Note that this applies only to the builtin shaders - interface for Kage stays
unchanged for compatibility.
Minor compatibility delta: when interpolating alpha values, previous code has
created nonsense values, such as, when interpolating from
fully-transparent-black (0,0,0,0) to opaque-white (1,1,1,1), something like
half-transparent-grey (0.25,0.25,0.25,0.5) where half-transparent-white
(0.5,0.5,0.5,0.5) is used by the new code.
I assume this is a strict improvement, however this may warrant some testing.
Possible later improvement could be moving the premultiplication from fragment
shader to CPU. Did not do this as it makes the code rather inconsistent of Kage
vs built-in shader usage.
Updates #1772
Textures cannot be treated as a regular variable, then they should
be treated differently from other uniform variables.
Add a new function texture0At replacing texture2D.
Updates #1239
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