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			551 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
// dear imgui: Renderer Backend for Metal
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// This needs to be used along with a Platform Backend (e.g. OSX)
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// Implemented features:
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//  [X] Renderer: User texture binding. Use 'MTLTexture' as ImTextureID. Read the FAQ about ImTextureID!
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//  [X] Renderer: Support for large meshes (64k+ vertices) with 16-bit indices.
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// You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
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// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
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// Read online: https://github.com/ocornut/imgui/tree/master/docs
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// CHANGELOG
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// (minor and older changes stripped away, please see git history for details)
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//  2019-05-29: Metal: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
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//  2019-04-30: Metal: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
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//  2019-02-11: Metal: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
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//  2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
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//  2018-07-05: Metal: Added new Metal backend implementation.
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#include "imgui.h"
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#include "imgui_impl_metal.h"
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#import <Metal/Metal.h>
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// #import <QuartzCore/CAMetalLayer.h> // Not supported in XCode 9.2. Maybe a macro to detect the SDK version can be used (something like #if MACOS_SDK >= 10.13 ...)
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#import <simd/simd.h>
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#pragma mark - Support classes
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// A wrapper around a MTLBuffer object that knows the last time it was reused
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@interface MetalBuffer : NSObject
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@property (nonatomic, strong) id<MTLBuffer> buffer;
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@property (nonatomic, assign) NSTimeInterval lastReuseTime;
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- (instancetype)initWithBuffer:(id<MTLBuffer>)buffer;
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@end
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// An object that encapsulates the data necessary to uniquely identify a
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// render pipeline state. These are used as cache keys.
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@interface FramebufferDescriptor : NSObject<NSCopying>
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@property (nonatomic, assign) unsigned long sampleCount;
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@property (nonatomic, assign) MTLPixelFormat colorPixelFormat;
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@property (nonatomic, assign) MTLPixelFormat depthPixelFormat;
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@property (nonatomic, assign) MTLPixelFormat stencilPixelFormat;
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- (instancetype)initWithRenderPassDescriptor:(MTLRenderPassDescriptor *)renderPassDescriptor;
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@end
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// A singleton that stores long-lived objects that are needed by the Metal
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// renderer backend. Stores the render pipeline state cache and the default
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// font texture, and manages the reusable buffer cache.
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@interface MetalContext : NSObject
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@property (nonatomic, strong) id<MTLDepthStencilState> depthStencilState;
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@property (nonatomic, strong) FramebufferDescriptor *framebufferDescriptor; // framebuffer descriptor for current frame; transient
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@property (nonatomic, strong) NSMutableDictionary *renderPipelineStateCache; // pipeline cache; keyed on framebuffer descriptors
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@property (nonatomic, strong, nullable) id<MTLTexture> fontTexture;
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@property (nonatomic, strong) NSMutableArray<MetalBuffer *> *bufferCache;
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@property (nonatomic, assign) NSTimeInterval lastBufferCachePurge;
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- (void)makeDeviceObjectsWithDevice:(id<MTLDevice>)device;
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- (void)makeFontTextureWithDevice:(id<MTLDevice>)device;
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- (MetalBuffer *)dequeueReusableBufferOfLength:(NSUInteger)length device:(id<MTLDevice>)device;
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- (void)enqueueReusableBuffer:(MetalBuffer *)buffer;
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- (id<MTLRenderPipelineState>)renderPipelineStateForFrameAndDevice:(id<MTLDevice>)device;
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- (void)emptyRenderPipelineStateCache;
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- (void)setupRenderState:(ImDrawData *)drawData
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           commandBuffer:(id<MTLCommandBuffer>)commandBuffer
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          commandEncoder:(id<MTLRenderCommandEncoder>)commandEncoder
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     renderPipelineState:(id<MTLRenderPipelineState>)renderPipelineState
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            vertexBuffer:(MetalBuffer *)vertexBuffer
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      vertexBufferOffset:(size_t)vertexBufferOffset;
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- (void)renderDrawData:(ImDrawData *)drawData
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         commandBuffer:(id<MTLCommandBuffer>)commandBuffer
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        commandEncoder:(id<MTLRenderCommandEncoder>)commandEncoder;
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@end
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static MetalContext *g_sharedMetalContext = nil;
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#pragma mark - ImGui API implementation
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bool ImGui_ImplMetal_Init(id<MTLDevice> device)
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{
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    ImGuiIO& io = ImGui::GetIO();
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    io.BackendRendererName = "imgui_impl_metal";
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    io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
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    static dispatch_once_t onceToken;
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    dispatch_once(&onceToken, ^{
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        g_sharedMetalContext = [[MetalContext alloc] init];
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    });
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    ImGui_ImplMetal_CreateDeviceObjects(device);
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    return true;
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}
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void ImGui_ImplMetal_Shutdown()
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{
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    ImGui_ImplMetal_DestroyDeviceObjects();
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}
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void ImGui_ImplMetal_NewFrame(MTLRenderPassDescriptor *renderPassDescriptor)
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{
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    IM_ASSERT(g_sharedMetalContext != nil && "No Metal context. Did you call ImGui_ImplMetal_Init() ?");
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    g_sharedMetalContext.framebufferDescriptor = [[FramebufferDescriptor alloc] initWithRenderPassDescriptor:renderPassDescriptor];
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}
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// Metal Render function.
