void setup() {
background(0);
fullScreen();
}
void draw() {
int g = 0;
float cCount = map(mouseY, 0, height, 1, 20);
for (int i = 0; i < width; i+=50) {
while(g < cCount) {
circle(i, mouseY, 20);
}
}
}
So what I'm trying to do is change the number of times circles are shown on the screen as I move the mouse. When the mouse moves down, more circles are shown on the screen all with the same Y coordinate but the distance between each circle is 50. As I move the mouse up, less circles are shown. Max circles is 20 and min is 1. I don't know how to set up a way for the number of circles to change as I move the mouse?
I think your approach is correct, but your code has some bugs that are not related to the problem itself.
In your while (g < cCount) loop, neither g nor cCount is updated, resulting in an infinite loop, but you don't really need that while loop anyway.
The following should work (but I haven't checked running the code myself, so it might have some bugs.
void draw() {
int circleCount = round(map(mouseY, 0, height, 1, 20));
for (int i = 0; i < circleCount; i+=1) {
circle(i*50, mouseY, 20);
}
}
Related
So I made the Sierpinski carpet fractal in processing using a Square data type which draw a square and has a function generate() that generates 9 equal squares out of itself and returns an ArrayList of (9-1)=8 squares removing the middle one (it is not added to the returned ArrayList) in order to generate the Sierpinski carpet.
Here is the class Square -
class Square {
PVector pos;
float r;
Square(float x, float y, float r) {
pos = new PVector(x, y);
this.r = r;
}
void display() {
noStroke();
fill(120,80,220);
rect(pos.x, pos.y, r, r);
}
ArrayList<Square> generate() {
ArrayList<Square> rects = new ArrayList<Square>();
float newR = r/3;
for (int i=0; i<3; i++) {
for (int j=0; j<3; j++) {
if (!(i==1 && j==1)) {
Square sq = new Square(pos.x+i*newR, pos.y+j*newR, newR);
rects.add(sq);
}
}
}
return rects;
}
}
This is the main sketch which moves forward the generation on mouse click -
ArrayList<Square> current;
void setup() {
size(600, 600);
current = new ArrayList<Square>();
current.add(new Square(0, 0, width));
}
void draw() {
background(255);
for (Square sq : current) {
sq.display();
}
}
void mousePressed() {
ArrayList<Square> next = new ArrayList<Square>();
for(Square sq: current) {
ArrayList<Square> rects = sq.generate();
next.addAll(rects);
}
current = next;
}
The problem :
The output that I am getting has very thin white lines which are not supposed to be there :
First generation -
Second generation -
Third generation -
My guess is that these lines are just the white background that shows up due to the calculations in generate() being off by a pixel or two. However I am not sure about how to get rid of these. Any help would be appreciated!
Here's a smaller example that demonstrates your problem:
size(1000, 100);
noStroke();
background(0);
float squareWidth = 9.9;
for(float squareX = 0; squareX < width; squareX += squareWidth){
rect(squareX, 0, squareWidth, height);
}
Notice that the black background is showing through the squares. Please try to post this kind of minimal example instead of your whole sketch in the future.
Anyway, there are three ways to fix this:
Option 1: Call the noSmooth() function.
By default, Processing uses anti-aliasing to make your drawings look smoother. Usually this is a good thing, but it can also add some fuzziness to the edges of shapes. If you disable anti-aliasing, your shapes will be more clear and you won't see the artifacts.
Option 2: Use a stroke with the same color as the fill.
As you've already discovered, this draws an outline around the shape.
Option 3: Use int values instead of float values.
You're storing your coordinates and sizes in float values, which can contain decimal places. The problem is, the screen (the actual pixels on your monitor) don't have decimal places (there is no such thing as half a pixel), so they're represented by int values. So when you convert a float value to an int, the decimal part is dropped, which can cause small gaps in your shapes.
If you just switch to using int values, the problem goes away:
size(1000, 100);
noStroke();
background(0);
int squareWidth = 10;
for(int squareX = 0; squareX < width; squareX += squareWidth){
rect(squareX, 0, squareWidth, height);
}
I'm fairly new to processing but I am having trouble shifting the z position on one of my line sets.
The x axis lines look as I need it to, but I am basically trying to bring up the Y set of lines so they arent just going downwards but are more linked up with the first set of lines. I hope I'm making sense, It's kind of hard to explain. Thanks!
