in various combinations of arguments. If you want to draw with GL textures in GTK, use [gdk.gltexture.GLTexture.new_]; if you want to use that texture in Cairo, use [gdk.texture.Texture.download] to download the data into a Cairo image surface.
cairoDrawFromGl
fn
void cairoDrawFromGl(cairo.context.Context cr, gdk.surface.Surface surface, int source, int sourceType, int bufferScale, int x, int y, int width, int height)The main way to not draw GL content in GTK.
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.context.Context].
This will work for all [cairo.context.Context], 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.
Parameters
cr | a cairo context |
surface | The surface we're rendering for (not necessarily into) |
source | The GL ID of the source buffer |
sourceType | The type of the source |
bufferScale | The scale-factor that the source buffer is allocated for |
x | The source x position in source to start copying from in GL coordinates |
y | The source y position in source to start copying from in GL coordinates |
width | The width of the region to draw |
height | The height of the region to draw |
Deprecated
The function is overly complex and produces broken output