| // dear imgui: Renderer Backend for Metal |
| // This needs to be used along with a Platform Backend (e.g. OSX) |
| |
| // Implemented features: |
| // [X] Renderer: User texture binding. Use 'MTLTexture' as ImTextureID. Read the FAQ about ImTextureID! |
| // [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices. |
| |
| // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this. |
| // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need. |
| // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp. |
| // Read online: https://github.com/ocornut/imgui/tree/master/docs |
| |
| // CHANGELOG |
| // (minor and older changes stripped away, please see git history for details) |
| // 2022-08-23: Metal: Update deprecated property 'sampleCount'->'rasterSampleCount'. |
| // 2022-07-05: Metal: Add dispatch synchronization. |
| // 2022-06-30: Metal: Use __bridge for ARC based systems. |
| // 2022-06-01: Metal: Fixed null dereference on exit inside command buffer completion handler. |
| // 2022-04-27: Misc: Store backend data in a per-context struct, allowing to use this backend with multiple contexts. |
| // 2022-01-03: Metal: Ignore ImDrawCmd where ElemCount == 0 (very rare but can technically be manufactured by user code). |
| // 2021-12-30: Metal: Added Metal C++ support. Enable with '#define IMGUI_IMPL_METAL_CPP' in your imconfig.h file. |
| // 2021-08-24: Metal: Fixed a crash when clipping rect larger than framebuffer is submitted. (#4464) |
| // 2021-05-19: Metal: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement) |
| // 2021-02-18: Metal: Change blending equation to preserve alpha in output buffer. |
| // 2021-01-25: Metal: Fixed texture storage mode when building on Mac Catalyst. |
| // 2019-05-29: Metal: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag. |
| // 2019-04-30: Metal: Added support for special ImDrawCallback_ResetRenderState callback to reset render state. |
| // 2019-02-11: Metal: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display. |
| // 2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window. |
| // 2018-07-05: Metal: Added new Metal backend implementation. |
| |
| #include "imgui.h" |
| #include "imgui_impl_metal.h" |
| #import <time.h> |
| #import <Metal/Metal.h> |
| |
| #pragma mark - Support classes |
| |
| // A wrapper around a MTLBuffer object that knows the last time it was reused |
| @interface MetalBuffer : NSObject |
| @property (nonatomic, strong) id<MTLBuffer> buffer; |
| @property (nonatomic, assign) double lastReuseTime; |
| - (instancetype)initWithBuffer:(id<MTLBuffer>)buffer; |
| @end |
| |
| // An object that encapsulates the data necessary to uniquely identify a |
| // render pipeline state. These are used as cache keys. |
| @interface FramebufferDescriptor : NSObject<NSCopying> |
| @property (nonatomic, assign) unsigned long sampleCount; |
| @property (nonatomic, assign) MTLPixelFormat colorPixelFormat; |
| @property (nonatomic, assign) MTLPixelFormat depthPixelFormat; |
| @property (nonatomic, assign) MTLPixelFormat stencilPixelFormat; |
| - (instancetype)initWithRenderPassDescriptor:(MTLRenderPassDescriptor*)renderPassDescriptor; |
| @end |
| |
| // A singleton that stores long-lived objects that are needed by the Metal |
| // renderer backend. Stores the render pipeline state cache and the default |
| // font texture, and manages the reusable buffer cache. |
| @interface MetalContext : NSObject |
