Reach 2
Reach 2 based on code from Keith Peters.
The arm follows the position of the mouse by calculating the angles with atan2().
int numSegments = 10; float[] x = new float[numSegments]; float[] y = new float[numSegments]; float[] angle = new float[numSegments]; float segLength = 26; float targetX, targetY; void setup() { size(640, 360); strokeWeight(20.0); stroke(255, 100); x[x.length-1] = width/2; // Set base x-coordinate y[x.length-1] = height; // Set base y-coordinate } void draw() { background(0); reachSegment(0, mouseX, mouseY); for(int i=1; i<numSegments; i++) { reachSegment(i, targetX, targetY); } for(int i=x.length-1; i>=1; i--) { positionSegment(i, i-1); } for(int i=0; i<x.length; i++) { segment(x[i], y[i], angle[i], (i+1)*2); } } void positionSegment(int a, int b) { x[b] = x[a] + cos(angle[a]) * segLength; y[b] = y[a] + sin(angle[a]) * segLength; } void reachSegment(int i, float xin, float yin) { float dx = xin - x[i]; float dy = yin - y[i]; angle[i] = atan2(dy, dx); targetX = xin - cos(angle[i]) * segLength; targetY = yin - sin(angle[i]) * segLength; } void segment(float x, float y, float a, float sw) { strokeWeight(sw); pushMatrix(); translate(x, y); rotate(a); line(0, 0, segLength, 0); popMatrix(); }
Functions Used
strokeWeight()
Sets the width of the stroke used for lines, points, and the border around shapes
Learn More
draw()
Called directly after setup(), the draw() function continuously executes the lines of code contained inside its block until the program is stopped or noLoop() is called
Learn More
atan2()
Calculates the angle (in radians) from a specified point to the coordinate origin as measured from the positive x-axis
Learn More
background()
The background() function sets the color used for the background of the Processing window
Learn More