Swap depth range to use minz/maxz

[unknownbrackets]

This does a few things:

1. Properly supports minz/maxz by using them as the depth range.
2. Flushes when clipEnable changes.
3. Sacrifices some bits of precision to allow for "fake clamping" of the depth range when clip is enabled. Currently, I've sacrificed 2 bits allowing depth between [-2.5, 2.5].

This actually fixes MotoGP for me (would be nice to confirm), since it is using clipEnable, and therefore clamping the depth.

Some flaws (not sure if important):

• Still does not handle rounding per my tests; e.g. without clip enabled, cuts off at precisely [0, 65535]. Not worse than before.
• Per-vertex depth rounding comes out with slightly offset values. I'm not sure if this is just a precision issue, or if I've made an error. But they are close and Phantasy Star Portable 1 works.
• Per-pixel depth rounding is potentially wrong now; but I couldn't get it to come out right (tried applying offset and scale.) Phantasy Star Portable 1 still works as-is if per-pixel is forced.

Could use help on the per-pixel rounding. This is what I tried:

    if (gstate_c.Supports(GPU_ROUND_FRAGMENT_DEPTH_TO_16BIT)) {
        const float offset = 0.5f * (DepthSliceFactor() - 1.0f) * (1.0f / DepthSliceFactor());
        const double scale = DepthSliceFactor() * 65535.0;
        WRITE(p, "  highp float z = gl_FragCoord.z;\n");
        WRITE(p, "  z = floor((z - %f) * %f) * %f + %f;\n", offset, scale, 1.0 / scale, offset);
        WRITE(p, "  gl_FragDepth = z;\n");
    }

Anyway, this seems like an improvement otherwise.

Fixes #8456 and fixes #8424.

-[Unknown]

[hrydgard]

Cool. Getting this tested with Heroes Phantasia might be a good idea if pixel depth rounding has changed..

[hrydgard]

Seems to work well in all the games I tried.

[daniel229]

Heroes Phantasia missing menu.

disable pixel depth rounding,menu appearing, but it will flicker badly.

[daniel229]

Where is DepthSliceFactor()

[unknownbrackets]

Sorry, add this to GPUStateUtils.cpp:

float DepthSliceFactor() {
    return depthSliceFactor;
}

And then GPUStateUtils.h:

float DepthSliceFactor();

-[Unknown]

[daniel229]

Pixel depth rounding works with that code,and even flicker less than before.

[daniel229]

That modified per-pixel rounding code make Phantasy Star Portable 2 JP missing text.

[unknownbrackets]

Turns out the issue was precision (sprintf("%f").) I've changed it to something simpler.

Also, how does Heroes Phantasia fair with static const float depthSliceFactor = 256.0f; instead of 4.0f?

-[Unknown]

[daniel229]

Phantasy Star Portable 2 JP now flicker even with PixelDepthRounding.
For Heroes Phantasia 256.0f seems not better or worse than 4.0f

[unknownbrackets]

If you change depthSliceFactor to 1.0f does Phantasy Star Portable 2 JP stop flickering? Or does it still flicker? Does 256 help it, either?

-[Unknown]

[daniel229]

Never mind,just forgot add game id to the list,it works fine.

[unknownbrackets]

Ah, great. So then sounds like pixel rounding is working fine now, and this fixes a few bugs otherwise. Yay.

-[Unknown]

[hrydgard]

@daniel229 please send pull requests with any missing game ids :)

[daniel229]

Fixed a minor issue in Danball Senki W.

[unknownbrackets]

That's probably the minz/maxz clipping. Cool.

-[Unknown]