Command buffer pools can't be reset until the commands have all been
executed. Having per-frame pools makes keeping track of pool lifetime
fairly easy.
Interleaving Vulkan objects with stucts containing vec4f_t results in
the vectors becoming unaligned when there is an odd number of objects in
a set, thus producing a segfault. Putting all the structs first prevents
any such issue.
The new render system now passes validation for the first frame (but
no drawing is done by the various subsystems yet). Something is wrong
with how swap chain semaphores are handled thus the second frame fails.
Frame buffer attachments can now be defined externally, with
"$swapchain" supported for now (in which case, the swap chain defines
the size of the frame buffer).
Also, render pass render areas and pipeline viewport and scissor rects
are updated when necessary.
I don't like the current name (update_framebuffer), but if the
referenced render pass doesn't have a framebuffer, one is created. The
renderpass is referenced via the active renderpass of the named render
step. Unfortunately, this has uncovered a bug in the setup of renderpass
objects: main.deferred has output's renderpass, and main.deferred_cube
and output have bogus renderpass objects.
Being able to specify the types in the push constant ranges makes it a
lot easier to get the specification correct. I never did like having to
do the offsets and sizes by hand as it was quite error prone. Right now,
float, int, uint, vec3, vec4 and mat4 are supported, and adheres to
layout std430.
The creation of the render jobs doesn't really belong with the running
of those jobs. This makes the code a little easier to navigate as it was
too easy to lost between load-time and run-time code.
