CODEWITHSUNDEEP
androidcanvasdrawingscalingscreen-resolution
tronious
tronious

Reputation: 1577

Drawing circles on canvas so they are equal or at least comparable sizes on different devices

I have an app that currently needs to draw some circles on a surfaceview's canvas.

Everything works fine, however I'm no understanding how to scale the circles correctly on different devices.

What I mean by this is that on my Galaxy S4, the circles are an appropriate size.

When I load the same app on my wife's Galaxy S3, the circles are huge in comparison.

I'm sure this is due to screen resolution and density, but I'm struggling with how to take the screen resolution/density into account to scale the circles correctly depending on the phone size.

Example of how a circle is drawn in my app. crcl.radius is currently a fixed size of 100. I know this 100 needs to be scaled based on the device but I can't wrap my head around the formula to do so. I'm assuming the conversion is relatively simple.

Disclaimer: somewhat new to Android (about 6 months using it).

myCanvas.drawCircle(crcl.x, crcl.y, crcl.radius, selected_paint);

Thank you in advance for any help you can give.

Upvotes: 1

Views: 1176

Answers (1)

Jossy Paul
Jossy Paul

Reputation: 1287

You can use a dp value instead of pixel. I think this should do the trick.

myCanvas.drawCircle(crcl.x, crcl.y,  dipToPixels(getApplicationContext(),crcl.radius), selected_paint);

This function converts dp to pixel.

public static float dipToPixels(Context context, float dipValue) {
DisplayMetrics metrics = context.getResources().getDisplayMetrics();
return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dipValue, metrics);
}

Upvotes: 2

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