luma.gl/dev-docs/RFCs/v7.0/framebuffer-texture-api-rfc.md

RFC: Framebuffer/Texture Methods as Global Functions

• Author: Ib Green
• Date: Dec, 2018
• Status: Implemented in v7.0

Summary

This RFC proposes to move a number of blit and copy related functions from the Framebuffer and Texture classes into global functions to ensure that they can be tree-shaken out of applications that don't use them.

Background

A not insignificant part of the RAW WebGL API consists of methods to copy and blit between textures and framebuffers. This jungle of functions are hard to discover and use for the typical user, yet they are an important part of the WebGL toolbox.

To simplify usage of these functions, luma.gl has religiously added wrappers of these functions to the Framebuffer and Texture classes.

The problem is that:

• these functions add considerable code size to these classes.
• many simpler applications don't use these methods, even if almost all applications use Framebuffers and thus textures.
• luma.gl relies on tree-shaking to reduce binary size, but methods cannot be tree-shaken.

Proposals

• The key proposal is to move methods from Framebuffer and Texture into global functions.

TBD - some work remains to unify the proposal

Method	Replacement
Framebuffer.readPixels	readPixelsToArray
Framebuffer.readPixelsToBuffer	readPixelsToBuffer
Frambuffer.copyToDataUrl	copyToDataUrl
Frambuffer.copyToImage	copyToImage
Frambuffer.copyToTexture	copyToTexture
Frambuffer.blit	blit
Texture.copyFramebuffer	copyToTexture
Texture.setImageData	setTextureImageData
Texture.setSubImageData	setTextureSubImageData
Texture.setImage3D	setImage3D

• Make all methods that accept Framebuffer objects as source or target, to accept Texture object in addition to Framebuffer object. Internally we will implement a utility method to wrap Texture object into a Framebuffer object.

Deprecation

All removed methods will be stubbed and emit a deprecation message pointing to the luma.gl upgrade guide.