Add a bunch of inline functions for graphene_rectangle_t.
We use those quite extensively in tight loops so making them as fast as
possible via inlining has massive benefits.
The current render-heavy benchmark I am playing (th paris-30k in node-editor)
went from 49fps to 85fps on my AMD.
Instead of creating a pipeline GObject, just ask for the VkPipeline.
And instead of having the Op handle it, just let the renderpass look
up/create the relevant pipeline while creating commands so that it can
insert vkCmdBindPipeline calls as-needed.
Intersection with a roudned clip takes too long.
Instead, rename the function to may_intersect() to be clear about what
it does and then just intersect with the regular rectangle.
If we don't clip anything, we stil have bounds - either the framebuffer
size or (more likely) the scissor rect. And we don't want to draw
anything that is outside these bounds.
So clip in those cases, too.
Stops gtk4-demo --run=listbox from trying to render the whole listbox
instead of only the visible parts.
If we have a rectangular clip without transforms, we can use
scissoring. This works particularly well because it allows intersecting
rounded rectangles with regular rectangles in all cases:
Use the scissor rect for the rectangle and the normal clipping code for
the rounded rectangle.
