libgkit_graphic

Graphic module for libgkit - a modern C++20 graphics library providing OpenGL rendering interfaces.

Repository Overview

This library provides a clean abstraction layer over OpenGL, designed with future Vulkan support in mind. The architecture follows a modular design with clear separation between core interfaces and backend implementations.

src/
├── core/           # Core rendering interfaces (gkit::graphic)
│   ├── Renderer.hpp    # Main rendering interface
│   └── Shader.hpp      # Shader program wrapper
├── openGL/         # OpenGL implementations (gkit::graphic::opengl)
│   ├── VertexArray.hpp
│   ├── VertexBuffer.hpp
│   ├── IndexBuffer.hpp
│   ├── VertexBufferLayout.hpp
│   ├── Texture.hpp
│   ├── FrameBuffer.hpp
│   ├── RenderBuffer.hpp
│   ├── StateManager.hpp
│   └── config.hpp      # Configuration (texture types, screen size)
└── debug/          # Debug utilities (GLCall macro, error logging)

Drawing Interface

The primary rendering entry point is the gkit::graphic::Renderer class:

gkit::graphic::Renderer renderer;

// Clear framebuffer
renderer.Clear();

// Draw indexed geometry
renderer.Draw(vertexArray, indexBuffer, shader);

// Draw non-indexed geometry
renderer.Draw(vertexArray, shader);

// Draw instanced geometry
renderer.DrawInstance(vertexArray, indexBuffer, shader, instanceCount);

Basic Usage Flow

1. Create vertex data - Use VertexBuffer to upload geometry
2. Define layout - Use VertexBufferLayout to specify attribute organization
3. Create vertex array - Combine buffers with VertexArray::AddBuffer()
4. Create index buffer - Use IndexBuffer for indexed rendering
5. Load shaders - Create Shader from file
6. Render - Call Renderer::Draw() with VA, IB, and Shader

Dependencies

Current temporary Dependencies (in test/extern/)

• GLM - Mathematics library
• stb_image - Image loading for textures
• GLFW - Window creation and input handling

Note for merging into main library:

• The src module currently depends on GLM and stb_image which are located in test/extern/. When merging into the main libgkit repository, these dependencies should be properly integrated as submodule dependencies or moved to a suitable location in the main library.
• The debug system (src/debug/) is currently using a temporary implementation and should be replaced with the main library's logging/debug infrastructure when merging.
• SCR_WIDTH and SCR_HEIGHT used in FrameBuffer, RenderBuffer, Texture are currently hardcoded in config.hpp. Should be dynamically obtained from window size in the future.

TODO (Before merging into main library)

• Adapt main library's math library (replace GLM dependency)
• Remove temporary debug system (src/debug/)
• Remove test folder
• Remove temporary shader file parsing and texture loading (replace with main library's file I/O, adapt resource reading format, further encapsulate rendering interfaces)

Build Requirements

• C++20 compatible compiler
• CMake 3.16+
• OpenGL 4.5+ capable graphics driver