An application can copy an image from a raster display screen to a bit map by calling GpiBitBlt or GpiWCBitBlt. Before copying the bit map, the application must call DevOpenDC to create a memory device context. This device context allows an application to treat a bit map in memory as though it were a device-the application can copy color information from pels on the display to the bit map.
Once an application creates a memory device context, associates it with a presentation space, and selects a bit map into the presentation space, the application can use the presentation-space handle as the first argument to GpiBitBlt or GpiWCBitBlt. If the application will be drawing the image on devices with different aspect ratios, the application should use GpiWCBitBlt to preserve the original dimensions of the bit map.