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13.2. System Independence with the GLUT Libraries 333
// The following code illustrates the format of the loading code
// - an external JPEG image manipulation library written in
// C is used from our C++ application
extern "C" {
extern long ReadJPG(char
*
filename, short info_only);
long x_sizeJ, y_sizeJ; // used by Library code
unsigned char
*
lpImage=NULL;
};
static unsigned char
*
LoadJpeg(char
*
filename, int
*
x, int
*
y){
unsigned char
*
screen;
long xs,ys,imagesize;
if(ReadJPG(filename,1) == 0)return NULL;
// test image is OK - if not return no pixels
xs=x_sizeJ; ys=y_sizeJ;
// if OK get width and height
imagesize=xs
*
ys
*
3
*
sizeof(unsigned char);
// allocate ...