From fb191067d7537be6eea7185f746267e63380ec2a Mon Sep 17 00:00:00 2001
From: Hugh Sanderson <hugh@hughsando.com>
Date: Sun, 15 Sep 2024 22:39:03 +0800
Subject: [PATCH] Get metal backend working better on SDL3

---
 project/ToolkitBuild.xml          |  2 +-
 project/src/metal/MetalContext.mm | 41 +++++++++++++++++--------------
 project/src/sdl2/SDL2Stage.cpp    |  9 ++++---
 samples/BunnyMark/Source/Main.hx  |  6 -----
 4 files changed, 28 insertions(+), 30 deletions(-)

diff --git a/project/ToolkitBuild.xml b/project/ToolkitBuild.xml
index 6427386ca..9e8b81f1b 100644
--- a/project/ToolkitBuild.xml
+++ b/project/ToolkitBuild.xml
@@ -29,6 +29,7 @@
    <set name="NME_DYNAMIC_ANGLE" value="1" if="NME_LOCAL_TOOLKIT" unless="NME_NO_ANGLE" />
    <set name="NATIVE_TOOLKIT_SDL_ANGLE" value="1" if="NME_ANGLE" />
    <set name="NATIVE_TOOLKIT_STATIC_ANGLE" value="1" if="NME_ANGLE" />
+   <set name="OBJC_ARC" value="1" if="NME_SDL3" />
 
    <set name="NME_LOCAL_TOOLKIT" value="1" if="android" />
 
@@ -274,7 +275,6 @@
       <compilerflag value="-DNME_SIMD_D" if="NME_SIMD_D" />
       <compilerflag value="${NME_SIMD_D}" if="NME_SIMD_D" />
       <compilerflag value="-I${ANGLE_DIR}/include" if="NME_ANGLE" />
-      <mflag value="-fobjc-arc" if="NME_LOCAL_TOOLKIT" />
 
 
       <cache value="1" unless="winrpi" />
diff --git a/project/src/metal/MetalContext.mm b/project/src/metal/MetalContext.mm
index 0f4190b3d..3e0f049f3 100644
--- a/project/src/metal/MetalContext.mm
+++ b/project/src/metal/MetalContext.mm
@@ -31,19 +31,6 @@
 {
 
 
-#ifdef NME_SDL3
-void *GetMetalLayerFromRenderer(SDL_Renderer *renderer)
-{
-   const CAMetalLayer *swapchain = (__bridge CAMetalLayer *)SDL_GetRenderMetalLayer(renderer);
-   return (void *)swapchain;
-}
-#elif defined(NME_SDL2)
-void *GetMetalLayerFromRenderer(SDL_Renderer *renderer)
-{
-   const CAMetalLayer *swapchain = (__bridge CAMetalLayer *)SDL_RenderGetMetalLayer(renderer);
-   return (void *)swapchain;
-}
-#endif
 
 static const double one_on_256 = 1.0/256.0;
 
@@ -498,7 +485,6 @@ void Dirty(const Rect &inRect)
       shader += shaderTail;
 
 
-      // printf("SHADER: %x whole=%d\n%s\n\n",progId, wholeTexture, shader.c_str() );
 
       __autoreleasing NSError *error = nil;
 
@@ -506,6 +492,7 @@ void Dirty(const Rect &inRect)
 
       id<MTLLibrary> lib  = [device newLibraryWithSource:librarySrc options:nil error:&error];
       if(!lib) {
+          printf("Shader compile failed: %x whole=%d\n%s\n\n",progId, wholeTexture, shader.c_str() );
           [NSException raise:@"Failed to compile shaders" format:@"%@", [error localizedDescription]];
       }
 
@@ -677,13 +664,16 @@ void bindUniforms(id<MTLRenderCommandEncoder> renderEncoder)
 
 };
 
-
+static size_t totalBuffer = 0;
 struct MetalBuffer
 {
    id<MTLBuffer> buffer;
+   int size;
 
    MetalBuffer(id<MTLDevice> device, const void *pointer, NSUInteger length)
    {
+      size = (int)length;
+      totalBuffer += length;
       buffer = [device newBufferWithBytes:pointer 
                              length:(NSUInteger)length 
                              options:MTLResourceCPUCacheModeWriteCombined ];
@@ -691,7 +681,12 @@ void bindUniforms(id<MTLRenderCommandEncoder> renderEncoder)
    
