WebGLRenderer: Fixed readRenderTargetPixelsAsync checking readability against incorrect render target

[greyb1t]

Description

readRenderTargetPixelsAsync was checking if the render target was readable before binding the render target to active framebuffer.

This resulted in the texture readability check occurring on the previously set framebuffer and not the render target we are reading pixels from.

I modified the webgl_interactive_cubes_gpu example to restore the render target to the default before we call readRenderTargetPixelsAsync as that reproduces the issue without the fix.

EDIT: For some reason the file diff looks disgusting, please refer to the "Commits" tab instead of "Files changed" for better clarity on what changed.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	336.02 78.26	336.02 78.26	+0 B +1 B
WebGPU	523.84 145.45	523.84 145.45	+0 B +0 B
WebGPU Nodes	523.31 145.34	523.31 145.34	+0 B +0 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	465.06 112.14	465.06 112.14	+0 B +1 B
WebGPU	594.24 161.05	594.24 161.05	+0 B +0 B
WebGPU Nodes	549.37 150.49	549.37 150.49	+0 B +0 B

[gkjohnson]

Thanks - the docs don't make it completely clear that the two gl enumerations are dependent on a bound framebuffer. Greggman's writeup on readpixels confirms it.

EDIT: For some reason the file diff looks disgusting, please refer to the "Commits" tab instead of "Files changed" for better clarity on what changed.

Looking at the diff without whitespace changes makes it easier to read. Add ?w=1 to the url.