I am new to processing. I wrote the following code with bouncing balls but the animation is not smooth. I have ran the application on various computers and I can occasionally see some jitter or tearing of some balls. I do not believe that it is related to the calculation time as it there are not much calculations involved for each frame. Moreover, I have read the processing is already double buffered.
The following is the concerned code:
final int MAX_BALLS = 50;
final int DISPLAY_WIDTH = 800;
final int DISPLAY_HEIGHT = 600;
final float MIN_SPEED = 1;
final float MAX_SPEED = 5;
final float MIN_SIZE = 30;
final float MAX_SIZE = 50;
Ball[] balls = new Ball[MAX_BALLS];
void setup() {
size(800, 600);
stroke(255);
background(0, 0, 0);
for (int i=0; i<balls.length; i++) {
balls[i] = new Ball(random(MIN_SIZE, MAX_SIZE), random(0, DISPLAY_WIDTH), random(0, DISPLAY_HEIGHT), random(MIN_SPEED, MAX_SPEED), random(MIN_SPEED, MAX_SPEED), 0, DISPLAY_WIDTH, 0, DISPLAY_HEIGHT);
}
}
void draw() {
clear();
for (int i = 0; i<balls.length; i++)
balls[i].draw();
}
class Ball {
private float size;
private float x;
private float y;
private float vx;
private float vy;
private float minx;
private float maxx;
private float miny;
private float maxy;
private float r;
private float g;
private float b;
public Ball(float size,float x, float y, float vx, float vy, float minx, float maxx, float miny, float maxy) {
this.size = size;
this.x = x;
this.y = y;
this.vx = vx;
this.vy = vy;
this.minx = minx;
this.maxx = maxx;
this.miny = miny;
this.maxy = maxy;
r = (int) random(30, 255);
g = (int) random(30, 255);
b = (int) random(30, 255);
}
void draw() {
x = x + vx;
if (x + size/2 > maxx) {
vx = -vx;
x = 2 * maxx - (x + size);
} else if (x - size/2 < minx) {
vx = -vx;
x = 2 * minx - (x - size);
}
y = y + vy;
if (y + size/2 > maxy) {
vy = -vy;
y = 2 * maxy - (y + size);
} else if (y -size/2 < miny) {
vy = -vy;
y = 2 * miny - (y - size);
}
stroke(r,g,b);
fill(r,g,b);
ellipse(x, y, size, size);
}
}
How can I get rid of the jitter and tearing? How do I ensure that the graphics card driver is used optimally. Note that I use Linux Mint 17.3 with MATE desktop manager. Same O.S. on all tested PCs and same behavior.
[EDIT 05/01/2016] After generating the circles off-screen and even using an offline image the size of the screen, I still get some tearing. This is the updated code:
final int MAX_BALLS = 50;
final float MIN_SPEED = 1;
final float MAX_SPEED = 5;
final float MIN_SIZE = 30;
final float MAX_SIZE = 50;
Ball[] balls = new Ball[MAX_BALLS];
PGraphics img;
void setup() {
frameRate(60);
fullScreen();
img = createGraphics(width, height);
img.stroke(255);
img.smooth();
for (int i=0; i<balls.length; i++) {
balls[i] = new Ball(random(MIN_SIZE, MAX_SIZE), random(0, width), random(0, height), random(MIN_SPEED, MAX_SPEED), random(MIN_SPEED, MAX_SPEED), 0, width, 0, height);
}
}
void draw() {
img.beginDraw();
img.background(0,0,0);
img.clear();
clear();
for (int i = 0; i<balls.length; i++)
balls[i].draw();
img.text((int)frameRate+"fps",10,15);
img.endDraw();
image(img, 0, 0); // Put the whole image at once on the screen
}
class Ball {
private float size;
private float x;
private float y;
private float vx;
private float vy;
private float minx;
private float maxx;
private float miny;
private float maxy;
private PGraphics circle;
private final int MARGIN = 10; // Margin to avoid circle to be drawn slightly outside the square
public Ball(float size,float x, float y, float vx, float vy, float minx, float maxx, float miny, float maxy) {
this.size = size;
this.x = x;
this.y = y;
this.vx = vx;
this.vy = vy;
this.minx = minx;
this.maxx = maxx;
this.miny = miny;
this.maxy = maxy;
int r = (int) random(30, 255);
int g = (int) random(30, 255);
int b = (int) random(30, 255);
circle = createGraphics((int) this.size + 2*MARGIN, (int) this.size + 2*MARGIN);
circle.beginDraw();
circle.background(0, 0);
circle.fill(r, g, b);
circle.ellipse(MARGIN + this.size/2, MARGIN + this.size/2, this.size, this.size);
circle.endDraw();
}
void draw() {
x = x + vx;
if (x + size/2 > maxx) {
vx = -vx;
x = 2 * maxx - (x + size);
} else if (x - size/2 < minx) {
vx = -vx;
x = 2 * minx - (x - size);
}
y = y + vy;
if (y + size/2 > maxy) {
vy = -vy;
y = 2 * maxy - (y + size);
} else if (y -size/2 < miny) {
vy = -vy;
y = 2 * miny - (y - size);
}
img.image(circle, x - this.size/2 - MARGIN, y - this.size/2 - MARGIN);
}
}
