Border of first circle is not displayed in overlapping circles - processing

I am trying to draw two intersecting circles, as shown in the attached snapshot.
The border of my first circle on left is not displayed since the second circle on right is overlayed on it.
Is there a way that I can see the border of both the circles in the intersecting region?
My code:
int x = 250;
void setup()
{
size(500,500);
background(255);
}
void draw()
{
coolCircles();
}
void coolCircles()
{
stroke(150);
ellipse(180, 250, x, x);
ellipse(360, 250, x, x);
}

Actually you're drawing filled circles. Use noFill():
void coolCircles()
{
noFill();
stroke(150);
ellipse(180, 250, x, x);
ellipse(360, 250, x, x);
}

Related

Using pushMatrix(), popMatrix(), translate(), and rotate()

I have a program that draws a flower with 4 petals to the screen where ever you click. Instead of redoing the petals one at a time I was just going to attempt to rotate the flower by a quarter turn and have it overlay the first flower, so it appears to have 8 petals. The problem is that it draws the second flower some distance away from the first in the x and y direction, but as I get closer to (0,0) they get closer to overlapping (and do at (0, 0)). I'm not sure why this is happening and would appreciate any help. I'm using Processing 3 for this program.
int c_center = 15;
int c_petal = 20;
int petalsize = 70;
color rcol;
void setup(){
fullScreen();
background(0);
}
void draw(){
rcol = color(random(255), random(255), random(255));
}
void mouseClicked(){
pushMatrix();
flower();
translate(mouseX, mouseY);
rotate(PI/4);
flower();
popMatrix();
}
void flower(){
//left petal
make_petal(mouseX - (petalsize - c_petal), mouseY, petalsize, c_petal);
//right petal
make_petal(mouseX + (petalsize - c_petal), mouseY, petalsize, c_petal);
//top petal
make_petal(mouseX, mouseY - (petalsize - c_petal), c_petal, petalsize);
//bottom petal
make_petal(mouseX, mouseY + (petalsize - c_petal), c_petal, petalsize);
//flower center
fill(random(255), random(255), random(255));
ellipse(mouseX, mouseY, c_center, c_center);
}
void make_petal(int a, int b, int c, int d){
fill(rcol);
ellipse(a, b, c, d);
}
You're mixing two styles of drawing together: your flower() function uses mouseX and mouseY to determine where to draw the petals, but then you're also calling translate(mouseX, mouseY);. So you're drawing petals relative to the mouse, but then moving the entire canvas by the mouse position, and then drawing more petals relative to the mouse again.
Instead, you probably want to only use one style of drawing. Specifically, you probably don't want your flower() function to care about the mouse position. Treat it like a "stamp" that draws things around the origin at 0,0. Then move the origin by calling translate() and rotate the stamp by calling rotate().
I corrected the code thanks to feedback, so it works now in case anyone is interested. I condensed it a little by just making one petal then rotating it through a loop.
int c_center = 20;
int c_petal = int(random(5, 15));
int petalsize = int(random(30, 60));
color rcol;
void setup(){
fullScreen();
background(0);
}
void draw(){
rcol = color(random(255), random(255), random(255));
}
void mouseClicked(){
pushMatrix();
translate(mouseX, mouseY);
for(int r = 0; r < 360; r+=5){
rotate(radians(r));
flower();
}
popMatrix();
}
void flower(){
//petal
make_petal(0, 0 - (petalsize - c_petal), c_petal, petalsize);
//flower center
fill(random(255), random(255), random(255));
ellipse(0, 0, c_center, c_center);
}
void make_petal(int a, int b, int c, int d){
fill(rcol);
ellipse(a, b, c, d);
}

How do you make something move to the previous mousepressed location?

