Support compute uniform buffers emulated with global memory (#924)

2 files changed, 41 insertions, 3 deletions

diff --git a/Ryujinx.Graphics.Gpu/Constants.cs b/Ryujinx.Graphics.Gpu/Constants.cs
index 65cd8846..cc476654 100644
--- a/Ryujinx.Graphics.Gpu/Constants.cs
+++ b/Ryujinx.Graphics.Gpu/Constants.cs
@@ -8,11 +8,18 @@ namespace Ryujinx.Graphics.Gpu
         /// <summary>
         /// Maximum number of compute uniform buffers.
         /// </summary>
-        public const int TotalCpUniformBuffers = 8;
+        /// <remarks>
+        /// This does not reflect the hardware count, the API will emulate some constant buffers using
+        /// global memory to make up for the low amount of compute constant buffers supported by hardware (only 8).
+        /// </remarks>
+        public const int TotalCpUniformBuffers = 17; // 8 hardware constant buffers + 9 emulated (14 available to the user).
 
         /// <summary>
-        /// Maximum number of compute storage buffers (this is an API limitation).
+        /// Maximum number of compute storage buffers.
         /// </summary>
+        /// <remarks>
+        /// The maximum number of storage buffers is API limited, the hardware supports a unlimited amount.
+        /// </remarks>
         public const int TotalCpStorageBuffers = 16;
 
         /// <summary>
@@ -21,8 +28,11 @@ namespace Ryujinx.Graphics.Gpu
         public const int TotalGpUniformBuffers = 18;
 
         /// <summary>
-        /// Maximum number of graphics storage buffers (this is an API limitation).
+        /// Maximum number of graphics storage buffers.
         /// </summary>
+        /// <remarks>
+        /// The maximum number of storage buffers is API limited, the hardware supports a unlimited amount.
+        /// </remarks>
         public const int TotalGpStorageBuffers = 16;
 
         /// <summary>
diff --git a/Ryujinx.Graphics.Gpu/Engine/Compute.cs b/Ryujinx.Graphics.Gpu/Engine/Compute.cs
index 9178cfb0..fc257f99 100644
--- a/Ryujinx.Graphics.Gpu/Engine/Compute.cs
+++ b/Ryujinx.Graphics.Gpu/Engine/Compute.cs
@@ -69,6 +69,34 @@ namespace Ryujinx.Graphics.Gpu.Engine
                 BufferManager.SetComputeUniformBuffer(index, gpuVa, size);
             }
 
+            for (int index = 0; index < info.CBuffers.Count; index++)
+            {
+                BufferDescriptor cb = info.CBuffers[index];
+
+                // NVN uses the "hardware" constant buffer for anything that is less than 8,
+                // and those are already bound above.
+                // Anything greater than or equal to 8 uses the emulated constant buffers.
+                // They are emulated using global memory loads.
+                if (cb.Slot < 8)
+                {
+                    continue;
+                }
+
+                ubEnableMask |= 1u << cb.Slot;
+
+                ulong cbDescAddress = BufferManager.GetComputeUniformBufferAddress(0);
+
+                int cbDescOffset = 0x260 + cb.Slot * 0x10;
+
+                cbDescAddress += (ulong)cbDescOffset;
+
+                ReadOnlySpan<byte> cbDescriptorData = _context.PhysicalMemory.GetSpan(cbDescAddress, 0x10);
+
+                SbDescriptor cbDescriptor = MemoryMarshal.Cast<byte, SbDescriptor>(cbDescriptorData)[0];
+
+                BufferManager.SetComputeUniformBuffer(cb.Slot, cbDescriptor.PackAddress(), (uint)cbDescriptor.Size);
+            }
+
             for (int index = 0; index < info.SBuffers.Count; index++)
             {
                 BufferDescriptor sb = info.SBuffers[index];