How do I detect collision with the background color in Processing 3 (java)?

Processing Coding Questions
1

I am creating a basic dungeon game where you spawn into a randomly generated dungeon and you need to fight monsters.

I just did a random generator where it will move a simulated character around the screen and draw a path of rectangles behind it. This is good and all but now that I am working on implimenting the character, I realise that I cannot detect collision with the background. I am attempting to use color collision. My current color detection is on line 94 and has a comment on 93. Here is my code so far (It is very long. Too lazy to trim it):

int rectNum = 0;
int gx = 400;
int gy = 400;
int gr;
int rx1 = -100;
int rx2 = -100;
int rx3 = -100;
int rx4 = -100;
int rx5 = -100;
int rx6 = -100;
int rx7 = -100;
int rx8 = -100;
int rx9 = -100;
int rx10 = -100;
int rx11 = -100;
int rx12 = -100;
int rx13 = -100;
int rx14 = -100;
int rx15 = -100;
int rx16 = -100;
int rx17 = -100;
int rx18 = -100;
int rx19 = -100;
int rx20 = -100;
int ry1;
int ry2;
int ry3;
int ry4;
int ry5;
int ry6;
int ry7;
int ry8;
int ry9;
int ry10;
int ry11;
int ry12;
int ry13;
int ry14;
int ry15;
int ry16;
int ry17;
int ry18;
int ry19;
int ry20;
int i = 0;
int gc = 0;
int whileCount = 0;
int x;
int y;
int sx = 25;
int sy = 25;
int draw = 0;
int right = 0;
int left = 0;
int up = 0;
int down = 0;
int speed = 3;

void setup() {
  size(900, 900);
}

void draw() {
  background(0, 0, 0);
  fill(#696969);
  noStroke();
  rect(rx1, ry1, 50, 50);
  rect(rx2, ry2, 50, 50);
  rect(rx3, ry3, 50, 50);
  rect(rx4, ry4, 50, 50);
  rect(rx5, ry5, 50, 50);
  rect(rx6, ry6, 50, 50);
  rect(rx7, ry7, 50, 50);
  rect(rx8, ry8, 50, 50);
  rect(rx9, ry9, 50, 50);
  rect(rx10, ry10, 50, 50);
  rect(rx11, ry11, 50, 50);
  rect(rx12, ry12, 50, 50);
  rect(rx13, ry13, 50, 50);
  rect(rx14, ry14, 50, 50);
  rect(rx15, ry15, 50, 50);
  rect(rx16, ry16, 50, 50);
  rect(rx17, ry17, 50, 50);
  rect(rx18, ry18, 50, 50);
  rect(rx19, ry19, 50, 50);
  rect(rx20, ry20, 50, 50);
  if (draw == 1) {
    fill(#FF00AA);
    ellipse(x, y, 20, 20);
    x += (right - left) * speed;
    y += (down - up) * speed;
  }
//Current Color Collision
  if (get(x - 5, y) == color(0, 0, 0) || get(x + 5, y) == color(0, 0, 0) || get(x, y + 5) == color(0, 0, 0) || get(x, y - 5) == color(0, 0, 0)) {
    x += (left - right) * speed;
    y += (up - down) * speed;
    println("eeee");
  }
  stroke(0);
  strokeWeight(20);
  noFill();
  rect(0, 0, 900, 900);
  if (i < 21) {
    gc = 0;
    whileCount = 0;
    while (gc == 0) { 
      whileCount ++;
      if (whileCount > 20) {
        reset();
      }
      gr = int(random(1, 5));
      println("While Stats: " + i + " " + gr + " " + whileCount);
      if (gr == 1) {
        if (gy + 50 < 900) {
          if (get(gx + 25, gy - 25) == color(0)) {
            gc = 1;
            gy -= 50;
            i++;
          }
        }
      }
      if (gr == 2) {
        if (gy - 50 > 0) {
          if (get(gx + 25, gy + 75) == color(0)) {
            gc = 1;
            gy += 50;
            i++;
          }
        }
      }
      if (gr == 3) {
        if (gx + 50 < 900) {
          if (get(gx + 75, gy + 25) == color(0)) {
            gc = 1;
            gx += 50;
            i++;
          }
        }
      }
      if (gr == 4) {
        if (gx - 50 > 0) {
          if (get(gx - 25, gy + 25) == color(0)) {
            gc = 1;
            gx -= 50;
            i++;
          }
        }
      }
      if (i == 1) {
        rx1 = gx;
        ry1 = gy;
      }
      if (i == 2) {
        rx2 = gx;
        ry2 = gy;
      }
      if (i == 3) {
        rx3 = gx;
        ry3 = gy;
      }
      if (i == 4) {
        rx4 = gx;
        ry4 = gy;
      }
      if (i == 5) {
        rx5 = gx;
        ry5 = gy;
      }
      if (i == 6) {
        rx6 = gx;
        ry6 = gy;
      }
      if (i == 7) {
        rx7 = gx;
        ry7 = gy;
      }
      if (i == 8) {
        rx8 = gx;
        ry8 = gy;
      }
      if (i == 9) {
        rx9 = gx;
        ry9 = gy;
      }
      if (i == 10) {
        rx10 = gx;
        ry10 = gy;
      }
      if (i == 11) {
        rx11 = gx;
        ry11 = gy;
      }
      if (i == 12) {
        rx12 = gx;
        ry12 = gy;
      }
      if (i == 13) {
        rx13 = gx;
        ry13 = gy;
      }
      if (i == 14) {
        rx14 = gx;
        ry14 = gy;
      }
      if (i == 15) {
        rx15 = gx;
        ry15 = gy;
      }
      if (i == 16) {
        rx16 = gx;
        ry16 = gy;
      }
      if (i == 17) {
        rx17 = gx;
        ry17 = gy;
      }
      if (i == 18) {
        rx18 = gx;
        ry18 = gy;
      }
      if (i == 19) {
        rx19 = gx;
        ry19 = gy;
      }
      if (i == 20) {
        rx20 = gx;
        ry20 = gy;
      }
    }
  }
  if (i > 20 && draw == 0) {
    if (get(sx, sy) == color(105, 105, 105)) {
      x = sx;
      y = sy;
      draw = 1;
    }
    else {
      if (sx > 875) {
        sx = 25;
        sy += 50;
      }
      else {
        sx += 50;
      }
    }
  }
}

