Examples: Comments + shallow coding convention tweak to be consistent across examples and with imgui_impl_osx
diff --git a/examples/README.txt b/examples/README.txt
index 5535c8d..e84fae8 100644
--- a/examples/README.txt
+++ b/examples/README.txt
@@ -166,12 +166,12 @@
example_apple_metal/
OSX & iOS + Metal.
It is based on the "cross-platform" game template provided with Xcode as of Xcode 9.
- Note that instead of the OSX bindings, you may want to use GLFW or SDL which will also support Windows, Linux along with OSX.
+ (NB: you may still want to use GLFW or SDL which will also support Windows, Linux along with OSX.)
= game template + imgui_impl_osx.mm + imgui_impl_metal.mm
example_apple_opengl2/
OSX + OpenGL2.
- Note that instead of the OSX bindings, you may want to use GLFW or SDL which will also support Windows, Linux along with OSX.
+ (NB: you may still want to use GLFW or SDL which will also support Windows, Linux along with OSX.)
= main.mm + imgui_impl_osx.mm + imgui_impl_opengl2.cpp
example_glfw_opengl2/
diff --git a/examples/example_apple_metal/README.md b/examples/example_apple_metal/README.md
index d43b492..4f62032 100644
--- a/examples/example_apple_metal/README.md
+++ b/examples/example_apple_metal/README.md
@@ -2,5 +2,7 @@
## Introduction
-This example shows how to render ImGui with Metal. It is based on the cross-platform game template provided with Xcode as of Xcode 9.
+This example shows how to integrate Dear ImGui with Metal. It is based on the "cross-platform" game template provided with Xcode as of Xcode 9.
+
+(NB: you may still want to use GLFW or SDL which will also support Windows, Linux along with OSX.)
diff --git a/examples/imgui_impl_metal.mm b/examples/imgui_impl_metal.mm
index 8ee0643..a4d235c 100644
--- a/examples/imgui_impl_metal.mm
+++ b/examples/imgui_impl_metal.mm
@@ -128,8 +128,10 @@
#pragma mark - MetalBuffer implementation
@implementation MetalBuffer
-- (instancetype)initWithBuffer:(id<MTLBuffer>)buffer {
- if ((self = [super init])) {
+- (instancetype)initWithBuffer:(id<MTLBuffer>)buffer
+{
+ if ((self = [super init]))
+ {
_buffer = buffer;
_lastReuseTime = [NSDate date].timeIntervalSince1970;
}
@@ -140,8 +142,10 @@
#pragma mark - FramebufferDescriptor implementation
@implementation FramebufferDescriptor
-- (instancetype)initWithRenderPassDescriptor:(MTLRenderPassDescriptor *)renderPassDescriptor {
- if ((self = [super init])) {
+- (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;
@@ -150,7 +154,8 @@
return self;
}
-- (nonnull id)copyWithZone:(nullable NSZone *)zone {
+- (nonnull id)copyWithZone:(nullable NSZone *)zone
+{
FramebufferDescriptor *copy = [[FramebufferDescriptor allocWithZone:zone] init];
copy.sampleCount = self.sampleCount;
copy.colorPixelFormat = self.colorPixelFormat;
@@ -159,7 +164,8 @@
return copy;
}
-- (NSUInteger)hash {
+- (NSUInteger)hash
+{
NSUInteger sc = _sampleCount & 0x3;
NSUInteger cf = _colorPixelFormat & 0x3FF;
NSUInteger df = _depthPixelFormat & 0x3FF;
@@ -168,12 +174,12 @@
return hash;
}
-- (BOOL)isEqual:(id)object {
+- (BOOL)isEqual:(id)object
+{
FramebufferDescriptor *other = object;
- if (![other isKindOfClass:[FramebufferDescriptor class]]) {
+ if (![other isKindOfClass:[FramebufferDescriptor class]])
return NO;
- }
- return other.sampleCount == self.sampleCount &&
+ return other.sampleCount == self.sampleCount &&
other.colorPixelFormat == self.colorPixelFormat &&
other.depthPixelFormat == self.depthPixelFormat &&
other.stencilPixelFormat == self.stencilPixelFormat;
@@ -185,7 +191,8 @@
@implementation MetalContext
- (instancetype)init {
- if ((self = [super init])) {
+ if ((self = [super init]))
+ {
_renderPipelineStateCache = [NSMutableDictionary dictionary];
_bufferCache = [NSMutableArray array];
_lastBufferCachePurge = [NSDate date].timeIntervalSince1970;
@@ -193,14 +200,20 @@
return self;
}
-- (void)makeDeviceObjectsWithDevice:(id<MTLDevice>)device {
+- (void)makeDeviceObjectsWithDevice:(id<MTLDevice>)device
+{
MTLDepthStencilDescriptor *depthStencilDescriptor = [[MTLDepthStencilDescriptor alloc] init];
depthStencilDescriptor.depthWriteEnabled = NO;
