Certain GPU vendors such as ARM's Mali do not have support for BCn textures whatsoever while other vendors such as AMD only have partial support (BC1-BC3). Most titles on the guest utilize BC textures and to address this on host GPUs without support for BCn, we need to decompress the texture on the CPU. This commit implements a CPU BCn texture decoder based off Swiftshader's BC decoder, it also adds the necessary infrastructure to have different formats for the `GuestTexture` and `Texture` objects.
The iterations of the inner loop for sector deswizzling was miscalculated as `SectorWidth * SectorHeight` while the result was correct at `32`, it should be determined by the amount of sector lines within a GOB i.e.: `(GobWidth / SectorWidth) * GobHeight`.
Support for mipmapped textures was not implemented which is fairly crucial to proper rendering of games as the only level that would load is the first level (highest resolution), that might result in a lot more memory bandwidth being utilized. Mipmapping also has associated benefits regarding aliasing as it has a minor anti-aliasing effect on distant textures.
This commit entirely implements mipmapping support but it does not extend to full support for views into specific mipmap levels due to the texture manager implemention being incomplete.
Maxwell DMA requires swizzled copies to/from textures and earlier it had to construct an arbitrary `GuestTexture` to do so but with the introduction of the cleaner API, this has become redundant which this commit cleans up and replaces with direct calls to the API with all the necessary values.
The API for texture swizzling is now more concrete and abstracted out from `GuestTexture`, this allows for neater usage in certain areas such as MaxwellDMA while having a `GuestTexture` wrapper as well allowing for neater usage in those cases.
The code itself has also been cleaned up slightly with all usage of `u32`s being upgraded to `size_t` as this is simply more efficient due to the compiler not needing to emulate wraparound behavior for integer types smaller than the processor word size.
The Fermi 2D engine implements both image blit and resolve operations, supporting subpixel sampling with both linear and point filtering.
Resolve operations are performed by sampling from the center of each pixel in order to resolve the final image from the MSAA samples
MSAA images are stored in memory like regular images but each pixels dimensions are scaled: e.g for 2x2 MSAA
```
112233
112233
445566
445566
```
These would be sampled with both duDx and duDy as 2 (integer part), resolving to the following:
```
123
456
```
Blit operations are performed by sampling from the corner of each pixel, scaling the image as one would expect.
This implementation isn't fully complete as Vulkan blit doesn't support some combinations which Fermi does, most notably between colour and depth stencil. These will be implemented properly at a later date, likely after the texture manager rework.
Out of Bounds Blit, used by some OpenGL games is also missing since supporting it requires texture aliasing, this will also be supported after the texture manager rework.
Co-authored-by: Billy Laws <blaws05@gmail.com>
Certain writes during swizzling went out of bounds due to incorrect `blockExtentY` calculation, the previous commit to fix this ended up breaking it further. This commit returns to the original commit's calculations with the proper addendum of a check for exact alignment with a GOB which is the case that was broken earlier.
The `GuestTexture::GetLayerStride` function was not always being utilized to retrieve the layer stride inside `Texture`, it would instead directly access the `guestTexture::layerStride` member. This is problematic as it may not be initialized and return `0` which would lead to a broken image copy.
Most engines have the capability to release a semaphore payload (or reduce in the case of GPFIFO) when a method is called or action is complete. Semaphores are used by games for both timing how long things take on GPU and waiting on resources so missing them can cause deadlocks or other related issues.
Textures can have more than one layer which we currently don't handle, all layers past the initial one will be filled with random data or 0s, leading to incorrect rendering. This has now been implemented now which fixes any titles which utilize array textures, such as "Super Mario Odyssey" or "Hatsune Miku: Project DIVA MegaMix".
The Maxwell3D RT layer count wasn't being set correctly as it has the same register as the depth values and is toggled between the two based on another register value.
The Maxwell GPU supports 3D textures which are tiled with the block-linear layout which didn't handle swizzling 3D textures correctly till now. This commit addresses that by implementing proper swizzling for 3D textures. Titles such as Cluster Truck and Super Mario Odyssey utilize 3D textures alongside a vast majority of other titles.
As per VMA docs: 'Allocation size returned in this variable may be greater than the size requested for the resource e.g. as VkBufferCreateInfo::size. Whole size of the allocation is accessible for operations on memory e.g. using a pointer after mapping with vmaMapMemory(), but operations on the resource e.g. using vkCmdCopyBuffer must be limited to the size of the resource.'
There were two issues here:
- If a skyline span was passed as a param then the 'T &object' version would be called, filling the span itself with random values rather than its contents
- Random numbers were repeated every call since independent_bits_engine copied generator state and thus it was never actually updated
This calculation for the amount of lines on the Y axis relative to the start of the last block was wrong and would instead determine the amount of lines to the last Y-axis GOB which wasn't accurate when padding was considered, this resulted in titles like Celeste having broken texture decoding (on a 1922x1082 texture) for the last ROB as most pixels would be masked out.
Certain titles such as BOTW trigger behavior to reuse an attachment within the same subpass, this caused an exception inside `RenderPassNode::AddAttachment` as it cannot find corresponding subpass for attachment. To fix this issue, we now assume that when it cannot find a subpass for an existing attachment, it is attached to the latest subpass and return the attachment.
Certain textures may be unaligned with a GOB's height of 8 lines, we already handle the case of being unaligned with a GOB's width of 64-bytes. This case occurs on titles such as SMO when going in-game.
The function now returns from a segmentation fault when a debugger is present, this allows the entire context to be intact which can allow the debugger to correctly pick up variables from all stack frames while it could not extrapolate most variables when trapped inside the signal handler without the values of all registers.
In the Maxwell 3D engine, instanced draws are implemented by repeating the exact same draw in sequence with special flag set in vertexBeginGl. This flag allows either incrementing the instance counter or resetting it, since we need to supply an instance count to the host API we defer all draws until state changes occur. If there are no state changes between draws we can skip them and count the occurences to get the number of instances to draw.
Implements register state that corresponds to the size of a single point sprite in Maxwell 3D, this is emitted by the shader compiler in the preamble but needs to be only applied if the input topology is a point primitive and it is invalid to set the point size in any other case.
Earlier texture locking design required the lock to be retained but since the introduction of `AttachTexture`, this no longer needs to be done. This being done caused deadlocks when the depth texture is sampled by the fragment shader while being bound as an RT since it would attempt to lock the texture again.
A basic `bcat:u` implementation to prevent titles such as "Kirby and the Forgotten Land" dependent on BCAT support from crashing due to the lack of an implementation.
This is a widely supported feature that games may require conditionally but due to it being supported on effectively all target devices, it was made mandatory. This is used by titles such as ARMS.
