How can I get this glaring color? - ios

I am getting difficulties for making this color view.
As you can see, this is not a single color.
I am struggling to get this colored view but seems like my skill is not enough for getting this color.
I am always eager to learn but for this time, I don't know how to I get this color.

The bars you are pointing to are nearly saturated magenta, roughly #ff64ff. However, they also have a bit of linear gradient on them to give them the tube shape, and a magenta "shadow" to give them glow effect. How to get them would be very dependent on the system you are using to draw them.

Related

How to do Water color painting in iOS using CoreGraphics? [duplicate]

I have been working with OpenGL in iOS, and setting the colors with glColor4f(r,g,b,a) and then drawing my own color on a white UIImageView. I basically have a brush, which is then moved around my user's touch, and then it paints the color onto the canvas. But this color needs to be water paint (like smudged color)
Does anyone understand/knows how to get a water color like this app does, and how the background UIImageView has a texture on it?
https://itunes.apple.com/us/app/hello-watercolor/id539414526?mt=8
or checkout water paint in this. http://www.fiftythree.com/paper
I created a bounty on this as I am really having a hard time to grasp how to derive such smooth flowing colors out of the normal colors. Even if you guys point me in the right direction, or to some sample code on how I can get the effect of water-paint, it would be really helpful ^_^
And as a bonus, it would be also be helpful if you can point out to me how to get canvas on which it is painted on looks realistic, and blended with the paint? Does Blending/GLSL have to do with any of this?
Is there any sample project on this?
If you are still struggling with the basics of getting realistic looking water colors working, you may want to experiment/prototype in photoshop first.
http://www.zoepiel.com/tutorials/watercolor/ shows some very effective tricks for creating watercolor images with simple tools.
The most interesting one is to multiply a group of watercolor layers with a greyscale watercolor paper image. The texture of the paper makes some parts remain white, and other parts saturate with color, just like real watercolor.
Each layer remains 'wet' in the sense that the colors within it blend, but the layers are 'dry' with respect to each other.
She also explains some of her brush and blur settings and shows what they do.
Once you can produce the desired effect in photoshop, you'll have clear specifications of what you want to do and you'll be quite a bit closer to programming it out.
Looking at the examples you posted, it looks like they are using a simple Gaussian Blur with a radius of double your brush size. This may be an incomplete solution, but it's at least the first level.

Render water-paint in iOS

I have been working with OpenGL in iOS, and setting the colors with glColor4f(r,g,b,a) and then drawing my own color on a white UIImageView. I basically have a brush, which is then moved around my user's touch, and then it paints the color onto the canvas. But this color needs to be water paint (like smudged color)
Does anyone understand/knows how to get a water color like this app does, and how the background UIImageView has a texture on it?
https://itunes.apple.com/us/app/hello-watercolor/id539414526?mt=8
or checkout water paint in this. http://www.fiftythree.com/paper
I created a bounty on this as I am really having a hard time to grasp how to derive such smooth flowing colors out of the normal colors. Even if you guys point me in the right direction, or to some sample code on how I can get the effect of water-paint, it would be really helpful ^_^
And as a bonus, it would be also be helpful if you can point out to me how to get canvas on which it is painted on looks realistic, and blended with the paint? Does Blending/GLSL have to do with any of this?
Is there any sample project on this?
If you are still struggling with the basics of getting realistic looking water colors working, you may want to experiment/prototype in photoshop first.
http://www.zoepiel.com/tutorials/watercolor/ shows some very effective tricks for creating watercolor images with simple tools.
The most interesting one is to multiply a group of watercolor layers with a greyscale watercolor paper image. The texture of the paper makes some parts remain white, and other parts saturate with color, just like real watercolor.
Each layer remains 'wet' in the sense that the colors within it blend, but the layers are 'dry' with respect to each other.
She also explains some of her brush and blur settings and shows what they do.
Once you can produce the desired effect in photoshop, you'll have clear specifications of what you want to do and you'll be quite a bit closer to programming it out.
Looking at the examples you posted, it looks like they are using a simple Gaussian Blur with a radius of double your brush size. This may be an incomplete solution, but it's at least the first level.

