// draw a shape using vector points
// as the corners (veteces)
size(500, 500);
background(255);
// set the colour of the edge
// and inside of the shape
strokeWeight(5);
stroke(0);
fill(127);
// draw the shape
// beginShape and endShape
// tells processing that you are drawing
// a shape
// each vertex call creates a corder point
// CLOSED says that it is a close shape
// (it joins up)
beginShape();
vertex(100, 100);
vertex(400, 200);
vertex(300, 400);
vertex(50, 300);
endShape();//CLOSE);
// a ball that moves with a given velocity
// the position of the ball
// this is a position vector
float ballx, bally;
// the velocity of the ball
// this is a direction vector
float velx, vely;
void setup()
{
size(500, 500);
// randomly setup the initial position
// and velocity of the ball
ballx = random(width);
bally = random(height);
velx = random(-1.0, 1.0);
vely = random(-1.0, 1.0);
}
void draw()
{
// update the position
ballx += velx;
bally += vely;
// draw
background(255);
strokeWeight(4);
ellipseMode(CENTER);
ellipse(ballx, bally, 10, 10);
}
// two balls that move in the same direction
// but at different speeds
// the direction and ball positions
float dirx, diry, ball1x, ball1y, ball2x, ball2y;
// the speeds of the two balls
float speed1 = 0.2, speed2 = 0.5;
void setup()
{
size(500, 500);
// both balls start at the top left
ball1x = 0.0;
ball1y = 0.0;
ball2x = 0.0;
ball2y = 0.0;
// the direction
dirx = 3.0;
diry = 2.0;
// normalise it (divide it by its length)
// to make it a proper direction
float len = sqrt(dirx*dirx + diry*diry);
dirx = dirx/len;
diry = diry/len;
}
void draw()
{
background(255);
ellipseMode(CENTER);
// the velocity of each ball is its speed times
// the shared direction
// add this to the position of each ball
ball1x += speed1*dirx;
ball1y += speed1*diry;
ball2x += speed2*dirx;
ball2y += speed2*diry;
// draw the balls
ellipse(ball1x, ball1y, 10, 10);
ellipse(ball2x, ball2y, 10, 10);
}
// a ball moves at constant speed between two points
// the start and end point, position of the ball and its speed
float startx, starty, endx, endy;
float ballx, bally;
float speed;
void setup()
{
size(500, 500);
// initialize the start and end points to random positions
// on the screen
startx = random(width);
starty = random(height);
endx = random(width);
endy = random(height);
// set the ball position to the start point
ballx = startx;
bally = starty;
speed = 0.5;
}
void draw()
{
background(255);
// find the direction between the start and
// end point
float xdisp = endx - ballx;
float ydisp = endy - bally;
float distance_to_end = sqrt(xdisp*xdisp + ydisp*ydisp);
if(distance_to_end > 0.1)
{
// first find the displacement by subtracting
// the start from the end
float dirx = endx - startx;
float diry = endy - starty;
// find the length of the displacement
float len = sqrt(dirx*dirx + diry*diry);
// divide the dispacement by its length to get the direction
dirx = dirx/len;
diry = diry/len;
// multiply the direction by the speed
// to get the velocity
// add this to the balls position
ballx += dirx*speed;
bally += diry*speed;
}
// draw a line between the start and end point
line(startx, starty, endx, endy);
// draw the ball
ellipseMode(CENTER);
ellipse(ballx, bally, 10, 10);
}
// translate, rotate and scale a rectangle
size(500, 500);
background(255);
// make sure that it rotates about
// the centre of the rectangle
rectMode(CENTER);
// try changing the order of transforms
translate(200, 300);
rotate(radians(23));
// non uniform scale
// scale x and y differently
scale(2, 0.5);
// draw the rectangle
rect(0,0, 100, 100);
// translate, rotate and scale 2 rectangles
// using pushMatrix and popMatrix
size(500, 500);
background(255);
// make sure that it rotates about
// the centre of the rectangle
rectMode(CENTER);
// create a new matrix and put
// it on the stack
pushMatrix();
translate(200, 300);
rotate(radians(23));
// non uniform scale
// scale x and y differently
scale(2, 0.5);
// draw the rectangle
rect(0,0, 100, 100);
// comment out the next line to see the difference
popMatrix();
// the transforms are now gone
// the following transforms are
// unaffected by the previous ones
pushMatrix();
translate(100, 100);
rotate(radians(-10));
scale(1.5, 1);
// draw the rectangle
rect(0,0, 100, 100);
popMatrix();
// translate a 3D box
// import the opengl library (to do 3D)
import processing.opengl.*;
// create a 3D screen using OPENGL
size(500, 500, OPENGL);
background(255);
// translate with an x,y and z
translate(200, 300, 10);
//rotateY(0.5);
// draw a box height, width, depth
box(50, 50, 100);