UNSIGNED_BYTE_2_3_3_REV:
120       return 1;
121    case GL_INT:
122    case GL_UNSIGNED_INT:
123    case GL_FLOAT:
124    case GL_UNSIGNED_INT_8_8_8_8:
125    case GL_UNSIGNED_INT_8_8_8_8_REV:
126    case GL_UNSIGNED_INT_10_10_10_2:
127    case GL_UNSIGNED_INT_2_10_10_10_REV:
128    case GL_UNSIGNED_INT_24_8_NV:
129       return 4;
130    default:
131       return 0;
132    }
133 }
134 
135 /*
136 ** Compute memory required for internal packed array of data of given type
137 ** and format.
138 */
139 GLint
__glImageSize(GLsizei width,GLsizei height,GLsizei depth,GLenum format,GLenum type,GLenum target)140 __glImageSize(GLsizei width, GLsizei height, GLsizei depth,
141               GLenum format, GLenum type, GLenum target)
142 {
143    int bytes_per_row;
144    int components;
145 
146    switch (target) {
147    case GL_PROXY_TEXTURE_1D:
148    case GL_PROXY_TEXTURE_2D:
149    case GL_PROXY_TEXTURE_3D:
150    case GL_PROXY_TEXTURE_4D_SGIS:
151    case GL_PROXY_TEXTURE_CUBE_MAP:
152    case GL_PROXY_TEXTURE_RECTANGLE_ARB:
153    case GL_PROXY_HISTOGRAM:
154    case GL_PROXY_COLOR_TABLE:
155    case GL_PROXY_TEXTURE_COLOR_TABLE_SGI:
156    case GL_PROXY_POST_CONVOLUTION_COLOR_TABLE:
157    case GL_PROXY_POST_COLOR_MATRIX_COLOR_TABLE:
158    case GL_PROXY_POST_IMAGE_TRANSFORM_COLOR_TABLE_HP:
159       return 0;
160    }
161 
162    if (width < 0 || height < 0 || depth < 0) {
163       return 0;
164    }
165 
166    /*
167     ** Zero is returned if either format or type are invalid.
168     */
169    components = __glElementsPerGroup(format, type);
170    if (type == GL_BITMAP) {
171       if (format == GL_COLOR_INDEX || format == GL_STENCIL_INDEX) {
172          bytes_per_row = (width + 7) >> 3;
173       }
174       else {
175          return 0;
176       }
177    }
178    else {
179       bytes_per_row = __glBytesPerElement(type) * width;
180    }
181 
182    return bytes_per_row * height * depth * components;
183 }
184