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Topic: Unhelpful Error (Read 266 times) |
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jbk303
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Unhelpful Error
« on: Feb 24th, 2004, 4:41am » |
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I am writing a polygon class for geometry class (Ha. Double ha.) I wrote this code:
Code:
Shape shape = new Shape(5);
void setup(){
size(300,300);
ellipseMode(CENTER_RADIUS); //necessary
}
void loop(){
shape.update();
shape.display();
}
class Shape{
int[] x; //point x coords
int[] y; //point y coords
int verts;//num vertices
Shape(int num){
x = new int[num];
y = new int[num];
verts=num;
for(int i=0; i<num; i++){ //Choose all the point locations
while(!mousePressed){
ellipse(mouseX, mouseY, 10, 10);
}
x[i] = mouseX;
y[i] = mouseY;
}
}
void update(){
for(int i=0; i<verts; i++){
if(mouseX < x[i]+5 && mouseX > x[i]-5 && mouseY < y[i]+5 && mouseY > y[i]-5){
while(mousePressed){ //Move the points around with the mouse WILL GET STUCK TOGETHER FIX
x[i]=mouseX;
y[i]=mouseY;
}
}
}
}
void display(){
for(int i=0; i<verts; i++){
ellipse(x[i], y[i], 10, 10);
line(x[i], y[i], x[(i+1)%verts], y[(i+1)%verts]); //Draw lines between adjacent vertices
}
}
}
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and recived this very helpful (Ha. Double ha.) error message:
Code:
java.lang.NullPointerException
at PdeRuntime.start(PdeRuntime.java:345)
at PdeEditor.doRun(PdeEditor.java:801)
at PdeEditorButtons.mouseReleased(PdeEditorButtons.java:418)
at java.awt.Component.processMouseEvent(Component.java:5134)
at java.awt.Component.processEvent(Component.java:4931)
at java.awt.Container.processEvent(Container.java:1566)
at java.awt.Component.dispatchEventImpl(Component.java:3639)
at java.awt.Container.dispatchEventImpl(Container.java:1623)
at java.awt.Component.dispatchEvent(Component.java:3480)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3450)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3165)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3095)
at java.awt.Container.dispatchEventImpl(Container.java:1609)
at java.awt.Component.dispatchEvent(Component.java:3480)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:450)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThrea d.java:197)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread. java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:144)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:136)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:99)
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Sorry about the comments (or lack thereof).
Anybody know whats wrong?
Thanks,
Josh
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arielm
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Re: Unhelpful Error
« Reply #1 on: Feb 24th, 2004, 10:20am » |
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i can see 2 potential (and linked) problems:
1) you're instantiating "shape" before setup() instead of within setup()
2) inside the "Shape" constructor, you're drawing some stuff
hth
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Ariel Malka | www.chronotext.org
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