The prompts used to generate the code for the application are included below. I've only included the first (moste interesting) part of the conversation, as the last bit was more of nitpicking and debugging related. There are however some debugging at the end of the conversation, and it's interesting to se how well ChatGPT can be helpful with that kind of tasks.
At the end of the conversation, I add a background image to the game. This image was generated using DreamStudio from stability.ai. This was the prompt (using the style "Digital art"):
An image of outer space, including mostly lots of distant stars and some small galaxies and colourful nebulae. Viewed from the surface of an alien moon.
Below follows the ChatGPT conversation.
User:
Hello. Can you help me with building an Asteroids game app using Flutter?
Sure, I'd be glad to help you get started with building an Asteroids game app in Flutter. Here's a high-level outline of the steps you would need to follow:
-
Set Up Flutter: Make sure you have Flutter SDK and Dart installed on your machine. Also, ensure you have a code editor such as Visual Studio Code installed.
-
Create a new Flutter project: Use the command
flutter create asteroids_gamein your terminal/command prompt. -
Designing the Game Objects (Asteroids, Spaceship, Bullets): You need to create objects for your game. This includes asteroids, the spaceship, and bullets. For each of these objects, you will need to define the following:
- Position
- Size
- Speed
- Direction
Also, consider how each object will be drawn on the screen. You might want to use
CustomPainterto draw your game objects. -
Game Logic:
- Movement: Define how the spaceship and asteroids move. The spaceship's movement might be controlled by the user (e.g., using on-screen buttons), while the asteroids could move randomly.
- Shooting: Implement functionality for the spaceship to shoot bullets. When a bullet is fired, it should move in the direction that the spaceship was facing at the time of firing.
- Collisions: Implement collision detection. You'll need to detect collisions between the spaceship and asteroids, and between bullets and asteroids.
- Scoring: Define how the player will score points (e.g., by hitting asteroids).
- Game Over: Define conditions for ending the game (e.g., when the spaceship collides with an asteroid).
-
Implementing User Interface:
- Use Flutter's widget tree to implement game UI, which might include start and end game screens, score display, and on-screen controls.
- Consider how to handle user input. For a mobile game, you might use
GestureDetectorto handle taps on the screen.
-
Testing:
- Always test your app. Flutter has a robust testing framework that allows for unit tests, widget tests, and integration tests.
-
Building and Publishing Your App:
- Once your game is functioning correctly and you're happy with it, you can build it for iOS and Android using
flutter build iosorflutter build apkrespectively. - After that, you can publish it on app stores.
- Once your game is functioning correctly and you're happy with it, you can build it for iOS and Android using
For your game, consider using a game engine built on top of Flutter, like Flame. It can simplify game development by providing useful features like a game loop, sprite and animation handling, collision detection, and more.
This is a high-level guide. Each step can be broken down further, and you'll likely encounter specific problems or have more detailed questions at each step. Feel free to ask for more information or clarification as needed!
User:
Could you start by helping me to create the needed classes and data structures as mentioned in step 3? Make them as simple as possible, to be able to implement a basic version of the game.
Sure! I'll outline some simple Dart classes for your Asteroids game in Flutter.
First, let's define a basic GameObject class. This will serve as the base class for all our game objects (Spaceship, Asteroid, Bullet).
class GameObject {
double xPos;
double yPos;
double size;
double speed;
double direction; // angle in radians
GameObject({required this.xPos, required this.yPos, required this.size, required this.speed, required this.direction});
}The GameObject class has properties for the position (xPos and yPos), size, speed, and direction.
