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/* $XFree86: xc/lib/GL/glx/compsize.c,v 1.6 2004/01/28 18:11:38 alanh Exp $ */
/*
** License Applicability. Except to the extent portions of this file are
** made subject to an alternative license as permitted in the SGI Free
** Software License B, Version 1.1 (the "License"), the contents of this
** file are subject only to the provisions of the License. You may not use
** this file except in compliance with the License. You may obtain a copy
** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
**
** http://oss.sgi.com/projects/FreeB
**
** Note that, as provided in the License, the Software is distributed on an
** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
**
** Original Code. The Original Code is: OpenGL Sample Implementation,
** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
** Copyright in any portions created by third parties is as indicated
** elsewhere herein. All Rights Reserved.
**
** Additional Notice Provisions: The application programming interfaces
** established by SGI in conjunction with the Original Code are The
** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
** Window System(R) (Version 1.3), released October 19, 1998. This software
** was created using the OpenGL(R) version 1.2.1 Sample Implementation
** published by SGI, but has not been independently verified as being
** compliant with the OpenGL(R) version 1.2.1 Specification.
**
*/
#include <GL/gl.h>
#include "size.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_SHORT_15_1_MESA:
case GL_UNSIGNED_SHORT_1_15_REV_MESA:
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:
case GL_UNSIGNED_INT_24_8_MESA:
case GL_UNSIGNED_INT_8_24_REV_MESA:
return 1;
default:
break;
}
switch(format) {
case GL_RGB:
case GL_BGR:
return 3;
case GL_422_EXT:
case GL_422_REV_EXT:
case GL_422_AVERAGE_EXT:
case GL_422_REV_AVERAGE_EXT:
case GL_YCBCR_422_APPLE:
case GL_LUMINANCE_ALPHA:
return 2;
case GL_RGBA:
case GL_BGRA:
case GL_ABGR_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:
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:
case GL_UNSIGNED_SHORT_15_1_MESA:
case GL_UNSIGNED_SHORT_1_15_REV_MESA:
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:
case GL_UNSIGNED_INT_24_8_MESA:
case GL_UNSIGNED_INT_8_24_REV_MESA:
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)
{
int bytes_per_row;
int components;
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;
}
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