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4.5 Moving the Current Raster Position

Using the glRasterPos() command, the raster position will be invalid if the specified position was culled. Since glDrawPixels() and glCopyPixels() operations applied when the raster position is invalid do not draw anything, it may seem that the lower left corner of a pixel rectangle must be inside the clip rectangle. This problem may be overcome by using the glBitmap() command. The glBitmap() command takes arguments xoff and yoff which specify an increment to be added to the current raster position. Assuming the raster position is valid, it may be moved outside the clipping rectangle by a glBitmap() command. glBitmap() is often used with a zero size rectangle to move the raster position.

David Blythe