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/*
* $Id: ImageDpy.c 3177 2008-04-01 14:47:24Z karstenm $
*
* This file contains routines that aid the display of images.
*/
/*
* Copyright 1993, 1994 University of British Columbia
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appears in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation. UBC makes no representations about the suitability of this
* software for any purpose. It is provided "as is" without express or
* implied warranty.
*
* Author: Arthur Pope, UBC Laboratory for Computational Intelligence
*/
/* From the Vista library: */
#include "viaio/Vlib.h"
#include "viaio/os.h"
#include "viaio/VImage.h"
/* File identification string: */
VRcsId ("$Id: ImageDpy.c 3177 2008-04-01 14:47:24Z karstenm $");
/*
* VImageWindowSize
*
* Compute the dimensions of a window that will display a correctly-
* proportioned image and not exceed specified limits.
*/
void VImageWindowSize (VImage image, int max_width, int max_height,
int *width, int *height)
{
VFloat pixel_aspect = 1.0, image_aspect, window_aspect;
/* Find the image's pixel aspect ratio: */
if (VGetAttr (VImageAttrList (image), VPixelAspectRatioAttr, NULL,
VFloatRepn, & pixel_aspect) == VAttrBadValue)
VWarning ("VImageWindowSize: Image has bad %s attribute",
VPixelAspectRatioAttr);
/* Compute the width and height of the rectangle within the window
that will contain the image: */
image_aspect = pixel_aspect *
(float) VImageNColumns (image) / (float) VImageNRows (image);
window_aspect = (float) max_width / (float) max_height;
if (image_aspect != window_aspect) {
if (image_aspect > window_aspect) {
/* Image is a wider rectangle than window. */
*width = max_width;
*height = max_width / image_aspect;
} else {
/* Image is taller rectangle than window. */
*width = max_height * image_aspect;
*height = max_height;
}
} else {
*width = max_width;
*height = max_height;
}
}
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