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-rw-r--r--examples/opengl/hellogl2/glwidget.cpp6
-rw-r--r--examples/opengl/hellogl2/glwidget.h1
-rw-r--r--src/gui/painting/qplatformbackingstore.cpp41
-rw-r--r--src/gui/painting/qplatformbackingstore.h6
-rw-r--r--src/platformsupport/eglconvenience/qeglplatformbackingstore.cpp4
-rw-r--r--src/platformsupport/eglconvenience/qeglplatformbackingstore_p.h3
-rw-r--r--src/plugins/platforms/xcb/qxcbbackingstore.cpp5
-rw-r--r--src/plugins/platforms/xcb/qxcbbackingstore.h3
-rw-r--r--src/widgets/kernel/qopenglwidget.cpp16
-rw-r--r--src/widgets/kernel/qwidgetbackingstore.cpp7
10 files changed, 71 insertions, 21 deletions
diff --git a/examples/opengl/hellogl2/glwidget.cpp b/examples/opengl/hellogl2/glwidget.cpp
index c8db3047a1..7764fa8dfc 100644
--- a/examples/opengl/hellogl2/glwidget.cpp
+++ b/examples/opengl/hellogl2/glwidget.cpp
@@ -52,6 +52,11 @@ GLWidget::GLWidget(QWidget *parent)
m_program(0)
{
m_core = QCoreApplication::arguments().contains(QStringLiteral("--coreprofile"));
+ // --transparent causes the clear color to be transparent. Therefore, on systems that
+ // support it, the widget will become transparent apart from the logo.
+ m_transparent = QCoreApplication::arguments().contains(QStringLiteral("--transparent"));
+ if (m_transparent)
+ setAttribute(Qt::WA_TranslucentBackground);
}
GLWidget::~GLWidget()
@@ -183,6 +188,7 @@ void GLWidget::initializeGL()
connect(context(), &QOpenGLContext::aboutToBeDestroyed, this, &GLWidget::cleanup);
initializeOpenGLFunctions();
+ glClearColor(0, 0, 0, m_transparent ? 0 : 1);
m_program = new QOpenGLShaderProgram;
m_program->addShaderFromSourceCode(QOpenGLShader::Vertex, m_core ? vertexShaderSourceCore : vertexShaderSource);
diff --git a/examples/opengl/hellogl2/glwidget.h b/examples/opengl/hellogl2/glwidget.h
index fcc6225999..2d642649f1 100644
--- a/examples/opengl/hellogl2/glwidget.h
+++ b/examples/opengl/hellogl2/glwidget.h
@@ -98,6 +98,7 @@ private:
QMatrix4x4 m_proj;
QMatrix4x4 m_camera;
QMatrix4x4 m_world;
+ bool m_transparent;
};
#endif
diff --git a/src/gui/painting/qplatformbackingstore.cpp b/src/gui/painting/qplatformbackingstore.cpp
index e5b06f499c..66a56ac32f 100644
--- a/src/gui/painting/qplatformbackingstore.cpp
+++ b/src/gui/painting/qplatformbackingstore.cpp
@@ -80,6 +80,7 @@ public:
#ifndef QT_NO_OPENGL
mutable GLuint textureId;
mutable QSize textureSize;
+ mutable bool needsSwizzle;
QOpenGLTextureBlitter *blitter;
#endif
};
@@ -229,13 +230,16 @@ static QRegion deviceRegion(const QRegion &region, QWindow *window)
void QPlatformBackingStore::composeAndFlush(QWindow *window, const QRegion &region,
const QPoint &offset,
- QPlatformTextureList *textures, QOpenGLContext *context)
+ QPlatformTextureList *textures, QOpenGLContext *context,
+ bool translucentBackground)
{
Q_UNUSED(offset);
context->makeCurrent(window);
QOpenGLFunctions *funcs = context->functions();
funcs->glViewport(0, 0, window->width() * window->devicePixelRatio(), window->height() * window->devicePixelRatio());
+ funcs->glClearColor(0, 0, 0, translucentBackground ? 0 : 1);
+ funcs->glClear(GL_COLOR_BUFFER_BIT);
if (!d_ptr->blitter) {
d_ptr->blitter = new QOpenGLTextureBlitter;
@@ -257,15 +261,22 @@ void QPlatformBackingStore::composeAndFlush(QWindow *window, const QRegion &regi
funcs->glEnable(GL_BLEND);
funcs->glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+ // Do not write out alpha. We need blending, but only for RGB. The toplevel may have
+ // alpha enabled in which case blending (writing out < 1.0 alpha values) would lead to
+ // semi-transparency even when it is not wanted.
