compsize.c   [plain text]

/*
 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice including the dates of first publication and
 * either this permission notice or a reference to
 * http://oss.sgi.com/projects/FreeB/
 * shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Except as contained in this notice, the name of Silicon Graphics, Inc.
 * shall not be used in advertising or otherwise to promote the sale, use or
 * other dealings in this Software without prior written authorization from
 * Silicon Graphics, Inc.
 */

#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_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, 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;
}