Merge all static and dynamic buffers to just one, "memory". Add a malloc
function for dynamic allocations.
Unify static allocation offsets into a "config" buffer containing scene setup
(number of paths, number of path segments), as well as the memory offsets of
the static allocations.
Finally, set an overflow flag when an allocation fail, and make sure to exit
shader execution as soon as that triggers. Add checks before beginning
execution in case the client wants to run two or more shaders before checking
the flag.
The "state" buffer is left alone because it needs zero'ing and because it is
accessed with the "volatile" keyword.
Fixes#40
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Handling f16 requires special work, compared to other scalars, as the minimum conversion operation for u32->f16 in GLSL (unpackHalf2x16) loads two f16s from one u32. This means that in order to minimize unnecessary calls to unpackHalf2x16, we should look-ahead to see if the current f16 has already been extracted in the process of dealing with the last f16. Similar considerations exist for write operations, where we want to pack, when possible, two f16s in one go (using packHalf2x16).
This patch adds a module that contains both scene and ptcl types (very
lightly adapted from piet-metal), as well as infrastructure for encoding
Rust-side.
WIP, it's not wired up in either the shader or on the Rust side.
This version will be similar but somewhat different to what's in
piet-metal now. Hopefully a little simpler to use (no distinction
between packed and unpacked structs) and better structured.
