I have a splash screen image that I display with splash.showFullScreen() but it doesn't re size it to the screen resolution so it either comes out tiled or to large depending on the display. I have tried everything I can think of but nothing works. This might sound like a stupid question which it probably is but I can't find the answer so if any can just help me with this? If it makes a difference I use a QPixmap named pixmap for the splash image. By the way I want the image to be stretched to the screen resolution.
You should scale the pixmap to the size of the screen with QPixmap::scaled(). You can get the screen resolution by calling QDesktopWidget::screenGeometry(). The desktop widget can be obtained by QApplication::desktop().
You can try something like this:
QDesktopWidget* desktopWidget = qApp->desktop();
QRect screenGeometry = desktopWidget->screenGeometry();
int screenWidth = screenGeometry.width();
int screenHeight = screenGeometry.height();
QPixmap pixmapForSplash = yourPixmap.scaled(screenWidth, screenHeight);
QSplashScreen splashScreen(pixmapForSplash);
(I'm sorry, I can not check this, because I do not have a development environment on this computer... I hope it is correct.)
I think you should call resize() method for your splash screen by the size of the available desktop geometry that you can get using QDesktopWidget::availableGeometry method. The QApplication::desktop() function is used to get an instance of QDesktopWidget.
slpashScreen.resize(QApplication::desktop()->avaiableGeometry().size());
If you use a QLabel to display the image, make sure the label is in a layout that will cause it to fill the entire parent widget and set the label to scale its contents using setScaledContents(true).
Related
I would like to ask you about an issue I do not succeed to fix.
I have a QApplication which load an image in the first mainwindow.
The code is the following:
QGraphicsScene *scene = new QGraphicsScene;
QPixmap pixmap(QString::fromStdString("image.png");
scene->addPixmap(pixmap);
ui->graphview->setScene(scene);
ui->graphview->show();
I am trying to fit the image to scale in the QGraphivsView, even when I resized my windows.
However, the image is displayed with its own size at running time and this size is not changing when windows is resized. For example, increasing my windows does not increase the image size and similarly for decreasing.
I tried even by addind the following code:
ui->graphview->fitInView(pixmap, Qt::KeepAspectRatioByExpanding);
But nothing is working.
I provide you an example on the following image of what is happening.
I have found a way however, it is not 100% satisfying.
I have replaced the resizeEvent function as on the example below:
void QMainWindows::resizeEvent(QResizeEvent *){
QRectF bounds = ui->graphQSYS->scene()->sceneRect();
ui->graphQSYS->fitInView(bounds, Qt::KeepAspectRatioByExpanding);
ui->graphQSYS->centerOn(bounds.center());
}
However, when resizing, the image quality is becoming really bad. Text written on it cannot be read anymore. Do you know another way to keep picture quality ?
Thank you very much.
This may be a simple question but I'm having a hard time finding a straight answer to it: is there a way to resize a loaded Texture in SFML 2.0? For instance, if I have a 3264x2448 png and I want to scale it down to fit a 900x1200 rendered window without cropping, how would I do so?
Is there a way to scale all rendered windows to fit whatever monitor
of whatever system the application is running on?
First, here's a way to scale the image to the current RenderWindow size.
// assuming the given dimension
// change this dynamically with the myRenderWindow->getView().getSize()
sf::Vector2f targetSize(900.0f, 1200.0f);
yourSprite.setScale(
targetSize.x / yourSprite.getLocalBounds().width,
targetSize.y / yourSprite.getLocalBounds().height);
Be aware that this may stretch your image if the aspect ratio is not maintained. You might want to add code to adjust the decision for your case.
Then, if you want to stretch the RenderWindow to fill all the screen, may I suggest you use fullscreen mode?
Here's a snippet of how it's done:
// add the flag to the other ones
mStyleFlag = sf::Style::Default | sf::Style::Fullscreen;
// get the video mode (which tells you the size and BPP information of the current display
std::vector<sf::VideoMode> VModes = sf::VideoMode::getFullscreenModes();
// then create (or automatically recreate) the RenderWindow
mMainWindow.create(VModes.at(0), "My window title", mStyleFlag);
is there a way to resize a loaded Texture in SFML 2.0?
Not an sf::Texture directly. But you can use an sf::Sprite: you load load your texture, you pass it to an sf::Sprite and you play with sf::Sprite::setScale or sf::Sprite::scale.
I'm creating 2D Map editor using opengl to draw simple 32x32 sprites but it seems that I cannot resize my QGLWidget to a large size (i.e size * sprite size -> 1024 * 32), using 1024 only seems to work fine (using glwidget->setMinimumSize(...)). I've been googling for a while now about this, the only interesting thing I found is subclassing QAbstractScrollArea and setting my QGLWidget as it's viewport (That's what QGraphicsView does), I also seen all Qt opengl examples but i couldn't find anything that could help (except Image Viewer example which is not exactly what I want), I also tried the following:
horizontalScrollBar()->setMaximum(width * 32);
verticalScrollBar()->setMaximum(height * 32);
with the widget resizable set to true/false on the scrollarea but still nothing.
Any ideas how would I do that? I can show more code if you ask me to.
Using Qt v4.7.3.
I have two ideas:
If it's possible, drop the idea of using a QGLWidget and place the sprites directly in a graphics scene (QGraphicsPixmapItem). Possibly not what you want, but the graphics scene is made to handle a lot of items, so most things you need (trigger mouse events on items for example) are already implemented.
Or just place the QGLWidget in a graphics scene using a QGraphicsWidget. This should automatically tell the scene its size, which then tells the view the size of the scene. The scroll bars appear automatically if the scene doesn't fit into the view.