void reset() {
  rectNum = 0;
  gx = 400;
  gy = 400;
  gr = 0;
  rx1 = -100;
  rx2 = -100;
  rx3 = -100;
  rx4 = -100;
  rx5 = -100;
  rx6 = -100;
  rx7 = -100;
  rx8 = -100;
  rx9 = -100;
  rx10 = -100;
  rx11 = -100;
  rx12 = -100;
  rx13 = -100;
  rx14 = -100;
  rx15 = -100;
  rx16 = -100;
  rx17 = -100;
  rx18 = -100;
  rx19 = -100;
  rx20 = -100;
  ry1 = 0;
  ry2 = 0;
  ry3 = 0;
  ry4 = 0;
  ry5 = 0;
  ry6 = 0;
  ry7 = 0;
  ry8 = 0;
  ry9 = 0;
  ry10 = 0;
  ry11 = 0;
  ry12 = 0;
  ry13 = 0;
  ry14 = 0;
  ry15 = 0;
  ry16 = 0;
  ry17 = 0;
  ry18 = 0;
  ry19 = 0;
  ry20 = 0;
  i = 0;
  gc = 0;
  whileCount = 0;
  x = -100;
  y = 0;
  sx = 25;
  sy = 25;
  draw = 0;
}

void keyPressed() {
  if (key == 'w') {up = 1;}
  if (key == 's') {down = 1;}
  if (key == 'a') {left = 1;}
  if (key == 'd') {right = 1;}
}

void keyReleased() {
  if (key == 'w') {up = 0;}
  if (key == 's') {down = 0;}
  if (key == 'a') {left = 0;}
  if (key == 'd') {right = 0;}
}

If anyone knows how to detect collision with a background color that would be absolutely amazing! Anything helps!

2

-a- your ball has 20 diameter == 10 radius
but the color collision looks ahead 5? step size?

-b- your logic:

IF ( left black OR right black OR up black OR down black ) move

has a flaw, it would mean you can move in any direction!
as long one direction shows black.

but you might need a extra IF for each walking direction
but only need to do ONE check, depending on the direction.

-c-
not sure the == color(0,0,0) will work,
better would be like " darker as "…

-d- collision detection is one of the most interesting coding ( math ) things,
color check just the first start.

but also questionable?
come on, we are the CODERs,
so we KNOW where we put the “obstacles” ( as long they are not moving …)

a better design would be a kind of LIST where we say where a obstacle has to be ( drawn ) and directly from that know if we can go there…

please when have time play

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