src/glx/compsize.c

   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
  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_YCBCR_422_APPLE:
  75    case GL_LUMINANCE_ALPHA:
  76       return 2;
  77    case GL_RGBA:
  78    case GL_BGRA:
  79    case GL_ABGR_EXT:
  80       return 4;
  81    case GL_COLOR_INDEX:
  82    case GL_STENCIL_INDEX:
  83    case GL_DEPTH_COMPONENT:
  84    case GL_RED:
  85    case GL_GREEN:
  86    case GL_BLUE:
  87    case GL_ALPHA:
  88    case GL_LUMINANCE:
  89    case GL_INTENSITY:
  90       return 1;
  91    default:
  92       return 0;
  93    }
  94 }
  95
  96 /*
  97 ** Return the number of bytes per element, based on the element type (other
  98 ** than GL_BITMAP).
  99 */
 100 GLint
 101 __glBytesPerElement(GLenum type)
 102 {
 103    switch (type) {
 104    case GL_UNSIGNED_SHORT:
 105    case GL_SHORT:
 106    case GL_UNSIGNED_SHORT_5_6_5:
 107    case GL_UNSIGNED_SHORT_5_6_5_REV:
 108    case GL_UNSIGNED_SHORT_4_4_4_4:
 109    case GL_UNSIGNED_SHORT_4_4_4_4_REV:
 110    case GL_UNSIGNED_SHORT_5_5_5_1:
 111    case GL_UNSIGNED_SHORT_1_5_5_5_REV:
 112    case GL_UNSIGNED_SHORT_8_8_APPLE:
 113    case GL_UNSIGNED_SHORT_8_8_REV_APPLE:
 114       return 2;
 115    case GL_UNSIGNED_BYTE:
 116    case GL_BYTE:
 117    case GL_UNSIGNED_BYTE_3_3_2:
 118    case GL_UNSIGNED_BYTE_2_3_3_REV:
 119       return 1;
 120    case GL_INT:
 121    case GL_UNSIGNED_INT:
 122    case GL_FLOAT:
 123    case GL_UNSIGNED_INT_8_8_8_8:
 124    case GL_UNSIGNED_INT_8_8_8_8_REV:
 125    case GL_UNSIGNED_INT_10_10_10_2:
 126    case GL_UNSIGNED_INT_2_10_10_10_REV:
 127    case GL_UNSIGNED_INT_24_8_NV:
 128       return 4;
 129    default:
 130       return 0;
 131    }
 132 }
 133
 134 /*
 135 ** Compute memory required for internal packed array of data of given type
 136 ** and format.
 137 */
 138 GLint
 139 __glImageSize(GLsizei width, GLsizei height, GLsizei depth,
 140               GLenum format, GLenum type, GLenum target)
 141 {
 142    int bytes_per_row;
 143    int components;
 144
 145    switch (target) {
 146    case GL_PROXY_TEXTURE_1D:
 147    case GL_PROXY_TEXTURE_2D:
 148    case GL_PROXY_TEXTURE_3D:
 149    case GL_PROXY_TEXTURE_4D_SGIS:
 150    case GL_PROXY_TEXTURE_CUBE_MAP:
 151    case GL_PROXY_TEXTURE_RECTANGLE_ARB:
 152    case GL_PROXY_HISTOGRAM:
 153    case GL_PROXY_COLOR_TABLE:
 154    case GL_PROXY_TEXTURE_COLOR_TABLE_SGI:
 155    case GL_PROXY_POST_CONVOLUTION_COLOR_TABLE:
 156    case GL_PROXY_POST_COLOR_MATRIX_COLOR_TABLE:
 157    case GL_PROXY_POST_IMAGE_TRANSFORM_COLOR_TABLE_HP:
 158       return 0;
 159    }
 160
 161    if (width < 0 || height < 0 || depth < 0) {
 162       return 0;
 163    }
 164
 165    /*
 166     ** Zero is returned if either format or type are invalid.
 167     */
 168    components = __glElementsPerGroup(format, type);
 169    if (type == GL_BITMAP) {
 170       if (format == GL_COLOR_INDEX || format == GL_STENCIL_INDEX) {
 171          bytes_per_row = (width + 7) >> 3;
 172       }
 173       else {
 174          return 0;
 175       }
 176    }
 177    else {
 178       bytes_per_row = __glBytesPerElement(type) * width;
 179    }
 180
 181    return bytes_per_row * height * depth * components;
 182 }