Convert Quads to Triangles in Vulkan (#3715)

* Add Index Buffer conversion for quads to Vulkan

Also adds a reusable repeating pattern index buffer to use for non-indexed
draws, and generalizes the conversion cache for buffers.

* Fix some issues

* End render pass before conversion

* Resume transform feedback after we ensure we're in a pass.

* Always generate UInt32 type indices for topology conversion

* No it's not.

* Remove unused code

* Rely on TopologyRemap to convert quads to tris.

* Remove double newline

* Ensure render pass ends before stride or I8 conversion

1 files changed, 25 insertions, 0 deletions

diff --git a/Ryujinx.Graphics.Vulkan/BufferHolder.cs b/Ryujinx.Graphics.Vulkan/BufferHolder.cs
index a2fc0c39..f449c102 100644
--- a/Ryujinx.Graphics.Vulkan/BufferHolder.cs
+++ b/Ryujinx.Graphics.Vulkan/BufferHolder.cs
@@ -370,6 +370,7 @@ namespace Ryujinx.Graphics.Vulkan
             {
                 holder = _gd.BufferManager.Create(_gd, (size * 2 + 3) & ~3);
 
+                _gd.PipelineInternal.EndRenderPass();
                 _gd.HelperShader.ConvertI8ToI16(_gd, cbs, this, holder, offset, size);
 
                 _cachedConvertedBuffers.Add(offset, size, key, holder);
@@ -388,6 +389,7 @@ namespace Ryujinx.Graphics.Vulkan
 
                 holder = _gd.BufferManager.Create(_gd, (size / stride) * alignedStride);
 
+                _gd.PipelineInternal.EndRenderPass();
                 _gd.HelperShader.ChangeStride(_gd, cbs, this, holder, offset, size, stride, alignedStride);
 
                 key.SetBuffer(holder.GetBuffer());
@@ -398,6 +400,29 @@ namespace Ryujinx.Graphics.Vulkan
             return holder.GetBuffer();
         }
 
+        public Auto<DisposableBuffer> GetBufferTopologyConversion(CommandBufferScoped cbs, int offset, int size, IndexBufferPattern pattern, int indexSize)
+        {
+            var key = new TopologyConversionCacheKey(_gd, pattern, indexSize);
+
+            if (!_cachedConvertedBuffers.TryGetValue(offset, size, key, out var holder))
+            {
+                // The destination index size is always I32.
+
+                int indexCount = size / indexSize;
+
+                int convertedCount = pattern.GetConvertedCount(indexCount);
+
+                holder = _gd.BufferManager.Create(_gd, convertedCount * 4);
+
+                _gd.PipelineInternal.EndRenderPass();
+                _gd.HelperShader.ConvertIndexBuffer(_gd, cbs, this, holder, pattern, indexSize, offset, indexCount);
+
+                _cachedConvertedBuffers.Add(offset, size, key, holder);
+            }
+
+            return holder.GetBuffer();
+        }
+
         public void Dispose()
         {
             _gd.PipelineInternal?.FlushCommandsIfWeightExceeding(_buffer, (ulong)Size);