depthStencilDescriptor.depthCompareFunction = MTLCompareFunctionAlways;
self.depthStencilState = [device newDepthStencilStateWithDescriptor:depthStencilDescriptor];
}
-- (void)makeFontTextureWithDevice:(id<MTLDevice>)device {
+// 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;
@@ -220,14 +233,18 @@
self.fontTexture = texture;
}
-- (MetalBuffer *)dequeueReusableBufferOfLength:(NSUInteger)length device:(id<MTLDevice>)device {
+- (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) {
+ if (now - self.lastBufferCachePurge > 1.0)
+ {
NSMutableArray *survivors = [NSMutableArray array];
- for (MetalBuffer *candidate in self.bufferCache) {
- if (candidate.lastReuseTime > self.lastBufferCachePurge) {
+ for (MetalBuffer *candidate in self.bufferCache)
+ {
+ if (candidate.lastReuseTime > self.lastBufferCachePurge)
+ {
[survivors addObject:candidate];
}
}
@@ -237,13 +254,12 @@
// 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)) {
+ for (MetalBuffer *candidate in self.bufferCache)
+ if (candidate.buffer.length >= length && (bestCandidate == nil || bestCandidate.lastReuseTime > candidate.lastReuseTime))
bestCandidate = candidate;
- }
- }
- if (bestCandidate != nil) {
+ if (bestCandidate != nil)
+ {
[self.bufferCache removeObject:bestCandidate];
bestCandidate.lastReuseTime = now;
return bestCandidate;
@@ -254,16 +270,19 @@
return [[MetalBuffer alloc] initWithBuffer:backing];
}
-- (void)enqueueReusableBuffer:(MetalBuffer *)buffer {
+- (void)enqueueReusableBuffer:(MetalBuffer *)buffer
+{
[self.bufferCache addObject:buffer];
}
-- (_Nullable id<MTLRenderPipelineState>)renderPipelineStateForFrameAndDevice:(id<MTLDevice>)device {
+- (_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) {
+ 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
@@ -314,7 +333,8 @@
"}\n";
id<MTLLibrary> library = [device newLibraryWithSource:shaderSource options:nil error:&error];
- if (library == nil) {
+ if (library == nil)
+ {
NSLog(@"Error: failed to create Metal library: %@", error);
return nil;
}
@@ -322,7 +342,8 @@
id<MTLFunction> vertexFunction = [library newFunctionWithName:@"vertex_main"];
id<MTLFunction> fragmentFunction = [library newFunctionWithName:@"fragment_main"];
- if (vertexFunction == nil || fragmentFunction == nil) {
+ if (vertexFunction == nil || fragmentFunction == nil)
+ {
NSLog(@"Error: failed to find Metal shader functions in library: %@", error);
return nil;
}
@@ -358,14 +379,16 @@
pipelineDescriptor.stencilAttachmentPixelFormat = self.framebufferDescriptor.stencilPixelFormat;
id<MTLRenderPipelineState> renderPipelineState = [device newRenderPipelineStateWithDescriptor:pipelineDescriptor error:&error];
- if (error != nil) {
+ if (error != nil)
+ {
NSLog(@"Error: failed to create Metal pipeline state: %@", error);
}
return renderPipelineState;
}
-- (void)emptyRenderPipelineStateCache {
+- (void)emptyRenderPipelineStateCache
+{
[self.renderPipelineStateCache removeAllObjects];
}
@@ -387,12 +410,15 @@
// Setup viewport, orthographic projection matrix
// Our visible imgui space lies from draw_data->DisplayPps (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,
+ MTLViewport viewport =
+ {
+ .originX = 0.0,
.originY = 0.0,
.width = double(fb_width),
.height = double(fb_height),
.znear = 0.0,
- .zfar = 1.0 };
+ .zfar = 1.0
+ };
[commandEncoder setViewport:viewport];
float L = drawData->DisplayPos.x;
float R = drawData->DisplayPos.x + drawData->DisplaySize.x;
@@ -412,7 +438,8 @@
size_t vertexBufferLength = 0;
size_t indexBufferLength = 0;
- for (int n = 0; n < drawData->CmdListsCount; n++) {
+ 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);
@@ -461,9 +488,8 @@
// Bind texture, Draw
- if (pcmd->TextureId != NULL) {
+ 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
@@ -479,7 +505,8 @@
}
__weak id weakSelf = self;
- [commandBuffer addCompletedHandler:^(id<MTLCommandBuffer>) {
+ [commandBuffer addCompletedHandler:^(id<MTLCommandBuffer>)
+ {
dispatch_async(dispatch_get_main_queue(), ^{
[weakSelf enqueueReusableBuffer:vertexBuffer];
[weakSelf enqueueReusableBuffer:indexBuffer];