Now, let's extend GameObject to create specific classes for the Spaceship, Asteroid, and Bullet.
class Spaceship extends GameObject {
// You might want to add additional properties or methods here
Spaceship(double xPos, double yPos, double size, double speed, double direction)
: super(xPos: xPos, yPos: yPos, size: size, speed: speed, direction: direction);
}
class Asteroid extends GameObject {
// You might want to add additional properties or methods here
Asteroid(double xPos, double yPos, double size, double speed, double direction)
: super(xPos: xPos, yPos: yPos, size: size, speed: speed, direction: direction);
}
class Bullet extends GameObject {
// You might want to add additional properties or methods here
Bullet(double xPos, double yPos, double size, double speed, double direction)
: super(xPos: xPos, yPos: yPos, size: size, speed: speed, direction: direction);
}Now, we need to create a class for managing the game state. This will keep track of all game objects and can handle creating and removing objects as needed.
class GameState {
Spaceship spaceship;
List<Asteroid> asteroids;
List<Bullet> bullets;
GameState({required this.spaceship, required this.asteroids, required this.bullets});
}In GameState, we have the Spaceship object, and lists of Asteroid and Bullet objects.
This is a very basic starting point and you will probably
need to add additional methods and properties to these classes as you
implement more game functionality. For example, you might add a move() method to the GameObject class to handle updating an object's position based on its speed and direction.
User:
Great! In the same manner, could you help me create the game logic mentioned in step 4?
Sure, I can provide some guidelines on how to add game logic. Let's take it one step at a time.
1. Movement:
Each game object will have its own way of moving. A common
method is to update the position based on the object's speed and
direction. Let's add a move method to the GameObject class to update the object's position.
void move(double time) {
// Update x and y position based on speed, direction and time
xPos += cos(direction) * speed * time;
yPos += sin(direction) * speed * time;
}2. Shooting:
When the spaceship shoots a bullet, we need to create a new Bullet instance at the spaceship's position and facing the same direction as the spaceship. We'll add a shoot method to the Spaceship class.
Bullet shoot() {
// Create a new bullet facing the same direction as the spaceship
return Bullet(xPos, yPos, 1.0, 10.0, direction);
}3. Collisions:
You need to detect when game objects collide. A simple way
is to check if the distance between objects is less than their combined
sizes (i.e., if their "circles" overlap). We'll add a collidesWith method to the GameObject class.
bool collidesWith(GameObject other) {
// Calculate distance between objects
double distance = sqrt(pow(xPos - other.xPos, 2) + pow(yPos - other.yPos, 2));
// Check if distance is less than the combined size of both objects
return distance < size + other.size;
}4. Scoring and Game Over:
For a simple scoring system, you might increase the score by one every time a bullet hits an asteroid. To check this, iterate over all bullets and asteroids and check if they collide. If they do, remove the bullet and the asteroid, and increase the score.
To check if the game is over, iterate over all asteroids and check if they collide with the spaceship. If they do, then the game is over.
You could add this logic to a GameController class, which handles updating the game state.
class GameController {
GameState gameState;
int score = 0;
GameController({required this.gameState});
void update(double time) {
// Update all game objects
gameState.spaceship.move(time);
gameState.asteroids.forEach((asteroid) => asteroid.move(time));
gameState.bullets.forEach((bullet) => bullet.move(time));
// Check for collisions between bullets and asteroids
gameState.bullets.removeWhere((bullet) {
for (Asteroid asteroid in gameState.asteroids) {
if (bullet.collidesWith(asteroid)) {
gameState.asteroids.remove(asteroid);
score += 1;
return true;
}
}
return false;
});
// Check for collisions between the spaceship and asteroids
for (Asteroid asteroid in gameState.asteroids) {
if (gameState.spaceship.collidesWith(asteroid)) {
// Game over
// You might want to throw an exception or set a flag here
}
}
}
}Remember, these are simple implementations. In a real game, you'd probably want more complex behavior. For example, asteroids might split into smaller asteroids when hit by a bullet, or the spaceship might have lives and only game over when no lives are left. You could add these features by adding more properties and methods to your classes.
User:
Fantastic! Now, can you help me write the UI code for this, as outlined in step 5?
Sure! Let's use Flutter's custom painting to draw the game objects on a canvas, and then place that canvas in the app UI.
