rotate bezier shape 180 degrees

Programming Questions

joshuakoo..

rotate bezier shape 180 degrees

in Programming Questions • 1 year ago

Hi.

Is there a good way to rotate a bezier vertex 180 degrees? I looked the forum, but didn't find anything that was working.

Hope you can help me out.

Replies(3)

jbum

Re: rotate bezier shape 180 degrees

1 year ago

To rotate any shape (including a bezier shape) 180 degrees, about its center, you need to know the coordinates of the center. Assuming you know them, and they are cx,cy, the code would be as follows:

pushMatrix();

translate(cx,cy); // move origin to center of object

rotate(radians(180)); // rotate about the origin

translate(-cx,-cy); // move back

// draw the shape here....

bezierCurve(......);

popMatrix();

A simple way to get the center, if you know the bounds, is to average two of the extreme points (e.g. top/left and bot/right)

float cx = (x1+x2)/2;

float cy = (y1+y2)/2;

jbum

Re: rotate bezier shape 180 degrees

1 year ago

Here's an example, where I'm rotating by an arbitrary amount. Same idea.

void setup()
{
size(800,600);
smooth();
}
void draw()
{
background(255);
int cx = 142; // i figured out the center manually
int cy = 125;
pushMatrix();
translate(cx,cy);
rotate(radians(millis()*.1));
translate(-cx,-cy);
bezier(50,50,150,150,150,150,200,50);
popMatrix();
}

joshuakoo..

Re: rotate bezier shape 180 degrees

1 year ago

Thanks!

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