    ~MetalBuffer()
    {
+      #ifndef OBJC_ARC
+      [buffer release];
+      #endif
+
       buffer = nil;
+      totalBuffer -= size;
    }
 };
 
@@ -740,7 +735,7 @@ void bindUniforms(id<MTLRenderCommandEncoder> renderEncoder)
 
 public:
 
-   MetalContext(void *inCAMetalLayer) :
+   MetalContext(CAMetalLayer *inCAMetalLayer) :
       swapchain(0),
       _device(nil),
       queue(nil),
@@ -749,7 +744,7 @@ void bindUniforms(id<MTLRenderCommandEncoder> renderEncoder)
       surface(nullptr)
    {
      frame = 0;
-     swapchain = (__bridge CAMetalLayer *)inCAMetalLayer;
+     swapchain = inCAMetalLayer;
      _device = swapchain.device;
      queue =  [_device newCommandQueue];
      width = height = 0;
@@ -977,9 +972,17 @@ void EndDirectRender() { }
 };
 
 
-HardwareRenderer *HardwareRenderer::CreateMetal(void *inLayer)
+HardwareRenderer *HardwareRenderer::CreateMetal(void *inRenderer)
 {
-   HardwareRenderer *ctx = new MetalContext(inLayer);
+   SDL_Renderer *renderer = (SDL_Renderer *)renderer;
+
+   #ifdef NME_SDL3
+   CAMetalLayer *metalLayer = (__bridge CAMetalLayer *)SDL_GetRenderMetalLayer(renderer);
+   #elif defined(NME_SDL2)
+   CAMetalLayer *metalLayer = (__bridge CAMetalLayer *)SDL_RenderGetMetalLayer(renderer);
+   #endif
+
+   HardwareRenderer *ctx = new MetalContext( metalLayer );
 
    return ctx;
 }
diff --git a/project/src/sdl2/SDL2Stage.cpp b/project/src/sdl2/SDL2Stage.cpp
index b995597d7..ec177157f 100644
--- a/project/src/sdl2/SDL2Stage.cpp
+++ b/project/src/sdl2/SDL2Stage.cpp
@@ -89,6 +89,9 @@ int InitSDL()
       SDL_SetHint(SDL_HINT_RENDER_DRIVER, "metal");
    else
       SDL_SetHint(SDL_HINT_RENDER_DRIVER, "opengl");
+      #ifdef NME_SDL3
+      SDL_SetHint(SDL_HINT_RENDER_METAL_PREFER_LOW_POWER_DEVICE, "0");
+      #endif
    #endif
 
    #ifdef NME_DYNAMIC_ANGLE
@@ -419,16 +422,14 @@ class SDLStage : public Stage
             }
             else
             {
-               void *swapchain = GetMetalLayerFromRenderer(mSDLRenderer);
-               mHardwareRenderer = HardwareRenderer::CreateMetal(swapchain);
+               mHardwareRenderer = HardwareRenderer::CreateMetal(mSDLRenderer);
             }
             #elif defined(NME_OGL)
             mHardwareRenderer = HardwareRenderer::CreateOpenGL(0, 0, sgIsOGL2);
 
             #elif defined(NME_METAL)
 
-            void *swapchain = GetMetalLayerFromRenderer(mSDLRenderer);
-            mHardwareRenderer = HardwareRenderer::CreateMetal(swapchain);
+            mHardwareRenderer = HardwareRenderer::CreateMetal(mSDLRenderer);
    
             #else
             #error "No valid HardwareRenderer"
diff --git a/samples/BunnyMark/Source/Main.hx b/samples/BunnyMark/Source/Main.hx
index 74cae2e92..3576d5ece 100644
--- a/samples/BunnyMark/Source/Main.hx
+++ b/samples/BunnyMark/Source/Main.hx
@@ -39,12 +39,6 @@ class Main extends Sprite
    {
       super();
 
-      trace("--");
-      for(ext in nme.gl.GL.getSupportedExtensions())
-         if (ext.indexOf("draw_buffer")>=0 || ext.indexOf("frame")>=0)
-            trace("  " + ext);
-      trace("--");
-
       bunnies = new Array();
       minX = 0;
       maxX = 800;