3D Graphics Programming with QuickDraw 3D 1.5.4

Pixel Types

The pixelType field of a memory device structure (of type TQADeviceMemory ) specifies a pixel format (that is, the size and organization of the memory associated with a single pixel in a memory pixmap). You use these constants to assign a value to that field and also to parameters to the QATextureNew and QABitmapNew functions.



 
typedef enum TQAImagePixelType {

    kQAPixel_Alpha1                     = 0,

    kQAPixel_RGB16                      = 1,

    kQAPixel_ARGB16                     = 2,

    kQAPixel_RGB32                      = 3,

    kQAPixel_ARGB32                     = 4,

    kQAPixel_CL4                        = 5,

    kQAPixel_CL8                        = 6,

    kQAPixel_RGB16_565                  = 7,

    kQAPixel_RGB24                      = 8

} TQAImagePixelType;

Constant descriptions

kQAPixel_Alpha1: A pixel occupies 1 bit of memory, which is interpreted as an alpha channel value. This value is relevant only for the QABitmapNew function. When a bit is 1, it is opaque and is rendered in the color passed to the QADrawBitmap function; when the bit is 0, it is completely transparent.
kQAPixel_RGB16: A pixel occupies 16 bits of memory, with the red component in bits 14 through 10, the green component in bits 9 through 5, and the blue component in bits 4 through 0. There is no per-pixel alpha channel value. As a result, the pixmap (perhaps defining a texture) is treated as opaque. (You can, however, apply transparency to the pixmap using the alpha channel values of a triangle vertex, for instance.)
kQAPixel_ARGB16: A pixel occupies 16 bits of memory, with the red component in bits 14 through 10, the green component in bits 9 through 5, and the blue component in bits 4 through 0. In addition, the pixel's alpha channel value is in bit 15. When the alpha value is 1, the pixmap is opaque; when the alpha value is 0, the pixmap is completely transparent.
kQAPixel_RGB32: A pixel occupies 32 bits of memory, with the red component in bits 23 through 16, the green component in bits 15 through 8, and the blue component in bits 7 through 0. There is no per-pixel alpha channel value. As a result, the pixmap (perhaps defining a texture) is treated as opaque. (You can, however, apply transparency to the pixmap using the alpha channel values of a triangle vertex, for instance.)
kQAPixel_ARGB32: A pixel occupies 32 bits of memory, with the red component in bits 23 through 16, the green component in bits 15 through 8, and the blue component in bits 7 through 0. In addition, the pixel's alpha channel value is in bits 31 through 24. When the alpha value is 255, the pixmap is opaque; when the alpha value is 0, the pixmap is completely transparent.
kQAPixel_CL4: A pixel value is an index into a 4-bit color lookup table. This color lookup table is always big-endian (that is, the high 4 bits affect the leftmost pixel). This pixel type is valid only as a parameter for the QATextureNew and QABitmapNew functions. Not all drawing engines support this pixel type; it is supported only when a drawing engine supports the kQAOptional_CL4 feature.
kQAPixel_CL8: A pixel value is an index into a 8-bit color lookup table. This pixel type is valid only as a parameter for the QATextureNew and QABitmapNew functions. Not all drawing engines support this pixel type; it is supported only when a drawing engine supports the kQAOptional_CL8 feature.
kQAPixel_RGB16_565: A pixel occupies 16 bits of memory, with the red component in bits 15 through 11, the green component in bits 10 through 5, and the blue component in bits 4 through 0. There is no per-pixel alpha channel value. This pixel type is currently defined only for Windows 32 devices.
kQAPixel_RGB24: A pixel occupies 24 bits of memory, with the red component in bits 23 through 16, the green component in bits 15 through 8, and the blue component in bits 7 through 0. There is no per-pixel alpha channel value. This pixel type is currently defined only for Windows 32 devices.