how to make only *one* image rotate?

mdobbe

Hey there! I'm writing some pretty simple code as the basis for a small interactive game. So far I'm just working on getting the background to function properly. What I am trying to do is have the "wheel" image (the color wheel) rotate every time the mouse is clicked. HOWEVER the way it is written right now the wheel does not rotate at all, and instead the "bg" image above it, which I want to remain static, is the one the rotates. Here are some pictures of what that looks like, with questions and code below:

So I have a few questions:
1) How do I write it so that the wheel image is the one that rotates?
2) Why does the bg image that is incorrectly rotating rotating from the (0,0) position instead of the center, when I specified imageMode(CENTER)?
3) How would you recommend making the image rotate once per click, instead of whenever the mouse is pressed?

Here's my code:

PImage bg;
PImage wheel;
float x = width;
float y = height;
int a = 0;

void setup() {
background(255);
size(750, 500);
imageMode(CENTER);
bg = loadImage("bg1.png");
wheel = loadImage("colorwheel.png");
}
void draw() {
background(255);
if(mousePressed){
a = (a+1);
}
wheel(750,0,a);
image(bg, 375, 250);
}
void wheel(int xloc, int yloc, int angle){
image(wheel, xloc, yloc);
rotate(angle);
}

Thank you!

Chrisir

You can isolate rotations by using pushMatrix and popMatrix enclosing the section

Also, rotate must take place before you draw the shape , before image

mdobbe

Perfect! Thank you! I completely forgot about push and pop. It's been great brushing up on everything again

Chrisir

Glad to hear!

;-)

Chrisir

As for the mouse:

Instead of mousePressed as a variable use the function mousePressed() of the same name - it registers the click only once, not multiple times (as the variable mousePresseddoes).

In this function set a boolean imageRotates (that you define before setup()) to its opposite:

imageRotates= ! imageRotates;

The ! means a logical NOT.

before rotate say

if(imageRotates) { 
     rotate(..........
}

Chrisir ;-)

mdobbe

Awesome! I didn't know that. Thanks for your help

Chrisir

;-)