First, let's create a GamePainter widget that will take the GameState and draw everything on a canvas.
class GamePainter extends CustomPainter {
final GameState gameState;
GamePainter({required this.gameState});
@override
void paint(Canvas canvas, Size size) {
final paint = Paint();
// Draw spaceship
paint.color = Colors.blue;
canvas.drawCircle(
Offset(gameState.spaceship.xPos, gameState.spaceship.yPos),
gameState.spaceship.size,
paint,
);
// Draw asteroids
paint.color = Colors.brown;
for (var asteroid in gameState.asteroids) {
canvas.drawCircle(
Offset(asteroid.xPos, asteroid.yPos),
asteroid.size,
paint,
);
}
// Draw bullets
paint.color = Colors.red;
for (var bullet in gameState.bullets) {
canvas.drawCircle(
Offset(bullet.xPos, bullet.yPos),
bullet.size,
paint,
);
}
}
@override
bool shouldRepaint(covariant CustomPainter oldDelegate) {
return true;
}
}Then, let's create a GameWidget to include the GamePainter inside a CustomPaint
widget. We'll also include a score display and a button to shoot
bullets. For simplicity, we'll control the spaceship's direction by
rotating it in place every frame.
class GameWidget extends StatefulWidget {
final GameController gameController;
GameWidget({required this.gameController});
@override
_GameWidgetState createState() => _GameWidgetState();
}
class _GameWidgetState extends State<GameWidget> {
late Timer _timer;
@override
void initState() {
super.initState();
// Start a timer to update the game state every 20ms
_timer = Timer.periodic(Duration(milliseconds: 20), (timer) {
setState(() {
widget.gameController.update(0.02);
});
});
}
@override
void dispose() {
super.dispose();
_timer.cancel();
}
@override
Widget build(BuildContext context) {
return Column(
children: [
CustomPaint(
painter: GamePainter(gameState: widget.gameController.gameState),
size: Size(300, 300), // for simplicity, we are using a fixed size
),
Text('Score: ${widget.gameController.score}'),
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.bullets.add(widget.gameController.gameState.spaceship.shoot());
});
},
child: Text('Shoot'),
),
],
);
}
}And finally, use GameWidget as the main widget of your app:
void main() {
// Create initial game state
var gameState = GameState(
spaceship: Spaceship(150, 150, 10, 5, 0),
asteroids: [Asteroid(50, 50, 20, 1, pi / 4), Asteroid(250, 250, 20, 1, pi * 3 / 4)],
bullets: [],
);
// Create game controller
var gameController = GameController(gameState: gameState);
runApp(
MaterialApp(
home: Scaffold(
body: GameWidget(gameController: gameController),
),
),
);
}In the above code, the game
runs in a fixed-size area, the spaceship rotates in place, and you shoot by pressing a button. You'll need to replace these simplifications with real game controls for a complete game.
Please note that you would usually want to manage game state using a more advanced state management solution (like Provider, Riverpod, Bloc,
etc.) instead of updating state directly from timers and button
presses. Also, be sure to handle edge cases such as objects moving off
the screen or game over condition.
User:
Great! Could you also add logic and buttons in the UI for the following actions:
- "Right" - Rotates the spaceship right
- "Left" - Rotates the spaceship left
- "+" - Increases speed of the spaceship
- "-" - Decreases speed of the spaceship
Please also use a triangle as the shape for the spaceship.
Sure! I can certainly help you with that.
