SDL3 + C++23 Project to render text

Goal

Learn how to use SDL3 to render text to screen while using SDL3-GPU. Assume we can use SDL3-TTF to draw the text.

Uses

• CPM.CMake for package management
• Ninja-Build for build engine
• CMake 4.0+ with cmakepresets for configuration and build
  • There is an issue, on my machine, with CMake 4.0. It fails to configure properly. Use v4.0.1
• C++ modules enabled
• Uses C++ Standard Library modules
  • MSVC (Windows only)
  • Clang (Linux with libc++ only)
• Focuses on SDL3 GPU
• HLSL for all shaders

to be figured out

• Intellisense, ccls and clangd cannot handle modules so don't work correctly

CMake commands

VSCode will run these automatically.

• On Windows

  # Configure Project
  cmake --preset windows-default
  # Build Project, parameter order matters
  cmake --build --preset windows-debug

• On Linux

  # Configure Project
  cmake --preset linux-default
  # Build Project, parameter order matters
  cmake --build --preset linux-debug

Example project dependencies

Uses following libraries retrieved from their project repos by CPM.CMake

• SDL3, obviously
• GLM, for math
• DXC, either from Windows SDK (for D3D12 backend) or Vulkan SDK (for Vulkan backend)

Basic notes on code structure

• As much as is possible, functions will not take ownership of pointers to objects.
• Where able, all SDL GPU types are wrapped into std::unique_ptr with custom deleters, so they self clean on destruction.

Function flow

• main
  • Application Init
    • SDL init
    • TTF init
    • Window create
    • GPU create
    • High Resolution Clock
  • Application Run
    • Scene Init
      • Set Clear Colour
      • Create Pipeline
        • Load Vertex Shader
        • Load Fragment/Pixel Shader
        • Set Vertex Attributes
        • Set Vertex Buffer Descriptions
        • Build Pipeline
      • Create TTF GPU Text Engine
      • Create TTF Font
      • Create TTF Text run with Text Engine and Font
      • Get Text mesh and texture from TTF Text
      • Create Perspective projection matrix
      • Create Text mesh transform matrix
    • Loop till quit event
      • Handle SDL events
        • Handle Keyboard and Mouse Inputs
      • Update Application State
      • Draw
        • Acquire GPU Command Buffer
        • Acquire Next swapchain image
        • Create Color Target
        • Begin GPU Render Pass
          • Bind Pipeline
          • Bind Vertex and Index buffers
          • Bind Texture and Sampler
          • Draw Indexed Primitives
        • End GPU Render Pass
        • Submit Command Buffer
      • Clock Tick
    • Clean/Destroy Scene
  • Application Stop
    • Destroy GPU
    • Destroy Window
    • TTF Quit
    • SDL Quit

references

• Building on linux with Clang and libc++ for module support, https://mattbolitho.github.io/posts/vcpkg-with-libcxx/
• CMake 3.30 magic encantations, https://www.kitware.com/import-std-in-cmake-3-30/
• CMake module compilations, https://www.kitware.com/import-cmake-the-experiment-is-over/