| @property (nonatomic, strong) id<MTLDevice> device; |
| @property (nonatomic, strong) id<MTLDepthStencilState> depthStencilState; |
| @property (nonatomic, strong) FramebufferDescriptor* framebufferDescriptor; // framebuffer descriptor for current frame; transient |
| @property (nonatomic, strong) NSMutableDictionary* renderPipelineStateCache; // pipeline cache; keyed on framebuffer descriptors |
| @property (nonatomic, strong, nullable) id<MTLTexture> fontTexture; |
| @property (nonatomic, strong) NSMutableArray<MetalBuffer*>* bufferCache; |
| @property (nonatomic, assign) double lastBufferCachePurge; |
| - (MetalBuffer*)dequeueReusableBufferOfLength:(NSUInteger)length device:(id<MTLDevice>)device; |
| - (id<MTLRenderPipelineState>)renderPipelineStateForFramebufferDescriptor:(FramebufferDescriptor*)descriptor device:(id<MTLDevice>)device; |
| @end |
| |
| struct ImGui_ImplMetal_Data |
| { |
| MetalContext* SharedMetalContext; |
| |
| ImGui_ImplMetal_Data() { memset(this, 0, sizeof(*this)); } |
| }; |
| |
| static ImGui_ImplMetal_Data* ImGui_ImplMetal_CreateBackendData() { return IM_NEW(ImGui_ImplMetal_Data)(); } |
| static ImGui_ImplMetal_Data* ImGui_ImplMetal_GetBackendData() { return ImGui::GetCurrentContext() ? (ImGui_ImplMetal_Data*)ImGui::GetIO().BackendRendererUserData : nullptr; } |
| static void ImGui_ImplMetal_DestroyBackendData(){ IM_DELETE(ImGui_ImplMetal_GetBackendData()); } |
| |
| static inline CFTimeInterval GetMachAbsoluteTimeInSeconds() { return (CFTimeInterval)(double)(clock_gettime_nsec_np(CLOCK_UPTIME_RAW) / 1e9); } |
| |
| #ifdef IMGUI_IMPL_METAL_CPP |
| |
| #pragma mark - Dear ImGui Metal C++ Backend API |
| |
| bool ImGui_ImplMetal_Init(MTL::Device* device) |
| { |
| return ImGui_ImplMetal_Init((__bridge id<MTLDevice>)(device)); |
| } |
| |
| void ImGui_ImplMetal_NewFrame(MTL::RenderPassDescriptor* renderPassDescriptor) |
| { |
| ImGui_ImplMetal_NewFrame((__bridge MTLRenderPassDescriptor*)(renderPassDescriptor)); |
| } |
| |
| void ImGui_ImplMetal_RenderDrawData(ImDrawData* draw_data, |
| MTL::CommandBuffer* commandBuffer, |
| MTL::RenderCommandEncoder* commandEncoder) |
| { |
| ImGui_ImplMetal_RenderDrawData(draw_data, |
| (__bridge id<MTLCommandBuffer>)(commandBuffer), |
| (__bridge id<MTLRenderCommandEncoder>)(commandEncoder)); |
| |
| } |
| |
| bool ImGui_ImplMetal_CreateFontsTexture(MTL::Device* device) |
| { |
| return ImGui_ImplMetal_CreateFontsTexture((__bridge id<MTLDevice>)(device)); |
| } |
| |
| bool ImGui_ImplMetal_CreateDeviceObjects(MTL::Device* device) |
| { |
| return ImGui_ImplMetal_CreateDeviceObjects((__bridge id<MTLDevice>)(device)); |
| } |
| |
| #endif // #ifdef IMGUI_IMPL_METAL_CPP |
| |
| #pragma mark - Dear ImGui Metal Backend API |
| |
| bool ImGui_ImplMetal_Init(id<MTLDevice> device) |
| { |
| ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_CreateBackendData(); |
| ImGuiIO& io = ImGui::GetIO(); |
| io.BackendRendererUserData = (void*)bd; |
| io.BackendRendererName = "imgui_impl_metal"; |
| io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes. |
| |
| bd->SharedMetalContext = [[MetalContext alloc] init]; |
| bd->SharedMetalContext.device = device; |
| |
| return true; |
| } |
| |
| void ImGui_ImplMetal_Shutdown() |
| { |
| ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData(); |
| IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?"); |
| ImGui_ImplMetal_DestroyDeviceObjects(); |
| ImGui_ImplMetal_DestroyBackendData(); |
| |
| ImGuiIO& io = ImGui::GetIO(); |
