CI: add cuda build

.github/workflows/cuda-build.yml

@@ -0,0 +1,47 @@
+name: cuda-build
+
+on:
+  push:
+    branches: [ "*" ]
+  pull_request:
+    branches: [ "*" ]
+  workflow_dispatch:
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  cuda-build:
+    strategy:
+      fail-fast: false
+      matrix:
+        cuda: [ '12.5.0' ]
+
+    name: GPU build (CUDA ${{ matrix.cuda }})
+
+    runs-on: ubuntu-latest
+    steps:
+    - uses: jimver/[email protected]
+      id: cuda-toolkit
+      with:
+        cuda: ${{ matrix.cuda }}
+        method: 'network'
+        sub-packages: '[ "nvcc" ]'
+
+    - name: check NVCC
+      run: nvcc -V
+
+    - name: install dependencies
+      run:
+        sudo apt install -y cmake libglu1-mesa-dev libpng-dev libx11-dev xorg-dev
+
+    - uses: actions/checkout@v4
+      with:
+        submodules: true
+
+    - name: build
+      run:
+        mkdir build;
+        cd build;
+        cmake ..;
+        make -j;

CMakeLists.txt

@@ -10,8 +10,6 @@ if (NOT CMAKE_CUDA_COMPILER)
     # required by CLion
 endif ()
 
-message("CUDA compiler: ${CMAKE_CUDA_COMPILER}")
-
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
@@ -28,6 +26,13 @@ endif ()
 enable_language(CUDA)
 include_directories("${CMAKE_CUDA_TOOLKIT_INCLUDE_DIRECTORIES}")
 
+message(STATUS "nvcc path: ${CMAKE_CUDA_COMPILER}")
+message(STATUS "nvcc version = ${CMAKE_CUDA_COMPILER_VERSION}")
+
+if (${CMAKE_CUDA_COMPILER_VERSION} VERSION_LESS "12.5.0")
+    message(FATAL_ERROR "you need NVCC >= 12.5.0 to build this project (required by cuda::std::optional)")
+endif ()
+
 add_subdirectory("src/ext")
 
 include_directories("src/ext/glad-3.3-core/include")

README.md

@@ -1,5 +1,7 @@
 # pbrt-minus
 
+[![cuda-build](https://github.com/w3ntao/pbrt-minus/actions/workflows/cuda-build.yml/badge.svg)](https://github.com/w3ntao/pbrt-minus/actions/workflows/cuda-build.yml)
+
 A simpler, less performant, physically based, GPU ray tracer rewritten from PBRT-v4.
 
 
@@ -20,7 +22,7 @@ A simpler, less performant, physically based, GPU ray tracer rewritten from PBRT
 
 Debian/Ubuntu:
 ```
-$ sudo apt install -y libglu1-mesa-dev libpng-dev libx11-dev xorg-dev
+$ sudo apt install -y cmake libglu1-mesa-dev libpng-dev libx11-dev xorg-dev
 ```
 
 Setting up for other distros should be similar.

src/pbrt/wavefront_integrators/path.cu

@@ -314,7 +314,7 @@ __global__ void generate_new_path(const IntegratorBase *base, const Filter *filt
 template <Material::Type material_type>
 __global__ void gpu_evaluate_material(const WavefrontPathIntegrator *integrator,
                                       PathState *path_state, Queues *queues) {
-    uint material_counter = NAN;
+    uint material_counter = UINT_MAX;
     uint *material_queue = nullptr;
 
     switch (material_type) {
@@ -480,7 +480,7 @@ PBRT_GPU void WavefrontPathIntegrator::sample_bsdf(uint path_idx, PathState *pat
 
 template <Material::Type material_type>
 void WavefrontPathIntegrator::evaluate_material() {
-    uint material_counter = NAN;
+    uint material_counter = UINT_MAX;
     switch (material_type) {
     case (Material::Type::coated_conductor): {
         material_counter = queues.coated_conductor_material_counter;