First, let's add a rotate and changeSpeed method to the Spaceship class to handle the desired operations:
class Spaceship extends GameObject {
// ...
void rotate(double angle) {
// Add the given angle to the current direction
direction += angle;
}
void changeSpeed(double amount) {
// Add the given amount to the current speed
speed += amount;
}
}Next, let's modify the GamePainter class to draw the spaceship as a triangle instead of a circle:
// Draw spaceship
paint.color = Colors.blue;
var path = Path();
path.moveTo(
gameState.spaceship.xPos + cos(gameState.spaceship.direction) * gameState.spaceship.size,
gameState.spaceship.yPos + sin(gameState.spaceship.direction) * gameState.spaceship.size
);
path.lineTo(
gameState.spaceship.xPos + cos(gameState.spaceship.direction + 2 * pi / 3) * gameState.spaceship.size,
gameState.spaceship.yPos + sin(gameState.spaceship.direction + 2 * pi / 3) * gameState.spaceship.size
);
path.lineTo(
gameState.spaceship.xPos + cos(gameState.spaceship.direction - 2 * pi / 3) * gameState.spaceship.size,
gameState.spaceship.yPos + sin(gameState.spaceship.direction - 2 * pi / 3) * gameState.spaceship.size
);
path.close();
canvas.drawPath(path, paint);Finally, let's add the buttons for rotating and changing the speed of the spaceship in the GameWidget:
class GameWidget extends StatefulWidget {
// ...
@override
Widget build(BuildContext context) {
return Column(
children: [
CustomPaint(
painter: GamePainter(gameState: widget.gameController.gameState),
size: Size(300, 300), // for simplicity, we are using a fixed size
),
Text('Score: ${widget.gameController.score}'),
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.bullets.add(widget.gameController.gameState.spaceship.shoot());
});
},
child: Text('Shoot'),
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.spaceship.rotate(-pi / 18); // Rotate 10 degrees to the left
});
},
child: Text('Left'),
),
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.spaceship.rotate(pi / 18); // Rotate 10 degrees to the right
});
},
child: Text('Right'),
),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.spaceship.changeSpeed(-1); // Decrease speed by 1
});
},
child: Text('-'),
),
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.spaceship.changeSpeed(1); // Increase speed by 1
});
},
child: Text('+'),
),
],
),
],
);
}
}In the above code, the "Left" button rotates the spaceship 10 degrees to the left, the "Right" button rotates the spaceship 10 degrees to
the right, the "-" button decreases the speed of the spaceship by 1, and the "+" button increases the speed of the spaceship by 1. Adjust the rotation angle and speed change as per your requirements.
User:
Great! Could you also help me write the game over logic?
- When all asteroids have been destroyed - write a large green text saying "Game Over" along with the total points.
- If colliding with an asteroid, instead write a large red text saying "You Crashed!" along with the total points.
For both these scenarios, first remove or hide the game UI, and also include a button saying "Play again", which restarts the game.
Sure! For this, we'll need to modify the GameController and GameWidget classes.
First, let's add an isGameOver flag to the GameController class to indicate whether the game is over, and a gameOverMessage string to store the game over message.
class GameController {
// ...
bool isGameOver = false;
String gameOverMessage = '';
// ...
void update(double time) {
// Do not update game state if game is over
if (isGameOver) return;
// Update all game objects
// ...
// Check for collisions between bullets and asteroids
// ...
// Check for collisions between the spaceship and asteroids
for (Asteroid asteroid in gameState.asteroids) {
if (gameState.spaceship.collidesWith(asteroid)) {
// Game over
isGameOver = true;
gameOverMessage = 'You Crashed!';
return;
}
}
// Check if all asteroids have been destroyed
if (gameState.asteroids.isEmpty) {
// Game over
isGameOver = true;
gameOverMessage = 'Game Over';
}
}
void restart() {
// Reset game state
gameState = GameState(
spaceship: Spaceship(150, 150, 10, 5, 0),
asteroids: [Asteroid(50, 50, 20, 2, pi / 4), Asteroid(250, 250, 20, 2, pi * 3 / 4)],
bullets: [],
);
score = 0;
isGameOver = false;
gameOverMessage = '';
}
}Then, in the GameWidget class, we can check the isGameOver flag to display the game over screen instead of the game UI:
class GameWidget extends StatefulWidget {
// ...