It's really basic but for example, I draw a rectangle and press somewhere (x,y), nothing happens but when I press again somewhere else(x2, y2), that rectangle will move to the first place I press(x, y). So wherever I press, the rectangle will move to the last place I press.
I have it so that the rect appears wherever I press but not the previous location.
void setup(){
background(234);
size(400, 400);
}
void draw(){
}
void mousePressed(){
background(234);
rect(mouseX, mouseY, 20, 20);
}
All you need to do is create your own variables, store the previously clicked position in that, and then use that to draw your rectangle.
float targetX;
float targetY;
void setup(){
background(234);
size(400, 400);
}
void draw(){
}
void mousePressed(){
background(234);
rect(targetX, targetY, 20, 20);
targetX = mouseX;
targetY = mouseY;
}
Notice that you'll have to decide what you want them to be the first time you click, since you don't have a previously clicked position yet. The default is 0, 0 in the upper-left corner.

Stop background from refreshing?

I am trying to get my gif to do something similar to this gif.
I have been able to get the line to draw, and the 'planets' to orbit, but can't figure out how to keep the line connecting the two circles, like the gif does.
Here's the basic code:
int x = 500;
int y = 500;
int radius = y/2;
int cX = x/2;
int cY = y/2;
String text1;
int lg_xBall;
int lg_yBall;
int sm_xBall;
int sm_yBall;
void setup() {
size(x, y);
smooth();
colorMode(RGB);
}
void draw() {
background(0);
stroke(255);
float t = millis()/1000.0f;
drawSmBallOrbit(100);
drawLgBallOrbit(100);
moveSmBall(t);
moveLgBall(t);
sun();
// showMouse();
connectingLines();
}
void drawCircle() { // This will draw a simple circle
stroke(1);
// x1=a+r*cos t, y1=b+r*sin t
ellipse(x/2, y/2, x/2, y/2);
}
void drawLines() { // This will draw lines from the center of the circle.
stroke(1);
line(x/2, y/2, radius/2, radius); // line from 6 to center
line(x/2, y/2, x/2, y/4); // line from 12 to center
for (int i = 0; i <= 5; i+=2.5) {
float x1 = x/2+radius/2*cos(i);
float y1 = y/2+radius/2*sin(i);
line(x/2, y/2, x1, y1);
}
}
void moveSmBall(float ky) { // This will create, and move, a small 'planet'
pushStyle();
stroke(100);
sm_xBall = (int)(cX+radius*cos(ky));
sm_yBall = (int)(cY+radius*sin(ky));
fill(190, 0, 0);
// background(0);
ellipse(sm_xBall, sm_yBall, 10, 10);
popStyle();
}
void drawSmBallOrbit(float opacity) {
pushStyle();
stroke(255, opacity);
strokeWeight(1);
noFill();
ellipse(x/2, y/2, cX+radius, cY+radius);
popStyle();
}
void moveLgBall(float kx) {
kx = kx/.7;
pushStyle();
lg_xBall = (int)(cX+radius*cos(kx)*.6);
lg_yBall = (int)(cY+radius*sin(kx)*.6);
fill(0, 0, 230);
ellipse(lg_xBall, lg_yBall, 30, 30);
popStyle();
}
void drawLgBallOrbit(float opacity) {
pushStyle();
stroke(255, opacity);
strokeWeight(1);
noFill();
ellipse(x/2, y/2, (cX+radius)*.6, (cY+radius)*.6);
popStyle();
}
void sun() {
pushStyle();
fill(250, 250, 0);
ellipse(cX, cY, 40, 40);
popStyle();
}
void connectingLines() {
line(sm_xBall, sm_yBall, lg_xBall, lg_yBall);
}
void showMouse() {
text("X: " + mouseX, x/2, y/2-30);
text("Y: " + mouseY, x/2, y/2-50);
}
Thanks for any help/advice!
The problem is that you're calling background() during every frame, which will clear away anything you've already drawn.
So you either need to stop calling background(), or you need to redraw the old lines every frame.
If you simply move the call to background() out of your draw() function and into your setup() function, you're about 50% there already:
void setup() {
size(x, y);
smooth();
colorMode(RGB);
background(0);
}
void draw() {
// background(0);
stroke(255);
float t = millis()/1000.0f;
drawSmBallOrbit(100);
drawLgBallOrbit(100);
moveSmBall(t);
moveLgBall(t);
sun();
// showMouse();
connectingLines();
}
However, the original animation does not show the previous positions of the ellipses. So you need to clear away the previous frame by calling the background() function, and then redraw previous line positions. You'd do that by having an ArrayList that holds those previous positions.
Here's a simple example that uses an ArrayList to redraw anywhere the mouse has been:
ArrayList<PVector> points = new ArrayList<PVector>();
void setup() {
size(500, 500);
}
void draw() {
background(0);
stroke(255);
points.add(new PVector(mouseX, mouseY));
for(PVector p : points){
ellipse(p.x, p.y, 10, 10);
}
}
You would need to do something very similar, but you'd have to keep track of two points at a time instead of one, since you're tracking two ellipses and not just the mouse position.

