so im building brick breaker on Java and so far I have most of the UI done but Im having an issue with showing my bricks on my UI. I have written the code for it in my paint method which builds my panel and then my panel is added to a JFrame in another class. Everything shows except for my bricks and I cant seem to figure out why..
// AnimationPanel.java
//
// Informatics 45 Spring 2010
// Code Example: Our Ball Animation Becomes a Game
/开发者_JS百科/
// This is relatively similar to our AnimationPanel in the previous version
// of our ball animation, with two changes:
//
// * The paddle is now drawn, in addition to just the ball. For fun, I've
// drawn the paddle in a different color than the ball.
//
// * This panel has a MouseMotionListener attached to it. The job of a
// MouseMotionListener is to listen for mouse movement within a component.
// In this case, any mouse movement within our AnimationPanel will turn
// into events, which we'll handle by adjusting the center x-coordinate
// of the paddle accordingly.
//
// * Because we need to calculate a new position for the paddle as the mouse
// moves, we'll need to be able to convert coordinates in both directions
// (i.e., fractional coordinates to pixel coordinates and pixel coordinates
// to fractional coordinates).
package inf45.spring2010.examples.animation2.gui;
import inf45.spring2009.examples.animation2.model.Animation;
import inf45.spring2009.examples.animation2.model.AnimationState;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class AnimationPanel extends JPanel
{
private Animation animation;
private inf45.spring2009.examples.animation2.model.AnimationState currentState;
boolean brickVisible[][];
int bricksInRow = 4;
int bricksInColumn = 8;
int brickWidth;
int brickHeight;
int bricksLeft;
public AnimationPanel(Animation animation)
{
this.animation = animation;
currentState = null;
setBackground(Color.WHITE);
addMouseMotionListener(
new MouseMotionAdapter()
{
public void mouseMoved(MouseEvent e)
{
updatePaddlePosition(e.getX());
}
});
}
public void updateState(AnimationState newState)
{
currentState = newState;
}
private void updatePaddlePosition(int pixelX)
{
double paddleCenterX = convertPixelXToX(pixelX);
animation.updatePaddleCenterX(paddleCenterX);
}
public void paint(Graphics g)
{
super.paint(g);
if (currentState == null)
{
return;
}
int centerPixelX = convertXToPixelX(currentState.getBallCenterX());
int centerPixelY = convertYToPixelY(currentState.getBallCenterY());
int radiusX = convertXToPixelX(currentState.getBallRadius());
int radiusY = convertYToPixelY(currentState.getBallRadius());
int topLeftPixelX = centerPixelX - radiusX;
int topLeftPixelY = centerPixelY - radiusY;
int paddleCenterPixelX = convertXToPixelX(currentState.getPaddleCenterX());
int paddleCenterPixelY = convertYToPixelY(currentState.getPaddleCenterY());
int paddleWidthPixels = convertXToPixelX(currentState.getPaddleWidth());
int paddleHeightPixels = convertYToPixelY(currentState.getPaddleHeight());
int paddleTopLeftPixelX = paddleCenterPixelX - (paddleWidthPixels / 2);
int paddleTopLeftPixelY = paddleCenterPixelY - (paddleHeightPixels / 2);
Graphics2D g2d = (Graphics2D) g;
/* for (int x = 0;x<bricksInRow;x++){
for (int y = 0;y<bricksInColumn;y++){
boolean bricks[][] = null;
brickVisible[x][y] = bricks[x][y] ;
{
g2d.setColor(Color.black);
g2d.fillRect(x*brickWidth,y*brickHeight,brickWidth-1,brickHeight-1);
}
}
}
*/
g2d.setRenderingHint(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(Color.BLUE);
g2d.fillOval(topLeftPixelX, topLeftPixelY, radiusX * 2, radiusY * 2);
g2d.setColor(Color.RED);
g2d.fillRect(
paddleTopLeftPixelX, paddleTopLeftPixelY,
paddleWidthPixels, paddleHeightPixels);
}
private int convertXToPixelX(double x)
{
return (int) (x * getWidth());
}
private int convertYToPixelY(double y)
{
return (int) (y * getHeight());
}
private double convertPixelXToX(int pixelX)
{
return (double) pixelX / getWidth();
}
}
It seems like you don't assign any value to brickHeight
and brickWidth
in your code. This might be the problem.
What MByD said, although as these fields are package-local you could possibly be setting these elsewhere. Also, there is also a NPE problem here:
boolean bricks[][] = null;
brickVisible[x][y] = bricks[x][y] ;
I'm not sure if you added this in before or after you found things weren't working, but this is a sure-fire NullPointerException
which will cause the rest of your paint code to not execute when thrown.
EDIT: I'm assuming you commented out the code that wasn't working, but this is the bit you want to make work.
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