@override
Widget build(BuildContext context) {
if (widget.gameController.isGameOver) {
return Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
widget.gameController.gameOverMessage,
style: TextStyle(fontSize: 32, color: widget.gameController.gameOverMessage == 'You Crashed!' ? Colors.red : Colors.green),
),
Text(
'Score: ${widget.gameController.score}',
style: TextStyle(fontSize: 24),
),
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.restart();
});
},
child: Text('Play again'),
),
],
);
} else {
return Column(
// Game UI
// ...
);
}
}
}This code displays a screen with the game over message and score in large text, and a "Play again" button when the game is over. The game over message is red if the player crashed into an asteroid, and green if they destroyed all asteroids. The "Play again" button resets the game state and starts a new game.
User:
Could you make the game UI full screen? Also place the buttons in a single row at the bottom, with spacing in-between. Could you also hook up keyboard key events for the buttons, for instance use the arrow keys for turning a speed control, and spacebar for shooting?
Certainly! To make the game UI fullscreen, you should let the CustomPaint widget take all available space by wrapping it with an Expanded widget.
For the buttons, you can use a Row widget with MainAxisAlignment.spaceBetween to place them in a single row with spacing in between. Then, wrap this Row in a Padding or Container widget to add some space at the bottom.
Regarding keyboard events, Flutter has a RawKeyboardListener
widget that can be used to listen for key events. You can wrap your
game widget with this to listen for key presses and call the
corresponding methods in your game controller.
Here's how you can modify the GameWidget class to incorporate these changes:
class GameWidget extends StatefulWidget {
// ...
@override
Widget build(BuildContext context) {
return RawKeyboardListener(
focusNode: FocusNode(),
autofocus: true,
onKey: (RawKeyEvent event) {
if (event is RawKeyDownEvent) {
switch (event.logicalKey.keyId) {
case 0x10007004d: // Arrow left key ID
setState(() {
widget.gameController.gameState.spaceship.rotate(-pi / 18);
});
break;
case 0x10007004e: // Arrow right key ID
setState(() {
widget.gameController.gameState.spaceship.rotate(pi / 18);
});
break;
case 0x100070052: // Arrow up key ID
setState(() {
widget.gameController.gameState.spaceship.changeSpeed(1);
});
break;
case 0x100070051: // Arrow down key ID
setState(() {
widget.gameController.gameState.spaceship.changeSpeed(-1);
});
break;
case 0x00000020: // Space key ID
setState(() {
widget.gameController.gameState.bullets.add(widget.gameController.gameState.spaceship.shoot());
});
break;
}
}
},
child: Column(
children: [
Expanded(
child: CustomPaint(
painter: GamePainter(gameState: widget.gameController.gameState),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.spaceship.rotate(-pi / 18);
});
},
child: Text('Left'),
),
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.spaceship.rotate(pi / 18);
});
},
child: Text('Right'),
),
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.spaceship.changeSpeed(-1);
});
},
child: Text('-'),
),
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.spaceship.changeSpeed(1);
});
},
child: Text('+'),
),
ElevatedButton(
onPressed: () {
setState(() {
widget.gameController.gameState.bullets.add(widget.gameController.gameState.spaceship.shoot());
});
},
child: Text('Shoot'),
),
],
),
),
],
),
);
}
}In this code, the RawKeyboardListener listens
for key down events and calls the appropriate method in the game
controller when the arrow keys or space bar are pressed. The left arrow
key rotates the spaceship left, the right arrow
User:
I get an error for RawKeyDownEvent. What are the imports needed for this app?
My apologies for any confusion. The RawKeyDownEvent class is part of the flutter/services.dart package. Here's a list of the main import statements you might need for this Flutter application:
import 'dart:async';
import 'dart:math';
import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';Let me know if you need further assistance.
User:
The key events doesn't seem to work. Are the key codes correct?
My apologies for the confusion. The key codes for Arrow keys and Spacebar key were incorrect in my previous response.
