A Generic Platform Package is prepared for one color format and contains all drawing operations with well-optimized software functions. Thus, it can be easily integrated into your target system by just implementing a few interface functions to the graphics subsystem and to the C library or the operating system running in your target.
If your target system provides also some graphics acceleration, single graphics operations can be redirected to your graphics API in order to use the hardware acceleration instead of the provided software functions.
The Generic Platform Packages are available for following color formats:
- RGBA8888 - 32 bit 8:8:8:8 color format for the red, green, blue and alpha channels. The order of the channels can be explicitly determined and the color channels can be pre-multiplied by the corresponding alpha value.
- RGBA4444 -16 bit 4:4:4:4 color format for the red, green, blue and alpha channels. The order of the channels can be explicitly determined and the color channels can be pre-multiplied by the corresponding alpha value.
- RGB565A8 - 16 bit 5:6:5 color format for the red, green and blue channels. The alpha information is stored separately as an 8 bit value per pixel. The order of the color channels can be determined explicitly and they can be pre-multiplied by the corresponding alpha value.Please note, the resulting alpha information can't be stored in the frame buffers when this format is used. The frame buffer remains thus opaque.
- RGB555A8 - 16 bit 5:5:5:1 color format for the red, green and blue channels. The additional 1 bit can be configured as a transparency bit. The alpha information is stored separately as an 8 bit value per pixel. The order of the color channels can be determined explicitly and they can be pre-multiplied by the corresponding alpha value.Please note, the resulting alpha information can't be stored in the frame buffers when this format is used. Only the transparence bit can be configured. Without this bit, the frame buffer will remain opaque.
- YUVA8888 - 32 bit 8:8:8:8 color format specialized to store the luminance and the color information. The order of the YUVA channels can be explicitly determined.
- Index8 - It refers to the generic 8-bit color format working with a global color look-up table (CLUT also called palette). Instead of color information, the frame buffer stores index numbers inside a color table. At the runtime the table is used to convert the index into the real color.
The suitable color format depends primarily on the format of the frame buffer in your target system.
Generic Platform Packages are delivered together with a document describing all porting details.
