Instead of standard Emscripten, use the Rexo compiler:

rexo compile triangle.cpp -o triangle.html

To understand OpenGL, one must understand the "Pipeline." In the old days (immediate mode), developers would simply say "draw this shape." Today, modern OpenGL relies on a programmable pipeline centered around Shaders.

This shift gives developers total artistic control. You aren't just drawing an object; you are writing the math that determines how light bounces off that object, how it reflects the environment, and how it casts shadows.

You might be wondering: "WebGPU is coming, why do I need OpenGL by Rexo Web?"

WebGPU is the future—it is modern, fast, and designed for the web. However, WebGPU is a new API. OpenGL by Rexo Web offers immediate value for legacy codebases. Furthermore, the Rexo team has announced "Rexo Next," which will act as a translation layer from OpenGL to WebGPU. This means your existing OpenGL code will eventually run even faster on future browsers without changing a single line of code.

Key OpenGL objects: