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Diffstat (limited to '3rdparty/imgui/examples/imgui_impl_metal.mm')
| -rw-r--r-- | 3rdparty/imgui/examples/imgui_impl_metal.mm | 517 |
1 files changed, 517 insertions, 0 deletions
diff --git a/3rdparty/imgui/examples/imgui_impl_metal.mm b/3rdparty/imgui/examples/imgui_impl_metal.mm new file mode 100644 index 00000000..fc6254c0 --- /dev/null +++ b/3rdparty/imgui/examples/imgui_impl_metal.mm @@ -0,0 +1,517 @@ +// dear imgui: Renderer for Metal +// This needs to be used along with a Platform Binding (e.g. OSX) + +// Implemented features: +// [X] Renderer: User texture binding. Use 'MTLTexture' as ImTextureID. Read the FAQ about ImTextureID in imgui.cpp. + +// You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this. +// If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp. +// https://github.com/ocornut/imgui + +// CHANGELOG +// (minor and older changes stripped away, please see git history for details) +// 2018-07-05: Metal: Added new Metal backend implementation. + +#include "imgui.h" +#include "imgui_impl_metal.h" + +#import <Metal/Metal.h> +#import <QuartzCore/CAMetalLayer.h> +#import <simd/simd.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) NSTimeInterval 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<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) NSTimeInterval lastBufferCachePurge; +- (void)makeDeviceObjectsWithDevice:(id<MTLDevice>)device; +- (void)makeFontTextureWithDevice:(id<MTLDevice>)device; +- (MetalBuffer *)dequeueReusableBufferOfLength:(NSUInteger)length device:(id<MTLDevice>)device; +- (void)enqueueReusableBuffer:(MetalBuffer *)buffer; +- (id<MTLRenderPipelineState>)renderPipelineStateForFrameAndDevice:(id<MTLDevice>)device; +- (void)emptyRenderPipelineStateCache; +- (void)renderDrawData:(ImDrawData *)drawData + commandBuffer:(id<MTLCommandBuffer>)commandBuffer + commandEncoder:(id<MTLRenderCommandEncoder>)commandEncoder; +@end + +static MetalContext *g_sharedMetalContext = nil; + +#pragma mark - ImGui API implementation + +bool ImGui_ImplMetal_Init(id<MTLDevice> device) +{ + static dispatch_once_t onceToken; + dispatch_once(&onceToken, ^{ + g_sharedMetalContext = [[MetalContext alloc] init]; + }); + + ImGui_ImplMetal_CreateDeviceObjects(device); + + return true; +} + +void ImGui_ImplMetal_Shutdown() +{ + ImGui_ImplMetal_DestroyDeviceObjects(); +} + +void ImGui_ImplMetal_NewFrame(MTLRenderPassDescriptor *renderPassDescriptor) +{ + IM_ASSERT(g_sharedMetalContext != nil && "No Metal context. Did you call ImGui_ImplMetal_Init?"); + + g_sharedMetalContext.framebufferDescriptor = [[FramebufferDescriptor alloc] initWithRenderPassDescriptor:renderPassDescriptor]; +} + +// Metal Render function. +void ImGui_ImplMetal_RenderDrawData(ImDrawData* draw_data, id<MTLCommandBuffer> commandBuffer, id<MTLRenderCommandEncoder> commandEncoder) +{ + [g_sharedMetalContext renderDrawData:draw_data commandBuffer:commandBuffer commandEncoder:commandEncoder]; +} + +bool ImGui_ImplMetal_CreateFontsTexture(id<MTLDevice> device) +{ + [g_sharedMetalContext makeFontTextureWithDevice:device]; + + ImGuiIO& io = ImGui::GetIO(); + io.Fonts->TexID = (__bridge void *)g_sharedMetalContext.fontTexture; // ImTextureID == void* + + return (g_sharedMetalContext.fontTexture != nil); +} + +void ImGui_ImplMetal_DestroyFontsTexture() +{ + ImGuiIO& io = ImGui::GetIO(); + g_sharedMetalContext.fontTexture = nil; + io.Fonts->TexID = nullptr; +} + +bool ImGui_ImplMetal_CreateDeviceObjects(id<MTLDevice> device) +{ + [g_sharedMetalContext makeDeviceObjectsWithDevice:device]; + + ImGui_ImplMetal_CreateFontsTexture(device); + + return true; +} + +void ImGui_ImplMetal_DestroyDeviceObjects() +{ + ImGui_ImplMetal_DestroyFontsTexture(); + [g_sharedMetalContext emptyRenderPipelineStateCache]; +} + +#pragma mark - MetalBuffer implementation + +@implementation MetalBuffer +- (instancetype)initWithBuffer:(id<MTLBuffer>)buffer +{ + if ((self = [super