| // Copyright 2013 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include <GLES2/gl2.h> |
| #include <GLES2/gl2ext.h> |
| #include <emscripten.h> |
| #include <emscripten/html5_webgl.h> |
| #include <emscripten/threading.h> |
| #include <webgl/webgl1.h> |
| #include "export.h" |
| #include "third_party/skia/include/core/SkCanvas.h" |
| #include "third_party/skia/include/core/SkColorSpace.h" |
| #include "third_party/skia/include/core/SkPicture.h" |
| #include "third_party/skia/include/core/SkSurface.h" |
| #include "third_party/skia/include/gpu/GrDirectContext.h" |
| #include "third_party/skia/include/gpu/gl/GrGLInterface.h" |
| #include "third_party/skia/include/gpu/gl/GrGLTypes.h" |
| #include "wrappers.h" |
| |
| using namespace Skwasm; |
| |
| using OnRenderCompleteCallback = void(uint32_t); |
| |
| namespace { |
| class Surface; |
| void fDispose(Surface* surface); |
| void fSetCanvasSize(Surface* surface, int width, int height); |
| void fRenderPicture(Surface* surface, SkPicture* picture); |
| void fNotifyRenderComplete(Surface* surface, uint32_t renderId); |
| void fOnRenderComplete(Surface* surface, uint32_t renderId); |
| |
| class Surface { |
| public: |
| // Main thread only |
| Surface(const char* canvasID) : _canvasID(canvasID) { |
| pthread_attr_t attr; |
| pthread_attr_init(&attr); |
| pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); |
| emscripten_pthread_attr_settransferredcanvases(&attr, _canvasID.c_str()); |
| |
| pthread_create( |
| &_thread, &attr, |
| [](void* context) -> void* { |
| static_cast<Surface*>(context)->_runWorker(); |
| return nullptr; |
| }, |
| this); |
| } |
| |
| // Main thread only |
| void dispose() { |
| emscripten_dispatch_to_thread(_thread, EM_FUNC_SIG_VI, |
| reinterpret_cast<void*>(fDispose), nullptr, |
| this); |
| } |
| |
| // Main thread only |
| void setCanvasSize(int width, int height) { |
| emscripten_dispatch_to_thread(_thread, EM_FUNC_SIG_VIII, |
| reinterpret_cast<void*>(fSetCanvasSize), |
| nullptr, this, width, height); |
| } |
| |
| // Main thread only |
| uint32_t renderPicture(SkPicture* picture) { |
| uint32_t renderId = ++_currentRenderId; |
| picture->ref(); |
| emscripten_dispatch_to_thread(_thread, EM_FUNC_SIG_VII, |
| reinterpret_cast<void*>(fRenderPicture), |
| nullptr, this, picture); |
| |
| // After drawing to the surface, the browser implicitly flushed the drawing |
| // commands at the end of the event loop. As a result, in order to make |
| // sure we call back after the rendering has actually occurred, we issue |
| // the callback in a subsequent event, after the flushing has happened. |
| emscripten_dispatch_to_thread( |
| _thread, EM_FUNC_SIG_VII, |
| reinterpret_cast<void*>(fNotifyRenderComplete), nullptr, this, |
| renderId); |
| return renderId; |
| } |
| |
| // Main thread only |
| void setOnRenderCallback(OnRenderCompleteCallback* callback) { |
| _onRenderCompleteCallback = callback; |
| } |
| |
| private: |
| // Worker thread only |
| void _runWorker() { |
| _init(); |
| emscripten_unwind_to_js_event_loop(); |
| } |
| |
| // Worker thread only |
| void _init() { |
| EmscriptenWebGLContextAttributes attributes; |
| emscripten_webgl_init_context_attributes(&attributes); |
| |
| attributes.alpha = true; |
| attributes.depth = true; |
| attributes.stencil = true; |
| attributes.antialias = false; |
| attributes.premultipliedAlpha = true; |
| attributes.preserveDrawingBuffer = 0; |
| attributes.powerPreference = EM_WEBGL_POWER_PREFERENCE_DEFAULT; |
| attributes.failIfMajorPerformanceCaveat = false; |
| attributes.enableExtensionsByDefault = true; |
| attributes.explicitSwapControl = false; |
| attributes.renderViaOffscreenBackBuffer = true; |
| attributes.majorVersion = 2; |
| |
| _glContext = |
| emscripten_webgl_create_context(_canvasID.c_str(), &attributes); |
| if (!_glContext) { |
| printf("Failed to create context!\n"); |
| return; |
| } |
| |
| makeCurrent(_glContext); |
| |
| _grContext = GrDirectContext::MakeGL(GrGLMakeNativeInterface()); |
| |
| // WebGL should already be clearing the color and stencil buffers, but do it |
