This is designed behavior. You should add new enum option to control the blend mode. Such as SDBlendMode, or directly use CGBlendMode

I use the Atop for the original use case which mixed the target rect's color, this API is not designed to be the same effect as UIImage.tintColor at my original introduction

there are also maybe use case which need other blend modes

I've created #3749 for this.

You can use blendMode: kCGBlendModeSourceIn to achieve your preferred filter solution.

Note: this tint is wrong word which cause misunderstanding. You think it should be replace the background image with target color, ignore what background image's own color.

But, in my original design, it's more like mix the background color with target color, keep the alpha from the background, but with color from target color, so I choose that sourceAtop as blend mode.

If you really want to change the default blend mode behavior, this may cause behavior break and need at least minor version bump

SourceAtop:

SourceIn

Thanks for your reply. I will also take a look at the PR.

@exponentChoi I decided to follow your idea. Change the default blend mode to sourceIn, match Tint Color naming on iOS

For user who still want the sourceAtop blend mode, they can use the new API param to opt-in

This is a behavior break changes and I'll notify user on release changelog