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Index › Programming Questions & Help › Syntax Questions › scaling with mouseDrag
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scaling with mouseDrag? (Read 782 times)
brewthom11
scaling with mouseDrag?
Dec 6th, 2009, 3:05pm  
I want to be able to click and drag my mouse and have an image load to the size and place I dragged. Any ideas? Can't quite get my head around this. I'm thinking I need to compare x and y before and after and figure the scale and placement from that. But can't quite get there.  Shocked
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NoahBuddy
Re: scaling with mouseDrag?
Reply #1 - Dec 7th, 2009, 1:08am  
Assuming you want to draw a rectangle:

Find the differences between mouseX and mouseY from mousePressed() to mouseReleased() to get the width and height.

Use the lower of each (x/y) to find the upper left corner and draw it with image().
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antiplastik
Re: scaling with mouseDrag?
Reply #2 - Dec 7th, 2009, 4:19am  
For convenience, I would use PVector and mouseDragged() :

Quote:
PVector click, drag;

void setup() {
  click = new PVector(0, 0);
  drag = new PVector(0, 0);
}

void draw() {
  background(255);
  rect(click.x, click.y, drag.x - click.x, drag.y - click.y);
}

void mousePressed() {
  click.set(mouseX, mouseY, 0);
  drag.set(mouseX, mouseY, 0);
}

void mouseDragged() {
  drag.set(mouseX, mouseY, 0);
}
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liudr
Re: scaling with mouseDrag?
Reply #3 - Dec 7th, 2009, 7:24am  
One slight improvement: now the image keeps its aspect ratio and rotates with the mouse. See if this is useful.

PVector click, drag;
PImage img1;
void setup() {
 size(640,480);
 click = new PVector(0, 0);
 drag = new PVector(0, 0);
 img1=loadImage("test.jpg");
 imageMode(CENTER);
 rectMode(CENTER);
}

void draw() {
 background(255);
 float w, h, imgDia, drawDia, imgAng, drawAng;
 imgDia=sqrt(pow(img1.width,2)+pow(img1.height,2));
 drawDia=sqrt(pow(drag.x-click.x,2)+pow(drag.y-click.y,2));
 imgAng=atan((float)img1.height/(float)img1.width);
 drawAng=((drag.x-click.x>0)?atan((drag.y-click.y)/(drag.x-click.x)):PI+atan((dr
ag.y-click.y)/(drag.x-click.x)))-(imgAng);
 println(imgAng*57.1+" "+drawAng*57.1);
 w=img1.width*drawDia/imgDia;
 h=img1.height*drawDia/imgDia;
 pushMatrix();
 translate((drag.x+click.x)/2, (drag.y+click.y)/2);
 rotate(drawAng);
 image(img1, 0, 0, w, h);
 noFill();
 stroke(255,0,0);
 rect(0, 0, w, h);
 popMatrix();
}

void mousePressed() {
 click.set(mouseX, mouseY, 0);
 drag.set(mouseX, mouseY, 0);
}

void mouseDragged() {
 drag.set(mouseX, mouseY, 0);
}
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cbt3491
Re: scaling with mouseDrag?
Reply #4 - Dec 8th, 2009, 10:26am  
Thanks to all. THis is the best forum ever! Smiley
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