Implement variable resolution

[jasonwebb]

Allows for larger, more "zoomed in" patterns while reducing performance costs.

[jasonwebb]

Figured it out! I remembered that textures drawn to a mesh (like the plane mesh covering the viewport) will be stretched to fit by default. So if the dimensions of the render target textures are set to a different size than the canvas element, they will be stretched, thereby caused each texel (?) to increase or decrease in size. No extra shader code required!