Function

Gdk-3.0 ▶ Gdk ▶ cairo_draw_from_glSince 3.16

  • This is 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 window 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 window 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: default.Context

      a cairo context

    • window: Gdk.Window

      The window we're rendering for (not necessarily into)

    • source: number

      The GL ID of the source buffer

    • source_type: number

      The type of the source

    • buffer_scale: number

      The scale-factor that the source buffer is allocated for

    • x: number

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

    • y: number

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

    • width: number

      The width of the region to draw

    • height: number

      The height of the region to draw

    Returns void

    3.16