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| |
| #include "qwasmopenglcontext.h" |
| #include "qwasmintegration.h" |
| #include <EGL/egl.h> |
| #include <emscripten/val.h> |
| |
| QT_BEGIN_NAMESPACE |
| |
| QWasmOpenGLContext::QWasmOpenGLContext(const QSurfaceFormat &format) |
| : m_requestedFormat(format) |
| { |
| m_requestedFormat.setRenderableType(QSurfaceFormat::OpenGLES); |
| |
| // if we set one, we need to set the other as well since in webgl, these are tied together |
| if (format.depthBufferSize() < 0 && format.stencilBufferSize() > 0) |
| m_requestedFormat.setDepthBufferSize(16); |
| |
| if (format.stencilBufferSize() < 0 && format.depthBufferSize() > 0) |
| m_requestedFormat.setStencilBufferSize(8); |
| |
| } |
| |
| QWasmOpenGLContext::~QWasmOpenGLContext() |
| { |
| if (m_context) { |
| // Destroy GL context. Work around bug in emscripten_webgl_destroy_context |
| // which removes all event handlers on the canvas by temporarily removing |
| // emscripten's JSEvents global object. |
| emscripten::val jsEvents = emscripten::val::global("window")["JSEvents"]; |
| emscripten::val::global("window").set("JSEvents", emscripten::val::undefined()); |
| emscripten_webgl_destroy_context(m_context); |
| emscripten::val::global("window").set("JSEvents", jsEvents); |
| m_context = 0; |
| } |
| } |
| |
| bool QWasmOpenGLContext::maybeCreateEmscriptenContext(QPlatformSurface *surface) |
| { |
| // Native emscripten/WebGL contexts are tied to a single screen/canvas. The first |
| // call to this function creates a native canvas for the given screen, subsequent |
| // calls verify that the surface is on/off the same screen. |
| QPlatformScreen *screen = surface->screen(); |
| if (m_context && !screen) |
| return false; // Alternative: return true to support makeCurrent on QOffScreenSurface with |
| // no screen. However, Qt likes to substitute QGuiApplication::primaryScreen() |
| // for null screens, which foils this plan. |
| if (!screen) |
| return false; |
| if (m_context) |
| return m_screen == screen; |
| |
| QString canvasId = QWasmScreen::get(screen)->canvasId(); |
| m_context = createEmscriptenContext(canvasId, m_requestedFormat); |
| m_screen = screen; |
| return true; |
| } |
| |
| EMSCRIPTEN_WEBGL_CONTEXT_HANDLE QWasmOpenGLContext::createEmscriptenContext(const QString &canvasId, QSurfaceFormat format) |
| { |
| EmscriptenWebGLContextAttributes attributes; |
| emscripten_webgl_init_context_attributes(&attributes); // Populate with default attributes |
| |
| attributes.preferLowPowerToHighPerformance = false; |
| attributes.failIfMajorPerformanceCaveat = false; |
| attributes.antialias = true; |
| attributes.enableExtensionsByDefault = true; |
| |
| if (format.majorVersion() == 3) { |
| attributes.majorVersion = 2; |
| } |
| |
| // WebGL doesn't allow separate attach buffers to STENCIL_ATTACHMENT and DEPTH_ATTACHMENT |
| // we need both or none |
| bool useDepthStencil = (format.depthBufferSize() > 0 || format.stencilBufferSize() > 0); |
| |
| // WebGL offers enable/disable control but not size control for these |
| attributes.alpha = format.alphaBufferSize() > 0; |
| attributes.depth = useDepthStencil; |
| attributes.stencil = useDepthStencil; |
| |
| EMSCRIPTEN_WEBGL_CONTEXT_HANDLE context = emscripten_webgl_create_context(canvasId.toUtf8().constData(), &attributes); |
| |
| return context; |
| } |
| |
| QSurfaceFormat QWasmOpenGLContext::format() const |
| { |
| return m_requestedFormat; |
| } |
| |
| GLuint QWasmOpenGLContext::defaultFramebufferObject(QPlatformSurface *surface) const |
| { |
| return QPlatformOpenGLContext::defaultFramebufferObject(surface); |
| } |
| |
| bool QWasmOpenGLContext::makeCurrent(QPlatformSurface *surface) |
| { |
| bool ok = maybeCreateEmscriptenContext(surface); |
| if (!ok) |
| return false; |
| |
| return emscripten_webgl_make_context_current(m_context) == EMSCRIPTEN_RESULT_SUCCESS; |
| } |
| |
| void QWasmOpenGLContext::swapBuffers(QPlatformSurface *surface) |
| { |
| Q_UNUSED(surface); |
| // No swapbuffers on WebGl |
| } |
| |
| void QWasmOpenGLContext::doneCurrent() |
| { |
| // No doneCurrent on WebGl |
| } |
| |
| bool QWasmOpenGLContext::isSharing() const |
| { |
| return false; |
| } |
| |
| bool QWasmOpenGLContext::isValid() const |
| { |
| // Note: we get isValid() calls before we see the surface and can |
| // create a native context, so no context is also a valid state. |
| return !m_context || !emscripten_is_webgl_context_lost(m_context); |
| } |
| |
| QFunctionPointer QWasmOpenGLContext::getProcAddress(const char *procName) |
| { |
| return reinterpret_cast<QFunctionPointer>(eglGetProcAddress(procName)); |
| } |
| |
| QT_END_NAMESPACE |