Function

Gdkcairo_draw_from_gl

Declaration [src]

void
gdk_cairo_draw_from_gl (
  cairo_t* cr,
  GdkSurface* surface,
  int source,
  int source_type,
  int buffer_scale,
  int x,
  int y,
  int width,
  int height
)

Description [src]

The main way to 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_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.

Parameters

cr cairo_t*
 

A cairo context.

 The data is owned by the caller of the function.
surface GdkSurface
 

The surface we’re rendering for (not necessarily into)

 The data is owned by the caller of the function.
source int
 

The GL ID of the source buffer.

source_type int
 

The type of the source.

buffer_scale int
 

The scale-factor that the source buffer is allocated for.

x int
 

The source x position in source to start copying from in GL coordinates.

y int
 

The source y position in source to start copying from in GL coordinates.

width int
 

The width of the region to draw.

height int
 

The height of the region to draw.