Right so I got all my lovely openGL stuff working and I can change the background colour via the property of the view or even the window however for the love of god I cant change it to an image.
I have tried adding it to the nib
I have tried adding a UIImageView as
a subview.
I have tried addiing it as a UIColor
with Pattern
I tried making the OpenGL view have a
clear background and setting the
image on the actual window.
Still no joy!
Issue a glClear then render 2 triangles (ie a quad) to the screen with the appropriate image texture mapped onto them.
Related
I am trying to make an app that can annotate PDFs.
What I have done, is add the PDF through a UIWebview, so my main UIViewControllerhas a UIWebView Delegate.
What I am trying to do is put my drawing layer, which is a UIView over the top of my PDF view.
I have tried setting the background colour to "clearColour" and the opaque property to no, I still get a weird affect.
I think the issue might be because of drawing a bitmap onto the UIView, but I would still like some insight, or an example if one exists.
Thanks.
This is an image of the problem, the little white band at the top is the PDF, the white box is the UIView which I am drawing on.
The code I used for the "drawing code" is here, see "SmoothedBIView"
http://mobile.tutsplus.com/tutorials/iphone/ios-sdk_freehand-drawing/
Sorry, just noticed you had two questions. Again maybe this project can help you.
First of all, I am newbie iPhone developer. I am using Particle created from Particle Designer(.pex file)(71squared). My application is not cocos2d. How to set the background image. My application has a image in background and adding this particle view with particle designes pex file as subview to it. Now, this particle view is hiding the background image with pex file's black background. I tried to put background to pex file when creating it. But it is not including that. I tried to put background image to view that I created to load this pex file, that didn't help. I tried to put background image to particle view that I am loading this view over, that didn't help. Is there any other way I could implement this?
Go here and download the zip to see an example
https://github.com/icanzilb/UIEffectDesignerView
I have numerous photos in portrait and landscape format. I want to be able to display a "crop" of the photo in a UIImageView on the iphone. If the picture is in landscape format I want it to resize to fit the frame, if it is in portrait format I need it to resize to fit the width, and then be cropped at the top and bottom. As if there is a "window" over the image - so it looks like a landscape picture.
It would be even better if this could be a UIButton - although I am aware that I can use touchesBegan and such on images to make it behave like a button if needs be.
Thanks for any help you can give me.
Thanks
Tom
In an ImageView, you can change the View Mode to Aspect Fill. It will give you the right scaling/cropping you want.
For interactions, you can use a Custom button with no drawing at all (no Title, no Image, no Background) with the same size as your ImageView. That would be safe with regards to the image aspect. I've tried similar stuff using the button's Background or Image properties, it can have some undesired effects (I've ran into a resizing issue on iOS 3.1.3 for instance).
1°) To Crop the Image, try to add a method to UIImage class to do it (you can google it without problem, or even on StackOverFlow)
2°) To add a "window" over your image, just add an UIImageView over your image wich has transparency. It should work ;-)
3°) To know when an image is touched, you can use "touchesBegan" to detect which image were selected. But I think it's the last of your problems ^^
What you cant to achieve isn't so hard, just to it step by step !
If you want more help in one step, say it. But I can't code it all for you ;-)
Good Luck
I am developing an iphone application which would let me modify the image by dragging other images over its top along with functionality that would let me choose a specific color from the image and replace it with some other color shades i choose. If anyone has some clue like how to actually implement it or some code, that would be great help for me to proceed in right direction
Thanks in advance :)
If you just want to overlay images, you can simply drag UIImageViews around and position them within the view hierarchy such that the appropriate images are overlaid one on top of the other.
For generating a new image out of those composited images, you may want to use something like CGContextDrawImage() within a UIView subclass's -drawRect: method or in a custom CGContext. You can also refer to these similar questions:
How can we combine images and get image object from this two images in iphone apps
Combining images
As far as selectively replacing a specific color within a UIImage, that's a commonly asked question here:
In a UIImage (or its derivatives), how can I replace one color with another?
How to make one color transparent on a UIImage?
I'm trying to place a red tint on all the screens of my iPhone application. I've experimented on a bitmap and found I get the effect I want by compositing a dark red color onto the screen image using Multiply (kCGBlendModeMultiply).
So the question is how to efficiently do this in real time on the iPhone?
One dumb way might be to grab a bitmap of the current screen, composite into the bitmap and then write the composited bitmap back to the screen. This seems like it would almost certainly be too slow. In addition, I need some way of knowing when part of the screen has been redrawn so I can update the tinting.
I can almost get the effect I want by putting a red, translucent, fullscreen UIView above everything. That tints everything red within further intervention on my part, but the effect is much "muddier" than results from the composite.
So do any wizards out there know of some mechanism I can use to automatically composite the red over the app in similar fashion to what the translucent red UIView does?
I managed to somewhat make this work but with some side-effects:
I setup a UIView on top of all my app-views (attached to the window) which is not userInteractionEnabled and which is opaque
This UIView carries some custom drawRect-method which first fills the complete area with red color and then after having made a "screenshot" of my window-viewhierarchy I am rendering this image with
CGContextSetBlendMode( c, kCGBlendModeMultiply);
to the UIView.
To constantly update this UIView to the current state of the apps UIViews I constantly produce "screenshots" and render them as fast as possible.
I setup an NSTimer which is doing this snapshotting/rendering in a defined frequency and which is added to the the NSRunLoop for "Tracking".
RESULT: some really laggy response from the UI with several fancy effects, but still usable though if you do not set the frequency of snapshotting/rendering to high.
See screenshot here...
The result looks okay, but the usability really suffers a lot. I had a look at the OpenGL-examples before trying this aproach, but OpenGL is a whole lot of different (mostly C) code which seems to be very near to the hardware and which gives you a real headache.
So, the described approach is what I will shoot for with my next app. I hope Apple accepts it even though it degrades UXP during nightvision mode. They should simply make CALayer filter-backed then my problem will definitely be solved a whole lot better and performing nicely.
You could try this: subclass UIView. Add code to -drawRect method to draw the overlay. Make your UIView subclass pose as UIView everywhere in your app with
class_poseAs ([CustomUIView class], [UIView class]);