Edit: Basically what Im trying to make is a tiled floor.
int grid = 80;
void setup() {
size (1024, 900, P3D);
}
void draw() {
int movement = mouseY-500;
background(0);
strokeWeight(2.5);
stroke(100, 255, 0, 60);
//floorx
for (int i = 0; i < width; i+=grid) {
line (i , height/2 , 0, i , height, 5000);
}
//floory
for (int i = 0; i < height; i+=grid) {
line (0, i + height/2, 0, width, i + height/2,0 );
}
}
I think that you want the grid to appear more geometrically correct. To achieve this you need different distances between the horizontal lines.
Try this in your floory part:
grid = 40;
//floory
for (int i = 0; i < height; i+=grid) {
line (0, i + height/2, 0, width, i + height/2, 0 );
grid += 20;
}
My pixels are updating every frame causing the effect to be re-applied to the previous frame. How can i make this effect only happen once and without using noLoop(). I just want there to be a large circle around the triangle. Please help. Thanks.
Here is the whole program. I set the frameRate to 1 so you can see the problem easier:
boolean up;
int x =-300;
int y =-300;
void setup()
{
size(600, 600);
frameRate(1);
}
void draw()
{
pushMatrix();
translate(300, 300);
float a = atan2(mouseY-300, mouseX-300);
rotate(a);
for (int i = x; i < x+width; i+=40)
for (int j = y; j < y+height; j+=40)
rect(i, j, 40, 40);
loadPixels();
for (int i = 0; i < pixels.length; i++)
{
x = i%width;
y = i/width;
color c = pixels[x+y*width];
float d = dist(x, y, width/2, height/2);
pixels[x+y*width] = color(brightness(c) - d);
}
updatePixels();
popMatrix();
fill(255, 0, 0);
triangle(280, 300, 300, 200, 320, 300);
if (up)
{
x += sin(a)*5;
y += cos(a)*5;
}
}
void keyPressed()
{
if (key=='w')up=true;
}
void keyReleased()
{
if (key=='w')up=false;
}
Re-draw everything in one frame.
Remember before you use your filter, you must undo the filter effects of the last time.
The usual ordering in your draw() function goes as follows:
Add a background / clear all the objects you added in the last frame & clearing the filter of your last frame.
Add your objects.
Lay your filter on top.
Try to refrain from doing any graphic related stuff in setup, hence it will be destroyed by this draw() function - paradigma.
This should already suffice as your answer. Quick note:
When you work with for e.g. a 3D - Shadow filter, applying the filter can take a very long time. Instead we try to store as many calculations we did on the previous frame, so we don't need to calculate everything over again. The same goes for the objects-layer. You don't want to calculate the shortest-path for a minion every frame, instead you calculate the shortest path once and only recalculate it, when something changes: Position of a box, player position, etc..
If you want just use your filter and move fluently around update your effect like this:
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
color c = pixels[x+y*width];
float d = dist(x, y, width/2, height/2);
pixels[x+y*width] = color(brightness(c) - d);
}
}
You had unnecessary calculation that consume lot of CPU resources. Redrawing background also helps to make clearer animation.
If you want generate this effect only once and then apply it. PGraphics could achieve something similar.
I'm trying to draw bears in processing, (Just simple circles), how can I get the bears equally spaced apart, and have the same space from the edge of the screen to the bears, on either side? As well as vertically.
I know this is vague, but I'm terrible at explaining things
Because you does not provide any code or example I will just tell you how to place circle in the middle of sketch.
For simplicity imagine this set up:
void setup(){
size(400, 400);
}
1) Very basic approach would be to hard code position of this circle into ellipse draw function.
ellipse(200, 200, 50, 50);
Where first two parameters are coordinates for circle center. Simple find out from size 400x400 that mid is on coord 200x200. This is bad approach and you should avoid using it.
2) Better approach would be to calculate center coord using global variables width and height
ellipse(width/2, height/2, 50, 50);
3) When you are drawing or moving more complex objects it is preferred to use some function to draw this objects always with same fixed position in our example
void draw_circle(){
ellipse(0, 0, 50, 50);
}
And just moving center of drawing using transformations so our draw function will looks like this
void draw(){
pushMatrix();
translate(width/2, height/2);
draw_circle();
popMatrix();
}
Using this you could be able to draw bears equally spaced apart and from sides.