+ funcs->glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_FALSE);
// Backingstore texture with the normal widgets.
- GLuint textureId = toTexture(deviceRegion(region, window), &d_ptr->textureSize);
+ GLuint textureId = toTexture(deviceRegion(region, window), &d_ptr->textureSize, &d_ptr->needsSwizzle);
if (textureId) {
QMatrix4x4 target = QOpenGLTextureBlitter::targetTransform(QRect(QPoint(), d_ptr->textureSize), windowRect);
- d_ptr->blitter->setSwizzleRB(true);
+ if (d_ptr->needsSwizzle)
+ d_ptr->blitter->setSwizzleRB(true);
d_ptr->blitter->blit(textureId, target, QOpenGLTextureBlitter::OriginTopLeft);
- d_ptr->blitter->setSwizzleRB(false);
+ if (d_ptr->needsSwizzle)
+ d_ptr->blitter->setSwizzleRB(false);
}
+ funcs->glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
// Textures for renderToTexture widgets that have WA_AlwaysStackOnTop set.
for (int i = 0; i < textures->count(); ++i) {
@@ -308,9 +319,15 @@ QImage QPlatformBackingStore::toImage() const
The default implementation returns a cached texture if \a dirtyRegion is
empty and the window has not been resized, otherwise it retrieves the
content using toImage() and performs a texture upload.
- */
-GLuint QPlatformBackingStore::toTexture(const QRegion &dirtyRegion, QSize *textureSize) const
+ If the red and blue components have to swapped, \a needsSwizzle will be set to \c true.
+ This allows creating textures from images in formats like QImage::Format_RGB32 without
+ any further image conversion. Instead, the swizzling will be done in the shaders when
+ performing composition. Other formats, that do not need such swizzling due to being
+ already byte ordered RGBA, for example QImage::Format_RGBA8888, must result in having \a
+ needsSwizzle set to false.
+ */
+GLuint QPlatformBackingStore::toTexture(const QRegion &dirtyRegion, QSize *textureSize, bool *needsSwizzle) const
{
QImage image = toImage();
QSize imageSize = image.size();
@@ -321,8 +338,16 @@ GLuint QPlatformBackingStore::toTexture(const QRegion &dirtyRegion, QSize *textu
if (dirtyRegion.isEmpty() && !resized)
return d_ptr->textureId;
- if (image.format() != QImage::Format_RGB32 && image.format() != QImage::Format_RGBA8888)
- image = image.convertToFormat(QImage::Format_RGBA8888);
+ // Fast path for RGB32 and RGBA8888, convert everything else to RGBA8888.
+ if (image.format() == QImage::Format_RGB32) {
+ if (needsSwizzle)
+ *needsSwizzle = true;
+ } else {
+ if (needsSwizzle)
+ *needsSwizzle = false;
+ if (image.format() != QImage::Format_RGBA8888)
+ image = image.convertToFormat(QImage::Format_RGBA8888);
+ }
QOpenGLFunctions *funcs = QOpenGLContext::currentContext()->functions();
diff --git a/src/gui/painting/qplatformbackingstore.h b/src/gui/painting/qplatformbackingstore.h
index fe0f460ed9..2c183f6d6f 100644
--- a/src/gui/painting/qplatformbackingstore.h
+++ b/src/gui/painting/qplatformbackingstore.h
@@ -110,9 +110,11 @@ public:
// offset is the (child) window's offset in relation to the window surface.
