I'm pretty new to OpenSceneGraph and I have the following problem:
I'm trying to build a 2D Head Up Display out of several images, so that it can resize depending on the screen's resolution. That means I have extra images for the corners and one image for the bar that connects the corners and so on.
Well, that's the idea. But I have no clue how to do that in OpenSceneGraph.
Can anybody help me?
So, when the window resizes, you'll get an event from osgViewer telling you about the change.
You need to resize your viewport when the window size changes, so your HUD geometry has some idea of what the pixel-size of the display is (most of the HUD examples setup for a nominal 1024x768 screen and then just let that stretch around as the window is resized, pretending like the new viewport is still 1024x768).
Once you've resized the viewpoer, you need to rearrange your geometry. Your corner pieces need to be laid out at the fixed pixel size you want them to always appear, then you need your connecting elements to change size, horizontally or vertically, to fill the space between the corner pieces. You usually rely on texture stretching or repeating to fill the space as the piece of geometry gets stretched.
If none of that makes any sense, I can describe more.
Related
We have a typical bootstrap SPA that we turned into a React site.
In one of the sections there's an image that appears in the right side of the layout, and it spans the section vertically (takes up about 50% horizontally).
When the window is reduced in size, at some intermediary positions, the image no longer spans the section vertically, making it float above what looks like a margin or a frame, but in fact, it's just the background color of the section whose aspect ratio is not enough to hold the image completely.
Is there a way to prevent this? It seems like the only solution would be to pick images that are have aspect ratios that are more amenable to the half the grid position they are being given.
I want to fit the Image + Label into Scrollable View.
It looks like so My setup
So trouble here is that width of the picture and the label did not match the screen width.
I tried to change the UIImageView width from 400 to 300 or so, BUT those changes either wont take the effect(if above 300), OR those changes make label disappear (with width setted up on 300 or below). Observe.
Funny thing is - label actually appears when you see view hierarchy, even though it looks kinda distorted. But no label on the iOS screen for you, sir.
I also tried to set equal width and height from the superview, but this option just disabling scroll, making view strictly fit the screen (label appears to be cropped)
I want the label to be nice and scrollable, but I also want to see it on the screen. Too much to ask?
EDIT: I just tried removing Auto-layout and got the same as with auto-layout. (click "Observe" link to take a look again, exact same situation) Could somebody explain why?
This is quite a simple fix. For the image, you should use equal width & center horizontally; however, make sure you use a fixed width. For the image to look nice, play with the scale modes - I find Aspect Fit/Fill work best.
The label should also be equal width & centered horizontally. You may need to calculate the height of the label programmatically if the text isn't always going to be the same size.
So the answer to my particular question was - shortening the actual text that is passed to the label.
Apparently UIScrollView can't handle stuff with crazy abnormal heights (I was passing a huuuge text to it) So in my particular situation solution was - shorten the text. Now it works like a charm (even though I still need to play a little with constraints to get rid of the warnings and stuff)
I'm using Sketch to create images that will be used in my Xcode 6 auto-layout storyboards. However I can not get the image sizes correct. They always appear too large and overflow the storyboard view controller. Is there a way in Xcode to see the dimensions the storyboard expects? Is there a systematic way to do this...rather than trial and error?
Storyboard, especially in auto layout mode, doesn't expect any dimensions – dimensions will depend on device screen (in reality) or on simulated metrics (in Interface Builder in Xcode).
What matters is aspect ratio and presence of three resource files (three sizes – regular, 2x and 3x).
You can see the list of dimensions here:
http://www.paintcodeapp.com/news/iphone-6-screens-demystified
So, let's say you want to insert an image that occupies the whole width of the screen, and the height is chosen automatically so that to keep the aspect ratio. What you could do:
Create images in Sketch with widths of 320, 750 and 1242 pixels. Save them as image.png, image#2x.png, image#3x.png.
Insert image in Interface Builder (Storyboard), add width constraint – equal as superview, instead of height constraint – keep aspect ratio.
If the image looked too big, Interface Builder will complain that preview image doesn't match constraints, you will see a little yellow arrow. Click on it, choose the warning and click again – Xcode will offer you to "Update frame". That will resize the image correctly if necessary. Don't forget to choose correct scaling mode (Aspect fit?) for your image.
Moreover, you can see current width and height of the simulated screen in Metrics tab. But those will change every time you change your preview (simulated) device type.
I am very unexperienced and rather new to Objective-C and I'd like to ask a methodical question. What I want to do is:
Load a user provided image to show on the screen. The user should be
able to zoom. So it seems best for me to use a NSScrollView to draw
the image. I have some other demands about the behavior
When the image is loaded, it should fit the NSScrollView without
being stretched in either direction.
When the user now changes the size of the NSScrollView (via changing
the size of the window) the image should be resized appropriately.
If the user at some point zooms the image, it shall not be resized
when changing the size of the NSScrollView. If the image is zoomed
to fit into the NSScrollView (means like when loaded) it should be
resized again when changing the size of the NSScrollView. I think
this is the same behavior as in Apple's preview app.
I guess this is easy to achieve for an experienced programmer, but I have some issues. Here's what I have tried.
I load the image via
[[NSImage alloc] initWithContentsOfFile:imagePathStr];
on a button click. I am also able that it is displayed to fit nicely (on load) into the NSScrollView by changing the size of the image before drawing it. But I can't get the behavior right on resizing or zoom (I use the NSScrollView biuld-in zoom ability). Can someone provide some kind of list of key points that needed to be executed to achieve what I want? Or do someone rather see my explicit code to tell me what I am doing wrong?
I have an NSView in a ScrollView and I'm trying to draw an image in it. The problem is that I want the upper left corner of the image locked to the upper left corner of the frame, instead of the lower left corner, which is what the View wants me to do. I will need to be able to zoom in and out, and rotate.
currently, I have a kludge of a system where I calculate how much I have to translate my image based on the size of the image and the size of the window. In order to do this, I needed to create an extra view outside the scrollview, so that I could get the size of the window, not including decorations. Then I can calculate the size of the view based on the size of the image and the size of the window, and based on THAT, I can figure out where to translate the image to.
My only other thought was to use the isFlipped: method, but that ends up reversing my image L-R which is bad.
Is there another way I should be doing this?
If you want 0,0 to be in the upper-left corner, then overriding -isFlipped to return YES is the way to go. It should not affect the coordinate systems of any subviews (I think!), but images drawn directly into the flipped view will appear upside-down unless you apply a transform to them.
View Programming Guide for Cocoa: View Geometry