From a9213debc7aebfba75827a71fcf15a8c1e091104 Mon Sep 17 00:00:00 2001
From: Billy Laws <blaws05@gmail.com>
Date: Sat, 17 Sep 2022 13:10:01 +0100
Subject: [PATCH] Implement constant buffer reading

---
 .../interconnect/maxwell_3d/constant_buffers.cpp  | 15 ++++++++++-----
 .../interconnect/maxwell_3d/constant_buffers.h    |  4 ++--
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.cpp b/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.cpp
index 0dff81ba..6aa7d523 100644
--- a/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.cpp
+++ b/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.cpp
@@ -24,17 +24,22 @@ namespace skyline::gpu::interconnect::maxwell3d {
         view.PurgeCaches();
     }
 
+    static void FlushHostCallback() {
+        // TODO: here we should trigger `Execute()`, however that doesn't currently work due to Read being called mid-draw and attached objects not handling this case
+        Logger::Warn("GPU dirty buffer reads for attached buffers are unimplemented");
+    }
+
+    void ConstantBuffer::Read(CommandExecutor &executor, span<u8> dstBuffer, size_t srcOffset) {
+        ContextLock lock{executor.tag, view};
+        view.Read(lock.IsFirstUsage(), FlushHostCallback, dstBuffer, srcOffset);
+    }
+
     ConstantBuffers::ConstantBuffers(DirtyManager &manager, const ConstantBufferSelectorState::EngineRegisters &constantBufferSelectorRegisters) : selectorState{manager, constantBufferSelectorRegisters} {}
 
     void ConstantBuffers::MarkAllDirty() {
         selectorState.MarkDirty(true);
     }
 
-    static void FlushHostCallback() {
-        // TODO: here we should trigger `Execute()`, however that doesn't currently work due to Read being called mid-draw and attached objects not handling this case
-        Logger::Warn("GPU dirty buffer reads for attached buffers are unimplemented");
-    }
-
     void ConstantBuffers::Load(InterconnectContext &ctx, span<u32> data, u32 offset) {
         auto &view{*selectorState.UpdateGet(ctx).view};
         auto srcCpuBuf{data.cast<u8>()};
diff --git a/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.h b/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.h
index cda23b9f..91623139 100644
--- a/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.h
+++ b/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.h
@@ -30,10 +30,10 @@ namespace skyline::gpu::interconnect::maxwell3d {
     struct ConstantBuffer {
         BufferView view;
 
-        void Read(CommandExecutor &executor, span<u8> dstBuffer, size_t srcOffset) const;
+        void Read(CommandExecutor &executor, span<u8> dstBuffer, size_t srcOffset);
 
         template<typename T>
-        T Read(CommandExecutor &executor, size_t srcOffset) const {
+        T Read(CommandExecutor &executor, size_t srcOffset) {
             T object;
             Read(executor, span<T>{object}.template cast<u8>(), srcOffset);
             return object;