virtual void flush(QWindow *window, const QRegion &region, const QPoint &offset) = 0;
#ifndef QT_NO_OPENGL
- virtual void composeAndFlush(QWindow *window, const QRegion &region, const QPoint &offset, QPlatformTextureList *textures, QOpenGLContext *context);
+ virtual void composeAndFlush(QWindow *window, const QRegion &region, const QPoint &offset,
+ QPlatformTextureList *textures, QOpenGLContext *context,
+ bool translucentBackground);
virtual QImage toImage() const;
- virtual GLuint toTexture(const QRegion &dirtyRegion, QSize *textureSize) const;
+ virtual GLuint toTexture(const QRegion &dirtyRegion, QSize *textureSize, bool *needsSwizzle) const;
#endif
virtual void resize(const QSize &size, const QRegion &staticContents) = 0;
diff --git a/src/platformsupport/eglconvenience/qeglplatformbackingstore.cpp b/src/platformsupport/eglconvenience/qeglplatformbackingstore.cpp
index 7b627f85ae..7923ef1cab 100644
--- a/src/platformsupport/eglconvenience/qeglplatformbackingstore.cpp
+++ b/src/platformsupport/eglconvenience/qeglplatformbackingstore.cpp
@@ -165,13 +165,15 @@ void QEGLPlatformBackingStore::flush(QWindow *window, const QRegion &region, con
}
void QEGLPlatformBackingStore::composeAndFlush(QWindow *window, const QRegion &region, const QPoint &offset,
- QPlatformTextureList *textures, QOpenGLContext *context)
+ QPlatformTextureList *textures, QOpenGLContext *context,
+ bool translucentBackground)
{
// QOpenGLWidget content provided as textures. The raster content should go on top.
Q_UNUSED(region);
Q_UNUSED(offset);
Q_UNUSED(context);
+ Q_UNUSED(translucentBackground);
QEGLPlatformScreen *screen = static_cast<QEGLPlatformScreen *>(m_window->screen());
QEGLPlatformWindow *dstWin = screen->compositingWindow();
diff --git a/src/platformsupport/eglconvenience/qeglplatformbackingstore_p.h b/src/platformsupport/eglconvenience/qeglplatformbackingstore_p.h
index 8b0566afa6..f3c4b9e559 100644
--- a/src/platformsupport/eglconvenience/qeglplatformbackingstore_p.h
+++ b/src/platformsupport/eglconvenience/qeglplatformbackingstore_p.h
@@ -68,7 +68,8 @@ public:
QImage toImage() const Q_DECL_OVERRIDE;
void composeAndFlush(QWindow *window, const QRegion &region, const QPoint &offset,
- QPlatformTextureList *textures, QOpenGLContext *context) Q_DECL_OVERRIDE;
+ QPlatformTextureList *textures, QOpenGLContext *context,
+ bool translucentBackground) Q_DECL_OVERRIDE;
const QPlatformTextureList *textures() const { return m_textures; }
diff --git a/src/plugins/platforms/xcb/qxcbbackingstore.cpp b/src/plugins/platforms/xcb/qxcbbackingstore.cpp
index ada5b0eedf..6258b29fc7 100644
--- a/src/plugins/platforms/xcb/qxcbbackingstore.cpp
+++ b/src/plugins/platforms/xcb/qxcbbackingstore.cpp
@@ -337,9 +337,10 @@ void QXcbBackingStore::flush(QWindow *window, const QRegion &region, const QPoin
#ifndef QT_NO_OPENGL
void QXcbBackingStore::composeAndFlush(QWindow *window, const QRegion &region, const QPoint &offset,
- QPlatformTextureList *textures, QOpenGLContext *context)
+ QPlatformTextureList *textures, QOpenGLContext *context,
+ bool translucentBackground)
{
- QPlatformBackingStore::composeAndFlush(window, region, offset, textures, context);
+ QPlatformBackingStore::composeAndFlush(window, region, offset, textures, context, translucentBackground);
Q_XCB_NOOP(connection());
diff --git a/src/plugins/platforms/xcb/qxcbbackingstore.h b/src/plugins/platforms/xcb/qxcbbackingstore.h
index af3c004c2d..725d0511af 100644
--- a/src/plugins/platforms/xcb/qxcbbackingstore.h
+++ b/src/plugins/platforms/xcb/qxcbbackingstore.h
@@ -62,7 +62,8 @@ public:
void flush(QWindow *window, const QRegion &region, const QPoint &offset);
#ifndef QT_NO_OPENGL
void composeAndFlush(QWindow *window, const QRegion &region, const QPoint &offset,
- QPlatformTextureList *textures, QOpenGLContext *context);
+ QPlatformTextureList *textures, QOpenGLContext *context,
+ bool translucentBackground);
#endif
QImage toImage() const;
void resize(const QSize &size, const QRegion &staticContents);
diff --git a/src/widgets/kernel/qopenglwidget.cpp b/src/widgets/kernel/qopenglwidget.cpp
index 68e3082c14..d8f31bfcc8 100644
--- a/src/widgets/kernel/qopenglwidget.cpp
+++ b/src/widgets/kernel/qopenglwidget.cpp
@@ -365,6 +365,10 @@ QT_BEGIN_NAMESPACE
where a semi-transparent QOpenGLWidget with other widgets visible underneath
is required.