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void ImGui_ImplMetal_RenderDrawData(ImDrawData* draw_data, id<MTLCommandBuffer> commandBuffer, id<MTLRenderCommandEncoder> commandEncoder)
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{
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    [g_sharedMetalContext renderDrawData:draw_data commandBuffer:commandBuffer commandEncoder:commandEncoder];
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}
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bool ImGui_ImplMetal_CreateFontsTexture(id<MTLDevice> device)
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{
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    [g_sharedMetalContext makeFontTextureWithDevice:device];
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    ImGuiIO& io = ImGui::GetIO();
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    io.Fonts->TexID = (__bridge void *)g_sharedMetalContext.fontTexture; // ImTextureID == void*
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    return (g_sharedMetalContext.fontTexture != nil);
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}
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void ImGui_ImplMetal_DestroyFontsTexture()
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{
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    ImGuiIO& io = ImGui::GetIO();
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    g_sharedMetalContext.fontTexture = nil;
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    io.Fonts->TexID = nullptr;
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}
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bool ImGui_ImplMetal_CreateDeviceObjects(id<MTLDevice> device)
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{
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    [g_sharedMetalContext makeDeviceObjectsWithDevice:device];
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    ImGui_ImplMetal_CreateFontsTexture(device);
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    return true;
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}
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void ImGui_ImplMetal_DestroyDeviceObjects()
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{
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    ImGui_ImplMetal_DestroyFontsTexture();
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    [g_sharedMetalContext emptyRenderPipelineStateCache];
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}
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#pragma mark - MetalBuffer implementation
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@implementation MetalBuffer
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- (instancetype)initWithBuffer:(id<MTLBuffer>)buffer
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{
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    if ((self = [super init]))
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    {
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        _buffer = buffer;
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        _lastReuseTime = [NSDate date].timeIntervalSince1970;
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    }
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    return self;
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}
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@end
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#pragma mark - FramebufferDescriptor implementation
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@implementation FramebufferDescriptor
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- (instancetype)initWithRenderPassDescriptor:(MTLRenderPassDescriptor *)renderPassDescriptor
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{
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    if ((self = [super init]))
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    {
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        _sampleCount = renderPassDescriptor.colorAttachments[0].texture.sampleCount;
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        _colorPixelFormat = renderPassDescriptor.colorAttachments[0].texture.pixelFormat;
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        _depthPixelFormat = renderPassDescriptor.depthAttachment.texture.pixelFormat;
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        _stencilPixelFormat = renderPassDescriptor.stencilAttachment.texture.pixelFormat;
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    }
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    return self;
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}
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- (nonnull id)copyWithZone:(nullable NSZone *)zone
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{
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    FramebufferDescriptor *copy = [[FramebufferDescriptor allocWithZone:zone] init];
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    copy.sampleCount = self.sampleCount;
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    copy.colorPixelFormat = self.colorPixelFormat;
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    copy.depthPixelFormat = self.depthPixelFormat;
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    copy.stencilPixelFormat = self.stencilPixelFormat;
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    return copy;
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}
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- (NSUInteger)hash
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{
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    NSUInteger sc = _sampleCount & 0x3;
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    NSUInteger cf = _colorPixelFormat & 0x3FF;
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    NSUInteger df = _depthPixelFormat & 0x3FF;
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    NSUInteger sf = _stencilPixelFormat & 0x3FF;
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    NSUInteger hash = (sf << 22) | (df << 12) | (cf << 2) | sc;
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    return hash;
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}
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- (BOOL)isEqual:(id)object
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{
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    FramebufferDescriptor *other = object;
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    if (![other isKindOfClass:[FramebufferDescriptor class]])
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        return NO;
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    return other.sampleCount == self.sampleCount      &&
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    other.colorPixelFormat   == self.colorPixelFormat &&
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    other.depthPixelFormat   == self.depthPixelFormat &&
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    other.stencilPixelFormat == self.stencilPixelFormat;
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}
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@end
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#pragma mark - MetalContext implementation
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@implementation MetalContext
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- (instancetype)init {
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    if ((self = [super init]))
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    {
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        _renderPipelineStateCache = [NSMutableDictionary dictionary];
