Initially it was free to do the SW blending because safe fbmask
will already do a sw blending.
Unsafe version uses a fast path with a limited blending. Therefore
SW blending isn't free anymore.
Improve the speed of the previous speed hack (xenosaga 1)
The hack relies on the undefined behavior of the hardware so it can
potentially generate rendering corruption.
This new hack drops the cache flusing when only the alpha channel is masked.
Alpha is a direct copy of the fragment. Normally masked bits will be constant
everywhere (RT, FS output, texture cache) so it would likely work.
Just in case, code is only enabled with the new shiny hack
runion/rempty/rinter requires x < z and y < w
Help issue #762 (accurate blending issue)
If you want to shine, please put better GSVector code (AVX512 is 2 instruction :p)
Function pointer was mangled to avoid any collision. Nowadays all symbols
are hidden so no risk of collision.
Syntax is nicer beside it would allow to put back GLES3.2. I think it
supports most of the used extension.
glActiveTexture & glBlendColor are provided without symbol query.
A couple of useless members were removed too.
Also fix wnd initialization
Coverity:
CID 146955 (#1 of 1): Uninitialized pointer read (UNINIT)
18. uninit_use: Using uninitialized value wnd[i].
* add lengthly comment to explain the format
* Likely reduce the number of shader permutation
* Avoid slow AEM (on GPU)
Expect regressions because TC needs some fixes
v2: fix palette mode
Intially GSBlendStateOGL was an alias of the m_blendMapD3D9 array
The object was replaced by an index in the array. Save 2k of memory duplication.
And too much useless code.
v2: push/pop blending state in DATE stuff
v3: remove m_state which is useless now
The purpose is to emulate correctly destination alpha factor
An alpha channel of 128 is 1.0 in the GS but only ~0.5 in the GPU
I think few draw call use destination alpha so impact on perf must remains small.
Actually it can partially be done with GL_ARB_shader_image_load_store
extension. However all drivers that support shader_image have
texture barrier too.
The idea is to use a floating texture to accumulate the data and
then do a final postprocessing pass to apply the modulo
v2:
* use bounding box to
* fix vertex corruption issue
* use negative number in shader which allow to use half float (+12
fps@4x)
Basically the code does the alpha multiplication in the shader therefore
the blend unit only does a pure addition. This way the multiplication is
accurate and accurate_blending doesn't requires a costly barrier.
This code also avoid variable duplication to make the code more separated.
Hopefully blending can be done in a separated function
It is preliminary work to support fast color clipping with HDR
v2: fix assertion compilation failure
v3: fix regression in not accurate mode
v3: Cs * As/Af is not an accumulation
Those cases don't need the Cd addition and were already optimized anyway
Fix a regression on GoW2
Do DATE algo selection before blending. This way we can detect bad
interaction.
Regroup all blending/colclip in a single block. Avoid to check abe &&
rt multiple times.
v2: only enable sw blending when abe is true
The updated medium level will run for all sprites. It helps sotc blooming effect and it remains
fast enough to be enabled by default (at least on 3D games)
The new high level will run for all sprites + color clipping
The idea is that sprites are often use for post-processing effect (ofc except 2D games)
Most of the time post-processing supports SW blending with a small speed penality. SW
blending is more accurate so it is better to use it.
Gain: 1% at 4x on SotC (it partially compensates recent additions)
When the color is constant and equal to 128, the MODULATE mode is
equivalent to the DECAL mode. It saves 5 instructions on the FS.
Accurate options do a better jobs. Technically it can still
be useful for old gpu/driver that doesn't support the GL4.5 extension.
On Windows, you can still rely on Dx
On linux, free driver support it (except Intel)
Code is not yet enabled because it requires extensive test
The idea is to replace point by a 1 pixels sprite with the help of
a geometry shader. In 4x, point will be replaced by a 4x4 sprite.
// GL42 interact very badly with sw blending. GL42 uses the primitiveID to find the primitive
// that write the bad alpha value. Sw blending will force the draw to run primitive by primitive
// (therefore primitiveID will be constant to 1)
It might help to fix a bit the color on a couple of games
accurate_fbmask = 1
Code uses GL4.5 extensions. So far it seems the effect is ony used a couple
of time and often in non-overlapping primitive. Speed impact will likely remain small
GS doesn't supports texture shuffle/swizzle so it is emulated in a
complex way.
The idea is to read/write the 32 bits color format as a 16 bit format.
This way, RG (16 lsb bits) or BA (16 msb bits) can be read or written with
square texture that targets pixels 1-8 or pixels 8-16.
However shuffle is limited. For example you can copy the green channel
to either the alpha channel or another green channel.
Note: Partial masking of channel is not yet implemented
V2: improve logging
V3: better support of green channel in shader
V4: improve detection of destination (issue due to rounding)
Gow uses 24 bits buffer, so only color is updated but blending is configured as Cd
so it is a NOP
In this case, we don't lookup the target in the texture cache. It reduces the complexity
to handle depth which can be located at same address as RT
Note: please test DX renderer
Jonathan Li