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Diffstat (limited to 'src/imgui/backends/imgui_impl_metal.mm')
-rw-r--r-- | src/imgui/backends/imgui_impl_metal.mm | 590 |
1 files changed, 590 insertions, 0 deletions
diff --git a/src/imgui/backends/imgui_impl_metal.mm b/src/imgui/backends/imgui_impl_metal.mm new file mode 100644 index 0000000..fd5686b --- /dev/null +++ b/src/imgui/backends/imgui_impl_metal.mm @@ -0,0 +1,590 @@ +// 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. +// Learn about Dear ImGui: +// - FAQ https://dearimgui.com/faq +// - Getting Started https://dearimgui.com/getting-started +// - Documentation https://dearimgui.com/docs (same as your local docs/ folder). +// - Introduction, links and more at the top of imgui.cpp + +// 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" +#ifndef IMGUI_DISABLE +#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 = offsetof(ImDrawVert, pos); + vertexDescriptor.attributes[0].format = MTLVertexFormatFloat2; // position + vertexDescriptor.attributes[0].bufferIndex = 0; + vertexDescriptor.attributes[1].offset = offsetof(ImDrawVert, uv); + vertexDescriptor.attributes[1].format = MTLVertexFormatFloat2; // texCoords + vertexDescriptor.attributes[1].bufferIndex = 0; + vertexDescriptor.attributes[2].offset = 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 + +//----------------------------------------------------------------------------- + +#endif // #ifndef IMGUI_DISABLE |