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        _bufferCache = [NSMutableArray array];
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        _lastBufferCachePurge = [NSDate date].timeIntervalSince1970;
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    }
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    return self;
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}
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- (void)makeDeviceObjectsWithDevice:(id<MTLDevice>)device
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{
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    MTLDepthStencilDescriptor *depthStencilDescriptor = [[MTLDepthStencilDescriptor alloc] init];
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    depthStencilDescriptor.depthWriteEnabled = NO;
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    depthStencilDescriptor.depthCompareFunction = MTLCompareFunctionAlways;
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    self.depthStencilState = [device newDepthStencilStateWithDescriptor:depthStencilDescriptor];
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}
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// We are retrieving and uploading the font atlas as a 4-channels RGBA texture here.
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// In theory we could call GetTexDataAsAlpha8() and upload a 1-channel texture to save on memory access bandwidth.
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// However, using a shader designed for 1-channel texture would make it less obvious to use the ImTextureID facility to render users own textures.
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// You can make that change in your implementation.
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- (void)makeFontTextureWithDevice:(id<MTLDevice>)device
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{
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    ImGuiIO &io = ImGui::GetIO();
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    unsigned char* pixels;
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    int width, height;
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    io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
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    MTLTextureDescriptor *textureDescriptor = [MTLTextureDescriptor texture2DDescriptorWithPixelFormat:MTLPixelFormatRGBA8Unorm
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                                                                                                 width:(NSUInteger)width
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                                                                                                height:(NSUInteger)height
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                                                                                             mipmapped:NO];
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    textureDescriptor.usage = MTLTextureUsageShaderRead;
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#if TARGET_OS_OSX
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    textureDescriptor.storageMode = MTLStorageModeManaged;
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#else
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    textureDescriptor.storageMode = MTLStorageModeShared;
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#endif
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    id <MTLTexture> texture = [device newTextureWithDescriptor:textureDescriptor];
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    [texture replaceRegion:MTLRegionMake2D(0, 0, (NSUInteger)width, (NSUInteger)height) mipmapLevel:0 withBytes:pixels bytesPerRow:(NSUInteger)width * 4];
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    self.fontTexture = texture;
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}
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- (MetalBuffer *)dequeueReusableBufferOfLength:(NSUInteger)length device:(id<MTLDevice>)device
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{
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    NSTimeInterval now = [NSDate date].timeIntervalSince1970;
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    // Purge old buffers that haven't been useful for a while
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    if (now - self.lastBufferCachePurge > 1.0)
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    {
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        NSMutableArray *survivors = [NSMutableArray array];
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        for (MetalBuffer *candidate in self.bufferCache)
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        {
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            if (candidate.lastReuseTime > self.lastBufferCachePurge)
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            {
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                [survivors addObject:candidate];
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            }
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        }
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        self.bufferCache = [survivors mutableCopy];
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        self.lastBufferCachePurge = now;
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    }
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    // See if we have a buffer we can reuse
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    MetalBuffer *bestCandidate = nil;
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    for (MetalBuffer *candidate in self.bufferCache)
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        if (candidate.buffer.length >= length && (bestCandidate == nil || bestCandidate.lastReuseTime > candidate.lastReuseTime))
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            bestCandidate = candidate;
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    if (bestCandidate != nil)
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    {
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        [self.bufferCache removeObject:bestCandidate];
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        bestCandidate.lastReuseTime = now;
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        return bestCandidate;
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    }
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    // No luck; make a new buffer
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    id<MTLBuffer> backing = [device newBufferWithLength:length options:MTLResourceStorageModeShared];
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    return [[MetalBuffer alloc] initWithBuffer:backing];
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}
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- (void)enqueueReusableBuffer:(MetalBuffer *)buffer
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{
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    [self.bufferCache addObject:buffer];
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}
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- (_Nullable id<MTLRenderPipelineState>)renderPipelineStateForFrameAndDevice:(id<MTLDevice>)device
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{
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    // Try to retrieve a render pipeline state that is compatible with the framebuffer config for this frame
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    // The hit rate for this cache should be very near 100%.