It sounds like you want a grid of equally spaced circles. For that you just need to divide your space into a grid in the x and y directions. The simplest way to do this is to wrap the kind of thing Majlik showed inside a double loop to move from cell to cell in your 'virtual' grid. To see this more clearly, in the code below there is an extra little bit so that if you press the 'g' key (for grid) you'll see the grid cells, with a circle centered in each one. You can press any other key to make the grid go away.
You can see that each way gives the same result: inside draw() uncomment the one you want and comment out the other 2.
int nx = 4; // number of circles horizontally
int ny = 5; // number of circles vertically
int divx;
int divy;
int diameter = 40;
void setup() {
size(600, 600);
// calculate width and hegith of each cell of the grid
divx = width/nx;
divy = height/ny;
}
// 3 ways to draw a regular grid of circles
void draw() {
background(200);
// show the cell layout if the g key was typed, otherwise don't
if(key == 'g')
drawGrid();
// 1 way
for(int i = 0; i < nx; i++) {
for(int j = 0; j < ny; j++ ) {
ellipse(i * divx + divx/2, j * divy + divy/2, diameter, diameter);
}
}
// another way
// for(int i = divx/2; i < width; i += divx) {
// for(int j = divy/2; j < height; j += divy ) {
// ellipse(i, j, diameter, diameter);
// }
// }
// yet another way
// for(int i = divx/2; i < width; i += divx) {
// for(int j = divy/2; j < height; j += divy ) {
// pushMatrix();
// translate(i, j);
// ellipse(0, 0, diameter, diameter);
// popMatrix();
// }
// }
}
void drawGrid() {
// draw vertical lines
for(int i = 1; i < nx; i++) {
line(i * divx, 0, i * divx, height);
}
// draw horizontal lines
for(int j = 1; j < ny; j++ ) {
line(0, j * divy, width, j * divy);
}
}
I am new to Processing.js and need a little bit support with this issue. I have made a HTML-Canvas animation where I have lines with a curtain like behavior which can be seen here:
Click
this is made with a canvas plugin called Paper.js
I now want to get similar effect on processing but don't really know how to figure it out. My attempt was:
float x;
float y;
void setup() {
size(1024, 768);
strokeWeight(2);
background(0, 0, 0);
}
void mouseMoved() {
x = mouseX;
y = mouseY;
}
void draw() {
background(0);
line(50, 50, x += x - x/5, y += y - y/5);
stroke(255, 255, 255);
line(50, 700, x += x - x/15, y += y - y/15);
stroke(255, 255, 255);
line(75, 50, x += x - x/25, y += y - y/25);
stroke(255, 255, 255);
line(75, 700, x += x - x/35, y += y - y/35);
// and so on, would create it within a loop
}
So what I am trying to do is basically get the same effect which I have done in HTML and adapt it in Processing.js.
Thanks in advance.
I'd strongly recommend ignoring the paper.js and reimplementing this properly. We're seeing a sequence of lines that connect to a historical line of coordinates, based on mouse position, so let's just implement that:
class Point {
float x, y;
Point(float _x, float _y) { x=_x; y=_y; }}
// our list of historical points
ArrayList<Point> points;
// the horizontal spacing of our lines has fixed interval
float interval;
// how many lines do we want to draw?
int steps = 50;
void setup() {
size(500, 500);
// initialise the "history" as just the midpoint
points = new ArrayList<Point>();
for (int i=0; i<steps; i++) {
points.add(new Point(width/2, height/2));
}
// compute the horizontal interval, because it's
// width-dependent. Never hard code dependent values.
interval = width/(float)steps;
// the lower we set this, the slower it animates.
frameRate(60);
}
void draw() {
// white background, black lines
background(255);
stroke(0);
// for each historic point, draw two
// lines. One from height 0 to the point,
// another from height [max] to the point.
Point p;
for (int i=0; i<steps; i++) {
p = points.get(i);
line(interval/2 + i*interval, 0, p.x, p.y);
line(interval/2 + i*interval, height, p.x, p.y);
}
// when we move the mouse, that counts as a new historic point
points.remove(0);
points.add(new Point(mouseX, mouseY));
}
Sketch running in the browser: http://jsfiddle.net/M2LRy/1/
(You could speed this up by using a round-robin array instead of an ArrayList, but ArrayLists are pretty convenient here)