I'm trying to rotate a shape but it isn't working. I tried altering the example code to see what the basic issue was, but I still get NullPointerException. What's the problem?

Here's the code as I altered it:

PShape button;


void setup()
{
 size(200,200);
 noStroke();
 fill(255);
 frameRate(30);
 loadShape("B-01.svg");
}

float angle;
float cosine;
//float jitter;

void draw()
{
background(102);
 
 if(second()%2 == 0){
   //jitter = (random(-0.1, 0.1));
 }
 angle = angle + 0.1;
 cosine = cos(angle);
 
 translate(width/2, height/2);
 rotate(cosine);
 shapeMode(CENTER);
 shape(button, 0, 0, 115, 115);  

It worked! Thanks!

I have another question:

So it works, but I want to use more than one rotating shape without both rotating around the same axis. I want each to be spinning independently in two different areas, spinning in place.

But some reason, when I duplicate the code to the first shape and alter the translate(), it doesn't seem to work. I think I'm missing a basic logic to translate() but I can't seem to figure out what the problem is. Please help!

Here's the code I have now:

Code:

PShape button;


void setup()
{
 size(200,200);
 noStroke();
 fill(255);
 frameRate(30);
 button = loadShape("B-01.svg"); 

}

float angle;
float cosine;

float angle2;
float cosine2;

void draw()
{
background(102);
 

 angle = angle + 0.1;
 cosine = cos(angle);
 
 translate(width/2, height/2);
 rotate(cosine);
 shapeMode(CENTER);
 shape(button, 0, 0, 115, 115);
 
 angle2 = angle2 + 0.1;
 cosine2 = cos(angle2);
 
 translate(width/4, width/4);
 rotate(cosine2);
 //shapeMode(CENTER);
 shape(button, 0, 0, 115, 115);
}
 

Hi can any one help me, how to rotate the ellipse for this code


PImage mapImage;
Table locationTable;
//Table nameTable;
int rowCount;
Table dataTable;
float dataMin;
float dataMax;
int col = 0 ;
int temp;
void setup( ) {
size(640, 400);
mapImage = loadImage("ireland.png");
locationTable = new Table("kumar.tsv");
rowCount = locationTable.getRowCount( );
// Read the data table.
dataTable = new Table("update.tsv");
//nameTable = new Table("irelandname.tsv");
PFont font = loadFont("Arial-BoldMT-16.vlw");
textFont(font);
// Find the minimum and maximum values.
for (int row = 0; row < rowCount; row++) {
float value = locationTable.getFloat(row, 3);
if (value > dataMax) {
dataMax = value;
}
if (value < dataMin) {
dataMin = value;
}
}
}
// Global variables set in drawData( ) and read in draw( )
float closestDist;
String closestText;
float closestTextX;
float closestTextY;
void draw( ) {
background(255);
image(mapImage, 0, 0);
closestDist = MAX_FLOAT;

for (int row = 0; row < rowCount; row++) {
String abbrev = locationTable.getRowName(row);
float x = locationTable.getFloat(abbrev, 1);
float y = locationTable.getFloat(abbrev, 2);
drawData(x, y, abbrev);

}
// Use global variables set in drawData( )
// to draw text related to closest circle.
if (closestDist != MAX_FLOAT) {
fill(0);
textAlign(CENTER);
text(closestText, closestTextX, closestTextY);
}
fill(0);
text("Emails Information",70,30);
}
void drawData(float x, float y, String abbrev) {
float value = locationTable.getFloat(abbrev, 3);
float radius = 0;
if (value >= 0 && value<=55) {
radius = map(value, 10, 55, 2, 15);
fill(#4422CC); // blue
} else {
radius = map(value, 0, 180, 4, 30);
fill(#FF4422); // red
}
ellipseMode(RADIUS);
ellipse(x, y, radius*0.8, radius*0.8);
float d = dist(x, y, mouseX, mouseY);
// Because the following check is done each time a new
// circle is drawn, we end up with the values of the
// circle closest to the mouse.
if ((d < radius + 2) && (d < closestDist)) {
closestDist = d;
String name = locationTable.getString(abbrev, 0);
closestText = name + " " + value;
closestTextX = x;
closestTextY = y-radius-4;
}
}
void keyPressed( ) {
if (key == CODED) {
  try{
     if (keyCode == RIGHT && col < 4 && col >= 0) {
       col = col+1;
       updateTable();
       }
    /*   if (keyCode == RIGHT && col ==4)
       {
          col=1;
       }
      */
       if (keyCode == LEFT && col > 0 && col < 4){
         col = col-1;  
         updateTable();
           
       }
  }catch(Exception e)
  {
    col=1;
 //   println("Error here:"+e);
  }
   
}
}

void updateTable(){
for (int row = 0; row < rowCount; row++) {
 float newValue = dataTable.getFloat(row, col);
//float newValue = random(dataMin, dataMax);
locationTable.setFloat(row, 3, newValue);
}
}

thank you

First advice: indent your code if you want people to look at it.
Second advice: be more precise in your questions: rotate how much (depending on what), around which point?

And rotating centered ellipses =

like Rapatsk1 said, how do you want to rotate an ellipse ? i am sure the answer to your question is pretty easy but nobody understands the question.

koogy wrote on Jun 8^th, 2010, 10:10am:

i believe this from bens book Visualizing Data Book for reading csvs

yep, me neither, i tried to reduce his code and made it work, but it doesnt make much sense to me.