emscripten-sdl2-ogles2

OpenGL to WebGL using Emscripten

Demonstrates the basics of porting desktop graphics to the web using Emscripten, via a collection of code samples. Code is written in C++, SDL2, and OpenGLES2 and transpiled into Javascript and WebGL by Emscripten.

Run Hello Triangle (source)

Demonstrates a colorful triangle using shaders, with support for mouse and touch input:

• Pan using left mouse or finger drag.
• Zoom using mouse wheel or pinch gesture.

Run Hello Texture (source)

Demonstrates a textured triangle, using SDL to load an image from a file.

Run Hello Text (source)

Demonstrates TrueType text, using SDL to render a string into a texture and apply it to a quad.

Run Hello Texture Atlas (source)

Demonstrates SGI’s Texfont text, loading a font texture atlas from a .txf file and applying it to a quad, as well as rendering of text strings.

Run Hello Image (source)

Demonstrates a checkberboard background texture created from an in-memory pixel array.

Motivation

Why Emscripten?

For users, running an app in the browser is the ultimate convenience: no need to manually install anything, and the app can run equally well on desktop, tablet, and phone. For developers, Emscripten does the work to produce optimal Javascript/WASM, replacing the boring and error-prone process of manually porting code.

Why SDL2?

These demos require OS-dependent stuff (keyboard, mouse, touch, text, audio, networking, etc.). SDL provides a cross-platform library to access this.

Why OpenGLES2?

WebGL provides GPU-accelerated graphics in the browser, and OpenGLES is the subset of OpenGL which most closely matches WebGL.