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    id<MTLRenderPipelineState> renderPipelineState = self.renderPipelineStateCache[self.framebufferDescriptor];
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    if (renderPipelineState == nil)
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    {
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        // No luck; make a new render pipeline state
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        renderPipelineState = [self _renderPipelineStateForFramebufferDescriptor:self.framebufferDescriptor device:device];
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        // Cache render pipeline state for later reuse
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        self.renderPipelineStateCache[self.framebufferDescriptor] = renderPipelineState;
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    }
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    return renderPipelineState;
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}
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- (id<MTLRenderPipelineState>)_renderPipelineStateForFramebufferDescriptor:(FramebufferDescriptor *)descriptor device:(id<MTLDevice>)device
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{
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    NSError *error = nil;
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    NSString *shaderSource = @""
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    "#include <metal_stdlib>\n"
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    "using namespace metal;\n"
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    "\n"
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    "struct Uniforms {\n"
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    "    float4x4 projectionMatrix;\n"
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    "};\n"
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    "\n"
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    "struct VertexIn {\n"
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    "    float2 position  [[attribute(0)]];\n"
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    "    float2 texCoords [[attribute(1)]];\n"
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    "    uchar4 color     [[attribute(2)]];\n"
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    "};\n"
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    "\n"
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    "struct VertexOut {\n"
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    "    float4 position [[position]];\n"
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    "    float2 texCoords;\n"
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    "    float4 color;\n"
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    "};\n"
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    "\n"
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    "vertex VertexOut vertex_main(VertexIn in                 [[stage_in]],\n"
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    "                             constant Uniforms &uniforms [[buffer(1)]]) {\n"
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    "    VertexOut out;\n"
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    "    out.position = uniforms.projectionMatrix * float4(in.position, 0, 1);\n"
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    "    out.texCoords = in.texCoords;\n"
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    "    out.color = float4(in.color) / float4(255.0);\n"
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    "    return out;\n"
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    "}\n"
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    "\n"
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    "fragment half4 fragment_main(VertexOut in [[stage_in]],\n"
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    "                             texture2d<half, access::sample> texture [[texture(0)]]) {\n"
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    "    constexpr sampler linearSampler(coord::normalized, min_filter::linear, mag_filter::linear, mip_filter::linear);\n"
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    "    half4 texColor = texture.sample(linearSampler, in.texCoords);\n"
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    "    return half4(in.color) * texColor;\n"
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    "}\n";
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    id<MTLLibrary> library = [device newLibraryWithSource:shaderSource options:nil error:&error];
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    if (library == nil)
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    {
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        NSLog(@"Error: failed to create Metal library: %@", error);
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        return nil;
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    }
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    id<MTLFunction> vertexFunction = [library newFunctionWithName:@"vertex_main"];
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    id<MTLFunction> fragmentFunction = [library newFunctionWithName:@"fragment_main"];
