CODEWITHSUNDEEP
javamatrixprocessingrect
Kith M.
Kith M.

Reputation: 111

Matrixes and for loops becoming inconsistent?

This is a follow-up post to my previous question, here. I got a remarkable response to instead of using array data tracking, to use matrixes. Now, the code here works just as planned (as in, the rectangles somewhat most of the time get filled in properly with white), but it's very inconsistent. When holding the left or right mouse button the colors phase over each other in a battle of randomness, and I don't know nearly that much about why this is happening. Just for reference, I'm using Java in Processing 3.

This is a result that I made with the project. As you can see, it looks fine.

Snapshot of my project

Except for that jitter when hovering over a rect, and that more than not the rectangles are not being filled in half the time. And plus, the hover color is cycling almost randomly.

int cols, rows;
int scl = 20;
boolean[][] matrix = new boolean[scl+1][scl+1];

void setup() {
  size(400, 400);
  int w = 400;
  int h = 400;
  cols = w / scl;
  rows = h / scl;
}

void draw() {
  background(255);
  for (int x = 0; x < cols; x++) {
    for (int y = 0; y < rows; y++) {
      int xpos = x*scl;
      int ypos = y*scl;

stroke(55);
  if ((mouseX >= xpos && mouseX <= xpos+scl) &&
    (mouseY >= ypos && mouseY <= ypos+scl)) {
    fill(75);
    if (mousePressed == true) {
      println("Clicked at: " + xpos + " and " + ypos);
      if (!matrix[xpos/scl][ypos/scl]) {
        matrix[xpos/scl][ypos/scl] = true;

      } else {
        matrix[xpos/scl][ypos/scl] = false;
      }
      fill(100);
      //here is the desired location for the fill to remain constant even 
      //after unclicking and leaving hover
    }
    println("Mouse at: " + xpos + " and " + ypos);
  } else {
    fill(50);
  }
  if (matrix[x][y]) {
    //fill(204, 102, 0);
    fill(240);
    rect(xpos, ypos, scl, scl);
  }
  rect(xpos, ypos, scl, scl);
    }
  }
}

Upvotes: 0

Views: 45

Answers (1)

Kevin Workman
Kevin Workman

Reputation: 42176

Remeber that Processing fires the draw() function 60 times per second.

So your check for whether the mouse is pressed is happening 60 times per second. That means you're toggling the state of whatever cell the mouse is in 60 times per second.

To fix that problem, you might switch to using the event functions like mousePressed() instead of constantly polling every frame.

From the reference:

int value = 0;

void draw() {
  fill(value);
  rect(25, 25, 50, 50);
}

void mousePressed() {
  if (value == 0) {
    value = 255;
  } else {
    value = 0;
  }
}

As for certain cells being skipped over, that's because when you move the mouse, it doesn't actually go through every pixel. It "jumps" from frame to frame. Those jumps are usually small enough that humans don't notice it, but they're large enough that it's skipping over cells.

One solution to this is to use the pmouseX and pmouseY variables to calculate a line from the previous mouse position to the current mouse position, and fill in any cells that would have been hit along the way.

Upvotes: 1

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