From c6d82209abeacd2336cde99e5a02b4596e70da83 Mon Sep 17 00:00:00 2001
From: riperiperi <rhy3756547@hotmail.com>
Date: Fri, 9 Sep 2022 00:30:19 +0100
Subject: Restride vertex buffer when stride causes attributes to misalign in
 Vulkan. (#3679)

* Vertex Buffer Alignment part 1

* Update CacheByRange

* Add Stride Change compute shader, fix storage buffers in helpers

* An AMD exclusive

* Reword

* Change rules - stride conversion when attrs misalign

* Fix stupid mistake

* Fix background pipeline compile

* Improve a few things.

* Fix some feedback

* Address Feedback

(the shader binary didn't change when i changed the source to use the subgroup size)

* Fix bug where rewritten buffer would be disposed instantly.
---
 .../Shaders/ChangeBufferStrideShaderSource.comp    | 64 ++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 Ryujinx.Graphics.Vulkan/Shaders/ChangeBufferStrideShaderSource.comp

(limited to 'Ryujinx.Graphics.Vulkan/Shaders/ChangeBufferStrideShaderSource.comp')

diff --git a/Ryujinx.Graphics.Vulkan/Shaders/ChangeBufferStrideShaderSource.comp b/Ryujinx.Graphics.Vulkan/Shaders/ChangeBufferStrideShaderSource.comp
new file mode 100644
index 00000000..081fc119
--- /dev/null
+++ b/Ryujinx.Graphics.Vulkan/Shaders/ChangeBufferStrideShaderSource.comp
@@ -0,0 +1,64 @@
+#version 450 core
+
+#extension GL_EXT_shader_8bit_storage : require
+
+layout (local_size_x = 64, local_size_y = 1, local_size_z = 1) in;
+
+layout (std140, set = 0, binding = 0) uniform stride_arguments
+{
+    ivec4 stride_arguments_data;
+};
+
+layout (std430, set = 1, binding = 1) buffer in_s
+{
+    uint8_t[] in_data;
+};
+
+layout (std430, set = 1, binding = 2) buffer out_s
+{
+    uint8_t[] out_data;
+};
+
+void main()
+{
+    // Determine what slice of the stride copies this invocation will perform.
+
+    int sourceStride = stride_arguments_data.x;
+    int targetStride = stride_arguments_data.y;
+    int bufferSize = stride_arguments_data.z;
+    int sourceOffset = stride_arguments_data.w;
+
+    int strideRemainder = targetStride - sourceStride;
+    int invocations = int(gl_WorkGroupSize.x);
+
+    int copiesRequired = bufferSize / sourceStride;
+
+    // Find the copies that this invocation should perform.
+    
+    // - Copies that all invocations perform.
+    int allInvocationCopies = copiesRequired / invocations;
+
+    // - Extra remainder copy that this invocation performs.
+    int index = int(gl_LocalInvocationID.x);
+    int extra = (index < (copiesRequired % invocations)) ? 1 : 0;
+
+    int copyCount = allInvocationCopies + extra;
+
+    // Finally, get the starting offset. Make sure to count extra copies.
+
+    int startCopy = allInvocationCopies * index + min(copiesRequired % invocations, index);
+
+    int srcOffset = sourceOffset + startCopy * sourceStride;
+    int dstOffset = startCopy * targetStride;
+
+    // Perform the copies for this region
+    for (int i=0; i<copyCount; i++) {
+        for (int j=0; j<sourceStride; j++) {
+            out_data[dstOffset++] = in_data[srcOffset++];
+        }
+
+        for (int j=0; j<strideRemainder; j++) {
+            out_data[dstOffset++] = uint8_t(0);
+        }
+    }
+}
-- 
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