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    if (vertexFunction == nil || fragmentFunction == nil)
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    {
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        NSLog(@"Error: failed to find Metal shader functions in library: %@", error);
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        return nil;
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    }
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    MTLVertexDescriptor *vertexDescriptor = [MTLVertexDescriptor vertexDescriptor];
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    vertexDescriptor.attributes[0].offset = IM_OFFSETOF(ImDrawVert, pos);
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    vertexDescriptor.attributes[0].format = MTLVertexFormatFloat2; // position
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    vertexDescriptor.attributes[0].bufferIndex = 0;
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    vertexDescriptor.attributes[1].offset = IM_OFFSETOF(ImDrawVert, uv);
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    vertexDescriptor.attributes[1].format = MTLVertexFormatFloat2; // texCoords
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    vertexDescriptor.attributes[1].bufferIndex = 0;
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    vertexDescriptor.attributes[2].offset = IM_OFFSETOF(ImDrawVert, col);
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    vertexDescriptor.attributes[2].format = MTLVertexFormatUChar4; // color
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    vertexDescriptor.attributes[2].bufferIndex = 0;
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    vertexDescriptor.layouts[0].stepRate = 1;
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    vertexDescriptor.layouts[0].stepFunction = MTLVertexStepFunctionPerVertex;
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    vertexDescriptor.layouts[0].stride = sizeof(ImDrawVert);
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    MTLRenderPipelineDescriptor *pipelineDescriptor = [[MTLRenderPipelineDescriptor alloc] init];
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    pipelineDescriptor.vertexFunction = vertexFunction;
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    pipelineDescriptor.fragmentFunction = fragmentFunction;
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    pipelineDescriptor.vertexDescriptor = vertexDescriptor;
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    pipelineDescriptor.sampleCount = self.framebufferDescriptor.sampleCount;
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    pipelineDescriptor.colorAttachments[0].pixelFormat = self.framebufferDescriptor.colorPixelFormat;
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    pipelineDescriptor.colorAttachments[0].blendingEnabled = YES;
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    pipelineDescriptor.colorAttachments[0].rgbBlendOperation = MTLBlendOperationAdd;
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    pipelineDescriptor.colorAttachments[0].alphaBlendOperation = MTLBlendOperationAdd;
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    pipelineDescriptor.colorAttachments[0].sourceRGBBlendFactor = MTLBlendFactorSourceAlpha;
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						|
    pipelineDescriptor.colorAttachments[0].sourceAlphaBlendFactor = MTLBlendFactorSourceAlpha;
 | 
						|
    pipelineDescriptor.colorAttachments[0].destinationRGBBlendFactor = MTLBlendFactorOneMinusSourceAlpha;
 | 
						|
    pipelineDescriptor.colorAttachments[0].destinationAlphaBlendFactor = MTLBlendFactorOneMinusSourceAlpha;
 | 
						|
    pipelineDescriptor.depthAttachmentPixelFormat = self.framebufferDescriptor.depthPixelFormat;
 | 
						|
    pipelineDescriptor.stencilAttachmentPixelFormat = self.framebufferDescriptor.stencilPixelFormat;
 | 
						|
 | 
						|
    id<MTLRenderPipelineState> renderPipelineState = [device newRenderPipelineStateWithDescriptor:pipelineDescriptor error:&error];
 | 
						|
    if (error != nil)
 | 
						|
    {
 | 
						|
        NSLog(@"Error: failed to create Metal pipeline state: %@", error);
 | 
						|
    }
 | 
						|
 | 
						|
    return renderPipelineState;
 | 
						|
}
 | 
						|
 | 
						|
- (void)emptyRenderPipelineStateCache
 | 
						|
{
 | 
						|
    [self.renderPipelineStateCache removeAllObjects];
 | 
						|
}
 | 
						|
 | 
						|
- (void)setupRenderState:(ImDrawData *)drawData
 | 
						|
           commandBuffer:(id<MTLCommandBuffer>)commandBuffer
 | 
						|
          commandEncoder:(id<MTLRenderCommandEncoder>)commandEncoder
 | 
						|
     renderPipelineState:(id<MTLRenderPipelineState>)renderPipelineState
 | 
						|
            vertexBuffer:(MetalBuffer *)vertexBuffer
 | 
						|
      vertexBufferOffset:(size_t)vertexBufferOffset
 | 
						|
{
 | 
						|
    [commandEncoder setCullMode:MTLCullModeNone];
 | 
						|
    [commandEncoder setDepthStencilState:g_sharedMetalContext.depthStencilState];
 | 
						|
 | 
						|
    // Setup viewport, orthographic projection matrix
 | 
						|
    // Our visible imgui space lies from draw_data->DisplayPos (top left) to
 | 
						|
    // draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayMin is typically (0,0) for single viewport apps.
