Azurik: Rise of Perathia

Known tricky behaviour

Skinning code / Shader rounding mode

This game suffers from issues with non-exact rounding in the shaders which do the skinning / skeletal animation.

IIRC Code is like:

A0 = c[113].x + c[113].z = 18
*do stuff with c[96+A0] to c[98+A0]*

A0 = c[113].x + c[113].z = 21
*do stuff with c[96+A0] to c[98+A0]* 

A0 = c[113].y * v2
*do stuff with c[96+A0] to c[98+A0]*

c[113] is vec4(15, 765, 3, 0). 765 = 3*255.
v2 is GL_UNSIGNED_BYTE, normalized => v2 = raw/255.
A0 = 765 * raw/255 = 3*raw.

This should all be working, but it's not. NV2A expects round-to-zero, GLSL and other modern graphic APIs have it undefined.. It works with A0 += 1.0/255.0 as a temporary hack