Kravickas--PS4-apps/shaders

GPU shaders (GCN2 / Sea Islands). Headers only - main.c includes shaders.h;
nothing here is compiled on its own (the Makefile builds src/*.c/.cpp/.s as
CPU code, which is why GCN assembly must not live in src/).

  vs_shader.h        MVP vertex shader (sky, floor, cube/model, stars, post quad)
  vs_shadow.h        same code, own hash, for the shadow pass
  ps_dark.h          sky gradient + sun disc + moon disc (source ps_dark.s)
  ps_floor.h         floor: POM on the height map, BC5 normal map (z rebuilt), shadow, fog (ps_floor.s)
  ps_shader.h        built-in cube: texture, Lambert, light colour, fog (source ps_shader.s)
  ps_model.h         loaded model: parallax, relief shadow, BC5 normal map, shadow, fog (ps_model.s)
  vs_model.h         loaded model VS: transform in user SGPRs, tangent export (vs_model.s)
  vs_model_shadow.h  loaded model, shadow pass (vs_model_shadow.s)
  ps_shadow.h        shadow pass: light-space depth
  ps_shadow_clear.h  shadow map clear
  ps_stars.h         stars (smooth splat, FP16 export for the additive blend)
  ps_blue.h          loading bar
  ps_post_*.h        bloom: down / blur / up-add, final composite (sRGB encode
                     + dither); sources in ps_post_*.s

Only the post shaders, ps_stars, ps_dark, ps_floor, ps_shader, ps_model and the
vs_model shaders have .s sources; the others were hand-encoded and their headers document the
instructions. To rebuild a post shader:
  llvm-mc -triple=amdgcn -mcpu=bonaire -show-encoding ps_post_down.s
then put the dwords between the SDK header token (0xBEEB03FF, n/2-1) and the
OrbShdr trailer (length = code bytes, new unique hash) in ps_post_down.h.
Inputs: s[0:1] = descriptor table (USER_SGPR 2); v2/v3 = POS_X/POS_Y_FLOAT
(SPI_PS_INPUT_ENA 0x302, pixel centres: PA_SU_VTX_CNTL.PIX_CENTER = 1).