name: gpu-build-only

permissions:  # https://github.com/actions/checkout/issues/254
  actions: write       # Necessary to cancel workflow executions
  checks: write        # Necessary to write reports
  pull-requests: write # Necessary to comment on PRs
  contents: read
  packages: write

on:
  push:
    paths-ignore:
      - '**.md'
      - 'images/**'
  pull_request:
    paths-ignore:
      - '**.md'
      - 'images/**'

jobs:
  build:
    strategy:
      fail-fast: false
      matrix:
        optix: [ optix-7.7.0, optix-8.1.0, optix-9.0.0 ]
        cuda: [ '12.9.1', '13.0.1', '13.1.1', '13.2.0' ]
        os: [ ubuntu-24.04, windows-2022 ]
        include:
          - os: windows-2022
            cuda: '13.2.0'
            optix: optix-9.0.0
            upload_binary: true

    name: GPU Build Only (${{ matrix.os }}, CUDA ${{ matrix.cuda }}, ${{ matrix.optix }})

    runs-on: ${{ matrix.os }}

    steps:
    - uses: jimver/cuda-toolkit@v0.2.35
      id: cuda-toolkit
      with:
        cuda: ${{ matrix.cuda }}
        use-github-cache: false
        use-local-cache: false
        log-file-suffix: ${{ matrix.os }}-${{ matrix.cuda }}-${{ matrix.optix }}.txt
   
    - name: Check NVCC
      run: nvcc -V

    - name: Checkout pbrt
      uses: actions/checkout@v5
      with:
        submodules: true

    - name: Checkout rgb2spectrum tables
      uses: actions/checkout@v5
      with:
        repository: mmp/rgb2spectrum
        path: build

    - name: Checkout OptiX headers
      uses: actions/checkout@v5
      with:
        ssh-key: ${{ secrets.CHECKOUT_KEY }}
        repository: mmp/optix-headers
        path: optix

    - name: Get cmake
      uses: lukka/get-cmake@latest

    - name: Install pkgconfig and zlib
      if: ${{ startsWith(matrix.os, 'windows-') }}
      run: |
        choco install pkgconfiglite

    - name: Install OpenGL
      if: ${{ startsWith(matrix.os, 'ubuntu-') }}
      run: |
        sudo apt-get update
        sudo apt-get install -y --no-install-recommends libx11-dev libxcursor-dev libxrandr-dev libxinerama-dev libxi-dev libxext-dev libxfixes-dev libgl1-mesa-dev libwayland-bin libwayland-dev wayland-protocols libxkbcommon-dev libxkbcommon-x11-0

    - name: Configure (Windows)
      if: ${{ startsWith(matrix.os, 'windows-') }}
      run: |
        cd build
        $env:CUDACXX = "$env:CUDA_PATH\bin\nvcc.exe"
        cmake .. `
          -T "cuda=$env:CUDA_PATH" `
          "-DCMAKE_TOOLCHAIN_FILE=$env:VCPKG_INSTALLATION_ROOT/scripts/buildsystems/vcpkg.cmake" `
          "-DPBRT_USE_PREGENERATED_RGB_TO_SPECTRUM_TABLES=True" `
          "-DPBRT_OPTIX_PATH=../optix/${{ matrix.optix }}" `
          "-DPBRT_GPU_SHADER_MODEL=sm_80"

    - name: Configure (Linux)
      if: ${{ startsWith(matrix.os, 'ubuntu-') }}
      run: |
        cd build
        cmake .. -DPBRT_USE_PREGENERATED_RGB_TO_SPECTRUM_TABLES=True -DPBRT_OPTIX_PATH=../optix/${{ matrix.optix }} -DPBRT_GPU_SHADER_MODEL=sm_80

    - name: Build
      # We need to limit the number of jobs so that it doesn't OOM 
      run: cmake --build build --parallel 3 --config Release

    - name: Save Windows executable
      if: ${{ matrix.upload_binary }}
      uses: actions/upload-artifact@v4
      with:
        name: pbrt.exe
        path: build/Release/pbrt.exe