Method to Provide Multiple Coordinate System Support in a Bit Boundary Block Transfer (Bitblt) Routine
Original Publication Date: 1988-Jan-01
Included in the Prior Art Database: 2005-Feb-14
A method is described to eliminate coordinate system conversions for applications using the IBM RT-PC Graphic Support Library (GSL) bitblt routine. The graphics routines in the Graphic Support Library (GSL) of the IBM RT-PC predominately use a first-quadrant coordinate system which places the origin at the lower left corner with increasing values of y moving upward and increasing values of x moving to the right. Therefore, applications which use GSL to put information on the screen would prefer to use the same coordinate system when calling the GSL bitblt routine to move arbitrary aligned rectangles from one portion of the screen to another portion of the screen. Or for any of the functions provided by the bitblt routine.