cairo-Image-Surfaces {RGtk2.10} | R Documentation |
Image Surfaces
Description
Rendering to memory buffers
Methods and Functions
cairoImageSurfaceCreate(format, width, height)
cairoImageSurfaceCreateForData(data, format, width, height, stride)
cairoImageSurfaceGetData(surface)
cairoImageSurfaceGetFormat(surface)
cairoImageSurfaceGetWidth(surface)
cairoImageSurfaceGetHeight(surface)
cairoImageSurfaceGetStride(surface)
Detailed Description
Image surfaces provide the ability to render to memory buffers
either allocated by cairo or by the calling code. The supported
image formats are those defined in CairoFormat
.
Enums and Flags
CairoFormat
CairoFormat
is used to identify the memory format of
image data.
New entries may be added in future versions.
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
not 0x80ff0000.)
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.
a8
- each pixel is a 8-bit quantity holding
an alpha value.
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.
rgb16-565
- This format value is deprecated. It has
never been properly implemented in cairo and should not be used
by applications. For example, any attempt to create an image
surface with a format of CAIRO_FORMAT_RGB16_565 will fail. This
format value was added as part of fixing cairo's xlib backend to
work with X servers advertising a 16-bit, 565 visual. But as it
turned out, adding this format to
CairoFormat
was not
necessary, and was a mistake, (cairo's xlib backend can work fine
with 16-bit visuals in the same way it works with BGR visuals
without any BGR formats in CairoFormat
). (Since 1.2)
Author(s)
Derived by RGtkGen from GTK+ documentation
References
http://www.cairographics.org/manual/cairo-Image-Surfaces.html
[Package
RGtk2.10 version 2.10.6
Index]