Support linux via v4l2, and add some build tests.

.github/workflows/linux-build.yml

@@ -0,0 +1,267 @@
+name: Linux Build
+
+on:
+  push:
+    branches: [ main, develop, support_linux ]
+  pull_request:
+    branches: [ main, develop ]
+
+jobs:
+  build-ubuntu:
+    name: "Build (${{ matrix.build_type }}-gcc)"
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        build_type: [Debug, Release]
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
+
+    - name: Install base dependencies
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y cmake build-essential gcc
+
+    - name: Install GLFW (for Release builds only)
+      if: matrix.build_type == 'Release'
+      run: |
+        sudo apt-get install -y libglfw3-dev
+        echo "GLFW_INSTALLED=true" >> $GITHUB_ENV
+
+    - name: Setup compiler
+      run: |
+        echo "CC=gcc" >> $GITHUB_ENV
+        echo "CXX=g++" >> $GITHUB_ENV
+
+    - name: Configure CMake
+      run: |
+        echo "Configuring build ${{ matrix.build_type }} with gcc"
+        cmake -B build/${{ matrix.build_type }} \
+              -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} \
+              -DCCAP_BUILD_EXAMPLES=ON \
+              -DCCAP_BUILD_TESTS=ON
+
+    - name: Build
+      run: cmake --build build/${{ matrix.build_type }} --config ${{ matrix.build_type }} --parallel $(nproc)
+
+    - name: Verify GLFW examples build status
+      working-directory: build/${{ matrix.build_type }}
+      run: |
+        echo "Checking built examples:"
+        ls -la | grep -E "(glfw|example)" || echo "No GLFW examples found"
+
+        if [ "${{ matrix.build_type }}" = "Release" ]; then
+          echo "Release build - checking if GLFW examples were built with system GLFW:"
+          if [ -f "4-example_with_glfw" ]; then
+            echo "✓ GLFW example successfully built with system GLFW"
+          else
+            echo "✗ GLFW example not found - this might indicate a build issue"
+            exit 1
+          fi
+        else
+          echo "Debug build - checking if bundled GLFW was used:"
+          if [ -f "4-example_with_glfw" ]; then
+            echo "✓ GLFW example successfully built with bundled GLFW"
+          else
+            echo "ℹ GLFW example not built - using bundled GLFW or GLFW disabled"
+          fi
+        fi
+
+    - name: Run Unit Tests
+      if: matrix.build_type == 'Release'
+      run: |
+        cd scripts
+        ./run_tests.sh --functional --exit-when-failed
+
+    - name: Upload artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: ccap-linux-gcc-${{ matrix.build_type }}
+        path: |
+          build/${{ matrix.build_type }}/libccap.a
+          build/${{ matrix.build_type }}/0-print_camera
+          build/${{ matrix.build_type }}/1-minimal_example
+          build/${{ matrix.build_type }}/2-capture_grab
+          build/${{ matrix.build_type }}/3-capture_callback
+          build/${{ matrix.build_type }}/4-example_with_glfw
+          build/${{ matrix.build_type }}/*_results.xml
+        if-no-files-found: warn
+
+  build-ubuntu-clang:
+    name: "Build (${{ matrix.build_type }}-clang)"
+    runs-on: ubuntu-latest
+    # Only run clang builds on push to main branch
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+
+    strategy:
+      matrix:
+        build_type: [Debug, Release]
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
+
+    - name: Install dependencies
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y cmake build-essential clang libglfw3-dev
+
+    - name: Setup compiler
+      run: |
+        echo "CC=clang" >> $GITHUB_ENV
+        echo "CXX=clang++" >> $GITHUB_ENV
+
+    - name: Configure CMake
+      run: |
+        echo "Configuring build ${{ matrix.build_type }} with clang (with system GLFW)"
+        cmake -B build/${{ matrix.build_type }} \
+              -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} \
+              -DCCAP_BUILD_EXAMPLES=ON \
+              -DCCAP_BUILD_TESTS=ON
+
+    - name: Build
+      run: cmake --build build/${{ matrix.build_type }} --config ${{ matrix.build_type }} --parallel $(nproc)
+
+    - name: Verify build outputs
+      working-directory: build/${{ matrix.build_type }}
+      run: |
+        echo "Checking built examples:"
+        ls -la | grep -E "(glfw|example)" || echo "No examples found"
+        echo "✓ Build completed successfully"
+
+    - name: Run Unit Tests
+      if: matrix.build_type == 'Release'
+      run: |
+        cd scripts
+        ./run_tests.sh --functional --exit-when-failed
+
