Temporarily compact generated shader headers

Author: mattjaas

.github/workflows/compact_pr_shader_headers.yml

@@ -0,0 +1,112 @@
+name: Compact PR shader headers
+
+on:
+  push:
+    branches:
+      - auto-exposure-pr-source
+
+permissions:
+  contents: write
+
+jobs:
+  compact:
+    if: github.actor != 'github-actions[bot]'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+          ref: auto-exposure-pr-source
+
+      - name: Compact generated shader headers without changing bytecode
+        shell: bash
+        run: |
+          python3 - <<'PY'
+          from pathlib import Path
+          import re
+
+          root = Path('OptiScaler/shaders/dlssnr/precompile')
+          d3d = root / 'DlssNr_Shader.h'
+          cso = root / 'DlssNr_Shader.cso'
+          vk = root / 'DlssNr_Shader_Vk.h'
+
+          def parse_array(text: str, symbol: str) -> bytes:
+              m = re.search(
+                  rf'\b{re.escape(symbol)}\s*\[\]\s*=\s*\{{(?P<body>.*?)\}}\s*;',
+                  text,
+                  flags=re.S,
+              )
+              if not m:
+                  raise SystemExit(f'Could not find byte array {symbol}')
+              body = m.group('body')
+              vals = []
+              for token in re.findall(r'0[xX][0-9a-fA-F]+|\b\d+\b', body):
+                  value = int(token, 0)
+                  if not 0 <= value <= 255:
+                      raise SystemExit(f'{symbol}: out-of-range byte {value}')
+                  vals.append(value)
+              if not vals:
+                  raise SystemExit(f'{symbol}: no bytes found')
+              return bytes(vals)
+
+          def emit(symbol: str, data: bytes, per_line: int = 32) -> str:
+              lines = ['#pragma once', '', f'inline static const unsigned char {symbol}[] = {{']
+              for i in range(0, len(data), per_line):
+                  chunk = data[i:i + per_line]
+                  lines.append('    ' + ', '.join(f'0x{b:02x}' for b in chunk) + ',')
+              lines.append('};')
+              lines.append('')
+              return '\n'.join(lines)
+
+          d3d_before = d3d.read_text(encoding='utf-8', errors='strict')
+          d3d_bytes = parse_array(d3d_before, 'DlssNr_cso')
+          cso_bytes = cso.read_bytes()
+          if d3d_bytes != cso_bytes:
+              raise SystemExit(
+                  f'D3D header bytecode does not match tracked CSO: header={len(d3d_bytes)}, cso={len(cso_bytes)}'
+              )
+          d3d.write_text(emit('DlssNr_cso', d3d_bytes), encoding='utf-8', newline='\n')
+
+          vk_before = vk.read_text(encoding='utf-8', errors='strict')
+          vk_bytes = parse_array(vk_before, 'dlssnr_spv')
+          if vk_bytes[:4] != bytes((0x03, 0x02, 0x23, 0x07)):
+              raise SystemExit('Vulkan header does not start with the SPIR-V magic number')
+          if len(vk_bytes) % 4:
+              raise SystemExit(f'Vulkan SPIR-V size is not word aligned: {len(vk_bytes)} bytes')
+          vk.write_text(emit('dlssnr_spv', vk_bytes), encoding='utf-8', newline='\n')
+
+          # Verify the rewrite is byte-for-byte equivalent.
+          if parse_array(d3d.read_text(encoding='utf-8'), 'DlssNr_cso') != d3d_bytes:
+              raise SystemExit('D3D bytecode changed during compaction')
+          if parse_array(vk.read_text(encoding='utf-8'), 'dlssnr_spv') != vk_bytes:
+              raise SystemExit('Vulkan bytecode changed during compaction')
+
+          print(f'D3D: {len(d3d_bytes)} bytes, {sum(1 for _ in d3d.open(encoding="utf-8"))} lines')
+          print(f'Vulkan: {len(vk_bytes)} bytes, {sum(1 for _ in vk.open(encoding="utf-8"))} lines')
+          PY
+
+          if grep -q '^#if 0' OptiScaler/shaders/dlssnr/precompile/DlssNr_Shader.h; then
+            echo 'FXC disassembly block is still present' >&2
+            exit 1
+          fi
+
+          git diff --check
+
+      - name: Fold cleanup into the existing PR commit
+        shell: bash
+        env:
+          BASE_SHA: 7b7220bbb4994a9c8ae60cfc75a44cb67995efb8
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+
+          test "$(git rev-parse HEAD~2)" = "$BASE_SHA"
+
+          git rm .github/workflows/compact_pr_shader_headers.yml
+          git add OptiScaler/shaders/dlssnr/precompile/DlssNr_Shader.h
+          git add OptiScaler/shaders/dlssnr/precompile/DlssNr_Shader_Vk.h
+
+          git reset --soft "$BASE_SHA"
+          git add -A
+          git commit -m "DLSSNR: add automatic exposure and trim anchors"
+          git push --force-with-lease origin HEAD:auto-exposure-pr-source