init])) + { + _buffer = buffer; + _lastReuseTime = [NSDate date].timeIntervalSince1970; + } + 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])) + { + _renderPipelineStateCache = [NSMutableDictionary dictionary]; + _bufferCache = [NSMutableArray array]; + _lastBufferCachePurge = [NSDate date].timeIntervalSince1970; + } + return self; +} + +- (void)makeDeviceObjectsWithDevice:(id<MTLDevice>)device +{ + MTLDepthStencilDescriptor *depthStencilDescriptor = [[MTLDepthStencilDescriptor alloc] init]; + depthStencilDescriptor.depthWriteEnabled = NO; + depthStencilDescriptor.depthCompareFunction = MTLCompareFunctionAlways; + self.depthStencilState = [device newDepthStencilStateWithDescriptor:depthStencilDescriptor]; +} + +// 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. +- (void)makeFontTextureWithDevice:(id<MTLDevice>)device +{ + ImGuiIO &io = ImGui::GetIO(); + unsigned char* pixels; + int width, height; + io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); + MTLTextureDescriptor *textureDescriptor = [MTLTextureDescriptor texture2DDescriptorWithPixelFormat:MTLPixelFormatRGBA8Unorm + width:width + height:height + mipmapped:NO]; + textureDescriptor.usage = MTLTextureUsageShaderRead; +#if TARGET_OS_OSX + textureDescriptor.storageMode = MTLStorageModeManaged; +#else + textureDescriptor.storageMode = MTLStorageModeShared; +#endif + id <MTLTexture> texture = [device newTextureWithDescriptor:textureDescriptor]; + [texture replaceRegion:MTLRegionMake2D(0, 0, width, height) mipmapLevel:0 withBytes:pixels bytesPerRow:width * 4]; + self.fontTexture = texture; +} + +- (MetalBuffer *)dequeueReusableBufferOfLength:(NSUInteger)length device:(id<MTLDevice>)device +{ + NSTimeInterval now = [NSDate date].timeIntervalSince1970; + + // 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]; +} + +- (void)enqueueReusableBuffer:(MetalBuffer *)buffer +{ + [self.bufferCache addObject:buffer]; +} + +- (_Nullable id<MTLRenderPipelineState>)renderPipelineStateForFrameAndDevice:(id<MTLDevice>)device +{ + // Try to retrieve a render pipeline state that is compatible with the framebuffer config for this frame + // Thie hit rate for this cache should be very near 100%. + id<MTLRenderPipelineState> renderPipelineState = self.renderPipelineStateCache[self.framebufferDescriptor]; + + if (renderPipelineState == nil) + { + // No luck; make a new render pipeline state + renderPipelineState = [self _renderPipelineStateForFramebufferDescriptor:self.framebufferDescriptor device:device]; + // Cache render pipeline state for later reuse + self.renderPipelineStateCache[self.framebufferDescriptor] = renderPipelineState; + } + + return renderPipelineState; +} + +- (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.sampleCount = self.framebufferDescriptor.sampleCount; + pipelineDescriptor.colorAttachments[0].pixelFormat = self.framebufferDescriptor.colorPixelFormat; + pipelineDescriptor.colorAttachments[0].blendingEnabled = YES; + pipelineDescriptor.colorAttachments[0].rgbBlendOperation = MTLBlendOperationAdd; + pipelineDescriptor.colorAttachments[0].alphaBlendOperation = MTLBlendOperationAdd; + pipelineDescriptor.colorAttachments[0].sourceRGBBlendFactor = MTLBlendFactorSourceAlpha; + pipelineDescriptor.colorAttachments[0].sourceAlphaBlendFactor = MTLBlendFactorSourceAlpha; + pipelineDescriptor.colorAttachments[0].destinationRGBBlendFactor = MTLBlendFactorOneMinusSourceAlpha; + pipelineDescriptor.colorAttachments[0].destinationAlphaBlendFactor = MTLBlendFactorOneMinusSourceAlpha; + pipelineDescriptor.depthAttachmentPixelFormat = self.framebufferDescriptor.depthPixelFormat; + pipelineDescriptor.stencilAttachmentPixelFormat = self.framebufferDescriptor.stencilPixelFormat; + + id<MTLRenderPipelineState> renderPipelineState = [device newRenderPipelineStateWithDescriptor:pipelineDescriptor error:&error]; + if (error != nil) + { + NSLog(@"Error: failed to create Metal pipeline state: %@", error); + } + + return