Shade mapping fix

[dbz400]

Reference

https://code.google.com/p/jpcsp/source/browse/trunk/src/jpcsp/graphics/shader.vert#208

Partially fix #5506

[hrydgard]

Ah, this might be right. Why do you say "partially"? How does it look with this change?

[thedax]

I'd guess "partially" because it still leaves the cars with a slight blue in weird areas:

[unknownbrackets]

Hmm, well, if this is correct, wouldn't software transform need the change too?

Also, it seems like the software renderer does actually do + for both, but it still doesn't look right according to the bug. So if this is wrong, maybe the software renderer is wrong.

-[Unknown]

[thedax]

Yeah, software transform would need the change too:

uv[1] = (1.0f + Dot(lightpos1, normal))/2.0f;

instead of

uv[1] = (1.0f - Dot(lightpos1, normal))/2.0f;

[dbz400]

Yep , i think it is partially correct but sometimes reflection is not right.At least it is better than 1.0f minus

[dbz400]

For SW transform , if do the changes as @thedax mentioned above , it seems to be no blue color issue and renders correct.

-SW T&L

-HW T&L

[hrydgard]

Why close this? I plan to merge this later today, after I'm done with the release.

[dbz400]

I see. That's would be good.

[hrydgard]

I believe this is right, but hard to be 100% sure without a good test.

[solarmystic]

@hrydgard @unknownbrackets
It's a bit late, I know, but this pull request actually improves the car reflections in Gran Turismo. Most easily noticeable during replays and when the camera pans over the car at the start of races.

Before (only the bottom portion of the car had reflections):-

After (the whole car is covered, even the windshleld):-

This pull request is definitely the right way to go. Thanks to @zschigi2 for the initial discovery.