NEW (v0.4): Create your Coloring Book App in a matter of minutes! This asset comes with a sample coloring app included that you can have up and running as soon as you add your own PNG images and define the color palette. Check the sample app (Android):
HERE. You can of course build on other platforms (HTML5 included).
This is a set of C# scripts that will let you create your own coloring book app with ease. All the paint fill logic is taken care of in a well performing, mobile ready manner.
This algorightm works on any PNG file, just import a lineart image into Unity and you are good to go. You can also import a photo of a coloring page - or your own drawing.
This logic is being used in my Coloring Book app and tested over thousands of Android and iOS devices. Works like charm in HTML5 as well. You can see my app in action on: Android and iOS for a sample app created with this algorithm.
While my coloring app is NOT INCLUDED this package, there is a sample app included for you to start with. You can test it here: on Android and look into its code to check the details.
What it does is simple - it allows you to load a Texture2D and provides you with a FillColor(x,y,Color) method. Any questions - let me know.
PS. This code includes a Bradley Local Threshold algorithm implementation which can be used to import a photo and binarize it for coloring book usage. Take a photo of a coloring book or draw something on a piece of paper and import its photo.
Credits: App screenshot generated via https://mockuphone.com/