renderPipelineState; +} + +- (void)emptyRenderPipelineStateCache +{ + [self.renderPipelineStateCache removeAllObjects]; +} + +- (void)renderDrawData:(ImDrawData *)drawData + commandBuffer:(id<MTLCommandBuffer>)commandBuffer + commandEncoder:(id<MTLRenderCommandEncoder>)commandEncoder +{ + // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates) + ImGuiIO &io = ImGui::GetIO(); + int fb_width = (int)(drawData->DisplaySize.x * io.DisplayFramebufferScale.x); + int fb_height = (int)(drawData->DisplaySize.y * io.DisplayFramebufferScale.y); + if (fb_width <= 0 || fb_height <= 0 || drawData->CmdListsCount == 0) + return; + drawData->ScaleClipRects(io.DisplayFramebufferScale); + + [commandEncoder setCullMode:MTLCullModeNone]; + [commandEncoder setDepthStencilState:g_sharedMetalContext.depthStencilState]; + + // Setup viewport, orthographic projection matrix + // Our visible imgui space lies from draw_data->DisplayPos (top left) to + // draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayMin is typically (0,0) for single viewport apps. + MTLViewport viewport = + { + .originX = 0.0, + .originY = 0.0, + .width = double(fb_width), + .height = double(fb_height), + .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 = viewport.znear; + float F = 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]; + + size_t vertexBufferLength = 0; + size_t indexBufferLength = 0; + for (int n = 0; n < drawData->CmdListsCount; n++) + { + const ImDrawList* cmd_list = drawData->CmdLists[n]; + vertexBufferLength += cmd_list->VtxBuffer.Size * sizeof(ImDrawVert); + indexBufferLength += cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx); + } + + MetalBuffer *vertexBuffer = [self dequeueReusableBufferOfLength:vertexBufferLength device:commandBuffer.device]; + MetalBuffer *indexBuffer = [self dequeueReusableBufferOfLength:indexBufferLength device:commandBuffer.device]; + + id<MTLRenderPipelineState> renderPipelineState = [self renderPipelineStateForFrameAndDevice:commandBuffer.device]; + [commandEncoder setRenderPipelineState:renderPipelineState]; + + [commandEncoder setVertexBuffer:vertexBuffer.buffer offset:0 atIndex:0]; + + size_t vertexBufferOffset = 0; + size_t indexBufferOffset = 0; + ImVec2 pos = drawData->DisplayPos; + for (int n = 0; n < drawData->CmdListsCount; n++) + { + const ImDrawList* cmd_list = drawData->CmdLists[n]; + ImDrawIdx idx_buffer_offset = 0; + + memcpy((char *)vertexBuffer.buffer.contents + vertexBufferOffset, cmd_list->VtxBuffer.Data, cmd_list->VtxBuffer.Size * sizeof(ImDrawVert)); + memcpy((char *)indexBuffer.buffer.contents + indexBufferOffset, cmd_list->IdxBuffer.Data, cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx)); + + [commandEncoder setVertexBufferOffset:vertexBufferOffset atIndex:0]; + + 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) + pcmd->UserCallback(cmd_list, pcmd); + } + else + { + ImVec4 clip_rect = ImVec4(pcmd->ClipRect.x - pos.x, pcmd->ClipRect.y - pos.y, pcmd->ClipRect.z - pos.x, pcmd->ClipRect.w - pos.y); + if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f) + { + // Apply scissor/clipping rectangle + MTLScissorRect scissorRect = { .x = NSUInteger(clip_rect.x), + .y = NSUInteger(clip_rect.y), + .width = NSUInteger(clip_rect.z - clip_rect.x), + .height = NSUInteger(clip_rect.w - clip_rect.y) }; + [commandEncoder setScissorRect:scissorRect]; + + + // Bind texture, Draw + if (pcmd->TextureId != NULL) + [commandEncoder setFragmentTexture:(__bridge id<MTLTexture>)(pcmd->TextureId) atIndex:0]; + [commandEncoder drawIndexedPrimitives:MTLPrimitiveTypeTriangle + indexCount:pcmd->ElemCount + indexType:sizeof(ImDrawIdx) == 2 ? MTLIndexTypeUInt16 : MTLIndexTypeUInt32 + indexBuffer:indexBuffer.buffer + indexBufferOffset:indexBufferOffset + idx_buffer_offset]; + } + } + idx_buffer_offset += pcmd->ElemCount * sizeof(ImDrawIdx); + } + + vertexBufferOffset += cmd_list->VtxBuffer.Size * sizeof(ImDrawVert); + indexBufferOffset += 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 |