BYOW Common Bugs

Deadlines

Warning: There are 3 deadlines for this project, and some deadlines require you to submit multiple deliverables. Please double-check that you submitted everything!
Assignment Tasks Deliverable Points Due Date
Team Formation - Task 0: Partnerships Pre-Project Google Form 5 Mon, Nov 11
11:59pm PT
Project 3A - Task 1: Setup
- Task 2: World Generation		 World Screenshots on Gradescope 10 Mon, Nov 18
11:59pm PT
Mid-Project Google Form 5
Project 3B - Task 3: Main Menu
- Task 4: Interactivity
- Task 5: Saving and Loading
- Task 6: Ambition Features
 Code on Gradescope
(0 pts, but required for checkoff)
 0 Tue, Nov 26
11:59pm PT
Live Checkoff with TA
(Checkoffs will happen Dec 2–6)		 100
Post-Project Google Form 5

Common Bugs

Overriding Equals

The Problem: Two instances of my class are saying they are not equal when they should be. Also, I set the instance of my class to be the key in a HashMap, but I can’t find it when I try to access that key.

The Solution: Make sure that if you create any classes, override the .equals() method AND the .hashcode() method. This will guarantee that two instances that are equal will have the same hashcode

Common UI Bugs

Invisible Text

Getting text to show up on screen can be somewhat tricky. Several things need to go right:

  • the font color needs to be set to something visible (i.e. white)
  • the location of the text needs to be in bounds
  • you need to call StdDraw.show() after the text is drawn so it shows up on screen
  • you need to make sure that your text does not get drawn over or cleared right after it is drawn (for example, TERenderer.renderTiles clears the entire screen)

Here’s some code that should correctly draw text:

TERenderer ter = new TERenderer();
ter.initialize(80, 40, 0, 0);
StdDraw.setPenColor(Color.WHITE);
StdDraw.text(40, 30, "I like cheese");
StdDraw.show();

Strange Tiles

The Problem:

One common glitch is that after implementing other parts of the UI, the tile characters will suddenly misbehave. Here’s a program that demonstrates the problem; paste this in your core folder if you want to follow along.

You’ll notice that the flowers no longer look like flowers anymore. This is because the font size is much too large, so the characters for each tile are spilling into the other tiles.

The Solution:

The problem is that the tiles are being drawn with too large a font size, so we’ll use a method that resets the font size. Call the resetFont method in your TERenderer class:

/** Sets the font to the correct font for drawing tiles */
public void resetFont() {
    Font font = new Font("Monaco", Font.BOLD, TILE_SIZE - 2);
    StdDraw.setFont(font);
}

Then, call the method before you draw the tiles:

Before After 
// render frame
ter.renderFrame(tiles);

// render frame
ter.resetFont();
ter.renderFrame(tiles);

Now, when you run FlowerWorld the tiles should be drawn correctly.

Flickering UI

The Problem:

One common glitch is a flickering UI. Here’s a program that demonstrates the problem; paste this in your core folder if you want to follow along.

You’ll notice the text “HUD goes here” should flicker. The reason why is because there are multiple StdDraw.show() calls per frame - one inside the renderFrame call, and one on line 31. This means that there are actually two frames being drawn on screen every loop: one without the text, and one with the text. It’s somewhat random which frame you see, which is why the UI flickers between the two.

The Solution:

The problem is that there’s an extra StdDraw.show() call inside renderFrame, so we’ll create a version of that method without it. Instead, use the drawTiles method in your TERenderer class:

    /**
     * Like renderFrame, but does not clear the screen or show the tiles
     */
    public void drawTiles(TETile[][] world) {
        for (int x = 0; x < world.length; x += 1) {
            for (int y = 0; y < world[x].length; y += 1) {
                world[x][y].draw(x + xOffset, y + yOffset);
            }
        }
    }

Replace the renderFrame call in the main game loop:

Before After 
// main game loop
while (true) {
    ter.renderFrame(tiles);
    ...
}

// main game loop
while (true) {
    StdDraw.clear(Color.BLACK);
    ter.drawTiles(tiles);
    ...
}

Now, when you run WaterWorld the text should no longer flicker.

Custom image not rendering

The Problem:

If you are creating custom images for your game, then you may run into a bug where your images aren’t rendering even after you have created a custom TETile with the correct filepath.

The Solution:

Make sure that your images are 16x16 pixels and stored as PNGs.