screamer

Screamer

Screamer is a declarative live coding language for creating visuals using ray marching. It builds on top of marching.js, a JavaScript library that compiles GLSL shaders. In comparison to marching.js, screamer is intended to be more concise and enable faster iteration / experimentation.

In music, a “screamer” is a sped-up march used in circuses to “stir audiences into a frenzy”.

Play

Try the playground. Here’s a few keyboard commands worth knowing. Use cmd and option in macOS instead of ctrl/alt:

• Ctrl+Enter: Execute the current line (as defined by where the cursor is placed).
• Shift+Ctrl+Enter: Execute current line and reset camera position.
• Alt+Enter: Execute current code “block”. Blocks are delimited by blank lines in the editor.
• Shift+Alt+Enter: Execute current code “block” and reset camera position.
• Ctrl+.: Clear the current scene.
• Shift+Ctrl+.: Pause / unpause the current scene.
• Alt+c: Enable camera controls. Use WASD + the arrow keys to move through the 3D scene. Hit Alt+C again to disable the controls and return to editing.
• Alt+=: Increase code size.
• Alt+-: Decrease code size.

Use

The standalone.html file shows an example of how to use screamer in your own webpage.

Reference

Read / play with the interactive reference. The reference will describe all the various functions found in screamer.

I also wrote a paper on screamer for anyone wanting to learn more about the motivation and design of the project.

Credits

• marching.js, the rendering engine
• peggy.js, provides the Parsing Expression Grammar the language is written in
• bitty.js, the code editor used by screamer