EAGL.Examples.LearnOpenGL.GettingStarted.HelloWindowClear (eagl v0.4.0)

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LearnOpenGL 1.2 - Hello Window Clear

This example demonstrates setting a custom clear color for the OpenGL framebuffer. It builds upon the 1.1 Hello Window example by showing how to control the background color.

Original C++ Source

This example is based on the original LearnOpenGL C++ tutorial: https://github.com/JoeyDeVries/LearnOpenGL/tree/master/src/1.getting_started/1.2.hello_window_clear

Framework Adaptation Notes

In the original LearnOpenGL C++ tutorial, this example introduces the concept of:

  • glClearColor() - setting the clear color state
  • glClear(GL_COLOR_BUFFER_BIT) - actually clearing the buffer

EAGL's Window framework automatically handles clearing for clean state, but this example demonstrates the pedagogical concepts by:

  • Explicitly calling glClearColor() to set a custom color
  • Showing the difference between state-setting and state-using functions
  • Explaining the OpenGL state machine concept

Original Tutorial Concepts Demonstrated

  1. OpenGL State Machine: glClearColor sets state, glClear uses that state
  2. Color Buffer Clearing: Essential for preventing visual artifacts
  3. RGBA Color Values: Understanding the 0.0-1.0 range for color components
  4. Render Loop Integration: Where clearing fits in the rendering pipeline

Key Learning Points

  • Understanding OpenGL's state-setting vs state-using functions
  • The importance of clearing buffers each frame
  • How color values work in OpenGL (0.0-1.0 range)
  • The difference between this and 1.1 (black vs colored background)

Usage

EAGL.Examples.LearnOpenGL.GettingStarted.HelloWindowClear.run_example()

Press ENTER to exit the example.

Summary

Functions

run_example()