| // again here to ensure Skia receives them in the expected state. |
| emscripten_glBindFramebuffer(GL_FRAMEBUFFER, 0); |
| emscripten_glClearColor(0, 0, 0, 0); |
| emscripten_glClearStencil(0); |
| emscripten_glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); |
| _grContext->resetContext(kRenderTarget_GrGLBackendState | |
| kMisc_GrGLBackendState); |
| |
| // The on-screen canvas is FBO 0. Wrap it in a Skia render target so Skia |
| // can render to it. |
| _fbInfo.fFBOID = 0; |
| _fbInfo.fFormat = GL_RGBA8_OES; |
| |
| emscripten_glGetIntegerv(GL_SAMPLES, &_sampleCount); |
| emscripten_glGetIntegerv(GL_STENCIL_BITS, &_stencil); |
| } |
| |
| // Worker thread only |
| void _dispose() { delete this; } |
| |
| // Worker thread only |
| void _setCanvasSize(int width, int height) { |
| if (_canvasWidth != width || _canvasHeight != height) { |
| emscripten_set_canvas_element_size(_canvasID.c_str(), width, height); |
| _canvasWidth = width; |
| _canvasHeight = height; |
| _recreateSurface(); |
| } |
| } |
| |
| // Worker thread only |
| void _recreateSurface() { |
| makeCurrent(_glContext); |
| GrBackendRenderTarget target(_canvasWidth, _canvasHeight, _sampleCount, |
| _stencil, _fbInfo); |
| _surface = SkSurface::MakeFromBackendRenderTarget( |
| _grContext.get(), target, kBottomLeft_GrSurfaceOrigin, |
| kRGBA_8888_SkColorType, SkColorSpace::MakeSRGB(), nullptr); |
| } |
| |
| // Worker thread only |
| void _renderPicture(const SkPicture* picture) { |
| if (!_surface) { |
| printf("Can't render picture with no surface.\n"); |
| return; |
| } |
| |
| makeCurrent(_glContext); |
| auto canvas = _surface->getCanvas(); |
| canvas->drawPicture(picture); |
| _surface->flush(); |
| } |
| |
| // Worker thread only |
| void _notifyRenderComplete(uint32_t renderId) { |
| emscripten_sync_run_in_main_runtime_thread( |
| EM_FUNC_SIG_VII, fOnRenderComplete, this, renderId); |
| } |
| |
| // Main thread only |
| void _onRenderComplete(uint32_t renderId) { |
| _onRenderCompleteCallback(renderId); |
| } |
| |
| std::string _canvasID; |
| OnRenderCompleteCallback* _onRenderCompleteCallback = nullptr; |
| uint32_t _currentRenderId = 0; |
| |
| int _canvasWidth = 0; |
| int _canvasHeight = 0; |
| |
| EMSCRIPTEN_WEBGL_CONTEXT_HANDLE _glContext = 0; |
| sk_sp<GrDirectContext> _grContext = nullptr; |
| sk_sp<SkSurface> _surface = nullptr; |
| GrGLFramebufferInfo _fbInfo; |
| GrGLint _sampleCount; |
| GrGLint _stencil; |
| |
| pthread_t _thread; |
| |
| friend void fDispose(Surface* surface); |
| friend void fSetCanvasSize(Surface* surface, int width, int height); |
| friend void fRenderPicture(Surface* surface, SkPicture* picture); |
| friend void fNotifyRenderComplete(Surface* surface, uint32_t renderId); |
| friend void fOnRenderComplete(Surface* surface, uint32_t renderId); |
| }; |
| |
| void fDispose(Surface* surface) { |
| surface->_dispose(); |
| } |
| |
| void fSetCanvasSize(Surface* surface, int width, int height) { |
| surface->_setCanvasSize(width, height); |
| } |
| |
| void fRenderPicture(Surface* surface, SkPicture* picture) { |
| surface->_renderPicture(picture); |
| picture->unref(); |
| } |
| |
| void fNotifyRenderComplete(Surface* surface, uint32_t renderId) { |
| surface->_notifyRenderComplete(renderId); |
| } |
| |
| void fOnRenderComplete(Surface* surface, uint32_t renderId) { |
| surface->_onRenderComplete(renderId); |
| } |
| } // namespace |
| |
| SKWASM_EXPORT Surface* surface_createFromCanvas(const char* canvasID) { |
| return new Surface(canvasID); |
| } |
| |
| SKWASM_EXPORT void surface_setOnRenderCallback( |
| Surface* surface, |
| OnRenderCompleteCallback* callback) { |
| surface->setOnRenderCallback(callback); |
| } |
| |
| SKWASM_EXPORT void surface_destroy(Surface* surface) { |
| surface->dispose(); |
| } |
| |
| SKWASM_EXPORT void surface_setCanvasSize(Surface* surface, |
| int width, |
| int height) { |
| surface->setCanvasSize(width, height); |
| } |
| |
| SKWASM_EXPORT uint32_t surface_renderPicture(Surface* surface, |
| SkPicture* picture) { |
| return surface->renderPicture(picture); |
| } |