luma.gl/docs/api-guide/shader-transpilation.md

Shader Transpilation

From v9 luma.gl requires GLSL shaders to be written in GLSL 3.00 ES syntax.

If platformInfo specifies that GLSL 1.0 is required by the Device, assembleShaders will attempt to transpile GLSL 3.0 shaders to GLSL ES 1.0.

This transpilation is a limited text replacement and requires that certain conventions be followed:

• Statements are written one per line.
• Only one fragment shader output is supported.
• GLSL 3.0-only features, such as 3D textures are not supported.

Text transformations are performed according to the following tables:

Vertex Shaders

3.00 ES	1.00 ES	Comment
in	attribute
out	varying

Fragment Shaders

3.00 ES	1.00 ES	Comment
in	varying
out vec4 <varName>	gl_FragColor	<varName> declaration is removed and usage in the code are replaced with gl_FragColor
texture	texture2D	texture will be replaced with texture2D to ensure 1.00 code is correct. See note on textureCube below.
textureCube *	textureCube	textureCube is not valid 3.00 syntax, but must be used to ensure 1.00 code is correct, because texture will be substituted with texture2D when transpiled to 100. Also textureCube will be replaced with correct texture syntax when transpiled to 300.