Fallback for no ARC, fix for #8166

backends/imgui_impl_metal.mm

@@ -162,6 +162,15 @@ void ImGui_ImplMetal_NewFrame(MTLRenderPassDescriptor* renderPassDescriptor)
 #ifdef IMGUI_IMPL_METAL_CPP
     bd->SharedMetalContext.framebufferDescriptor = [[[FramebufferDescriptor alloc] initWithRenderPassDescriptor:renderPassDescriptor]autorelease];
 #else
+    // if no ARC
+    if (!__has_feature(objc_arc)) 
+    {
+        // check for existing framebufferDescriptor, destroy if there is one
+        if (bd->SharedMetalContext.framebufferDescriptor) 
+        {
+            CFRelease((__bridge CFTypeRef)bd->SharedMetalContext.framebufferDescriptor);
+        }
+    }
     bd->SharedMetalContext.framebufferDescriptor = [[FramebufferDescriptor alloc] initWithRenderPassDescriptor:renderPassDescriptor];
 #endif
     if (bd->SharedMetalContext.depthStencilState == nil)
@@ -238,8 +247,59 @@ void ImGui_ImplMetal_RenderDrawData(ImDrawData* drawData, id<MTLCommandBuffer> c
 
     size_t vertexBufferLength = (size_t)drawData->TotalVtxCount * sizeof(ImDrawVert);
     size_t indexBufferLength = (size_t)drawData->TotalIdxCount * sizeof(ImDrawIdx);
-    MetalBuffer* vertexBuffer = [ctx dequeueReusableBufferOfLength:vertexBufferLength device:commandBuffer.device];
-    MetalBuffer* indexBuffer = [ctx dequeueReusableBufferOfLength:indexBufferLength device:commandBuffer.device];
+    MetalBuffer *vertexBuffer = nil;
+    MetalBuffer *indexBuffer = nil;
+    // if ARC do what did before
+    if (__has_feature(objc_arc)) 
+    {
+      vertexBuffer = [ctx dequeueReusableBufferOfLength:vertexBufferLength
+                                                 device:commandBuffer.device];
+      indexBuffer = [ctx dequeueReusableBufferOfLength:indexBufferLength
+                                                device:commandBuffer.device];
+    } 
+    else 
+    {
+        // else caching
+        @synchronized(ctx.bufferCache) 
+        {
+            // Find suitable buffers in the cache
+
+            for (NSInteger i = ctx.bufferCache.count - 1; i >= 0; i--) 
+            {
+                MetalBuffer *buffer = ctx.bufferCache[i];
+
+            // If buffer is large enough for vertex data and not yet   assigned
+            if (!vertexBuffer && buffer.buffer.length >=   vertexBufferLength) 
+            {
+                vertexBuffer = buffer;
+                [ctx.bufferCache removeObjectAtIndex:i];
+                continue;
+            }
+
+            // If buffer is large enough for index data and not yet assigned
+            if (!indexBuffer && buffer.buffer.length >= indexBufferLength) 
+            {
+                indexBuffer = buffer;
+                [ctx.bufferCache removeObjectAtIndex:i];
+            }
+
+            // If we found both buffers, break
+            if (vertexBuffer && indexBuffer)
+                break;
+            }
+        }
+        // Create buffers only in case none found before
+        if (!vertexBuffer) 
+        {
+            vertexBuffer = [ctx dequeueReusableBufferOfLength:vertexBufferLength
+                                        device:commandBuffer.device];
+        }
+        if (!indexBuffer) 
+        {
+            indexBuffer = [ctx dequeueReusableBufferOfLength:indexBufferLength
+                                        device:commandBuffer.device];
+        }
+    }
 
     ImGui_ImplMetal_SetupRenderState(drawData, commandBuffer, commandEncoder, renderPipelineState, vertexBuffer, 0);
 

backends/imgui_impl_osx.mm

@@ -788,8 +788,8 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view)
                 default:
                     return io.WantCaptureKeyboard;
             }
-
-            NSEventModifierFlags modifier_flags = [event modifierFlags];
+            // Declaration shadows a local variable
+            modifier_flags = [event modifierFlags];
             io.AddKeyEvent(key, (modifier_flags & mask) != 0);
             io.SetKeyEventNativeData(key, key_code, -1); // To support legacy indexing (<1.87 user code)
         }