| io.BackendRendererName = nullptr; |
| io.BackendRendererUserData = nullptr; |
| io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset; |
| } |
| |
| void ImGui_ImplMetal_NewFrame(MTLRenderPassDescriptor* renderPassDescriptor) |
| { |
| ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData(); |
| IM_ASSERT(bd->SharedMetalContext != nil && "No Metal context. Did you call ImGui_ImplMetal_Init() ?"); |
| bd->SharedMetalContext.framebufferDescriptor = [[FramebufferDescriptor alloc] initWithRenderPassDescriptor:renderPassDescriptor]; |
| |
| if (bd->SharedMetalContext.depthStencilState == nil) |
| ImGui_ImplMetal_CreateDeviceObjects(bd->SharedMetalContext.device); |
| } |
| |
| static void ImGui_ImplMetal_SetupRenderState(ImDrawData* drawData, id<MTLCommandBuffer> commandBuffer, |
| id<MTLRenderCommandEncoder> commandEncoder, id<MTLRenderPipelineState> renderPipelineState, |
| MetalBuffer* vertexBuffer, size_t vertexBufferOffset) |
| { |
| IM_UNUSED(commandBuffer); |
| ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData(); |
| [commandEncoder setCullMode:MTLCullModeNone]; |
| [commandEncoder setDepthStencilState:bd->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]; |
| } |
| |
| // Metal Render function. |
| void ImGui_ImplMetal_RenderDrawData(ImDrawData* drawData, id<MTLCommandBuffer> commandBuffer, id<MTLRenderCommandEncoder> commandEncoder) |
| { |
| ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData(); |
| MetalContext* ctx = bd->SharedMetalContext; |
| |
| // 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; |
| |
| // Try to retrieve a render pipeline state that is compatible with the framebuffer config for this frame |
| // The hit rate for this cache should be very near 100%. |
| id<MTLRenderPipelineState> renderPipelineState = ctx.renderPipelineStateCache[ctx.framebufferDescriptor]; |
| if (renderPipelineState == nil) |
| { |
| // No luck; make a new render pipeline state |
| renderPipelineState = [ctx renderPipelineStateForFramebufferDescriptor:ctx.framebufferDescriptor device:commandBuffer.device]; |
| |
| // Cache render pipeline state for later reuse |
| ctx.renderPipelineStateCache[ctx.framebufferDescriptor] = renderPipelineState; |
| } |
| |
| size_t vertexBufferLength = (size_t)drawData->TotalVtxCount * sizeof(ImDrawVert); |
| size_t indexBufferLength = (size_t)drawData->TotalIdxCount * sizeof(ImDrawIdx); |
| MetalBuffer* vertexBuffer = [ctx dequeueReusableBufferOfLength:vertexBufferLength device:commandBuffer.device]; |
| MetalBuffer* indexBuffer = [ctx dequeueReusableBufferOfLength:indexBufferLength device:commandBuffer.device]; |
| |
| ImGui_ImplMetal_SetupRenderState(drawData, commandBuffer, commandEncoder, renderPipelineState, vertexBuffer, 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) |
| ImGui_ImplMetal_SetupRenderState(drawData, commandBuffer, commandEncoder, renderPipelineState, vertexBuffer, 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; |
| if (pcmd->ElemCount == 0) // drawIndexedPrimitives() validation doesn't accept this |
| 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); |
| } |
| |
| [commandBuffer addCompletedHandler:^(id<MTLCommandBuffer>) |
| { |
| dispatch_async(dispatch_get_main_queue(), ^{ |
| ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData(); |
| if (bd != nullptr) |
| { |
| @synchronized(bd->SharedMetalContext.bufferCache) |
| { |
| [bd->SharedMetalContext.bufferCache addObject:vertexBuffer]; |
