We notice that masks can be described by 2 parameters:
1. Whether they have 0 or 1 as their high bits.
2. Whether they shift to the left or to the right on the next line.
Describing masks this way allows us to lift them to template variables and simplify the code.
We also avoid handling the mask in the `RenderLine` loop entirely.
Also fixes a foliage rendering bug: Transparent foliage pixels were previously blended but they should have been simply skipped.
When rendering directly to the output buffer, we need to maintain the
state of what has been drawn and what needs redrawing per-buffer.
We previously tried to do it implicitly by checking `SDL_DOUBLEBUF` and
other flags. The previous implementation was broken in several
ways, resulting in rendering issues on devices that support 8-bit output
directly.
Changes this mechanism to explicitly maintain buffer state per output
buffer. The new mechanism doesn't require knowledge of the number of
buffers, and thus also works correctly with triple-buffering.
Fixes#5447
The format is almost identical to CL2, except it uses the frame header
to store frame width and height instead of 5 32-line offsets.
This means we always have access to frame dimensions, so we can use it
as an on-disk format for our graphics as well.
Additionally, we may be able to optimize the rendering even more
in the future now that we have guaranteed knowledge of frame dimensions.
Convert CEL files to CL2 at load time. CL2 format is more efficient and is about as fast to render.
CEL vs CL2 sizes, on dLvl 5: https://gist.github.com/glebm/9bbdd76962abcd4fd2405ecd3379af97
Memory:
* Peak memory (while loading): -300 KiB
* Memory in-game (dLvl5): -700 KiB
* RG99 binary size: -15 KiB (1333096 -> 1317192)
Performance on rg99:
* On average, -1 FPS in town.
* Same FPS in dungeon (20 FPS on dLvl 1).
Gleb Mazovetskiy
KPhoenix
staphen
Anders Jenbo
KPhoenix
obligaron
Andrew James
Mikołaj Piróg
Trihedraf