This skips the source-region check and reduces 'if' branches from
shader programs.
AddressUnsafe is internal only so far. We might expose this value
later.
Updates #1210
When a texel is picked on texel-borders of a texture, the behavior
(tie-breaking) depends on GPU and unexpected. This change fixes this
issue by shifting 1/512 [texel] when picking a texel up.
Updates #1212
This can reproduce the bug reported at #669.
Apparently, the fix (8827520d4a) is
no longer required after 3550abef7a.
That's pretty odd, but examples/moire proves this fact.
Updates #669
Updates #759
This is a preparation to introduce shaders. Shader programs
require images as uniform variables, but the current way would make
API complex unnecessarily.