CPU_Rasterizer

A high-performance, cross-platform, CPU-based software renderer written from scratch in modern C++20. This project demonstrates rasterization techniques, including terrain generation from noise, model loading, and custom shader effects, with all windowing and input handled by SDL2.

Features

• High-Performance Software Rendering: Optimized for multi-core CPUs.
• Procedural Terrain Generation: Creates dynamic landscapes using OpenSimplex noise.
• Custom Shader Support: A flexible shader system for implementing custom lighting and color effects.
• Model and Texture Loading: Supports .obj for 3D models and a custom .bytes format for textures.
• Cross-Platform: Uses CMake to build and run on Windows, macOS, and Linux.
• Modern C++20: Leverages modern C++ features for clean, efficient, and maintainable code.

Prerequisites

• C++20 compatible compiler (e.g., MSVC v143+, GCC 13+, Clang 16+)
• CMake 3.14+
• SDL2: Handled automatically via FetchContent if not found on your system.

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Building and Running

This project is configured with CMake and can be built using the command line or your favorite C++ IDE.

Visual Studio (MSVC)

1. Launch Visual Studio and select "Open a local folder".
2. Navigate to and select the root directory of the CPU_Rasterizer project.
3. Visual Studio will automatically detect CMakeLists.txt and configure the project.
4. Once configured, select the desired target (CPU_Rasterizer or terrain_demo) from the "Select Startup Item" dropdown in the main toolbar.
5. Press the green Run button (▶️) to build and run the selected demo.

CLion

1. Launch CLion and select File > Open.
2. Navigate to and select the project's root CMakeLists.txt file or the project folder.
3. CLion will automatically load and sync the CMake project.
4. In the top-right corner, select the desired target (CPU_Rasterizer or terrain_demo) from the configurations dropdown.
5. Click the Run (▶️) or Debug (🐞) button to build and run.

Visual Studio Code

1. Make sure you have the C++ Extension Pack and CMake Tools extensions from Microsoft installed.
2. Open the CPU_Rasterizer project folder in VS Code.
3. A prompt will ask you to configure the project; select Yes. If it doesn't, open the Command Palette (Ctrl+Shift+P) and run CMake: Configure.
4. Use the status bar at the bottom to:
   • Select the build variant (Debug, Release, etc.).
   • Select the active build target ([CPU_Rasterizer] or [terrain_demo]).
   • Click the Build button or press F7.
   • Click the Run button or press Ctrl+F5.

Command Line (Universal)

1. Clone the repository:

   git clone [https://github.com/luckynee/CPU_Rasterizer.git](https://github.com/luckynee/CPU_Rasterizer.git)
   cd CPU_Rasterizer

2. Configure the build (creates a build directory):

   # For a Release build
   cmake -S . -B build -DCMAKE_BUILD_TYPE=Release

3. Build the executables:

   # This command works for Makefiles, Ninja, and MSBuild
   cmake --build build

4. Run the demos (executables are inside the build directory):

   # Run the core engine demo
   ./build/CPU_Rasterizer
   
   # Run the terrain demo
   ./build/terrain_demo

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Supported Formats

• 3D Models: .obj. A standard, widely supported format for 3D geometry.
• Textures: .bytes. A custom raw pixel data format used by this project for simplicity and fast loading.

Project Structure

• src/core_engine/ — Core rasterizer engine, math utilities, and shader classes.
• src/demos/ — Source code for the demo applications.
• resource/ — Contains .obj models and .bytes textures.

Troubleshooting

• If you encounter build errors, ensure your compiler fully supports C++20.
• On Windows, the SDL2.dll is automatically copied next to the executables. If the program fails to start with a DLL error, clean your build directory and rebuild.

Note for Windows users:

• The project directory path should not contain spaces. MinGW has known issues handling spaces in directory paths, which can cause build failures.

CMake Build Types:

• This project supports three CMake build types: Debug, Release, and RelWithDebInfo.
• You can specify the build type when configuring CMake, for example:

  cmake -DCMAKE_BUILD_TYPE=Release ...