• Benjamin Otte's avatar
    gdk: Add Cairo context implementations for all backends · 813e9c95
    Benjamin Otte authored
    And make the GdkCairoContext as abstract.
    
    The idea of this and thje following commits is to get rid of all
    Cairo code in gdksurface.c (and $backend/gdksurface-$backend.c)
    by moving that code into the Cairo context files.
    In particular, the GdkSurfaceClass.begin_frame/end_frame()
    functions (which are currently exclusively used by the Cairo code
    should end up being moved to GdkDrawContextClass.begin/end_frame().
    
    This has multiple benefits:
    
    1. It unifies code between the different drawing contexts.
       GL lives in GLContext, Vulkan in VulkanContext and Cairo in
       CairoContext. In turn, this makes it way easier to reason about
       what's going on in surface-specific code. Currently pretty much
       all backends do things wrong when they want to sync to drawing
       or to the frame clock.
    
    2. It makes the API of GdkSurface smaller. No drawing code (apart
       from creating the contexts) needs to remain.
    
    3. It confines Cairo to the Drawcontext, thereby making it way
       more obvious when backends are still using it in situations
       where it may now conflict with OpenGL (like when doing the dnd
       failed animation or in the APIs that I'm removing in this
       branch).
    
    4. We have 2 very different types of Cairo contexts: The X/win32
       model, where we have a natively supported Cairo backend but do
       double buffering ourselves and use similar surfaces and the
       Wayland/Broadway model where we use image surfaces without any
       Cairo backend support and have to submit the buffers manually.
       By not sharing code between those 2 versions, we can make the
       actual code way smaller. We also get around the need to create
       1x1 image surfaces in the Wayland backend where we pretend
       there's a native Cairo surface.
    813e9c95
gdkcairocontext-win32.h 1.96 KB