bug list

PNG export: layers that have too high a Z won't show up in export, special-case behavior for near/far Z in renderable export?

rewrite Cursor.screen_to_world to produce same results as gluUnProject:
https://www.opengl.org/wiki/GluProject_and_gluUnProject_code
https://www.opengl.org/sdk/docs/man2/xhtml/gluUnProject.xml

more on above: when camera tilt engaged, cursor is closest to accurate along middle of bottom edge - apply aspect correction to both axes?
multiplying y by aspect (w/h) causes more distortion, but recenters most accurate point at middle of screen instead


lower priority:

problem discovered during 2015-01-04~06:
GLSL really can't handle int/uint attributes!  charIndex looks fine in numpy int32 array data but comes into GLSL totally screwy.  works fine when the array and attribute are floats instead.  bug for PyOpenGL devs?
possible test program: two quads side by side, each doing some trivial shader that involves an arbitrary number, only difference being one is driven by an int attribute and the other by a float.