Warning: cairo_draw_from_gl is deprecated since 4.6.
The main way to not draw GL content in GTK.
The function is overly complex and produces broken output in various combinations of arguments. If you want to draw with GL textures in GTK, use [[email protected]]; if you want to use that texture in Cairo, use [[email protected]] to download the data into a Cairo image surface.
It takes a render buffer ID (source_type
== GL_RENDERBUFFER) or a texture id (source_type
== GL_TEXTURE) and
draws it onto cr
with an OVER operation, respecting the current clip. The top left corner of the rectangle specified by
x
, y
, width
and height
will be drawn at the current (0,0) position of the `cairo_t`.
This will work for *all* `cairo_t`, as long as surface
is realized, but the fallback implementation that reads back the
pixels from the buffer may be used in the general case. In the case of direct drawing to a surface with no special effects applied to
cr
it will however use a more efficient approach.
For GL_RENDERBUFFER the code will always fall back to software for buffers with alpha components, so make sure you use GL_TEXTURE if using alpha.
Calling this may change the current GL context.
cr |
a cairo context |
surface |
The surface we're rendering for (not necessarily into) |
source |
The GL ID of the source buffer |
source_type |
The type of the |
buffer_scale |
The scale-factor that the |
x |
The source x position in |
y |
The source y position in |
width |
The width of the region to draw |
height |
The height of the region to draw |