2D Gradation Pattern Sample code

int [][] gradationPattern = { {5, 4, 3, 4, 5},
{4, 3, 2, 3, 4},
{3, 2, 1, 2, 3},
{4, 3, 2, 3, 4},
{5, 4, 3, 4, 5} };
void setup() {
size (500, 500);
background(0);
}

void draw() {
noStroke();
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
int gp = gradationPattern[i][j];
drawUnit(i, j, gp);

}
}


}
void drawUnit(int i, int j, int gp) {

switch (gp) {
case 1:
fill(gp*50);
rect(i*100, j*100, 100, 100);
break;
case 2:
fill(gp*50);
ellipse(i*100+50, j*100+50, 100, 100);
break;
default:
break;

}
}