Please use the LogicalKeyboardKey constants for these keys. The revised onKey event listener code would look like this:
onKey: (RawKeyEvent event) {
if (event is RawKeyDownEvent) {
if (event.logicalKey == LogicalKeyboardKey.arrowLeft) {
setState(() {
widget.gameController.gameState.spaceship.rotate(-pi / 18);
});
} else if (event.logicalKey == LogicalKeyboardKey.arrowRight) {
setState(() {
widget.gameController.gameState.spaceship.rotate(pi / 18);
});
} else if (event.logicalKey == LogicalKeyboardKey.arrowUp) {
setState(() {
widget.gameController.gameState.spaceship.changeSpeed(1);
});
} else if (event.logicalKey == LogicalKeyboardKey.arrowDown) {
setState(() {
widget.gameController.gameState.spaceship.changeSpeed(-1);
});
} else if (event.logicalKey == LogicalKeyboardKey.space) {
setState(() {
widget.gameController.gameState.bullets.add(widget.gameController.gameState.spaceship.shoot());
});
}
}
},This revised code uses the LogicalKeyboardKey
constants to compare the keys, which is a more reliable and clear
method than comparing raw key codes. Let me know if you face any more
issues.
User:
Great, thanks! Could you also make it so that when game objects leave the screen, they re-appear on the opposite side?
Certainly, we can update the update methods in the Spaceship, Asteroid, and Bullet
classes to check if the objects are off-screen and, if so, to wrap them
around to the other side. For this, we need to know the size of the
screen, which we can get using MediaQuery.
In your GameController, you need to capture
the size of the screen during the initialization. Then, we can use this
in the game objects to adjust their positions when they move off-screen.
Here's how you can modify your GameController:
class GameController {
// Add a Size property for the screen size
Size screenSize;
// Update constructor to take screenSize
GameController(this.screenSize) {
// ... existing initialization code ...
}
// ... existing methods ...
}When you create your GameController instance in GameWidget, get the screen size using MediaQuery:
final screenSize = MediaQuery.of(context).size;
final gameController = GameController(screenSize);Then, in your GameObject subclasses, you can adjust the update method to wrap the object's position around the screen edges:
class Spaceship extends GameObject {
// ... existing properties and methods ...
@override
void update(double time) {
xPos += cos(direction) * speed;
yPos += sin(direction) * speed;
// Wrap around screen edges
if (xPos < 0) xPos = screenSize.width;
if (xPos > screenSize.width) xPos = 0;
if (yPos < 0) yPos = screenSize.height;
if (yPos > screenSize.height) yPos = 0;
}
}
class Asteroid extends GameObject {
// ... existing properties and methods ...
@override
void update(double time) {
xPos += cos(direction) * speed;
yPos += sin(direction) * speed;
// Wrap around screen edges
if (xPos < 0) xPos = screenSize.width;
if (xPos > screenSize.width) xPos = 0;
if (yPos < 0) yPos = screenSize.height;
if (yPos > screenSize.height) yPos = 0;
}
}
class Bullet extends GameObject {
// ... existing properties and methods ...
@override
void update(double time) {
xPos += cos(direction) * speed;
yPos += sin(direction) * speed;
// Wrap around screen edges
if (xPos < 0) xPos = screenSize.width;
if (xPos > screenSize.width) xPos = 0;
if (yPos < 0) yPos = screenSize.height;
if (yPos > screenSize.height) yPos = 0;
}
}This code adjusts the x and y positions of the objects so that when they go off one edge of the screen, they reappear on the opposite edge.
User:
I'm not sure this works, should perhaps the screen size instead be passed to the update method of GameController? And would it perhaps suffice to implement the logic for wrapping around screen edges in the GameObject base class? And pass screen size as a parameter to the move method?
My apologies for any confusion. You're correct, passing the screen size to the update method of GameController and implementing the logic for wrapping around screen edges in the GameObject base class would be a more efficient and elegant solution.
First, let's modify the GameController's update method to accept screen size:
void update(double time, Size screenSize) {
// ...