| [bd->SharedMetalContext.bufferCache addObject:indexBuffer]; |
| } |
| } |
| }); |
| }]; |
| } |
| |
| bool ImGui_ImplMetal_CreateFontsTexture(id<MTLDevice> device) |
| { |
| ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData(); |
| ImGuiIO& io = ImGui::GetIO(); |
| |
| // We are retrieving and uploading the font atlas as a 4-channels RGBA texture here. |
| // In theory we could call GetTexDataAsAlpha8() and upload a 1-channel texture to save on memory access bandwidth. |
| // However, using a shader designed for 1-channel texture would make it less obvious to use the ImTextureID facility to render users own textures. |
| // You can make that change in your implementation. |
| unsigned char* pixels; |
| int width, height; |
| io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); |
| MTLTextureDescriptor* textureDescriptor = [MTLTextureDescriptor texture2DDescriptorWithPixelFormat:MTLPixelFormatRGBA8Unorm |
| width:(NSUInteger)width |
| height:(NSUInteger)height |
| mipmapped:NO]; |
| textureDescriptor.usage = MTLTextureUsageShaderRead; |
| #if TARGET_OS_OSX || TARGET_OS_MACCATALYST |
| textureDescriptor.storageMode = MTLStorageModeManaged; |
| #else |
| textureDescriptor.storageMode = MTLStorageModeShared; |
| #endif |
| id <MTLTexture> texture = [device newTextureWithDescriptor:textureDescriptor]; |
| [texture replaceRegion:MTLRegionMake2D(0, 0, (NSUInteger)width, (NSUInteger)height) mipmapLevel:0 withBytes:pixels bytesPerRow:(NSUInteger)width * 4]; |
| bd->SharedMetalContext.fontTexture = texture; |
| io.Fonts->SetTexID((__bridge void*)bd->SharedMetalContext.fontTexture); // ImTextureID == void* |
| |
| return (bd->SharedMetalContext.fontTexture != nil); |
| } |
| |
| void ImGui_ImplMetal_DestroyFontsTexture() |
| { |
| ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData(); |
| ImGuiIO& io = ImGui::GetIO(); |
| bd->SharedMetalContext.fontTexture = nil; |
| io.Fonts->SetTexID(0); |
| } |
| |
| bool ImGui_ImplMetal_CreateDeviceObjects(id<MTLDevice> device) |
| { |
| ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData(); |
| MTLDepthStencilDescriptor* depthStencilDescriptor = [[MTLDepthStencilDescriptor alloc] init]; |
| depthStencilDescriptor.depthWriteEnabled = NO; |
| depthStencilDescriptor.depthCompareFunction = MTLCompareFunctionAlways; |
| bd->SharedMetalContext.depthStencilState = [device newDepthStencilStateWithDescriptor:depthStencilDescriptor]; |
| ImGui_ImplMetal_CreateFontsTexture(device); |
| |
| return true; |
| } |
| |
| void ImGui_ImplMetal_DestroyDeviceObjects() |
| { |
| ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData(); |
| ImGui_ImplMetal_DestroyFontsTexture(); |
| [bd->SharedMetalContext.renderPipelineStateCache removeAllObjects]; |
| } |
| |
| #pragma mark - MetalBuffer implementation |
| |
| @implementation MetalBuffer |
| - (instancetype)initWithBuffer:(id<MTLBuffer>)buffer |
| { |
| if ((self = [super init])) |
| { |
| _buffer = buffer; |
| _lastReuseTime = GetMachAbsoluteTimeInSeconds(); |
| } |
| return self; |
| } |
| @end |
| |
| #pragma mark - FramebufferDescriptor implementation |
| |
| @implementation FramebufferDescriptor |
| - (instancetype)initWithRenderPassDescriptor:(MTLRenderPassDescriptor*)renderPassDescriptor |
| { |
| if ((self = [super init])) |
| { |
| _sampleCount = renderPassDescriptor.colorAttachments[0].texture.sampleCount; |
| _colorPixelFormat = renderPassDescriptor.colorAttachments[0].texture.pixelFormat; |
