cairo_format_t is used to identify the memory format of
image data.
New entries may be added in future versions.
CAIRO_FORMAT_INVALID
no such format exists or is supported.
CAIRO_FORMAT_ARGB32
each pixel is a 32-bit quantity, with
alpha in the upper 8 bits, then red, then green, then blue.
The 32-bit quantities are stored native-endian. Pre-multiplied
alpha is used. (That is, 50% transparent red is 0x80800000,
not 0x80ff0000.)
CAIRO_FORMAT_RGB24
each pixel is a 32-bit quantity, with
the upper 8 bits unused. Red, Green, and Blue are stored
in the remaining 24 bits in that order.
CAIRO_FORMAT_A8
each pixel is a 8-bit quantity holding
an alpha value.
CAIRO_FORMAT_A1
each pixel is a 1-bit quantity holding
an alpha value. Pixels are packed together into 32-bit
quantities. The ordering of the bits matches the
endianess of the platform. On a big-endian machine, the
first pixel is in the uppermost bit, on a little-endian
machine the first pixel is in the least-significant bit.
CAIRO_FORMAT_RGB16_565
each pixel is a 16-bit quantity
with red in the upper 5 bits, then green in the middle
6 bits, and blue in the lower 5 bits.
cairo_format_t is used to identify the memory format of image data. New entries may be added in future versions. CAIRO_FORMAT_INVALID no such format exists or is supported. CAIRO_FORMAT_ARGB32 each pixel is a 32-bit quantity, with alpha in the upper 8 bits, then red, then green, then blue. The 32-bit quantities are stored native-endian. Pre-multiplied alpha is used. (That is, 50% transparent red is 0x80800000, not 0x80ff0000.) CAIRO_FORMAT_RGB24 each pixel is a 32-bit quantity, with the upper 8 bits unused. Red, Green, and Blue are stored in the remaining 24 bits in that order. CAIRO_FORMAT_A8 each pixel is a 8-bit quantity holding an alpha value. CAIRO_FORMAT_A1 each pixel is a 1-bit quantity holding an alpha value. Pixels are packed together into 32-bit quantities. The ordering of the bits matches the endianess of the platform. On a big-endian machine, the first pixel is in the uppermost bit, on a little-endian machine the first pixel is in the least-significant bit. CAIRO_FORMAT_RGB16_565 each pixel is a 16-bit quantity with red in the upper 5 bits, then green in the middle 6 bits, and blue in the lower 5 bits.