Passing an array from JS to WebGL using a texture

You can pass an array through to shaders as a uniform, but (a) accessing elements can be painful (Google for "index expression must be constant"), and (b) IIRC the OpenGL ES spec states that an implementation only needs to support a relatively small (128 elements?) array size. As such, it's worth knowing how to (ab)use textures to serve as arrays.

External references:

• http://stackoverflow.com/questions/4725424/passing-an-array-of-vectors-to-a-uniform
• https://www.khronos.org/webgl/public-mailing-list/archives/1012/msg00091.html
• http://www.khronos.org/message_boards/viewtopic.php?f=35&t=3663
• http://code.google.com/p/angleproject/issues/detail?id=49
• http://www.khronos.org/webgl/wiki/WebGL_and_OpenGL_Differences#Non-Power_of_Two_Texture_Support