如何在数组中打印星形三角形（用作画布）

Question

我试图使用像三角形这样的形状输出图像，以二维数组打印所有图像。我需要三角类的帮助;

矩形类：

public class Rectangle {

 int width;
 int height;
 int x;
 int y;

 public Rectangle(int x, int y, int w, int h) {

  this.width = w;
  this.height = h;
  this.x = x;
  this.y = y;

 }
 public void draw(Canvas c) {
  for (int i = 0; i <= width; i++) {
   for (int j = 0; j <= height; j++) {
    c.drawAt('*', i + x, j + y);
   }
   System.out.println();
  }
 }
}

主要编程：

public class Senary {
 public static void main(String[] args) {

  Canvas c = new Canvas(60, 40);
  c.fillBackground(' ');
  Rectangle r = new Rectangle(2, 2, 2, 2);
  Triangle1 t = new Triangle1(10, 10, 5, 4);
  r.draw(c);
  t.draw(c);
  c.drawToScreen();
 }
}

Canvas as 2D array：

 public class Canvas {

  char[][] buffer;
  int width;
  int height;
  public Canvas(int w, int h) {
   this.width = w;
   this.height = h;
   buffer = new char[height][width];
  }
  public void fillBackground(char c) {
   for (int i = 0; i < height; i++) {
    for (int j = 0; j < width; j++) {
     buffer[i][j] = c;
    }
   }
  }

  public void drawAt(char c, int i, int j) {
   buffer[j][i] = c;
  }
  public void drawToScreen() {
   for (int i = 0; i < height; i++) {
    for (int j = 0; j < width; j++) {
     System.out.print(buffer[i][j]);
    }
    System.out.println();
   }
  }
 }      

三角类：

   public class Triangle1 {
    int base;
    int length;
    int x;
    int y;

    public Triangle1(int x, int y, int l, int b) {
     this.base = b;
     this.length = l;
     this.x = x;
     this.y = y;

    }
    public void draw(Canvas c) {
     for (int i = 1; i <= length; i++) {
      for (int j = base; j >= i; j--) {
       System.out.println(" ");
      }
      for (int k = 1; k <= (2 * i - 1); k++)
       c.drawAt('*', i + x, k + y);
     }
     System.out.println();
    }
   }

必须通过从构造函数中获取长度，基数，x轴，y轴来打印此三角形。有人可以帮忙吗？

输出应该是：

   *      ****
  ***     ****
 *****    ****
*******   ****

根据x，y三角形和矩形必须打印！