From 8d8bb050554b6c95042dd9462e744055dd35cf8c Mon Sep 17 00:00:00 2001
From: "Daniel R." <47796739+polybiusproxy@users.noreply.github.com>
Date: Sat, 21 Dec 2024 10:20:24 +0100
Subject: [PATCH] renderer_vulkan: add support for Polygon draws (#1798)

---
 src/video_core/buffer_cache/buffer_cache.cpp  | 36 +++++++++++++++----
 .../renderer_vulkan/liverpool_to_vk.cpp       |  1 +
 .../renderer_vulkan/liverpool_to_vk.h         |  9 +++++
 .../renderer_vulkan/vk_rasterizer.cpp         |  7 ++--
 4 files changed, 43 insertions(+), 10 deletions(-)

diff --git a/src/video_core/buffer_cache/buffer_cache.cpp b/src/video_core/buffer_cache/buffer_cache.cpp
index e9fc0649..f265fb68 100644
--- a/src/video_core/buffer_cache/buffer_cache.cpp
+++ b/src/video_core/buffer_cache/buffer_cache.cpp
@@ -235,25 +235,44 @@ bool BufferCache::BindVertexBuffers(
 }
 
 u32 BufferCache::BindIndexBuffer(bool& is_indexed, u32 index_offset) {
-    // Emulate QuadList primitive type with CPU made index buffer.
+    // Emulate QuadList and Polygon primitive types with CPU made index buffer.
     const auto& regs = liverpool->regs;
-    if (regs.primitive_type == AmdGpu::PrimitiveType::QuadList && !is_indexed) {
-        is_indexed = true;
+    if (!is_indexed) {
+        bool needs_index_buffer = false;
+        if (regs.primitive_type == AmdGpu::PrimitiveType::QuadList ||
+            regs.primitive_type == AmdGpu::PrimitiveType::Polygon) {
+            needs_index_buffer = true;
+        }
+
+        if (!needs_index_buffer) {
+            return regs.num_indices;
+        }
 
         // Emit indices.
         const u32 index_size = 3 * regs.num_indices;
         const auto [data, offset] = stream_buffer.Map(index_size);
-        Vulkan::LiverpoolToVK::EmitQuadToTriangleListIndices(data, regs.num_indices);
+
+        switch (regs.primitive_type) {
+        case AmdGpu::PrimitiveType::QuadList:
+            Vulkan::LiverpoolToVK::EmitQuadToTriangleListIndices(data, regs.num_indices);
+            break;
+        case AmdGpu::PrimitiveType::Polygon:
+            Vulkan::LiverpoolToVK::EmitPolygonToTriangleListIndices(data, regs.num_indices);
+            break;
+        default:
+            UNREACHABLE();
+            break;
+        }
+
         stream_buffer.Commit();
 
         // Bind index buffer.
+        is_indexed = true;
+
         const auto cmdbuf = scheduler.CommandBuffer();
         cmdbuf.bindIndexBuffer(stream_buffer.Handle(), offset, vk::IndexType::eUint16);
         return index_size / sizeof(u16);
     }
-    if (!is_indexed) {
-        return regs.num_indices;
-    }
 
     // Figure out index type and size.
     const bool is_index16 =
@@ -288,6 +307,9 @@ u32 BufferCache::BindIndexBuffer(bool& is_indexed, u32 index_offset) {
         cmdbuf.bindIndexBuffer(stream_buffer.Handle(), offset, index_type);
         return new_index_size / index_size;
     }
+    if (regs.primitive_type == AmdGpu::PrimitiveType::Polygon) {
+        UNREACHABLE();
+    }
 
     // Bind index buffer.
     const u32 index_buffer_size = regs.num_indices * index_size;
diff --git a/src/video_core/renderer_vulkan/liverpool_to_vk.cpp b/src/video_core/renderer_vulkan/liverpool_to_vk.cpp
index ec0bb3bb..6df89dba 100644
--- a/src/video_core/renderer_vulkan/liverpool_to_vk.cpp
+++ b/src/video_core/renderer_vulkan/liverpool_to_vk.cpp
@@ -117,6 +117,7 @@ vk::PrimitiveTopology PrimitiveType(AmdGpu::PrimitiveType type) {
     case AmdGpu::PrimitiveType::PatchPrimitive:
         return vk::PrimitiveTopology::ePatchList;
     case AmdGpu::PrimitiveType::QuadList:
+    case AmdGpu::PrimitiveType::Polygon:
         // Needs to generate index buffer on the fly.
         return vk::PrimitiveTopology::eTriangleList;
     case AmdGpu::PrimitiveType::RectList:
diff --git a/src/video_core/renderer_vulkan/liverpool_to_vk.h b/src/video_core/renderer_vulkan/liverpool_to_vk.h
index ebd09f0e..72bddc6b 100644
--- a/src/video_core/renderer_vulkan/liverpool_to_vk.h
+++ b/src/video_core/renderer_vulkan/liverpool_to_vk.h
@@ -98,6 +98,15 @@ void ConvertQuadToTriangleListIndices(u8* out_ptr, const u8* in_ptr, u32 num_ver
     }
 }
 
+inline void EmitPolygonToTriangleListIndices(u8* out_ptr, u32 num_vertices) {
+    u16* out_data = reinterpret_cast<u16*>(out_ptr);
+    for (u16 i = 1; i < num_vertices - 1; i++) {
+        *out_data++ = 0;
+        *out_data++ = i;
+        *out_data++ = i + 1;
+    }
+}
+
 static inline vk::Format PromoteFormatToDepth(vk::Format fmt) {
     if (fmt == vk::Format::eR32Sfloat) {
         return vk::Format::eD32Sfloat;
diff --git a/src/video_core/renderer_vulkan/vk_rasterizer.cpp b/src/video_core/renderer_vulkan/vk_rasterizer.cpp
index bd8906f8..df05b73a 100644
--- a/src/video_core/renderer_vulkan/vk_rasterizer.cpp
+++ b/src/video_core/renderer_vulkan/vk_rasterizer.cpp
@@ -246,11 +246,12 @@ void Rasterizer::DrawIndirect(bool is_indexed, VAddr arg_address, u32 offset, u3
     }
 
     const auto& regs = liverpool->regs;
-    if (regs.primitive_type == AmdGpu::PrimitiveType::QuadList) {
-        // For QuadList we use generated index buffer to convert quads to triangles. Since it
+    if (regs.primitive_type == AmdGpu::PrimitiveType::QuadList ||
+        regs.primitive_type == AmdGpu::PrimitiveType::Polygon) {
+        // We use a generated index buffer to convert quad lists and polygons to triangles. Since it
         // changes type of the draw, arguments are not valid for this case. We need to run a
         // conversion pass to repack the indirect arguments buffer first.
-        LOG_WARNING(Render_Vulkan, "QuadList primitive type is not supported for indirect draw");
+        LOG_WARNING(Render_Vulkan, "Primitive type is not supported for indirect draw");
         return;
     }