diff options
Diffstat (limited to 'src/plugins/platforms/wasm/qwasmopenglcontext.cpp')
-rw-r--r-- | src/plugins/platforms/wasm/qwasmopenglcontext.cpp | 59 |
1 files changed, 27 insertions, 32 deletions
diff --git a/src/plugins/platforms/wasm/qwasmopenglcontext.cpp b/src/plugins/platforms/wasm/qwasmopenglcontext.cpp index ae43e2ebf0..0eaffdb77e 100644 --- a/src/plugins/platforms/wasm/qwasmopenglcontext.cpp +++ b/src/plugins/platforms/wasm/qwasmopenglcontext.cpp @@ -41,40 +41,31 @@ QWasmOpenGLContext::QWasmOpenGLContext(const QSurfaceFormat &format) QWasmOpenGLContext::~QWasmOpenGLContext() { - if (m_context) + if (m_context) { emscripten_webgl_destroy_context(m_context); + m_context = 0; + } } -void QWasmOpenGLContext::maybeRecreateEmscriptenContext(QPlatformSurface *surface) +bool QWasmOpenGLContext::maybeCreateEmscriptenContext(QPlatformSurface *surface) { - // Native emscripten contexts are tied to a single surface. Recreate - // the context if the surface is changed. - if (surface != m_surface) { - m_surface = surface; - - // Destroy existing context - if (m_context) - emscripten_webgl_destroy_context(m_context); - - // Create new context - const QString canvasId = QWasmScreen::get(surface->screen())->canvasId(); - m_context = createEmscriptenContext(canvasId, m_requestedFormat); - - // Register context-lost callback. - auto callback = [](int eventType, const void *reserved, void *userData) -> EM_BOOL - { - Q_UNUSED(eventType); - Q_UNUSED(reserved); - // The application may get contex-lost if e.g. moved to the background. Set - // m_contextLost which will make isValid() return false. Application code will - // then detect this and recrate the the context, resulting in a new QWasmOpenGLContext - // instance. - reinterpret_cast<QWasmOpenGLContext *>(userData)->m_contextLost = true; - return true; - }; - bool capture = true; - emscripten_set_webglcontextlost_callback(canvasId.toLocal8Bit().constData(), this, capture, callback); - } + // 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) @@ -113,7 +104,9 @@ GLuint QWasmOpenGLContext::defaultFramebufferObject(QPlatformSurface *surface) c bool QWasmOpenGLContext::makeCurrent(QPlatformSurface *surface) { - maybeRecreateEmscriptenContext(surface); + bool ok = maybeCreateEmscriptenContext(surface); + if (!ok) + return false; return emscripten_webgl_make_context_current(m_context) == EMSCRIPTEN_RESULT_SUCCESS; } @@ -136,7 +129,9 @@ bool QWasmOpenGLContext::isSharing() const bool QWasmOpenGLContext::isValid() const { - return (m_contextLost == false); + // 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) |