Triangle Draw Method

Question

I have trouble drawing a triangle with the draw(Graphics g) method in Java. I can draw a rectangle like so:

public void draw(Graphics g) {
    g.setColor(colorFill);
    g.fillRect(p.x, p.y, width, height);
    g.setColor(colorBorder);
    g.drawRect(p.x, p.y, width, height);
    drawHandles(g);

Where p represents "the top left corner of the shapes". How would I draw the triangle in the same manner?

Could someone give me an example for a standard triangle?

Answer 1

There is not a drawTriangle method neither in Graphics nor Graphics2D. You need to do it by yourself. You can draw three lines using the drawLine method or use one these methods:

• drawPolygon(int[] xPoints, int[] yPoints, int nPoints)
• drawPolygon(Polygon p)
• drawPolyline(int[] xPoints, int[] yPoints, int nPoints)

These methods work with polygons. You may change the prefix draw to fill when you want to fill the polygon defined by the point set. I inserted the documentation links. Take a look to learn how to use them.

There is the GeneralPath class too. It can be used with Graphics2D, which is capable to draw Shapes. Take a look:

• http://docs.oracle.com/javase/tutorial/2d/geometry/arbitrary.html

Answer 2

You should try using the Shapes API.

Take a look at JPanel repaint from another class which is all about drawing triangles, look to the getPath method for some ideas

You should also read up on GeneralPath & Drawing Arbitrary Shapes.

This method is much easy to apply AffineTransformations to