In p5.play I want to set a sprite's opacity(like Fade). How can I do that?
sprite.opacity = 0.5 //something like that
There are two ways you can do this, depending on what you're trying to make transparent.
Changing the color
This method can only be used if you don't plan on adding images to your sprites. We can use this basic function:
sprite.shapeColor.setAlpha(50)
As I said, this method can only be used with colors.
Changing the images
It is by no means efficient, but it technically works
tint(255, 0-255);
drawSprites(sprite);
tint(255)
Related
My CAMetalLayer background color is black, even if i'm assigning new color as the backgroundColor property.
Am i missing something? Thanks!
Link to the original project :
https://github.com/audiokit/MetalParticles
This project takes a rather unconventional approach to clearing the drawable's texture each frame: it replaces the textures contents with an array of zeros that is the same size as the texture (width * height * 4). Subsequently, it encodes some compute work that actually draws the particles. This is almost certainly not the most efficient way to achieve this effect, but if you want to make the smallest change that could possibly work (as opposed to experimenting with making the code as efficient as possible), Just fill the blankBitmapRawData array with your desired clear color (near line 82 of ParticleLab.swift).
I have gone through your code and can not see a place where you are setting background Color.
The metal layer is added as a sublayer to it, so you have to set it explicitly.
Add this line at the end of your init method in ParticialLab class and see if it works.
self.backgroundColor = UIColor.redColor().CGColor
I found that self.isOpaque = false was needed on the layer.
I've got the following node set as follow.
box.physicsBody.allowsRotation = YES;
No mater what force applies to this box, I want it to never fall down or rotate more than a certain angle, just like a tree or a spring that might bend all the way down but has a tendency to go back to it's initial angle or position.
Is there a any trick or method to that?
I was thinking maybe joining an invisible un-rotatable physics body under the box and use a joint spring method for that which I have no Idea how that works!
Or, maybe there be a trick to play with the pivot. Any idea?
In the update: method you will have to continuously check the desired node's properties. In your case it is going to be the zRotation property of your node.
Add this code in your update: method:
if(yourNode.zRotation > 0.5)
yourNode.zRotation = 0.5;
if(yourNode.zRotation < -0.5)
yourNode.zRotation = -0.5;
Change the 0.5 value to your desired value or replace it with a static const float.
I have a circle-shaped dynamic body and I need to resize it during the game (It appears like a point, then it grows to a circle and after that it starts moving). How should I do that?
I have an idea - it's to use some animation (Circle has the same radius, but due to animation it looks like the circle grows), but I'm not sure if it's right way or not. (Besides I don't know how to realize it)
For scaling circle, if you are using sprite just scale it sprite.setScale(float), if your sprite is attached to Box2d Circle-shape then get the Body's shape and set the radius
Shape shape = body.getFixture().getShape;
shape.setRadius(radiusValue);
and if you are using ShapeRenderer just multiply the points of ShapeRenderer.
I assume that you are talking about a Box2D body.
It is not possible to change a circle-shaped fixture with Box2D. Box2D is a rigid body simulator. What you would have to do is destroy the fixture and replace it with a smaller/bigger version of the circle. But this will cause a lot of problems, since you cannot destroy a fixture when there is still a contact for example.
It would be better to keep the circle the same size and just simulate a change in size with an animation of a texture on top.
If you cannot simulate that, then maybe try the following approach: Have several versions of that circle in different sizes and keep them on top of each other. Implement a ContactFilter which will only cause contacts for the one circle which is currently "active".
Inside any Object class with box2d, I use the following for dynamic resizing:
public void resize(float newradius) {
this.body.destroyFixture(this.fixture);
fixtureDef.density = (float) (this.mass/(Math.PI*newradius*newradius));
this.radius = newradius;
CircleShape circle = new CircleShape();
circle.setRadius(newradius);
this.fixtureDef.shape = circle;
circle.dispose();
this.fixture = body.createFixture(fixtureDef);
this.fixture.setUserData(this);
}
You can also see the following topic: How to change size after it has been created
I’m trying to put together what seems to be a simple case of two NSTextFields with dynamic width and fixed spacing in between. I cannot figure out an effective way to do so though.
I’m looking to get something like this:
The blue boxes are the NSTextFields. When more text is entered into one, it should grow and thus make the other one shrink, maintaining the lead space, trailing space and the spacing in between the fields. The first one should take the priority if both of the fields have too much text. Each field will also clearly have a maximum and a minimum possible width it can reach.
How would I go around handling this, preferably utilising IB autolayout as much as possible?
It seems to me that all of constraints you mentioned directly translate into interface builder --
First view has width >= something.
First view has width <= something
Same for Second view.
Space between views is fixed.
Second view wants to be as small as possible (have its width at 0) but this has lower lower priority than the previous constraints and lower priority than inner content size constraints.
The code I had to add to my view controller, after applying the constraints as per the ilya’s answer:
In controlTextDidChange (_controlWidthConstraint refers to the fixed width constraint of the input; it’s probably 0 by default for the second input):
// Get the new width that fits
float oldWidth = textControl.frame.size.width;
[input sizeToFit];
float controlWidth = textControl.frame.size.width;
// Don’t let the sizeToFit method modify the frame though
NSRect controlRect = textControl.frame;
controlRect.size.width = oldWidth;
textControl.frame = controlRect;
_controlWidthConstraint.constant = controlWidth;
The key lies in invalidating the intrinsicContentSize for the text field when text is input.
You can check a sample project here, to get you on the right track.
Little description:
I get an image from my scanner using Capture Core Framework and background color is gray. So I want to do white background.
I'm looking for best way to remove this color. I looked at Image Core Filters. And as I understood I should use those ones, but I couldn't find included/ready filterfor this task. So, Do I have to write it myself?
It means to remove color I should write my own filter and apply it to my images? Right? Thank you.
UPD: I develop for Mac os
Why not just simply change the brightness of your image? If this gray background color value is fixed then you can increase the brightness a little bit, as a preprocess step, until you're satisfied.
A filter isn't quite the right tool for the job here. Filters apply a colour-shifting algorithm, pixel by pixel, to all of the pixels in an image.
This would be appropriate in your case if there was something completely unique about the pixels that you want to turn to white. For example, if the background you wish to eliminate was in a very narrow colour range that did not occur in any other part of the image. This is the technique used in greenscreen/bluescreen filming, which only works if that green or blue colour does not occur anywhere in the image regions you want to keep.
But - as you say in one of your comments - you cannot do this as that grey level you want to get rid of will not be unique to the background, so any filter you apply that would pick out those pixes may also affect pixels in the scanned subjectmatter.
What you really need is a way to select a region of interest and apply a filter to that region alone. You could use openCV for this. In fact it has a function that can achieve your result in one go:
http://docs.opencv.org/modules/imgproc/doc/miscellaneous_transformations.html?highlight=floodfill#int
floodFill(InputOutputArray image, //image to process
Point seedPoint, //starting pixel
Scalar newVal, //New value of the repainted domain pixels
Rect* rect, //optional output param (you won't need it)
Scalar loDiff, //max lower brightness/colour diff to select
Scalar upDiff, //max upper brightness/colour diff to select
int flags) //you want FLOODFILL_FIXED_RANGE
This function starts from a seedPoint, which should be any pixel that you can guarantee will be a part of the background grey you want to eliminate. (0,0) might work for you. It then interrogates neighbouring pixels, including them in the ROI array if they are sufficiently similar. The resulting array is a connected region. If your background grey uniformly falls between loDiff and upDiff - and your subject scan has a defined edge which does NOT fall into this range, you will get your result - selection and remapping of all background pixels to newVal (white).