Update:
As described in this link, you can use OpenGL in any graphics view:
view.setViewport(new QGLWidget(QGLFormat(QGL::SampleBuffers)));
view.setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
So, this is my problem: I have this very big image, and I want to show only a specific part of it. After the user pressing a specific key I want the image to move, showing another part of it. The transition from one part of the image to another have to be smooth, animated.
I tried using a QLabel to show the image but it always shows the center of the image, and I do not really know how to make the animation. What would you guys suggest?
Interesting question. Here is something I just tested and seems to work.
Add a QGraphicsView with dimensions the dimensions of the part of the image you want to display, eg 100x100. Create a QGraphicsScene and add it to the view:
QGraphicsScene* pScene = new QGraphicsScene(this);
ui->graphicsView->setScene(pScene);
Now add your image into the scene. In my case I has an image in my resource file. The trick is to set the sceneRect to the position you want to display. I wanted to display an 100x100 part of the image starting from 0,300 :
pItem = pScene->addPixmap(QPixmap::fromImage(QImage(":/photos/image")));
pScene->setSceneRect(0,300,100,100);
In order to test the smooth moving I added a button which when clicked is triggering a slot called move. This slot simply updates the sceneRect. In my simple example I just move the image 100 pixels right. In a real world scenario you could also move it diagonally or vertically and check the image limits.
void move()
{
for (unsigned i=currentX; i<currentX + 100; i++)
{
ui->graphicsView->scene()->setSceneRect(i,300,100,100);
qApp->processEvents();
}
currentX += 100;
}
Notice the currentX variable. It is nothing more than the last image position. Also we must call the processEvents in order to "see" the image moving smoothly.
You could use QPixmap::copy( int x, int y, int width, int height ) to copy a region of the image and display that.
Few options:
Try using a Q3CanvasSprite (within in a Q3Canvas). It is designed more for splitting one image into multiple ones but not for animating between them. You could try abusing it and declaring (say) 100 frames (10 per digit, which would be used as animation steps) or just use the move() method.
Try QGraphicsPixmapItem::setOffset() (within a QGraphicsScene). This might be overkill as QGraphicsScene is made for large number of images).
I'm not sure, but maybe this can be done with QStateMachine and QAbstractAnimation.
I am just starting with MFC so please be tolerant ;).
I have wrote (it was mostly generated to be honest) a simple application which should do the Paint chores: drawing lines, rectangulars, ellipses, changing a color of object to be drawn etc.
I need to save what has been drawn on the screen into a bmp file. Any ideas how can I achieve this ?
I do not know if that's relevant but I am drawing objects on the screen without the use of any CBitmaps or things like that. Here is a part of code responsible for drawing :
CPaintDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
Anchor.x=point.x;
Anchor.y=point.y;
OldPoint.x=Anchor.x;
OldPoint.y=Anchor.y;
if(pDoc->shapeCount>=MAX_SHAPES) return;
pDoc->shapeCount++;
if(bFreehand)
{
pDoc->m_shape[pDoc->shapeCount-1] = new Shape;
pDoc->m_shape[pDoc->shapeCount-1]->shape = ePoint;
}
if(bLine)
{
pDoc->m_shape[pDoc->shapeCount-1] = new CLine;
pDoc->m_shape[pDoc->shapeCount-1]->shape = eLine;
}
if(bRectangle)
{
pDoc->m_shape[pDoc->shapeCount-1] = new CRectangle;
pDoc->m_shape[pDoc->shapeCount-1]->shape = eRectangle;
}
if(bEllipse)
{
pDoc->m_shape[pDoc->shapeCount-1] = new CEllipse;
pDoc->m_shape[pDoc->shapeCount-1]->shape=eEllipse;
}
pDoc->m_shape[pDoc->shapeCount-1]->x=point.x;
pDoc->m_shape[pDoc->shapeCount-1]->y=point.y;
pDoc->m_shape[pDoc->shapeCount-1]->x2=point.x;
pDoc->m_shape[pDoc->shapeCount-1]->y2=point.y;
pDoc->m_shape[pDoc->shapeCount-1]->Pen=CurrentPen;
pDoc->m_shape[pDoc->shapeCount-1]->Brush=CurrentBrush;
bButtonDown=true;
SetCapture();
I have found this way to do it but I don't know how to obtain screen width and height to fill it in the CreateBitmap parameter's list
CBitmap *bitmap;
bitmap.CreateBitmap(desktopW, desktopH, 1, 32, rgbData);
CImage image;
image.Attach(bitmap);
image.Save(_T("C:\\test.bmp"), Gdiplus::ImageFormatBMP);
The CreateBitmap call only requires the desktop width and height if the image you wish to save is actually the entire size of the screen. If that's indeed your intent, you can use CWnd::GetDesktopWindow() to get a CWnd object that you can query for its width and height:
http://msdn.microsoft.com/en-us/library/bkxb36k8(v=VS.80).aspx
That gets dodgy in general...if for no other reason than multi-monitor scenarios...so I'd recommend against it unless you really feel like writing a screen capture app.
What you probably want to do isn't to take a full screen shot, but just save the contents of your program's window. Typically you'd do this by breaking out the drawing logic of your program so that in the paint method you call a helper function that is written to take a CDC device context. Then you can either call that function on the window-based DC you get in the paint call or on a DC you create from the bitmap to do your save. Note that you can use a CBitmap in CDC::SelectObject:
http://msdn.microsoft.com/en-us/library/432f18e2(v=VS.71).aspx
(Though let me pitch you on not using MFC. Try Qt instead. Way better.)