How to rotate a line in a circle (radar like) in Processing while also plotting points?

I am trying to rotate a line around in a circle that represents the direction a sensor is facing, while also plotting distance measurements. So I can't use background() in the draw function to clear the screen, because it erases the plotting of the distance readings. I've tried pggraphics and a few others ways, but can't seem to find a way to do it.
This is what I have right now:
void setup() {
background(255,255,255);
size(540, 540);
}
void draw() {
translate(width/2, height/2);
ellipse(0,0,100,100);
newX = x*cos(theta)- y*sin(theta);
newY = x*sin(theta)+ y*cos(theta);
theta = theta + PI/100;
//pushMatrix();
fill(255, 255);
line(0, 0, newX, newY);
rotate(theta);
//popMatrix();
}
I am new to Processing, and coding in general, but can anyone point me in the right direction on how to do this? Thanks
This is what it outputs: http://imgur.com/I825mjE
You can use background(). You just need to redraw the readings on each frame. You could store the readings in an ArrayList, which allows you to add new readings, change them and remove them.
An example:
ArrayList<PVector> readings;
int readingsCount = 15;
void setup() {
size(540, 540);
// create collection of random readings
readings = new ArrayList<PVector>();
for(float angle = 0; angle < TWO_PI; angle += TWO_PI/ readingsCount) {
float distance = random(100, 200);
// the new reading has an angle...
PVector newReading = PVector.fromAngle(angle);
// ... and a distance
newReading.mult(distance);
// Add the new reading to the collection
readings.add(newReading);
}
}
void draw() {
background(255);
// Put (0, 0) in the middle of the screen
translate(width/2, height/2);
float radius = 250;
noFill();
ellipse(0, 0, 2*radius, 2*radius);
// draw spinning line
float angle = frameCount * 0.1;
line(0, 0, radius * cos(angle), radius * sin(angle));
// draw readings
for(PVector p : readings) {
ellipse(p.x, p.y, 20, 20);
}
}

Processing: How to split screen?

I'm trying to create a multi-player game with Processing, but can't figure out how to split screen into two to display different situation of the players?
like in c#,we have
Viewport leftViewport,rightViewport;
to solve the problem.
Thanks a lot
In processing all drawing operations like rect, eclipse etc. are done on a PGraphics element. You could create two new PGraphic objects with the renderer of your choice, draw on them and add them to your main view:
int w = 500;
int h = 300;
void setup() {
size(w, h);
leftViewport = createGraphics(w/2, h, P3D);
rightViewport = createGraphics(w/2, h, P3D);
}
void draw(){
//draw something fancy on every viewports
leftViewport.beginDraw();
leftViewport.background(102);
leftViewport.stroke(255);
leftViewport.line(40, 40, mouseX, mouseY);
leftViewport.endDraw();
rightViewport.beginDraw();
rightViewport.background(102);
rightViewport.stroke(255);
rightViewport.line(40, 40, mouseX, mouseY);
rightViewport.endDraw();
//add the two viewports to your main panel
image(leftViewport, 0, 0);
image(rightViewport, w/2, 0);
}

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