 | 
						|
    MTLViewport viewport =
 | 
						|
    {
 | 
						|
        .originX = 0.0,
 | 
						|
        .originY = 0.0,
 | 
						|
        .width = (double)(drawData->DisplaySize.x * drawData->FramebufferScale.x),
 | 
						|
        .height = (double)(drawData->DisplaySize.y * drawData->FramebufferScale.y),
 | 
						|
        .znear = 0.0,
 | 
						|
        .zfar = 1.0
 | 
						|
    };
 | 
						|
    [commandEncoder setViewport:viewport];
 | 
						|
 | 
						|
    float L = drawData->DisplayPos.x;
 | 
						|
    float R = drawData->DisplayPos.x + drawData->DisplaySize.x;
 | 
						|
    float T = drawData->DisplayPos.y;
 | 
						|
    float B = drawData->DisplayPos.y + drawData->DisplaySize.y;
 | 
						|
    float N = (float)viewport.znear;
 | 
						|
    float F = (float)viewport.zfar;
 | 
						|
    const float ortho_projection[4][4] =
 | 
						|
    {
 | 
						|
        { 2.0f/(R-L),   0.0f,           0.0f,   0.0f },
 | 
						|
        { 0.0f,         2.0f/(T-B),     0.0f,   0.0f },
 | 
						|
        { 0.0f,         0.0f,        1/(F-N),   0.0f },
 | 
						|
        { (R+L)/(L-R),  (T+B)/(B-T), N/(F-N),   1.0f },
 | 
						|
    };
 | 
						|
    [commandEncoder setVertexBytes:&ortho_projection length:sizeof(ortho_projection) atIndex:1];
 | 
						|
 | 
						|
    [commandEncoder setRenderPipelineState:renderPipelineState];
 | 
						|
 | 
						|
    [commandEncoder setVertexBuffer:vertexBuffer.buffer offset:0 atIndex:0];
 | 
						|
    [commandEncoder setVertexBufferOffset:vertexBufferOffset atIndex:0];
 | 
						|
}
 | 
						|
 | 
						|
- (void)renderDrawData:(ImDrawData *)drawData
 | 
						|
         commandBuffer:(id<MTLCommandBuffer>)commandBuffer
 | 
						|
        commandEncoder:(id<MTLRenderCommandEncoder>)commandEncoder
 | 
						|
{
 | 
						|
    // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
 | 
						|
    int fb_width = (int)(drawData->DisplaySize.x * drawData->FramebufferScale.x);
 | 
						|
    int fb_height = (int)(drawData->DisplaySize.y * drawData->FramebufferScale.y);
 | 
						|
    if (fb_width <= 0 || fb_height <= 0 || drawData->CmdListsCount == 0)
 | 
						|
        return;
 | 
						|
 | 
						|
    id<MTLRenderPipelineState> renderPipelineState = [self renderPipelineStateForFrameAndDevice:commandBuffer.device];
 | 
						|
 | 
						|
    size_t vertexBufferLength = (size_t)drawData->TotalVtxCount * sizeof(ImDrawVert);
 | 
						|
    size_t indexBufferLength = (size_t)drawData->TotalIdxCount * sizeof(ImDrawIdx);
 | 
						|
    MetalBuffer* vertexBuffer = [self dequeueReusableBufferOfLength:vertexBufferLength device:commandBuffer.device];
 | 
						|
    MetalBuffer* indexBuffer = [self dequeueReusableBufferOfLength:indexBufferLength device:commandBuffer.device];
 | 
						|
 | 
						|
    [self setupRenderState:drawData commandBuffer:commandBuffer commandEncoder:commandEncoder renderPipelineState:renderPipelineState vertexBuffer:vertexBuffer vertexBufferOffset:0];
 | 
						|
 | 
						|
    // Will project scissor/clipping rectangles into framebuffer space
 | 
						|
    ImVec2 clip_off = drawData->DisplayPos;         // (0,0) unless using multi-viewports
 | 
						|
    ImVec2 clip_scale = drawData->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
 | 
						|
 | 
						|
    // Render command lists
 | 
						|
    size_t vertexBufferOffset = 0;
 | 
						|
    size_t indexBufferOffset = 0;
 | 
						|
    for (int n = 0; n < drawData->CmdListsCount; n++)
 | 
						|
    {
 | 
						|
        const ImDrawList* cmd_list = drawData->CmdLists[n];
 | 
						|
 | 
						|
        memcpy((char *)vertexBuffer.buffer.contents + vertexBufferOffset, cmd_list->VtxBuffer.Data, (size_t)cmd_list->VtxBuffer.Size * sizeof(ImDrawVert));
 | 
						|
        memcpy((char *)indexBuffer.buffer.contents + indexBufferOffset, cmd_list->IdxBuffer.Data, (size_t)cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx));
