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			557 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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| 
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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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| 
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| // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
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| // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
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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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| 
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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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| //  2021-08-24: Metal: Fixed a crash when clipping rect larger than framebuffer is submitted. (#4464)
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| //  2021-05-19: Metal: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
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| //  2021-02-18: Metal: Change blending equation to preserve alpha in output buffer.
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| //  2021-01-25: Metal: Fixed texture storage mode when building on Mac Catalyst.
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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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| 
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| #include "imgui.h"
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| #include "imgui_impl_metal.h"
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| 
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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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| 
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| #pragma mark - Support classes
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| 
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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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| 
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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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| 
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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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| 
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| static MetalContext *g_sharedMetalContext = nil;
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| 
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| #pragma mark - ImGui API implementation
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| 
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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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| 
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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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| 
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|     ImGui_ImplMetal_CreateDeviceObjects(device);
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| 
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|     return true;
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| }
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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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| 
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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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| 
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|     g_sharedMetalContext.framebufferDescriptor = [[FramebufferDescriptor alloc] initWithRenderPassDescriptor:renderPassDescriptor];
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| }
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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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| 
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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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| 
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|     ImGuiIO& io = ImGui::GetIO();
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|     io.Fonts->SetTexID((__bridge void *)g_sharedMetalContext.fontTexture); // ImTextureID == void*
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| 
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|     return (g_sharedMetalContext.fontTexture != nil);
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| }
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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->SetTexID(nullptr);
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| }
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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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| 
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|     ImGui_ImplMetal_CreateFontsTexture(device);
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| 
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|     return true;
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| }
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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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| 
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| #pragma mark - MetalBuffer implementation
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| 
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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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| 
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| #pragma mark - FramebufferDescriptor implementation
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| @end
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| 
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| #pragma mark - MetalContext implementation
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| 
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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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| 
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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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| 
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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 || TARGET_OS_MACCATALYST
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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|     return renderPipelineState;
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| }
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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;
 | |
|     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].sourceRGBBlendFactor = MTLBlendFactorSourceAlpha;
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|     pipelineDescriptor.colorAttachments[0].destinationRGBBlendFactor = MTLBlendFactorOneMinusSourceAlpha;
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|     pipelineDescriptor.colorAttachments[0].alphaBlendOperation = MTLBlendOperationAdd;
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|     pipelineDescriptor.colorAttachments[0].sourceAlphaBlendFactor = MTLBlendFactorOne;
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|     pipelineDescriptor.colorAttachments[0].destinationAlphaBlendFactor = MTLBlendFactorOneMinusSourceAlpha;
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|     pipelineDescriptor.depthAttachmentPixelFormat = self.framebufferDescriptor.depthPixelFormat;
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|     pipelineDescriptor.stencilAttachmentPixelFormat = self.framebufferDescriptor.stencilPixelFormat;
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| 
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|     id<MTLRenderPipelineState> renderPipelineState = [device newRenderPipelineStateWithDescriptor:pipelineDescriptor error:&error];
 | |
|     if (error != nil)
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|     {
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|         NSLog(@"Error: failed to create Metal pipeline state: %@", error);
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|     }
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| 
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|     return renderPipelineState;
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| }
 | |
| 
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| - (void)emptyRenderPipelineStateCache
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| {
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|     [self.renderPipelineStateCache removeAllObjects];
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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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| {
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|     [commandEncoder setCullMode:MTLCullModeNone];
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|     [commandEncoder setDepthStencilState:g_sharedMetalContext.depthStencilState];
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| 
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|     // Setup viewport, orthographic projection matrix
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|     // Our visible imgui space lies from draw_data->DisplayPos (top left) to
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|     // draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayMin is typically (0,0) for single viewport apps.
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|     MTLViewport viewport =
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|     {
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|         .originX = 0.0,
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|         .originY = 0.0,
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|         .width = (double)(drawData->DisplaySize.x * drawData->FramebufferScale.x),
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|         .height = (double)(drawData->DisplaySize.y * drawData->FramebufferScale.y),
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|         .znear = 0.0,
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|         .zfar = 1.0
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|     };
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|     [commandEncoder setViewport:viewport];
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| 
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|     float L = drawData->DisplayPos.x;
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|     float R = drawData->DisplayPos.x + drawData->DisplaySize.x;
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|     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
 | |
|                 ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
 | |
|                 ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
 | |
| 
 | |
|                 // Clamp to viewport as setScissorRect() won't accept values that are off bounds
 | |
|                 if (clip_min.x < 0.0f) { clip_min.x = 0.0f; }
 | |
|                 if (clip_min.y < 0.0f) { clip_min.y = 0.0f; }
 | |
|                 if (clip_max.x > fb_width) { clip_max.x = (float)fb_width; }
 | |
|                 if (clip_max.y > fb_height) { clip_max.y = (float)fb_height; }
 | |
|                 if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
 | |
|                     continue;
 | |
| 
 | |
|                 // Apply scissor/clipping rectangle
 | |
|                 MTLScissorRect scissorRect =
 | |
|                 {
 | |
|                     .x = NSUInteger(clip_min.x),
 | |
|                     .y = NSUInteger(clip_min.y),
 | |
|                     .width = NSUInteger(clip_max.x - clip_min.x),
 | |
|                     .height = NSUInteger(clip_max.y - clip_min.y)
 | |
|                 };
 | |
|                 [commandEncoder setScissorRect:scissorRect];
 | |
| 
 | |
|                 // Bind texture, Draw
 | |
|                 if (ImTextureID tex_id = pcmd->GetTexID())
 | |
|                     [commandEncoder setFragmentTexture:(__bridge id<MTLTexture>)(tex_id) 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
 | 
