Anansi: Collecting Items

We collect the bonus items with the player ship. Everyone likes collectibles and scoring. The more the better. We can easily add let's say another 5 score points to the player's score when the ship picks up an item.

What do we have to do with our engine? We have to

• check if the player ship collides with a bonus item
• add points to the player's score
• remove the sprite
• add a ScoreTransition to the screen

Should be easy to do and done quickly, since it's similar to code we already have. Let's get coding.

We define the score value for the picking up of bonus items in the Settings class.

public static int SCORE_BONUS_STROYENT = 5;

We check if the player sprite collides with the bonus sprites

/**
 * Let player ship pick up bonus items. 
 * @param stroyentList
 */
private void checkBonusCollisions( List stroyentList) {
 
 for( Player player: playerList) {
  for( SpriteBase target: stroyentList) {
   
   // consider only alive sprites
   if( !target.isAlive())
    continue;

   if( player.collidesWith( target)) {
    
    // stop movement of sprite
    target.stopMovement();
    
    // show score
    spawnScoreTransition( target, Settings.SCORE_BONUS_STROYENT);

    // destroy sprite, set health to 0
    target.kill();
    
    // remove the sprite from screen by flagging it as removable
    target.remove();
    
   }
  }
 }
}

And we invoke the check method in the game loop

// bonus items
checkBonusCollisions( stroyentList);

That's it. You can see how it looks like in this screenshot, check out the fading text objects with "5" around the player ship:

Anansi: Screenshots

I'd like to get rid of the border around the screenshots of our game. Until now I did them with windows print screen key. JavaFX has a built-in snapshot command. So let's use that one.

Here's a small utility class that I created using a tutorial on the Oracle website.

package game.utils;

import java.io.File;
import java.io.IOException;

import javafx.embed.swing.SwingFXUtils;
import javafx.scene.image.WritableImage;
import javafx.stage.FileChooser;
import javafx.stage.Stage;

import javax.imageio.ImageIO;

public class Utils {

 /**
  * Take a screenshot of the scene in the given stage, open file save dialog and save it.
  * @param stage
  */
 public static void screenshot( Stage stage) {
  
  // take screenshot
     WritableImage image = stage.getScene().snapshot( null);

     // create file save dialog
     FileChooser fileChooser = new FileChooser();
     
     // title
        fileChooser.setTitle("Save Image");
        
        // initial directory
        fileChooser.setInitialDirectory(
                new File(System.getProperty("user.home"))
            );              
        
        // extension filter
        fileChooser.getExtensionFilters().addAll(
            // new FileChooser.ExtensionFilter("All Images", "*.*"),
            // new FileChooser.ExtensionFilter("JPG", "*.jpg"),
            new FileChooser.ExtensionFilter("PNG", "*.png")
        );
        
        // show dialog
        File file = fileChooser.showSaveDialog( stage);
        if (file != null) {
         
            try {
             
                // save file
                ImageIO.write(SwingFXUtils.fromFXImage(image, null), "png", file);
                
            } catch (IOException ex) {
             
                System.err.println(ex.getMessage());
                
            }
        }
 }
 
}

We can use it by extending our KEY_RELEASED event handler. The utility method demands a stage as parameter, so we need to keep a reference of the primary stage in a global variable.

Stage primaryStage;
 
@Override
public void start(Stage primaryStage) {

    this.primaryStage = primaryStage;
    ...

}
         

The screenshot key will be F12.

...
 @Override
 public void handle(KeyEvent event) {
 
  // register key up
  keyboardBitSet.set(event.getCode().ordinal(), false);
 
  // take screenshot, open save dialog and save it
  if( event.getCode() == KeyCode.F12) {
   
   // pause game
   gameLoop.stop();
   
   // save screenshot
   Utils.screenshot( primaryStage);
  
   // resume game
   gameLoop.start();
  
  }
 
 }
...

And now we got nice PNG files without the windows border whenever we press the screenshot key: