Display Hardware Recommendations

For display hardware used with Windows CE, Microsoft makes several recommendations to improve performance and to facilitate driver development. Following the recommendations enables you to implement your display driver more easily, although you can write a fully functional driver even if your hardware does not conform to these recommendations.

Microsoft strongly recommends that your display hardware uses a linear-frame buffer. All the display’s memory should be contiguous, and one linear-access window should cover the entire frame buffer. If your hardware does not meet these qualifications, you must make substantive modifications to the GPE classes, if you choose to use them. For more information, see Using the Graphics Primitive Engine Classes.

Your display hardware should use a supported combination of pixel format, packing, and pixel ordering. For more information, see Display Buffer Formats. The display hardware’s frame buffer should have the following properties:

• Top-down format, with pixel (0,0) at the top left and pixel (width-1, height-1) at the lower right.
• The frame buffer’s stride—the number of bytes in memory that it takes to represent one scan line on the display—should be a multiple of 4 bytes, even if this means padding the end of each scan line with unused bytes.
• The entire frame buffer must be accessible by the CPU without requiring the CPU to perform bank selection.
• Frame buffers should not use bit planes, in which separate frame buffers are used for each color channel or intensity component.

Microsoft also recommends using display hardware that can accelerate the following operations, in order of decreasing importance:

• Solid-color fills, specifically, blit operations whose pbo->iSolidColor member is not 0xFFFFFFFF.
• SRCCOPY blit operations.
• Cursor display, if your platform uses a cursor.
• Solid-line drawing with sub-pixel precision.
• Masked SRCCOPY blit operations.