| _depthPixelFormat = renderPassDescriptor.depthAttachment.texture.pixelFormat; |
| _stencilPixelFormat = renderPassDescriptor.stencilAttachment.texture.pixelFormat; |
| } |
| return self; |
| } |
| |
| - (nonnull id)copyWithZone:(nullable NSZone*)zone |
| { |
| FramebufferDescriptor* copy = [[FramebufferDescriptor allocWithZone:zone] init]; |
| copy.sampleCount = self.sampleCount; |
| copy.colorPixelFormat = self.colorPixelFormat; |
| copy.depthPixelFormat = self.depthPixelFormat; |
| copy.stencilPixelFormat = self.stencilPixelFormat; |
| return copy; |
| } |
| |
| - (NSUInteger)hash |
| { |
| NSUInteger sc = _sampleCount & 0x3; |
| NSUInteger cf = _colorPixelFormat & 0x3FF; |
| NSUInteger df = _depthPixelFormat & 0x3FF; |
| NSUInteger sf = _stencilPixelFormat & 0x3FF; |
| NSUInteger hash = (sf << 22) | (df << 12) | (cf << 2) | sc; |
| return hash; |
| } |
| |
| - (BOOL)isEqual:(id)object |
| { |
| FramebufferDescriptor* other = object; |
| if (![other isKindOfClass:[FramebufferDescriptor class]]) |
| return NO; |
| return other.sampleCount == self.sampleCount && |
| other.colorPixelFormat == self.colorPixelFormat && |
| other.depthPixelFormat == self.depthPixelFormat && |
| other.stencilPixelFormat == self.stencilPixelFormat; |
| } |
| |
| @end |
| |
| #pragma mark - MetalContext implementation |
| |
| @implementation MetalContext |
| - (instancetype)init |
| { |
| if ((self = [super init])) |
| { |
| self.renderPipelineStateCache = [NSMutableDictionary dictionary]; |
| self.bufferCache = [NSMutableArray array]; |
| _lastBufferCachePurge = GetMachAbsoluteTimeInSeconds(); |
| } |
| return self; |
| } |
| |
| - (MetalBuffer*)dequeueReusableBufferOfLength:(NSUInteger)length device:(id<MTLDevice>)device |
| { |
| uint64_t now = GetMachAbsoluteTimeInSeconds(); |
| |
| @synchronized(self.bufferCache) |
| { |
| // Purge old buffers that haven't been useful for a while |
| if (now - self.lastBufferCachePurge > 1.0) |
| { |
| NSMutableArray* survivors = [NSMutableArray array]; |
| for (MetalBuffer* candidate in self.bufferCache) |
| if (candidate.lastReuseTime > self.lastBufferCachePurge) |
| [survivors addObject:candidate]; |
| self.bufferCache = [survivors mutableCopy]; |
| self.lastBufferCachePurge = now; |
| } |
| |
| // See if we have a buffer we can reuse |
| MetalBuffer* bestCandidate = nil; |
| for (MetalBuffer* candidate in self.bufferCache) |
| if (candidate.buffer.length >= length && (bestCandidate == nil || bestCandidate.lastReuseTime > candidate.lastReuseTime)) |
| bestCandidate = candidate; |
| |
| if (bestCandidate != nil) |
| { |
| [self.bufferCache removeObject:bestCandidate]; |
| bestCandidate.lastReuseTime = now; |
| return bestCandidate; |
| } |
| } |
| |
| // No luck; make a new buffer |
| id<MTLBuffer> backing = [device newBufferWithLength:length options:MTLResourceStorageModeShared]; |
| return [[MetalBuffer alloc] initWithBuffer:backing]; |
| } |
| |
| // Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling. |
| - (id<MTLRenderPipelineState>)renderPipelineStateForFramebufferDescriptor:(FramebufferDescriptor*)descriptor device:(id<MTLDevice>)device |
| { |
| NSError* error = nil; |
| |
| NSString* shaderSource = @"" |
| "#include <metal_stdlib>\n" |
| "using namespace metal;\n" |
| "\n" |
| "struct Uniforms {\n" |
| " float4x4 projectionMatrix;\n" |
| "};\n" |
| "\n" |
| "struct VertexIn {\n" |
| " float2 position [[attribute(0)]];\n" |
| " float2 texCoords [[attribute(1)]];\n" |
