[vk] Correct polygon draw topology mapping for line and point modes (#2834)

Co-authored-by: Ribbit <ribbit@placeholder.com>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2834
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: crueter <crueter@eden-emu.dev>
Co-authored-by: Ribbit <ribbit@eden-emu.dev>
Co-committed-by: Ribbit <ribbit@eden-emu.dev>

1 files changed, 70 insertions, 6 deletions

diff --git a/src/video_core/buffer_cache/buffer_cache.h b/src/video_core/buffer_cache/buffer_cache.h
index 39c56fb33f..ddd940c6d2 100644
--- a/src/video_core/buffer_cache/buffer_cache.h
+++ b/src/video_core/buffer_cache/buffer_cache.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <algorithm>
+#include <cstring>
 #include <memory>
 #include <numeric>
 
@@ -15,6 +16,8 @@
 #include "video_core/guest_memory.h"
 #include "video_core/host1x/gpu_device_memory_manager.h"
 #include "video_core/texture_cache/util.h"
+#include "video_core/polygon_mode_utils.h"
+#include "video_core/renderer_vulkan/line_loop_utils.h"
 
 namespace VideoCommon {
 
@@ -353,14 +356,37 @@ void BufferCache<P>::UpdateComputeBuffers() {
 
 template <class P>
 void BufferCache<P>::BindHostGeometryBuffers(bool is_indexed) {
+    const auto& draw_state = maxwell3d->draw_manager->GetDrawState();
     if (is_indexed) {
         BindHostIndexBuffer();
-    } else if constexpr (!HAS_FULL_INDEX_AND_PRIMITIVE_SUPPORT) {
-        const auto& draw_state = maxwell3d->draw_manager->GetDrawState();
-        if (draw_state.topology == Maxwell::PrimitiveTopology::Quads ||
-            draw_state.topology == Maxwell::PrimitiveTopology::QuadStrip) {
-            runtime.BindQuadIndexBuffer(draw_state.topology, draw_state.vertex_buffer.first,
-                                        draw_state.vertex_buffer.count);
+    } else {
+        if constexpr (!P::IS_OPENGL) {
+            const auto polygon_mode = VideoCore::EffectivePolygonMode(maxwell3d->regs);
+            if (draw_state.topology == Maxwell::PrimitiveTopology::Polygon &&
+                polygon_mode == Maxwell::PolygonMode::Line && draw_state.vertex_buffer.count > 1) {
+                const u32 vertex_count = draw_state.vertex_buffer.count;
+                const u32 generated_count = vertex_count + 1;
+                const bool use_u16 = vertex_count <= 0x10000;
+                const u32 element_size = use_u16 ? sizeof(u16) : sizeof(u32);
+                auto staging = runtime.UploadStagingBuffer(
+                    static_cast<size_t>(generated_count) * element_size);
+                std::span<u8> dst_span{staging.mapped_span.data(),
+                                       generated_count * static_cast<size_t>(element_size)};
+                Vulkan::LineLoop::GenerateSequentialWithClosureRaw(dst_span, element_size);
+                const auto synthetic_format = use_u16 ? Maxwell::IndexFormat::UnsignedShort
+                                                      : Maxwell::IndexFormat::UnsignedInt;
+                runtime.BindIndexBuffer(draw_state.topology, synthetic_format,
+                                        draw_state.vertex_buffer.first, generated_count,
+                                        staging.buffer, static_cast<u32>(staging.offset),
+                                        generated_count * element_size);
+            }
+        }
+        if constexpr (!HAS_FULL_INDEX_AND_PRIMITIVE_SUPPORT) {
+            if (draw_state.topology == Maxwell::PrimitiveTopology::Quads ||
+                draw_state.topology == Maxwell::PrimitiveTopology::QuadStrip) {
+                runtime.BindQuadIndexBuffer(draw_state.topology, draw_state.vertex_buffer.first,
+                                            draw_state.vertex_buffer.count);
+            }
         }
     }
     BindHostVertexBuffers();
@@ -689,6 +715,44 @@ void BufferCache<P>::BindHostIndexBuffer() {
     const u32 offset = buffer.Offset(channel_state->index_buffer.device_addr);
     const u32 size = channel_state->index_buffer.size;
     const auto& draw_state = maxwell3d->draw_manager->GetDrawState();
+    if constexpr (!P::IS_OPENGL) {
+        const auto polygon_mode = VideoCore::EffectivePolygonMode(maxwell3d->regs);
+        const bool polygon_line =
+            draw_state.topology == Maxwell::PrimitiveTopology::Polygon &&
+            polygon_mode == Maxwell::PolygonMode::Line;
+        if (polygon_line && draw_state.index_buffer.count > 1) {
+            const u32 element_size = draw_state.index_buffer.FormatSizeInBytes();
+            const size_t src_bytes = static_cast<size_t>(draw_state.index_buffer.count) * element_size;
+            const size_t total_bytes = src_bytes + element_size;
+            auto staging = runtime.UploadStagingBuffer(total_bytes);
+            std::span<u8> dst_span{staging.mapped_span.data(), total_bytes};
+            std::span<const u8> src_span;
+            if (!draw_state.inline_index_draw_indexes.empty()) {
+                const u8* const src =
+                    draw_state.inline_index_draw_indexes.data() +
+                    static_cast<size_t>(draw_state.index_buffer.first) * element_size;
+                src_span = {src, src_bytes};
+            } else if (const u8* const cpu_base =
+                           device_memory.GetPointer<u8>(channel_state->index_buffer.device_addr)) {
+                const u8* const src = cpu_base +
+                                      static_cast<size_t>(draw_state.index_buffer.first) * element_size;
+                src_span = {src, src_bytes};
+            } else {
+                const DAddr src_addr =
+                    channel_state->index_buffer.device_addr +
+                    static_cast<DAddr>(draw_state.index_buffer.first) * element_size;
+                device_memory.ReadBlockUnsafe(src_addr, dst_span.data(), src_bytes);
+                src_span = {dst_span.data(), src_bytes};
+            }
+            Vulkan::LineLoop::CopyWithClosureRaw(dst_span, src_span, element_size);
+            buffer.MarkUsage(offset, size);
+            runtime.BindIndexBuffer(draw_state.topology, draw_state.index_buffer.format,
+                                    draw_state.index_buffer.first, draw_state.index_buffer.count + 1,
+                                    staging.buffer, static_cast<u32>(staging.offset),
+                                    static_cast<u32>(total_bytes));
+            return;
+        }
+    }
     if (!draw_state.inline_index_draw_indexes.empty()) [[unlikely]] {
         if constexpr (USE_MEMORY_MAPS_FOR_UPLOADS) {
             auto upload_staging = runtime.UploadStagingBuffer(size);