Removal of Custom resolution from GSdx

[gregory]

Hello All,

Currently GSdx allows to set a custom internal resolution. There a lots of cons and I didn't even find a pro.

So if you use this feature, please tell us and why you still need it.

The list of issue:
1/ Custom resolution is not the real resolution of the internal resolution. It is actually the maximum that the game can use. It is completely broken with snow engines game.
2/ Bad rounding => upscaling glitches (likely more than upscaling using the Native x# options)
3/ Various line of code to handle it => make it more difficult to be improved
4/ Lots of room in the GUI whereas it could only be a combo box from 1x to 6x

[Rassane]

I used it in cases of a GPU bottleneck where I wanted res>native but the GPU was too weak for 2x, but that was back in the days when I had a 9400GT

[hellbringer616]

I was about to mention that, some use it as a speed back of sorts. Personally I side with its removal if it will improve, or pave the way to improvements in the emulator.

[ssakash]

I would suggest to only drop it on the GUI, the code should still remain so that customization might be possible through INI files.

[gregory]

I have an improvement in mind (for the future as I'm too busy right now). Currently when game try to do a post-processing effect it scales down the RT to a small texture (not all effects but some)
1/ It uses shader to (badly) interpolate the texture
2/ It reduces the quality

The idea will be to avoid this rescaling. This way we can use
1/ a raw texture copy (avoid to use shader for nothing)
2/ keep same quality on the RT for post-processing effect (with likely a better quality on the egde due to less interpolation)

Is there really a speed boost or is it limited to few percentage. If someone want to do some tests on an Intel GPU, please share some numbers.

[refraction]

hmm i wonder if we can cheat and do a Native x-2 scaling to scale it down. Never tried it but the scaling options are handled much better than custom resolution, then people using the custom res to scale down the picture could use that.

[gregory]

??? What do you mean? You mean a 1.5X

[refraction]

No i mean negative, to shrink it down as they are using it as a speedhack by making the RT's scale smaller.

[ssakash]

how would that avoid usage of the shader ? It would still use the same interpolation on textures.

[gregory]

You mean 0.5 What is the quality vs native?

For most game, native is around 640x512. And 2x is around 1280x1024, I think it is doable even in a low-cost APU. I think the speed difference was due to memory limit in some games. I don't think it is related to the number of pixel to compute.