 | 
						|
 | 
						|
        for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
 | 
						|
        {
 | 
						|
            const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
 | 
						|
            if (pcmd->UserCallback)
 | 
						|
            {
 | 
						|
                // User callback, registered via ImDrawList::AddCallback()
 | 
						|
                // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
 | 
						|
                if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
 | 
						|
                    [self setupRenderState:drawData commandBuffer:commandBuffer commandEncoder:commandEncoder renderPipelineState:renderPipelineState vertexBuffer:vertexBuffer vertexBufferOffset:vertexBufferOffset];
 | 
						|
                else
 | 
						|
                    pcmd->UserCallback(cmd_list, pcmd);
 | 
						|
            }
 | 
						|
            else
 | 
						|
            {
 | 
						|
                // Project scissor/clipping rectangles into framebuffer space
 | 
						|
                ImVec4 clip_rect;
 | 
						|
                clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
 | 
						|
                clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
 | 
						|
                clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
 | 
						|
                clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
 | 
						|
 | 
						|
                if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
 | 
						|
                {
 | 
						|
                    // Apply scissor/clipping rectangle
 | 
						|
                    MTLScissorRect scissorRect =
 | 
						|
                    {
 | 
						|
                        .x = NSUInteger(clip_rect.x),
 | 
						|
                        .y = NSUInteger(clip_rect.y),
 | 
						|
                        .width = NSUInteger(clip_rect.z - clip_rect.x),
 | 
						|
                        .height = NSUInteger(clip_rect.w - clip_rect.y)
 | 
						|
                    };
 | 
						|
                    [commandEncoder setScissorRect:scissorRect];
 | 
						|
 | 
						|
 | 
						|
                    // Bind texture, Draw
 | 
						|
                    if (pcmd->TextureId != NULL)
 | 
						|
                        [commandEncoder setFragmentTexture:(__bridge id<MTLTexture>)(pcmd->TextureId) atIndex:0];
 | 
						|
 | 
						|
                    [commandEncoder setVertexBufferOffset:(vertexBufferOffset + pcmd->VtxOffset * sizeof(ImDrawVert)) atIndex:0];
 | 
						|
                    [commandEncoder drawIndexedPrimitives:MTLPrimitiveTypeTriangle
 | 
						|
                                               indexCount:pcmd->ElemCount
 | 
						|
                                                indexType:sizeof(ImDrawIdx) == 2 ? MTLIndexTypeUInt16 : MTLIndexTypeUInt32
 | 
						|
                                              indexBuffer:indexBuffer.buffer
 | 
						|
                                        indexBufferOffset:indexBufferOffset + pcmd->IdxOffset * sizeof(ImDrawIdx)];
 | 
						|
                }
 | 
						|
            }
 | 
						|
        }
 | 
						|
 | 
						|
        vertexBufferOffset += (size_t)cmd_list->VtxBuffer.Size * sizeof(ImDrawVert);
 | 
						|
        indexBufferOffset += (size_t)cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx);
 | 
						|
    }
 | 
						|
 | 
						|
    __weak id weakSelf = self;
 | 
						|
    [commandBuffer addCompletedHandler:^(id<MTLCommandBuffer>)
 | 
						|
    {
 | 
						|
        dispatch_async(dispatch_get_main_queue(), ^{
 | 
						|
            [weakSelf enqueueReusableBuffer:vertexBuffer];
 | 
						|
            [weakSelf enqueueReusableBuffer:indexBuffer];
 | 
						|
        });
 | 
						|
    }];
 | 
						|
}
 | 
						|
 | 
						|
@end
 |