| " uchar4 color [[attribute(2)]];\n" |
| "};\n" |
| "\n" |
| "struct VertexOut {\n" |
| " float4 position [[position]];\n" |
| " float2 texCoords;\n" |
| " float4 color;\n" |
| "};\n" |
| "\n" |
| "vertex VertexOut vertex_main(VertexIn in [[stage_in]],\n" |
| " constant Uniforms &uniforms [[buffer(1)]]) {\n" |
| " VertexOut out;\n" |
| " out.position = uniforms.projectionMatrix * float4(in.position, 0, 1);\n" |
| " out.texCoords = in.texCoords;\n" |
| " out.color = float4(in.color) / float4(255.0);\n" |
| " return out;\n" |
| "}\n" |
| "\n" |
| "fragment half4 fragment_main(VertexOut in [[stage_in]],\n" |
| " texture2d<half, access::sample> texture [[texture(0)]]) {\n" |
| " constexpr sampler linearSampler(coord::normalized, min_filter::linear, mag_filter::linear, mip_filter::linear);\n" |
| " half4 texColor = texture.sample(linearSampler, in.texCoords);\n" |
| " return half4(in.color) * texColor;\n" |
| "}\n"; |
| |
| id<MTLLibrary> library = [device newLibraryWithSource:shaderSource options:nil error:&error]; |
| if (library == nil) |
| { |
| NSLog(@"Error: failed to create Metal library: %@", error); |
| return nil; |
| } |
| |
| id<MTLFunction> vertexFunction = [library newFunctionWithName:@"vertex_main"]; |
| id<MTLFunction> fragmentFunction = [library newFunctionWithName:@"fragment_main"]; |
| |
| if (vertexFunction == nil || fragmentFunction == nil) |
| { |
| NSLog(@"Error: failed to find Metal shader functions in library: %@", error); |
| return nil; |
| } |
| |
| MTLVertexDescriptor* vertexDescriptor = [MTLVertexDescriptor vertexDescriptor]; |
| vertexDescriptor.attributes[0].offset = IM_OFFSETOF(ImDrawVert, pos); |
| vertexDescriptor.attributes[0].format = MTLVertexFormatFloat2; // position |
| vertexDescriptor.attributes[0].bufferIndex = 0; |
| vertexDescriptor.attributes[1].offset = IM_OFFSETOF(ImDrawVert, uv); |
| vertexDescriptor.attributes[1].format = MTLVertexFormatFloat2; // texCoords |
| vertexDescriptor.attributes[1].bufferIndex = 0; |
| vertexDescriptor.attributes[2].offset = IM_OFFSETOF(ImDrawVert, col); |
| vertexDescriptor.attributes[2].format = MTLVertexFormatUChar4; // color |
| vertexDescriptor.attributes[2].bufferIndex = 0; |
| vertexDescriptor.layouts[0].stepRate = 1; |
| vertexDescriptor.layouts[0].stepFunction = MTLVertexStepFunctionPerVertex; |
| vertexDescriptor.layouts[0].stride = sizeof(ImDrawVert); |
| |
| MTLRenderPipelineDescriptor* pipelineDescriptor = [[MTLRenderPipelineDescriptor alloc] init]; |
| pipelineDescriptor.vertexFunction = vertexFunction; |
| pipelineDescriptor.fragmentFunction = fragmentFunction; |
| pipelineDescriptor.vertexDescriptor = vertexDescriptor; |
| pipelineDescriptor.rasterSampleCount = self.framebufferDescriptor.sampleCount; |
| pipelineDescriptor.colorAttachments[0].pixelFormat = self.framebufferDescriptor.colorPixelFormat; |
| pipelineDescriptor.colorAttachments[0].blendingEnabled = YES; |
| pipelineDescriptor.colorAttachments[0].rgbBlendOperation = MTLBlendOperationAdd; |
| pipelineDescriptor.colorAttachments[0].sourceRGBBlendFactor = MTLBlendFactorSourceAlpha; |
| pipelineDescriptor.colorAttachments[0].destinationRGBBlendFactor = MTLBlendFactorOneMinusSourceAlpha; |
| pipelineDescriptor.colorAttachments[0].alphaBlendOperation = MTLBlendOperationAdd; |
| pipelineDescriptor.colorAttachments[0].sourceAlphaBlendFactor = MTLBlendFactorOne; |
| 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; |
| } |
| |
| @end |