| Flutter Impeller |

Public Member Functions | Static Public Member Functions | List of all members
impeller::SurfaceMTL Class Referencefinal

`#include <surface_mtl.h>`

Inheritance diagram for impeller::SurfaceMTL:

## Public Member Functions
| ~SurfaceMTL () override
id< MTLDrawable > | drawable () const
IRect | coverage () const
bool | Present () const override
Public Member Functions inherited from impeller::Surface
| Surface ()
| Surface (const RenderTarget &target_desc)
virtual | ~Surface ()
const ISize & | GetSize () const
bool | IsValid () const
const RenderTarget & | GetTargetRenderPassDescriptor () const

## Static Public Member Functions
static id< CAMetalDrawable > | GetMetalDrawableAndValidate (const std::shared_ptr< Context > &context, CAMetalLayer *layer)
| Wraps the current drawable of the given Metal layer to create a surface Impeller can render to. The surface must be created as late as possible and discarded immediately after rendering to it. More...
static std::unique_ptr< SurfaceMTL > | MakeFromMetalLayerDrawable (const std::shared_ptr< Context > &context, id< CAMetalDrawable > drawable, std::optional< IRect > clip_rect=std::nullopt)
static std::unique_ptr< SurfaceMTL > | MakeFromTexture (const std::shared_ptr< Context > &context, id< MTLTexture > texture, std::optional< IRect > clip_rect, id< CAMetalDrawable > drawable=nil)

## Detailed Description

Definition at line 17 of file surface_mtl.h.

## Constructor & Destructor Documentation

## ◆ ~SurfaceMTL()

impeller::SurfaceMTL::~SurfaceMTL | ( |  | ) |
| override default

## Member Function Documentation

## ◆ coverage()

IRect impeller::SurfaceMTL::coverage | ( |  | ) | const

Definition at line 221 of file surface_mtl.mm.

221 {
222 return IRect::MakeSize(resolve_texture_->GetSize());
223 }

References impeller::TRect< T >::MakeSize().

## ◆ drawable()

id<MTLDrawable> impeller::SurfaceMTL::drawable | ( |  | ) | const
| inline

Definition at line 56 of file surface_mtl.h.

56 { return drawable_; }

Referenced by MakeFromMetalLayerDrawable(), MakeFromTexture(), and Present().

## ◆ GetMetalDrawableAndValidate()

id< CAMetalDrawable > impeller::SurfaceMTL::GetMetalDrawableAndValidate | ( | const std::shared_ptr< Context > & | context,
|  | CAMetalLayer * | layer
| ) |  |
| static

Wraps the current drawable of the given Metal layer to create a surface Impeller can render to. The surface must be created as late as possible and discarded immediately after rendering to it.

Parameters

  [in] | context | The context
  [in] | layer | The layer whose current drawable to wrap to create a surface.

Returns
  A pointer to the wrapped surface or null.

Definition at line 25 of file surface_mtl.mm.

27 {
28 TRACE_EVENT0("impeller", "SurfaceMTL::WrapCurrentMetalLayerDrawable");
29
30 if (context == nullptr || !context->IsValid() || layer == nil) {
31 return nullptr;
32 }
33
34 id<CAMetalDrawable> current_drawable = nil;
35 {
36 TRACE_EVENT0("impeller", "WaitForNextDrawable");
37 current_drawable = [layer nextDrawable];
38 }
39
40 if (!current_drawable) {
41 VALIDATION_LOG << "Could not acquire current drawable.";
42 return nullptr;
43 }
44 return current_drawable;
45 }

References VALIDATION_LOG.

## ◆ MakeFromMetalLayerDrawable()

std::unique_ptr< SurfaceMTL > impeller::SurfaceMTL::MakeFromMetalLayerDrawable | ( | const std::shared_ptr< Context > & | context,
|  | id< CAMetalDrawable > | drawable,
|  | std::optional< IRect > | clip_rect = `std::nullopt`
| ) |  |
| static

Definition at line 123 of file surface_mtl.mm.

126 {
127 return SurfaceMTL::MakeFromTexture(context, drawable.texture, clip_rect,
128 drawable);
129 }

References drawable(), and MakeFromTexture().

