IABSD.fr/xenocara/lib/mesa/src/glx/compsize.c

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• Author : jsg
  Date : 2023-11-02 04:31:01
  Hash : 60059fee
  Message : Import Mesa 23.1.9

• lib/mesa/src/glx/compsize.c

• /*
   * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
   * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
   *
   * SPDX-License-Identifier: SGI-B-2.0
   */
  
  #include <GL/gl.h>
  #include "glxclient.h"
  
  /*
  ** Return the number of elements per group of a specified format
  */
  GLint
  __glElementsPerGroup(GLenum format, GLenum type)
  {
     /*
      ** To make row length computation valid for image extraction,
      ** packed pixel types assume elements per group equals one.
      */
     switch (type) {
     case GL_UNSIGNED_BYTE_3_3_2:
     case GL_UNSIGNED_BYTE_2_3_3_REV:
     case GL_UNSIGNED_SHORT_5_6_5:
     case GL_UNSIGNED_SHORT_5_6_5_REV:
     case GL_UNSIGNED_SHORT_4_4_4_4:
     case GL_UNSIGNED_SHORT_4_4_4_4_REV:
     case GL_UNSIGNED_SHORT_5_5_5_1:
     case GL_UNSIGNED_SHORT_1_5_5_5_REV:
     case GL_UNSIGNED_SHORT_8_8_APPLE:
     case GL_UNSIGNED_SHORT_8_8_REV_APPLE:
     case GL_UNSIGNED_INT_8_8_8_8:
     case GL_UNSIGNED_INT_8_8_8_8_REV:
     case GL_UNSIGNED_INT_10_10_10_2:
     case GL_UNSIGNED_INT_2_10_10_10_REV:
     case GL_UNSIGNED_INT_24_8_NV:
        return 1;
     default:
        break;
     }
  
     switch (format) {
     case GL_RGB:
     case GL_BGR:
     case GL_RGB_INTEGER_EXT:
     case GL_BGR_INTEGER_EXT:
        return 3;
     case GL_RG:
     case GL_422_EXT:
     case GL_422_REV_EXT:
     case GL_422_AVERAGE_EXT:
     case GL_422_REV_AVERAGE_EXT:
     case GL_DEPTH_STENCIL_NV:
     case GL_YCBCR_422_APPLE:
     case GL_LUMINANCE_ALPHA:
     case GL_LUMINANCE_ALPHA_INTEGER_EXT:
        return 2;
     case GL_RGBA:
     case GL_BGRA:
     case GL_ABGR_EXT:
     case GL_RGBA_INTEGER_EXT:
     case GL_BGRA_INTEGER_EXT:
        return 4;
     case GL_COLOR_INDEX:
     case GL_STENCIL_INDEX:
     case GL_DEPTH_COMPONENT:
     case GL_RED:
     case GL_GREEN:
     case GL_BLUE:
     case GL_ALPHA:
     case GL_LUMINANCE:
     case GL_INTENSITY:
     case GL_RED_INTEGER_EXT:
     case GL_GREEN_INTEGER_EXT:
     case GL_BLUE_INTEGER_EXT:
     case GL_ALPHA_INTEGER_EXT:
     case GL_LUMINANCE_INTEGER_EXT:
        return 1;
     default:
        return 0;
     }
  }
  
  /*
  ** Return the number of bytes per element, based on the element type (other
  ** than GL_BITMAP).
  */
  GLint
  __glBytesPerElement(GLenum type)
  {
     switch (type) {
     case GL_UNSIGNED_SHORT:
     case GL_SHORT:
     case GL_UNSIGNED_SHORT_5_6_5:
     case GL_UNSIGNED_SHORT_5_6_5_REV:
     case GL_UNSIGNED_SHORT_4_4_4_4:
     case GL_UNSIGNED_SHORT_4_4_4_4_REV:
     case GL_UNSIGNED_SHORT_5_5_5_1:
     case GL_UNSIGNED_SHORT_1_5_5_5_REV:
     case GL_UNSIGNED_SHORT_8_8_APPLE:
     case GL_UNSIGNED_SHORT_8_8_REV_APPLE:
        return 2;
     case GL_UNSIGNED_BYTE:
     case GL_BYTE:
     case GL_UNSIGNED_BYTE_3_3_2:
     case GL_UNSIGNED_BYTE_2_3_3_REV:
        return 1;
     case GL_INT:
     case GL_UNSIGNED_INT:
     case GL_FLOAT:
     case GL_UNSIGNED_INT_8_8_8_8:
     case GL_UNSIGNED_INT_8_8_8_8_REV:
     case GL_UNSIGNED_INT_10_10_10_2:
     case GL_UNSIGNED_INT_2_10_10_10_REV:
     case GL_UNSIGNED_INT_24_8_NV:
        return 4;
     default:
        return 0;
     }
  }
  
  /*
  ** Compute memory required for internal packed array of data of given type
  ** and format.
  */
  GLint
  __glImageSize(GLsizei width, GLsizei height, GLsizei depth,
                GLenum format, GLenum type, GLenum target)
  {
     int bytes_per_row;
     int components;
  
     switch (target) {
     case GL_PROXY_TEXTURE_1D:
     case GL_PROXY_TEXTURE_2D:
     case GL_PROXY_TEXTURE_3D:
     case GL_PROXY_TEXTURE_4D_SGIS:
     case GL_PROXY_TEXTURE_CUBE_MAP:
     case GL_PROXY_TEXTURE_RECTANGLE_ARB:
     case GL_PROXY_HISTOGRAM:
     case GL_PROXY_COLOR_TABLE:
     case GL_PROXY_TEXTURE_COLOR_TABLE_SGI:
     case GL_PROXY_POST_CONVOLUTION_COLOR_TABLE:
     case GL_PROXY_POST_COLOR_MATRIX_COLOR_TABLE:
     case GL_PROXY_POST_IMAGE_TRANSFORM_COLOR_TABLE_HP:
        return 0;
     }
  
     if (width < 0 || height < 0 || depth < 0) {
        return 0;
     }
  
     /*
      ** Zero is returned if either format or type are invalid.
      */
     components = __glElementsPerGroup(format, type);
     if (type == GL_BITMAP) {
        if (format == GL_COLOR_INDEX || format == GL_STENCIL_INDEX) {
           bytes_per_row = (width + 7) >> 3;
        }
        else {
           return 0;
        }
     }
     else {
        bytes_per_row = __glBytesPerElement(type) * width;
     }
  
     return bytes_per_row * height * depth * components;
  }