Processing 1.0 - Processing Discourse - Line(x,y,angle,length)

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Index › Programming Questions & Help › Syntax Questions › Line(x,y,angle,length)

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Line(x,y,angle,length) (Read 921 times)

Janis Jakaitis

Line(x,y,angle,length)
Dec 18^th, 2009, 9:38am

Hello

I'm trying to build simple "radar" application. With help of Arduino my ultrasonic ranging sensor mounted on servo is returing servo angle and cm as ints. Angle is from 0 to 180 and cm are from 4 to 300.

I'm seeking for formula able to draw line from one common point to specific length with exact angle. Something like line(x,y,angle, length)

Will be much obliged for any help

P.S. After trying to refresh my school trigenometry studies with help of Google I'm completelly lost.

------
Arduino, PIC, Processing = good hobby

Re: Line(x,y,angle,length)
Reply #1 - Dec 18^th, 2009, 10:10am

Angle in radians.

Code:


void setup()
{
  size(200, 200);  
}

void draw()
{
  background(0);
  stroke(255);
  lineAngle(100, 100, (millis()/1000.0), 50);
}

void lineAngle(int x, int y, float angle, float length)
{
  line(x, y, x+cos(angle)*length, y-sin(angle)*length);
}

Cedric

Re: Line(x,y,angle,length)
Reply #2 - Dec 18^th, 2009, 10:21am

You can use this formula to calculate the second point of your line

x = cos( a );
y = sin( a );

so this would become :

Code:

 
void setup() {
  size(400,400);
  smooth();
  background(0);

}

float speed = 0.015;
float a;

void draw() {
  fill(0,10);
  noStroke();

 
 rect(0,0,width,height);
  
 float px = width/2 + cos( a  )*120;
 float py = height/2 + sin( a  )*120;
 
 stroke(0,255,0,120);
 strokeWeight(3);
 line(width/2,height/2,px,py);


a+=speed;

}

edit: im to slow

twitter.com/CedricKiefer

Janis Jakaitis YaBB Newbies Offline Posts: 6 Riga, Latvia	Re: Line(x,y,angle,length) Reply #3 - Dec 18^th, 2009, 11:06am Yes! And radians = deg * (3,14/180) ! Thank you, code is working excelent
	------ Arduino, PIC, Processing = good hobby

koogy God Member Offline Posts: 788	Re: Line(x,y,angle,length) Reply #4 - Dec 18^th, 2009, 11:13am there are degrees() and radians() methods to do the conversion for you... (but i can never remember whether they convert TO degrees or FROM degrees)

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