How to I load a very large image eg 1024*4608 using cocos2d-iphone and be able to scroll the image?
Your application will be more responsive if you break up your very large image into tiles. Tiles are smaller images, usually 256 X 256, that can be reassembled by your application into the large image. You display just the tiles that are visible. This uses less phone memory.
Here's a blog post with some Cocos2D-iPhone image scrolling.
Related
I am using QSplashScreen to display a splash screen for my QtQuick 2 application. I am using a decent quality image (838 X 500). It displays correctly in some screen resolutions. But for some other resolutions like 2K resolution, it looks like some low quality transformation is applied.
Already tried Qt::SmoothTransformation
Connecting my laptop to my monitor (I have 2K monitor) and selecting 'Duplicate display' option in display management, produces low quality image. Selecting 'Second screen only' produces decent quality image.
QPixmap pixmap(qApp->applicationDirPath()+"/splash.png");
QSplashScreen splash(pixmap.scaledToWidth(screen_width*0.35,Qt::SmoothTransformation));
splash.show();
Is there a way to display an image without loosing the quality?
I am experiencing the same issue with 'Image' in QML.
If Qt is attempting to render the image at the same "physical" size on a higher resolution display, then it will have no choice but to upscale the image. You should provide a higher resolution image:
https://doc.qt.io/qt-5/scalability.html#loading-files-depending-on-platform
The target platforms might automate the loading of alternative
resources for different display densities in various ways. On iOS, the
#2x filename suffix is used to indicate high DPI versions of images.
The Image QML type and the QIcon class automatically load #2x versions
of images and icons if they are provided. The QImage and QPixmap
classes automatically set the devicePixelRatio of #2x versions of
images to 2, but you need to add code to actually use the #2x
versions:
if ( QGuiApplication::primaryScreen()->devicePixelRatio() >= 2 ) {
imageVariant = "#2x";
} else {
imageVariant = "";
}
Forget the part about iOS - I think it's outdated, because it has applied to all platforms for a while now.
So in your case, you should add a splash#2x.png that is twice the resolution (and detail) of splash.png. If you're just using QPixmap, you will need to add the code above to ensure the correct image variant is selected. If you're using QML's Image type, it will select it automatically.
I'm trying to retrieve file icons on Windows. I follow this guide http://pogopixels.com/blog/getting-the-48x48-or-256x256-icon-of-a-file-on-windows/
I use SHIL_JUMBO to get the maximum size possible. However, not all icons returned are big enough, such as the QuickTime icon in the attached image. The size of the whole pixmap returned is still 256x256 but it does not fill the entire space. My program will then scale it down, making it too tiny to see.
I'm wondering if I can retrieve some extra info such as the size of the original icon, so I know that it's too small to scale down.
Picture and c++ files can be found here: http://phantomworksstudios.com/cpp/ss/
Ok so I have been having a lot of problems with my toolbars. such as them not displaying correctly, can't set the button size via height and width no matter what I do, the bitmaps are off set by 1 pixel to the right which are the back,forward,stop, etc icons. and the other icons such as the clip board and new file which is the last tool bar under the rest are cut off bad. I think its still trying to strip the tool bar list as 16x16 but the bitmap I have icons as 14x14.
The icons are within a bmp file which is 32 bit depth
one is 16x16 while the last one is 14x14
I have no idea what is going on and no matter what I can't seem to get it working like it should:
In a MFC SDI application containing a single CView, I pass the output device context pDC->m_hDC to a mapping library to render the map within the CMyView::OnDraw() method.
I would like the rendered image to appear in the centre of the cview surrounded by a black background, i.e. the image size would be smaller than the CView client rect size. I have experimented with CDC::SetViewportOrg() and set the device size in the mapping library, however unfortunately the mapping library draws outside of the device size set.
What is the best way of limiting the image to the desired size? Should I be looking at clipping functions? Or do I have to manually draw over the undesired parts of the image.
Well you can do it 2 ways.
1) You could SetBoundsRect to the boundaries you want.
2) You could just bit blt the section of the image you want into the DC.
Method 2 would be my preferred method as there is no extra logic. It only ever even tries to draw the part you are blitting :)
We have a touch screen, and the toolbar is too small to hit with my meaty fingers. Is there an easy way I can have an option to make the toolbar buttons bigger and easier to hit?
So far I've attempted a few things:
m_toolbar.SetSizes( CSize(64,64), CSize(50,50) );
m_toolbar.SetSizes( CSize(64,64), CSize(50,50) );
m_toolbar.GetToolBarCtrl().SetButtonWidth( 64, 64 );
m_toolbar.GetToolBarCtrl().SetButtonSize( CSize(64, 64) );
None of these approaches stretches the images as well. The buttons get larger, and are fully functional, but the images do not overlap the buttons the way they normally would. I would prefer to keep a single image list for the icons, and have the images stretched to fit.
At toolbar creation time, create an empty CImageList with size 64x64 (let's call it large). Load the original image list from resources (we call it small).
Iterate over each image in small and copy/resize it to large.
Then assign large to your toolbar. Somewhat cumbersome bui should work.
HTH,
As far as I know there is no way to make images resize with the size of the buttons. MFC applications use bmp and not vectorial images.
So you will have to supply a bmp images with the disired sizes.
You can use a CImageList and SetImageList to set the images but then you will have to
initialize images there with the disired size also.