## ◆ MakeFromTexture()

std::unique_ptr< SurfaceMTL > impeller::SurfaceMTL::MakeFromTexture | ( | const std::shared_ptr< Context > & | context,
|  | id< MTLTexture > | texture,
|  | std::optional< IRect > | clip_rect,
|  | id< CAMetalDrawable > | drawable = `nil`
| ) |  |
| static

Definition at line 131 of file surface_mtl.mm.

135 {
136 bool partial_repaint_blit_required = ShouldPerformPartialRepaint(clip_rect);
137
138 // The returned render target is the texture that Impeller will render the
139 // root pass to. If partial repaint is in use, this may be a new texture which
140 // is smaller than the given MTLTexture.
141 auto render_target =
142 WrapTextureWithRenderTarget(*context->GetResourceAllocator(), texture,
143 partial_repaint_blit_required, clip_rect);
144 if (!render_target) {
145 return nullptr;
146 }
147
148 // If partial repainting, set a "source" texture. The presence of a source
149 // texture and clip rect instructs the surface to blit this texture to the
150 // destination texture.
151 auto source_texture = partial_repaint_blit_required
152 ? render_target->GetRenderTargetTexture()
153 : nullptr;
154
155 // The final "destination" texture is the texture that will be presented. In
156 // this case, it's always the given drawable.
157 std::shared_ptr<Texture> destination_texture;
158 if (partial_repaint_blit_required) {
159 // If blitting for partial repaint, we need to wrap the drawable. Simply
160 // reuse the texture descriptor that was already formed for the new render
161 // target, but override the size with the drawable's size.
162 auto destination_descriptor =
163 render_target->GetRenderTargetTexture()->GetTextureDescriptor();
164 destination_descriptor.size = {static_cast<ISize::Type>(texture.width),
165 static_cast<ISize::Type>(texture.height)};
166 destination_texture = TextureMTL::Wrapper(destination_descriptor, texture);
167 } else {
168 // When not partial repaint blit is needed, the render target texture _is_
169 // the drawable texture.
170 destination_texture = render_target->GetRenderTargetTexture();
171 }
172
173 return std::unique_ptr<SurfaceMTL>(new SurfaceMTL(
174 context, // context
175 *render_target, // target
176 render_target->GetRenderTargetTexture(), // resolve_texture
177 drawable, // drawable
178 source_texture, // source_texture
179 destination_texture, // destination_texture
180 partial_repaint_blit_required, // requires_blit
181 clip_rect // clip_rect
182 ));
183 }

References drawable(), impeller::TextureMTL::Wrapper(), and impeller::WrapTextureWithRenderTarget().

Referenced by MakeFromMetalLayerDrawable().

## ◆ Present()

bool impeller::SurfaceMTL::Present | ( |  | ) | const
| override virtual

Reimplemented from impeller::Surface.

Definition at line 226 of file surface_mtl.mm.