+    - name: Upload artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: ccap-linux-clang-${{ matrix.build_type }}
+        path: |
+          build/${{ matrix.build_type }}/libccap.a
+          build/${{ matrix.build_type }}/0-print_camera
+          build/${{ matrix.build_type }}/1-minimal_example
+          build/${{ matrix.build_type }}/2-capture_grab
+          build/${{ matrix.build_type }}/3-capture_callback
+          build/${{ matrix.build_type }}/4-example_with_glfw
+          build/${{ matrix.build_type }}/*_results.xml
+        if-no-files-found: warn
+
+  build-ubuntu-arm64:
+    name: "Build ARM64 (${{ matrix.build_type }}-gcc)"
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        build_type: [Debug, Release]
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
+
+    - name: Install cross-compilation toolchain
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y cmake build-essential gcc-aarch64-linux-gnu g++-aarch64-linux-gnu
+        echo "Cross-compilation toolchain installed"
+
+    - name: Configure CMake for ARM64
+      run: |
+        echo "Configuring build ${{ matrix.build_type }} for ARM64 (cross-compilation)"
+        cmake -B build/arm64/${{ matrix.build_type }} \
+              -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} \
+              -DCMAKE_C_COMPILER=aarch64-linux-gnu-gcc \
+              -DCMAKE_CXX_COMPILER=aarch64-linux-gnu-g++ \
+              -DCMAKE_SYSTEM_NAME=Linux \
+              -DCMAKE_SYSTEM_PROCESSOR=aarch64 \
+              -DCMAKE_CROSSCOMPILING=ON \
+              -DCCAP_BUILD_EXAMPLES=ON \
+              -DCCAP_BUILD_TESTS=OFF
+
+    - name: Build ARM64
+      run: cmake --build build/arm64/${{ matrix.build_type }} --config ${{ matrix.build_type }} --parallel $(nproc)
+
+    - name: Verify build outputs
+      working-directory: build/arm64/${{ matrix.build_type }}
+      run: |
+        echo "Checking built ARM64 binaries:"
+        ls -la | grep -E "(ccap|example)" || echo "No examples found"
+        echo "Verifying ARM64 architecture:"
+        file libccap.a | grep -q "aarch64" && echo "✓ Library is ARM64" || echo "⚠ Library architecture verification failed"
+        if [ -f "0-print_camera" ]; then
+          file 0-print_camera | grep -q "aarch64" && echo "✓ Binary is ARM64" || echo "⚠ Binary architecture verification failed"
+        fi
+        echo "✓ ARM64 cross-compilation completed successfully"
+
+    - name: Upload ARM64 artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: ccap-linux-arm64-gcc-${{ matrix.build_type }}
+        path: |
+          build/arm64/${{ matrix.build_type }}/libccap.a
+          build/arm64/${{ matrix.build_type }}/0-print_camera
+          build/arm64/${{ matrix.build_type }}/1-minimal_example
+          build/arm64/${{ matrix.build_type }}/2-capture_grab
+          build/arm64/${{ matrix.build_type }}/3-capture_callback
+          build/arm64/${{ matrix.build_type }}/4-example_with_glfw
+          build/arm64/${{ matrix.build_type }}/*_results.xml
+        if-no-files-found: warn
+
+  build-fedora:
+    name: "Build Fedora (${{ matrix.build_type }})"
+    runs-on: ubuntu-latest
+    container: fedora:latest
+
+    strategy:
+      matrix:
+        build_type: [Debug, Release]
+
+    steps:
+    - name: Install Git first
+      run: |
+        dnf update -y
+        dnf install -y git
+
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
+
+    - name: Install dependencies
+      run: |
+        dnf install -y cmake gcc-c++ make
+
+    - name: Configure CMake
+      run: |
+        cmake -B build/${{ matrix.build_type }} \
+              -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} \
+              -DCCAP_BUILD_EXAMPLES=ON \
+              -DCCAP_BUILD_TESTS=ON
+
+    - name: Build
+      run: cmake --build build/${{ matrix.build_type }} --config ${{ matrix.build_type }} --parallel $(nproc)
+
+    - name: Run Unit Tests
+      if: matrix.build_type == 'Release'
+      run: |
+        cd scripts
+        ./run_tests.sh --functional --exit-when-failed
+
+    - name: Upload artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: ccap-fedora-${{ matrix.build_type }}
+        path: |
+          build/${{ matrix.build_type }}/libccap.a
+          build/${{ matrix.build_type }}/0-print_camera
+          build/${{ matrix.build_type }}/1-minimal_example
+          build/${{ matrix.build_type }}/2-capture_grab
+          build/${{ matrix.build_type }}/3-capture_callback
+          build/${{ matrix.build_type }}/*_results.xml
+        if-no-files-found: warn