Getting Started

Installation

# Install from source
git clone https://github.com/markxbrooks/picogl.git
cd picogl
pip install -e .

6.2.2 Your First PicoGL Program Let’s create a simple program that displays a colored cube:

from picogl.renderer import MeshData
from picogl.ui.backend.glut.window.object import RenderWindow
import numpy as np

def main():
    # Define cube vertices (8 corners of a cube)
    vertices = np.array([
        # Front face
        [-1, -1,  1], [ 1, -1,  1], [ 1,  1,  1], [-1,  1,  1],
        # Back face
        [-1, -1, -1], [-1,  1, -1], [ 1,  1, -1], [ 1, -1, -1],
        # Top face
        [-1,  1, -1], [-1,  1,  1], [ 1,  1,  1], [ 1,  1, -1],
        # Bottom face
        [-1, -1, -1], [ 1, -1, -1], [ 1, -1,  1], [-1, -1,  1],
        # Right face
        [ 1, -1, -1], [ 1,  1, -1], [ 1,  1,  1], [ 1, -1,  1],
        # Left face
        [-1, -1, -1], [-1, -1,  1], [-1,  1,  1], [-1,  1, -1]
    ], dtype=np.float32)

    # Define colors for each vertex
    colors = np.array([
        # Front face (red)
        [1, 0, 0], [1, 0, 0], [1, 0, 0], [1, 0, 0],
        # Back face (green)
        [0, 1, 0], [0, 1, 0], [0, 1, 0], [0, 1, 0],
        # Top face (blue)
        [0, 0, 1], [0, 0, 1], [0, 0, 1], [0, 0, 1],
        # Bottom face (yellow)
        [1, 1, 0], [1, 1, 0], [1, 1, 0], [1, 1, 0],
        # Right face (magenta)
        [1, 0, 1], [1, 0, 1], [1, 0, 1], [1, 0, 1],
        # Left face (cyan)
        [0, 1, 1], [0, 1, 1], [0, 1, 1], [0, 1, 1]
    ], dtype=np.float32)

    # Create mesh data
    data = MeshData.from_raw(vertices=vertices, colors=colors)

    # Create render window
    window = RenderWindow(
        width=800,
        height=600,
        title="My First PicoGL Cube",
        data=data
    )

    # Initialize and run
    window.initialize()
    window.run()

if __name__ == "__main__":
    main()

Save this code as my_first_cube.py and run it:

  python my_first_cube.py

You should see a window with a colorful cube that you can rotate with your mouse! 6.2.3 Understanding the Code Let’s break down what this code does:

1. Import PicoGL modules: - MeshData: Container for vertex and color data - RenderWindow: Window for displaying 3D content
2. Define vertices: 24 vertices defining 6 faces of a cube
3. Define colors: One color per vertex
4. Create mesh data: Combine vertices and colors into a mesh
5. Create window: Set up the display window
6. Run: Start the interactive display 6.2.4 Key Concepts

MeshData

MeshData is the core data structure for objects:

data = MeshData.from_raw(
    vertices=vertices, # 3D positions
    colors=colors, # RGB colors
    normals=normals, # Surface normals (optional)
    uvs=uvs # Texture coordinates (optional)
)

RenderWindow

RenderWindow provides the display interface. It handles: • OpenGL context creation • Window management • User input (mouse, keyboard) • Rendering loop

window = RenderWindow(
    width=800, # Window width
    height=600, # Window height
    title="My App", # Window title
    data=mesh_data # Mesh to display
)