247fig4.txt at [bf01bf4035]

Login

File tip/247fig4.txt artifact 840685a532 part of check-in bf01bf4035


/*
 *--------------------------------------------------------------
 *
 * ScaleBitmap --
 *
 *	This procedure is invoked to rescale a bitmap item in a
 *	canvas. It is one of the standard item procedures for
 *	bitmap items, and is invoked by the generic canvas code,
 *	for example during the "scale" widget command.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The item referred to by itemPtr is rescaled so that the
 *	following transformation is applied to all point coordinates:
 *		x' = originX + scaleX*(x-originX)
 *		y' = originY + scaleY*(y-originY)
 *
 *--------------------------------------------------------------
 */

static void
ScaleBitmap(canvasPtr, itemPtr, originX, originY, scaleX, scaleY)
    Tk_Canvas *canvasPtr;	/* Canvas containing rectangle. */
    Tk_Item *itemPtr;		/* Rectangle to be scaled. */
    double originX, originY;	/* Origin about which to scale rect. */
    double scaleX;		/* Amount to scale in X direction. */
    double scaleY;		/* Amount to scale in Y direction. */
{
    ...
}