Question

If I was given color A and color B, how can one go aboit generating a gradient on a canvas which can be later converted to a bitmap.

Such that

public Bitmap makeGradient(Color from, Color to){}

Would actually work?

I hope this is not too vague. I thankyou for your time and effort.

Ps. There is a question on stackoverflow that answers this but I amstill confused 🙁

Here it is: Generating gradients programmatically?

Answer 1

One way to go about creating a radial gradient might be to define the focus point as well as the extent of the gradient and when you generate the image you’d calculate the distance between the current pixel and the focus point, divide it by the gradient extent and clip the result to 1. Then use the formula in the question you linked.

Something like this pseudocode:

double d = distance(currentPixel, focusPoint); //I'll leave the implementation for you
double factor = Math.max(1.0, d/extent);

int red = (int) (firstCol.getRed() * factor + secondCol.getRed() * (1.0 - factor) );
int green= (int) firstCol.getGreen() * factor + secondCol.getGreen()* (1.0 - factor) );
int blue = (int) (firstCol.getBlue() * factor + secondCol.getBlue()* (1.0 - factor) );

This would mean that the farther a pixel is from the focus point the more firstCol will contribute to it (pixels that are outside the extent of the gradient will only use firstCol since factor should be 1.0 for those).