I am trying to understand if it is possible to access (read / write) single pixels within an image in Corona. Looking at http://docs.coronalabs.com/api/library/display/newImage.html and surrounding documents seems its not available, but I would appreciate a short confirmation from a Corona expert.
(some tags to make it searchable in the future: getpixel, setpixel, bitmap, corona)
Since Daily Build 2106 you can get the color of a pixel in the display:
Color Sample Function
And for setpixel you can place a new rect of 1×1.
newRect Function
In one word: no :)
I think Corona is going to implement this in the future, but I'm not sure.
Its not there, here is the place users can vote for that feature on corona website http://feedback.coronalabs.com/forums/188732-corona-sdk-feature-requests-feedback/suggestions/3625203-bitmap-manipulation-read-pixel-e-g-for-selecti
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I’m trying to build a drawing/painting app for the iPad, with textured brush tips and paper.
So far, all drawing app example codes I've come across seem to work by stroking a path. However, I'd like to actually apply a texture all along the path, to simulate say, an oil brush, or charcoal.
Here is an example of a brush tip texture: Bursh tip
The result when painting with the same brush tip: Result
In the results, the top output is what it looks like when the "brush tip" texture is applied far apart along the path.
The bottom result is the texture applied with very small steps along the path. Those who've worked in Photoshop with custom brushes will find this familiar.
I had once prototyped this in Processing years ago (I've since lost the source code), and got it to work in real-time.
In Processing, I converted both the brush tip PNG and the canvas (or the image I'm painting on to) into an array of integers. Then, I simply copied the values from the brush tip to the canvas texture, at the appropriate index. At the end of the cycle, I displayed the image, for that time-step. Repeat this dozens of times in-between each point returned by the mouse.
How would I approach this in iOS, and in real-time? I tried this (https://blog.avenuecode.com/how-to-use-uikit-for-low-level-image-processing-in-swift) but it's way too slow.
This makes me believe Metal might be the only way forward. Is that true, or am complicating this unnecessarily?
Thank you for any guidance!
PS. I'm coding in Swift 5, targeting iOS 13, in Xcode 11.5.
Welcome!
I recommend you check out Core Image. It's Apple's framework for image processing (on a higher level than Metal, though it can integrate with Metal). Unfortunately, the documentation is a bit out-dated, but I'm sure you can translate it into Swift.
Here Apple describes how you would realize a painting app with Core Image and here you can download the corresponding sample project.
I want to create some objects (boxes, cylinders, pyramids, doesnt really matter) which display text / a number on the side / on all of it's sides. Short of making individual materials with the numbers displayed on them by hand, is there a simple way to achieve this?
I am using Swift 4 in XCode.
First thing, please try not to be discouraged. Thank you for reaching out to the ARKit community on stack :-)
We are here to help each other.
(I do feel your pain…and why I am trying to help)
Here is an interesting stack page that has helped me with placing items on the sides of objects(like boxes cylinders, pyramids).
I hope it can help you or others.
SCNBox different colour or texture on each face
Rickster pointed out some other possibilities.
We all learn by sharing what we know.
Smartdog
Depends on what you mean by "by hand". If you want the text displayed on the surface of the geometry, like a texture map, then texture-mapping it is the way to go. If you draw your text into a UIImage, you can set that as the material contents, which is a bit more dynamic than, say, creating a bunch of PNGs that each have a different number on them. Just make sure to choose an image size/resolution that looks good at the size your objects are displayed at.
For anyone lost in the internet trying to find an answer to this it's stupidly simple. Use SCNText and set it as a node. I just wasted 7 hours of my life trying to make number .dae models position themselves next to each other because there is no mention of this feature anywhere.
I hope I saved you as much pain as I just endured discovering this.
I'm trying to develop a simplistic 2D browser game with dart.
The player is drawn from a png-image represented by an ImageElement in dart.
I want the player-image to turn towards the mousepointer, but cant find how to rotate an image in dart.
Any suggestions as to how this might be done?
I would highly recommend using the StageXL library for this (https://pub.dartlang.org/packages/stagexl). It's basically a recreation of the Flash APIs for Dart. It makes doing that sort of thing very easy, and it's often used to create Dart games.
I ended up using multiple images for the 8 general directions the player can move and set them accordingly.
I have a platform application with a series of platforms in an array and a player. Since the map is quite large, I would like to implement a minimap to keep the player from being lost/confused. What is the best way to implement this (the way with the least resource consumption)? Thank you!
If your whole level is in a big display group, you could save the image to a file, load it in and scale it down to the size of your minimap.
What I basically need to achieve is a Fruit Ninja - style "slash" effect, where the "slash" trails the user's touch and follows the shape of the user's gesture, and is thinner the longer the distance the user has swiped.
The simplest way to achieve this seemed to be to collect all the points the user passes through in a UIBezierPath, and "stretch" an image through the length of the BezierPath. This would achieve the kind of "trailing" effect I was looking for and also ensure that the line is thinner if the distance travelled is longer.
However I can't seem to find a way to actually implement this. Is this even possible?
Alternatives? Thanks.
P.S: This is for a low-medium priority section of a regular app and not a game, so I would like to avoid having go down to OpenGL and spend a lot of time to achieve this (with completely custom drawing, etc). Something at the SDK level would be preferred, and if that's not possible at all, we'll just figure out a different UI.
Thanks!
For pretty easy-to-use stretching teqhniques of images/views you could look into
https://github.com/hfossli/AGGeometryKit/
I recommend trying to draw using CoreGraphics. See this link
http://www.effectiveui.com/blog/2011/12/02/how-to-build-a-simple-painting-app-for-ios/
Okay. Maybe you can use this.
https://github.com/hfossli/AGDraw
Just something I wrote a while ago. Hit clear and try to draw something (clear will toggle between two types of strokes). You'll see the width of the penstroke will increase with the velocity you use.. I guess that fits your need. If you fix some bugs, please make a pull request. You are free to use the code, but I will add a MIT license later.