+ Note that this does not apply when there are no other widgets underneath and
+ the intention is to have a semi-transparent window. In that case the
+ traditional approach of setting Qt::WA_TranslucentBackground is sufficient.
+
\e{OpenGL is a trademark of Silicon Graphics, Inc. in the United States and other
countries.}
@@ -670,11 +674,13 @@ QOpenGLWidget::~QOpenGLWidget()
OpenGL widgets, individual calls to this function can be replaced by one single call to
QSurfaceFormat::setDefaultFormat() before creating the first widget.
- \note Requesting an alpha buffer via this function will not lead to the desired results
- and should be avoided. Instead, use Qt::WA_AlwaysStackOnTop to enable semi-transparent
- QOpenGLWidget instances with other widgets visible underneath. Keep in mind however that
- this breaks the stacking order, so it will no longer be possible to have other widgets
- on top of the QOpenGLWidget.
+ \note Requesting an alpha buffer via this function, or by setting
+ Qt::WA_TranslucentBackground, will not lead to the desired results when the intention is
+ to make other widgets beneath visible. Instead, use Qt::WA_AlwaysStackOnTop to enable
+ semi-transparent QOpenGLWidget instances with other widgets visible underneath. Keep in
+ mind however that this breaks the stacking order, so it will no longer be possible to
+ have other widgets on top of the QOpenGLWidget. When the intention is to have a
+ semi-transparent top-level window, Qt::WA_TranslucentBackground is sufficient.
\sa format(), Qt::WA_AlwaysStackOnTop, QSurfaceFormat::setDefaultFormat()
*/
diff --git a/src/widgets/kernel/qwidgetbackingstore.cpp b/src/widgets/kernel/qwidgetbackingstore.cpp
index 6f635611f0..bb4518ec5e 100644
--- a/src/widgets/kernel/qwidgetbackingstore.cpp
+++ b/src/widgets/kernel/qwidgetbackingstore.cpp
@@ -113,7 +113,12 @@ void QWidgetBackingStore::qt_flush(QWidget *widget, const QRegion &region, QBack
#ifndef QT_NO_OPENGL
if (widgetTextures) {
widget->window()->d_func()->sendComposeStatus(widget->window(), false);
- backingStore->handle()->composeAndFlush(widget->windowHandle(), region, offset, widgetTextures, tlw->d_func()->shareContext());
+ // A window may have alpha even when the app did not request
+ // WA_TranslucentBackground. Therefore the compositor needs to know whether the app intends
+ // to rely on translucency, in order to decide if it should clear to transparent or opaque.
+ const bool translucentBackground = widget->testAttribute(Qt::WA_TranslucentBackground);
+ backingStore->handle()->composeAndFlush(widget->windowHandle(), region, offset, widgetTextures,
+ widget->d_func()->shareContext(), translucentBackground);
widget->window()->d_func()->sendComposeStatus(widget->window(), true);
} else
#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-10 11:38:52 +0000