line by line-grid: My sketch does not start properly

injuvik

Dear coders,

i want to draw a line by line-grid in Processing, but my program does not work anyway, it does not start properly, i guess it is because i try to reset x in the for-loop.

I there a good solution for that?

float y;
float a;

int cols = 16;
int rows = 50;

void setup() {
  size(540, 540);  
  noStroke();
  frameRate(10);
}

void draw() {
  background(#0000ff);
  for (float x = 0; x < width*height; x+=width/cols) {

    if (x > width) {
      y += height/rows;
      x = 0;
    }

    fill(#ff0000);

    rect(x, y, 1, 1);
  }

  // saveFrame();
}

kfrajer

Clarity over compactness ;)

Kf

float y;
float a;

int cols = 16;
int rows = 50;

void setup() {
  size(540, 540); 
  stroke(0);
  fill(#ff0000);
  frameRate(10);
}

void draw() {
  background(#0000ff);
  for (float x = 0; x < width; x+=width/cols) {
    for (float y = 0; y < height; y+=height/rows) {      
      rect(x, y, 5, 5);
    }
  }
}

Chrisir

you need another for-loop variable than x

(you shouldn't manipulate the for-loop variable in most cases)

float y=0;
//float a;

int cols = 16;
int rows = 50;

void setup() {
  size(540, 540);  
  //  noStroke();
  noFill();

  // frameRate(10);
}

void draw() {

  //  background(0);

  float x2=0;
  y=0;
  for (int i = 0; i < cols*rows; i++) {

    //fill(#ff0000);
    float size1=width/cols-4;
    float size2=height/rows-4;
    stroke(255);
    fill(255); 
    rect(x2, y, size1, size2);

    x2 += width/cols;

    // new line
    if (x2 > width) {
      y += height/rows;
      x2 = 0;
    }
  }

  // saveFrame();
}

injuvik

Great, thank you guys!

koogs

for (int i = 0 ; i < cols * rows ; i += 1) {
  rect((i % cols) * (width / cols), (i / cols) * (height / rows), 5, 5);
}

x is remainder of i / cols (multiplied by width of each column)

y is the INTEGER division of i / cols (multiplied by the height of each row)

Compactness over clarity 8)

(but seriously, use kf's solution. much easier and, in fact, shorter than your original)