// Update all game objects
gameState.spaceship.update(time, screenSize);
for (Asteroid asteroid in gameState.asteroids) {
asteroid.update(time, screenSize);
}
for (Bullet bullet in gameState.bullets) {
bullet.update(time, screenSize);
}
// ...
}Then, we should modify the GameObject's move method to accept screen size:
void move(Size screenSize) {
xPos += cos(direction) * speed;
yPos += sin(direction) * speed;
// Wrap around screen edges
if (xPos < 0) xPos = screenSize.width;
if (xPos > screenSize.width) xPos = 0;
if (yPos < 0) yPos = screenSize.height;
if (yPos > screenSize.height) yPos = 0;
}And finally, you need to pass the screen size to the update method of GameController in your GameWidget:
final screenSize = MediaQuery.of(context).size;
// ...
gameController.update(t, screenSize);
// ...This way, you're maintaining the screen boundary logic in a single place, and it's much easier to manage.
User:
Thanks, but there seem to be a discrepancy between the naming of the move and update methods.
I apologize for the confusion. It seems there was a misunderstanding in my previous message. We should use update method in GameObject and its subclasses, not move. Let's correct this:
In GameObject class:
void update(double time, Size screenSize) {
xPos += cos(direction) * speed * time;
yPos += sin(direction) * speed * time;
// Wrap around screen edges
if (xPos < 0) xPos = screenSize.width;
if (xPos > screenSize.width) xPos = 0;
if (yPos < 0) yPos = screenSize.height;
if (yPos > screenSize.height) yPos = 0;
}Then in your Spaceship, Asteroid, and Bullet classes, you would call the super's update method.
Here's an example for the Spaceship class:
class Spaceship extends GameObject {
// ... existing properties and methods ...
@override
void update(double time, Size screenSize) {
super.update(time, screenSize);
// any additional spaceship-specific updates here
}
}Same goes for Asteroid and Bullet classes:
class Asteroid extends GameObject {
// ... existing properties and methods ...
@override
void update(double time, Size screenSize) {
super.update(time, screenSize);
// any additional asteroid-specific updates here
}
}
class Bullet extends GameObject {
// ... existing properties and methods ...
@override
void update(double time, Size screenSize) {
super.update(time, screenSize);
// any additional bullet-specific updates here
}
}I hope this clears up the confusion. Let me know if you need further clarification.
User:
There seem to be a problem with the size of the CustomPaint.
The issue might be due to the fact that the CustomPainter
doesn't know its size until the layout phase, but we're trying to get
the size in the build phase which occurs before layout. To solve this,
we could use a LayoutBuilder to get the constraints and thus the size of the widget.
Here's how you can modify your GameWidget:
class GameWidget extends StatefulWidget {
// ...
@override
Widget build(BuildContext context) {
return RawKeyboardListener(
focusNode: FocusNode(),
autofocus: true,
onKey: //... your key handling logic
child: Column(
children: [
Expanded(
child: LayoutBuilder(
builder: (BuildContext context, BoxConstraints constraints) {
final screenSize = Size(constraints.maxWidth, constraints.maxHeight);
return CustomPaint(
size: screenSize,
painter: GamePainter(gameState: widget.gameController.gameState),
);
},
),
),
//... your bottom row with buttons
],
),
);
}
}In the builder method of LayoutBuilder, we are given the constraints from which we can derive the size of the widget. We use these values to create our screenSize, and pass it to the CustomPaint.
Please remember to update your game loop to pass the screenSize to the GameController's update method:
gameController.update(t, screenSize);I hope this helps, and let me know if you face any more issues!
User:
Please use this background image for the whole application: https://prototyingstorage.blob.core.windows.net/files/space-background.png
To use a background image, you can add an Image.network as the first child of your Stack widget:
Stack(
children: <Widget>[
Image.network(
'https://prototyingstorage.blob.core.windows.net/files/space-background.png',
width: screenSize.width,
height: screenSize.height,
fit: BoxFit.cover,
),
//...
],
);
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