Fix Syphon Filter lens flares by adding compat flag to read back the depth buffer #16907
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hrydgard
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Is possible fix this Aldo for infra ppspp android & windows? So will fix also on multiplayer games ? |
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I'm not sure what you mean, this fix is not related to muliplayer functionality in any way |
| void FramebufferManagerCommon::NotifyRenderFramebufferSwitched(VirtualFramebuffer *prevVfb, VirtualFramebuffer *vfb, bool isClearingDepth) { | ||
| if (ShouldDownloadFramebuffer(vfb) && !vfb->memoryUpdated) { | ||
| // TODO: Isn't this wrong? Shouldn't we download the prevVfb if anything? |
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Probably, I think it didn't have prevVfb as a parameter before and this worked well enough. Maybe this was a consideration for performance? Not sure if it's cheaper to download framebuffer B after rendering to A.
For Danganronpa, anyway, it renders its scenemap every frame iirc.
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But it's really a curious time to download vfb given that this is when we start rendering to it, isn't it? Though of course, in a way that's fine, we'll just be one frame behind on the readbacks...
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Well, it's only really being used for Danganronpa, which is a game that - at least for these scenemap readbacks - would probably be totally fine with async readbacks.
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| ReadFramebufferToMemory(vfb, 0, 0, vfb->width, vfb->height, RASTER_COLOR); | ||
| vfb->usageFlags = (vfb->usageFlags | FB_USAGE_DOWNLOAD | FB_USAGE_FIRST_FRAME_SAVED) & ~FB_USAGE_DOWNLOAD_CLEAR; | ||
| } else { | ||
| DownloadFramebufferOnSwitch(prevVfb); | ||
| } | ||
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| if (prevVfb && ShouldDownloadFramebufferDepth(prevVfb)) { |
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I guess we could skip this if isClearingDepth... not sure if Syphon Filter does that.
-[Unknown]
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Well the point of this is to download the framebuffer after it's been renderered to, here we're switching from prevVfb to vfb, so the right check would be if depth has been written during the pass I guess.. Clearing doesn't really enter into the equestion, or am I missing something?
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Oh right sorry, I was mixing in the wrong vfb comment and forgot this is checking prevVfb.
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This fixes the lens flare occlusion in the Syphon Filter games by reading back the depth buffer from the GPU so that the checks that the game performs work, if a compat flag is set, making these games feel way more "solid" and playable - the flares really were quite distracting. Fixes #10229. Fixes one part of #15923.
Unfortunately, it also slows things down quite drastically on mobile, at least, unless you use the speedhack "Skip GPU readbacks" which will turn this off.
The heuristic about which framebuffer to read from are quite basic too, I have plans to detect that in a safer way, but this does seem to be good enough for these games in particular.
Later I plan to introduce some tricks from #16900 to get the speed back up even with readbacks enabled (though occlusion will be delayed a frame or two, it'll hardly be noticeable).