libqgl

A simple portability and ease-of-use driven graphics library based on OpenGL.

Started from forking pedroth's linux-framebuffer into 7ways.

Installation

Check out these instructions. And use "libqgl" as the package name.

Build & Dependencies

Required build tools: make, gcc (or clang), pkg-config. On Debian/Ubuntu, a minimal install:

sudo apt-get install build-essential pkg-config libglfw3-dev libpng-dev libxxhash-dev

Build the library:

make

Build examples and tests:

make examples
make test

Usage

If you have an editor that uses a language server, then you'll get help about the functions in it.

Quick start:

#include <ttypt/qgl.h>

int main(void)
{
	uint32_t w, h;

	qgl_size(&w, &h);
	qgl_fill(0, 0, w, h, 0xFF202020);
	qgl_flush();
	return 0;
}

Backend selection:

• Windows/macOS use the GLFW backend (requires GLFW development libraries).
• Linux uses GLFW when the DISPLAY environment variable is set (running under X11/Wayland); otherwise it falls back to the framebuffer backend when a compatible framebuffer device is available (this may require device permissions or running as root).

Modules:

• Core rendering + textures: include/ttypt/qgl.h
• UI layout + styling: include/ttypt/qgl-ui.h
• Bitmap fonts: include/ttypt/qgl-font.h
• Tilemaps: include/ttypt/qgl-tm.h

Docs / manpages: Manpages are provided when this project is packaged; if they are not installed on your system, consult the header files in include/ttypt/ for API documentation or read the source comments.

Testing

QGL includes a comprehensive test suite covering all public APIs:

# Build and run all tests
make test

# Build tests without running
make test-build

The test suite includes 64 test functions across 8 test files:

• Core rendering and initialization
• Texture loading and drawing
• Font rendering and measurement
• Tilemap creation and rendering
• UI layout engine (flexbox-style)
• UI styling and caching
• Integration scenarios

See individual test files in tests/ for detailed API usage examples.

Examples

Six example programs demonstrate QGL features:

# Build all examples
make examples

# Run an example (requires test fixtures)
cd tests && python3 generate_fixtures.py && cd ..
LD_LIBRARY_PATH=./lib ./examples/01_basic_rendering

Available examples:

• 01_basic_rendering.c - Basic QGL initialization and rendering
• 02_textures.c - Texture loading and drawing
• 03_fonts.c - Bitmap font rendering and text wrapping
• 04_tilemaps.c - Tilemap creation and rendering
• 05_ui_layout.c - Flexbox-style UI layout
• 06_ui_advanced.c - Advanced UI with styling and caching

See examples/README.md for detailed descriptions and build instructions.

Note: To generate the test fixtures required by some examples, run:

cd tests && python3 generate_fixtures.py && cd ..