feat: introduce RGB9E5 converter tool and HDR format support

- Added a new executable `rgb9e5_converter` for converting HDR images to and from RGB9E5 format, enhancing texture processing capabilities.
- Implemented unit tests for RGB9E5 format to ensure conversion accuracy and integrity.
- Introduced documentation for the RGB9E5 HDR image format, detailing specifications and usage.
- Added a new CI workflow for performance benchmarking, integrating enhanced metrics collection and reporting.
- Updated CMake configuration to include new tools and tests, improving build structure and maintainability.

These changes enhance the engine's support for HDR textures and streamline the benchmarking process, contributing to overall performance and usability improvements.

Author: timfox

.github/workflows/benchmark.yml

@@ -0,0 +1,143 @@
+name: Performance Benchmark
+
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main, develop ]
+  workflow_dispatch:
+
+jobs:
+  benchmark:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Set up Python
+      uses: actions/setup-python@v4
+      with:
+        python-version: '3.9'
+
+    - name: Install dependencies
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y cmake ninja-build clang-18 gcc-13 python3-matplotlib python3-seaborn python3-pandas python3-numpy jq
+
+    - name: Configure CMake
+      run: |
+        mkdir -p build
+        cd build
+        cmake .. -G Ninja \
+          -DCMAKE_C_COMPILER=clang-18 \
+          -DCMAKE_CXX_COMPILER=clang++-18 \
+          -DBUILD_BENCHMARKS=ON \
+          -DBUILD_TESTS=OFF \
+          -DBUILD_SERVER=OFF \
+          -DBUILD_RADIANT=OFF
+
+    - name: Build benchmarks
+      run: |
+        cd build
+        ninja renderer_bench
+
+    - name: Run enhanced benchmarks
+      run: |
+        ./scripts/ci_benchmark.sh
+
+    - name: Upload benchmark results
+      uses: actions/upload-artifact@v4
+      with:
+        name: benchmark-results-${{ github.run_number }}
+        path: |
+          tests/benchmarks/
+          bench_reports/
+          bench_results.json
+        retention-days: 30
+
+    - name: Upload benchmark report
+      uses: actions/upload-artifact@v4
+      with:
+        name: benchmark-report-${{ github.run_number }}
+        path: bench_reports/benchmark_report.html
+        retention-days: 30
+
+    - name: Comment PR with benchmark results
+      if: github.event_name == 'pull_request'
+      uses: actions/github-script@v7
+      with:
+        script: |
+          const fs = require('fs');
+          const path = require('path');
+
+          // Read benchmark summary
+          let summary = {};
+          try {
+            const summaryPath = path.join(process.cwd(), 'bench_results.json');
+            if (fs.existsSync(summaryPath)) {
+              summary = JSON.parse(fs.readFileSync(summaryPath, 'utf8'));
+            }
+          } catch (e) {
+            console.log('Could not read benchmark results:', e);
+          }
+
+          // Generate comment
+          let comment = '## 🚀 Performance Benchmark Results\n\n';
+
+          if (summary.summary) {
+            const data = summary.summary;
+            comment += `**Duration:** ${data.duration_seconds?.toFixed(2) || 'N/A'}s\n`;
+            comment += `**Peak Memory:** ${data.memory_end_mb?.toFixed(1) || 'N/A'}MB\n\n`;
+
+            const operations = ['pathTracer', 'rtx', 'denoiser', 'fsr'];
+            comment += '| Operation | Avg Time | Min | Max | P95 | Stability |\n';
+            comment += '|-----------|----------|-----|-----|-----|-----------|\n';
+
+            operations.forEach(op => {
+              if (data[op]) {
+                const opData = data[op];
+                const avg = opData.avg_ms?.toFixed(3) || 'N/A';
+                const min = opData.min_ms?.toFixed(3) || 'N/A';
+                const max = opData.max_ms?.toFixed(3) || 'N/A';
+                const p95 = opData.p95_ms?.toFixed(3) || 'N/A';
+                const stddev = opData.stddev_ms || 0;
+                const cv = avg !== 'N/A' ? ((stddev / parseFloat(avg)) * 100).toFixed(1) : 'N/A';
+                const stability = cv !== 'N/A' ? (parseFloat(cv) < 10 ? '🟢' : parseFloat(cv) < 25 ? '🟡' : '🔴') : '❓';
+
+                comment += `| ${op} | ${avg}ms | ${min}ms | ${max}ms | ${p95}ms | ${stability} ${cv}% |\n`;
+              }
+            });
+          }
+
+          if (summary.regressions && summary.regressions.length > 0) {
+            comment += '\n### ⚠️ Performance Regressions Detected\n\n';
+            summary.regressions.forEach(reg => {
+              comment += `🔴 **${reg.operation}**: +${reg.regression_percent?.toFixed(1) || 'N/A'}% slower\n`;
+            });
+          } else {
+            comment += '\n✅ **No performance regressions detected**\n';
+          }
+
+          comment += '\n📊 [Detailed Report](https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}) (download artifacts)\n';
+
+          // Post comment
+          github.rest.issues.createComment({
+            issue_number: context.issue.number,
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            body: comment
+          });
+
+    - name: Fail on performance regression
+      if: github.event_name == 'pull_request'
+      run: |
+        if [ -f "bench_results.json" ]; then
+          if jq -e '.regressions | length > 0' bench_results.json > /dev/null; then
+            echo "Performance regression detected!"
+            jq '.regressions' bench_results.json
+            exit 1
+          else
+            echo "No performance regressions detected."
+          fi
+        fi

CMakeLists.txt

@@ -4634,6 +4634,28 @@ ADD_EXECUTABLE(test_rtx_switchmode
 ADD_EXECUTABLE(test_wayland_toggle
 	src/tests/test_wayland_toggle.cpp
 )
+
+# RGB9E5 converter tool for HDR texture processing
+ADD_EXECUTABLE(rgb9e5_converter
+	tools/rgb9e5_converter.c
+)
+TARGET_INCLUDE_DIRECTORIES(rgb9e5_converter PRIVATE
+	${CMAKE_SOURCE_DIR}/src
+)
+TARGET_LINK_LIBRARIES(rgb9e5_converter PRIVATE m)
+SET_TARGET_PROPERTIES(rgb9e5_converter PROPERTIES
+	RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/tools"
+)
+
+# RGB9E5 format unit tests
+ADD_EXECUTABLE(test_rgb9e5
+	src/tests/test_rgb9e5.c
+)
+target_compile_definitions(test_rgb9e5 PRIVATE UNIT_TEST)
+SET_TARGET_PROPERTIES(test_rgb9e5 PROPERTIES
+	RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/tests"
+)
+ADD_TEST(NAME test_rgb9e5 COMMAND test_rgb9e5)
 ADD_EXECUTABLE(test_profiler_integration
 	src/tests/test_profiler_integration.c
 	src/unix/unix_shared.c