- Simplified shader names, prefix embedded strings by "glsl_"
- Extracted shader compilation in common function
- Add shader version string and common structs in canvas code rather than in every shader file
- Renamed zIndex with shapeIndex everywhere
- Reverted to using 4 bits of subpixel precision and computing cross products with 32 bits integers, for perf reasons
- Fixed some confusion in tile array size vs number of elements (could still clean-up naming a bit though)
- Fixed bug where triangles on the left or below canvas boundaries where bucketted to the first colum/row of tiles
- Fixed bug in mouse button message handling (was always sending press on left button)