Coloring Shapes in iOS app

We are building an iPad kids application in which a kid is requested to color different shapes with specific color. For example, consider an image with sky and trees , etc. all overlapping and a kid has selected a color for example "Blue" and then he taps the sky , the sky should turn to blue otherwise it should say "wrong color"
My questions are:
1- How to implement the coloring of the sky only with the selected color. We have implemented a Coco2d Floodfilling but it is too slow.
2- How to tie each part of the image with a specific right color. We suggested loading a fully colored image in a background layer and testing it at the tap .... BUT how to implement it.
Thanks
Are the shapes originally vectorial? If so, a solution would be to work directly with them as vectors, parsing them into CoreAnimation shapes.
You can give a try to SVGKit or get some inspiration from it. You'll get CAShapeLayers where you can change the fillColor property.
I believe that this way would be much more responsive (and the app size much more lighter) than doing tricks with images ;-)

how to fill solid color into the shape of a transparent PNG file with actionscript3?

For example, I have a transparent png file, the shape is a car.
In the png file, I only draw the white border shape.
Outside and inside the border are all transparent.
I want to use actionscript3 code to show the car object with different color, it means only fill color inside the border, and for the outside of the border, keep transparent.
How to do that?
So far, the simplest workaround is to prepare many images with PhotoShop, but it's not good enough for me. When I have many shapes and use many colors, I've to prepare many many images.
Add more details:
(Because I'm using white border, you may not see the basic png file if your background of browser is white)
Change my boarder of shape to black, hope this is helpful to understand my question.
Since you're working with loaded images/pixels you can make use of BitmapData's floodFill() which pretty much does what you need. There's an example in bellow the method description as well.
It does pretty much what you need, although in some cases it might not be perfect. It's worth having a look at Jan's optimizing the floodFill() method article which goes more in depth.
A simple solution is to use multiple layers. The top layer would contain just the border. The lower layer would contain just the car with no border. You can adjust the colour of the car layer using a ColorTransform or ColorMatrixFilter.

Drawing dashed borders

Imagine you are drawing a map of county borders. You are given a set of polygons, one for each boundary, and you draw each polygon.
In places where two counties share a border you just end up drawing the border twice. In the absence of partial transparency effects, and with a solid pen, this is no problem.
But, on maps, borders of this kind are customarily shown by dash-dotted lines. In this case, situations like the one depicted below can happen:
Notice how the dash pattern, which normally is dash-dot-dot, gets screwed up where the two areas share a border. In this case, it happened to become a longdash-dot pattern, but in general it could do anything from coincidentally looking normal to creating a solid line.
How does/should map rendering software prevent artifacts of this kind from occuring?
The artifact is due the fact that the piece of border is drawn twice. Instead of trying to supress such artifacts, you could try to not draw border sections twice, by keeping a list of segments already drawn in memory, and if you encounter a stretch that's already drawn, you don't draw it again.
Your brush pattern colors some pixels black and leaves some pixels alone. Instead of leaving the pixel alone, can you set up your brush pattern to color those pixels white (or whatever your background color is)?
Another possibility is to always draw your county borders twice -- once with a solid white pattern, and again with the brush pattern of your choice.
I suppose they break their border lines into segments, then remove the overlaps.
This is mostly a geometric problem, not a drawing problem.
Instead of going with a dashed line, you could do it Zip-a-tone style, like this:
Zip-a-tone was this graphic art stuff that was basically a sticky sheet of plastic with a regular (printable) pattern of dots on it. To use it, you would lay a big sheet of it over your drawing and cut it around the areas on your drawing that you wanted zip-a-toned, and then peel off the parts you didn't want.
For this image, I just went with an alternating checkerboard pattern, with the lines two pixels wide. Because all the lines are drawn from one big (virtual) block of this checkerboard pattern, you never have to worry about weird artifacts at the joints or any overlap effects.
Angled lines are a bit tricky, but basically you imagine the edges of the line sort of cutting through pixels, and thus you draw them at the appropriate shade of grade instead of full black (in the case of the 45 degree line here, the pixels are drawn with RGB(170, 170, 170), but any angle could be rendered with appropriate shades).
I'm not sure if GDI+ could do this easily using the textured brushes, but maybe. Otherwise you'd have to custom-code it. The advantage of this method over just solid gray lines would be that this would allow some of the background to show through.
This is an interesting question that I never really thought about. I think the only real solution is to render the entire complex figure as a series of lines or paths that do not overlap anywhere. I'm not surprised that GDI+ doesn't handle this situation in any automatic way.

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