Support for stretched grids

[chrishavlin]

it'd be nice!

and maybe not too hard to implement?

would need to conditionally pass down the cell spacing for a block to the shaders to adjust the scaling from ray position to texture coordinates, possibly just as some extra vertex attributes.

[chrishavlin]

adding some notes from slack discussions with @matthewturk

vertex attributes might be hard/impossible since we'd need variable length attributes.

uniforms might work but there may be some scaling issues (relevant https://www.khronos.org/opengl/wiki/Uniform_Buffer_Object ).

additional 1d textures might be the way to go, could store 1d cell widths for each dimension, do a look-up given a ray position (e.g., https://docs.gl/sl4/texelFetch ) and calculate the full 3d texture coordinate from that.