226 {
227 auto context = context_.lock();
228 if (!context) {
229 return false;
230 }
231
232 #ifdef IMPELLER_DEBUG
233 context->GetResourceAllocator()->DebugTraceMemoryStatistics();
234 #endif // IMPELLER_DEBUG
235
236 if (requires_blit_) {
237 if (!(source_texture_ && destination_texture_)) {
238 return false;
239 }
240
241 auto blit_command_buffer = context->CreateCommandBuffer();
242 if (!blit_command_buffer) {
243 return false;
244 }
245 auto blit_pass = blit_command_buffer->CreateBlitPass();
246 if (!clip_rect_.has_value()) {
247 VALIDATION_LOG << "Missing clip rectangle.";
248 return false;
249 }
250 blit_pass->AddCopy(source_texture_, destination_texture_, std::nullopt,
251 clip_rect_->GetOrigin());
252 blit_pass->EncodeCommands(context->GetResourceAllocator());
253 if (!context->GetCommandQueue()->Submit({blit_command_buffer}).ok()) {
254 return false;
255 }
256 }
257 #ifdef IMPELLER_DEBUG
258 ContextMTL::Cast(context.get())->GetGPUTracer()->MarkFrameEnd();
259 #endif // IMPELLER_DEBUG
260
261 if (drawable_) {
262 id<MTLCommandBuffer> command_buffer =
263 ContextMTL::Cast(context.get())
264 ->CreateMTLCommandBuffer("Present Waiter Command Buffer");
265
266 id<CAMetalDrawable> metal_drawable =
267 reinterpret_cast<id<CAMetalDrawable>>(drawable_);
268 if ([metal_drawable conformsToProtocol:@protocol(FlutterMetalDrawable)]) {
269 [(id<FlutterMetalDrawable>)metal_drawable
270 flutterPrepareForPresent:command_buffer];
271 }
272
273 // Intel iOS simulators do not seem to give backpressure on Metal drawable
274 // aquisition, which can result in Impeller running head of the GPU
275 // workload by dozens of frames. Slow this process down by blocking
276 // on submit until the last command buffer is at least scheduled.
277 #if defined(FML_OS_IOS_SIMULATOR) && defined(FML_ARCH_CPU_X86_64)
278 constexpr bool alwaysWaitForScheduling = true;
279 #else
280 constexpr bool alwaysWaitForScheduling = false;
281 #endif // defined(FML_OS_IOS_SIMULATOR) && defined(FML_ARCH_CPU_X86_64)
282
283 // If the threads have been merged, or there is a pending frame capture,
284 // then block on cmd buffer scheduling to ensure that the
285 // transaction/capture work correctly.
286 if ([[NSThread currentThread] isMainThread] ||
287 [[MTLCaptureManager sharedCaptureManager] isCapturing] ||
288 alwaysWaitForScheduling) {
289 TRACE_EVENT0("flutter", "waitUntilScheduled");
290 [command_buffer commit];
291 #if defined(FML_OS_IOS_SIMULATOR) && defined(FML_ARCH_CPU_X86_64)
292 [command_buffer waitUntilCompleted];
293 #else
294 [command_buffer waitUntilScheduled];
295 #endif // defined(FML_OS_IOS_SIMULATOR) && defined(FML_ARCH_CPU_X86_64)
296 [drawable_ present];
297 } else {
298 // The drawable may come from a FlutterMetalLayer, so it can't be
299 // presented through the command buffer.
300 id<CAMetalDrawable> drawable = drawable_;
301 [command_buffer addScheduledHandler:^(id<MTLCommandBuffer> buffer) {
302 [drawable present];
303 }];
304 [command_buffer commit];
305 }
306 }
307
308 return true;
309 }

References impeller::BackendCast< ContextMTL, Context >::Cast(), impeller::ContextMTL::CreateMTLCommandBuffer(), drawable(), and VALIDATION_LOG.

The documentation for this class was generated from the following files:

- impeller/renderer/backend/metal/surface_mtl.h
- impeller/renderer/backend/metal/surface_mtl.mm

impeller::TSize::Type
T Type
Definition: size.h:20
impeller::WrapTextureWithRenderTarget
static std::optional< RenderTarget > WrapTextureWithRenderTarget(Allocator &allocator, id< MTLTexture > texture, bool requires_blit, std::optional< IRect > clip_rect)
Definition: surface_mtl.mm:47
FlutterMetalDrawable-p
Definition: surface_mtl.mm:16
impeller::SurfaceMTL::MakeFromTexture
static std::unique_ptr< SurfaceMTL > MakeFromTexture(const std::shared_ptr< Context > &context, id< MTLTexture > texture, std::optional< IRect > clip_rect, id< CAMetalDrawable > drawable=nil)
Definition: surface_mtl.mm:131
impeller::SurfaceMTL::drawable
id< MTLDrawable > drawable() const
Definition: surface_mtl.h:56
impeller::TextureMTL::Wrapper
static std::shared_ptr< TextureMTL > Wrapper(TextureDescriptor desc, id< MTLTexture > texture, std::function< void()> deletion_proc=nullptr)
Definition: texture_mtl.mm:41
VALIDATION_LOG
#define VALIDATION_LOG
Definition: validation.h:73
impeller::TRect::MakeSize
constexpr static TRect MakeSize(const TSize< U > &size)
Definition: rect.h:146
impeller::BackendCast< ContextMTL, Context >::Cast
static ContextMTL & Cast(Context &base)
Definition: backend_cast.h:13
impeller::ContextMTL::CreateMTLCommandBuffer
id< MTLCommandBuffer > CreateMTLCommandBuffer(const std::string &label) const
Definition: context_mtl.mm:369