small blackout - how drag existing rect, xValue

Programming Questions

Chrisir

small blackout - how drag existing rect, xValue

in Programming Questions • 1 year ago

hello,

I encounter a small blackout here.

What is the new x-Value when I drag an existing rect?

The dragging and clicking is no problem but I fail to find the right formula for the new x-value.

I want to click the existing rect and then move the mouse and when I drag it, the rect slowly moves accordingly.
At the moment though it jumps because I got the new values wrong...

This is what I got in mouseDragged()

float m = map(mouseX-initialMouseValue.x, 0, width, -200, 200);
rectPos.x = m; // use map

initialMouseValue.x being a value stored at the beginning of the dragging in mousePressed() - it is the x-value of the mouse at the beginning of the dragging.

Thanks!

Greetings,

Chrisir

Replies(5)

Kobby

Re: small blackout - how drag existing rect, xValue

1 year ago

Well my first questions are where is the mouse positioned in relation to the rectangle and what Rectmode are you in?

If the rect is being measured from the top left and you click the mouse somewhere in the middle you need to increment the x position of the rectangle based on the movement of the mouse. Also your range for your map doesn't include negative values which is what would happen in the case of left motion. So:

float m = map(mouseX-initialMouseValue.x, -width, width, -200, 200);
rectPos.x += m;

may be a smoother solution or will get you pointed in the right direction

Or you could use pmouseX to get the mouse position of the previous frame and map that.

float m = map(mouseX - pmouseX, -width, width, -200,200);
rectPos.x += m;

might be an even simpler solution

Hope this helps!

Chrisir

Re: small blackout - how drag existing rect, xValue

1 year ago

let me see, rectMode is CORNER

the mouse positioned in relation to the rectangle :
is more or less within in the rect

yours doesn't work for me when I drag...

Greetings, Chrisir

Chrisir

Re: small blackout - how drag existing rect, xValue

1 year ago

excellent

float m = map(mouseX - pmouseX, -width, width, -200,200);
rectPos.x += m;

works for me...

Kobby

Re: small blackout - how drag existing rect, xValue

1 year ago

sweet i figured pmouseX would work just fine somehow.

Chrisir

Re: small blackout - how drag existing rect, xValue

1 year ago

That actually helped me a lot!

Thank you so much!

Now it all falls into place!

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