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Index › Programming Questions & Help › Syntax Questions › Rotating an Image

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Rotating an Image (Read 657 times)

Dave0710

Rotating an Image
Oct 23^rd, 2009, 7:13pm

Hey Guys, I'm new to processing and am trying to rotate an image in place (i.e. the spinning rainbow circle of death for Macs when you load something). For some reason it spins around the coordinate (0,0) instead. Can someone please help me change my code so that I can control how much the image rotates according to the angle I give it?

PImage a;

float x,y;
float r;

void setup(){
size(800,800);
a = loadImage("Arrow.jpg");
x = y = width/2;
r = 0;}

void draw(){
background(255);
translate(x,y,0);
rotate(r);
imageMode(CENTER);
image(a,x,y,100,100);
r = r + 0.01;}

ChristianT

Re: Rotating an Image
Reply #1 - Oct 23^rd, 2009, 9:22pm

First, you'll need to use the 2D version of translate:

translate(x,y);

Giving it three coordinates messes things up because you are not using a 3D renderer.

Now you will notice that the image rotates around (x,y) but moves along a circle touching the corners of your sketch display.

To fix this, you need to put the image at coordinates 0,0:

image(a,0,0,100,100);

This is necessary because rotate(r) always rotates around (0,0). The translate(x,y) is applied after the rotation, thus making it look like as if it was rotated around (x,y).

Dave0710 YaBB Newbies Offline Posts: 10	Re: Rotating an Image Reply #2 - Oct 23^rd, 2009, 9:30pm THANK YOU SO MUCH!!! Arghh, I can't believe changing something so minute can make my life so much less stressful.

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