tecs

Description:

tecs

TECS #
Simple archetype based ECS written in dart.
Made for learning purposes so keep that in mind before using it.
Any improvements or suggestions are welcome.
World #
import 'package:tecs/tecs.dart';

// Create a World
final world = World();

// Reset and Clear the World
world.clear();
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Entities #
// Create Entities
final entity1 = world.createEntity();
final entity2 = world.createEntity();

// Remove Entities
world.removeEntity(entity1); // returns true
world.removeEntity(entity2); // returns true
world.removeEntity(entity1); // returns false, entity1 is not alive
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// Check Entity Status
final entity1Status = world.isAlive(entity1);
if(entity1Status) {
print("entity1 is alive");
} else {
print("entity1 is dead");
}
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Components #
class PositionComponent extends Component {
PositionComponent({
required this.x,
required this.y,
});

double x;
double y;
}
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class VelocityComponent extends Component {
VelocityComponent({
required this.x,
required this.y,
});

double x;
double y;
}
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// Add a component to an entity
world.addComponent(entity1, PositionComponent(x: 150, y: 150));
world.addComponent(entity1, VelocityComponent(x: -800, y: 400));

// Add components to an entity in bulk
world.addComponents(entity1, components: [
PositionComponent(x: 150, y: 150),
VelocityComponent(x: -800, y: 400),
]);
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// Get component of an entity (returns null if the entity does not have the component)
final position = world.getComponent<PositionComponent>(entity1);
final velocity = world.getComponent<VelocityComponent>(entity1);
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// Remove a component
world.removeComponent<PositionComponent>(entity1);
world.removeComponent<VelocityComponent>(entity1);

// Remove components in bulk
world.removeComponents(entity1, components: [
PositionComponent,
VelocityComponent,
]);
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Queries #
final queryResult = world.query([PositionComponent, VelocityComponent]);

for (final row in queryResult.rows) {
final position = row.get<PositionComponent>();
final velocity = row.get<VelocityComponent>();

position.x += velocity.x;
position.y += velocity.y;
}
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Systems #
// extending with System<T> you can change the type of argument the update function will take.
class MoveSystem extends System<double> {
@override
void update(double deltaTime) {
// has access to the world
final queryResult = world.query([PositionComponent, VelocityComponent]);

for (final row in queryResult.rows) {
final position = row.get<PositionComponent>();
final velocity = row.get<VelocityComponent>();

position.x += velocity.x * deltaTime;
position.y += velocity.y * deltaTime;
}
}
}
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// Add a system
world.addSystem(MoveSystem());
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// Update all systems sequantially (add order matters)

// A game loop that provides 'double deltaTime'
world.update(deltaTime);
// A game loop that provides 'double deltaTime'
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System Tags #
// You can give tags to your systems to update differently and pass different arguments.
// You can use the new records capability dart3 provides to accept multiple arguments
class RenderSystem extends System<({Canvas canvas, Size size})> {
@override
void update(args) {
final queryResult = world.query([RectComponent, ColorComponent]);

for (final row in queryResult.rows) {
final rect = row.get<RectComponent>();
final color = row.get<ColorComponent>();

final paint = Paint()
..color = color.value
..style = PaintingStyle.fill;

args.canvas.drawRect(rect.value, paint);
}
}
}
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// Add the system with tag
world.addSystem(MoveSystem()); // default
world.addSystem(CollisionSystem()); // default

world.addSystem(RenderSystem(), tag: "render");
world.addSystem(RenderCollidersDebug(), tag: "render");
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// A game loop that provides 'double deltaTime'
world.update(deltaTime); // MoveSystem and CollisionSystem will run
// A game loop that provides 'double deltaTime'

// A render loop that provides canvas and size
world.update(canvas, size, tag: "render"); // RenderSystem and RenderCollidersDebug will run
// A render loop that provides canvas and size
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Resources #
class GameTime {
double seconds = 0;
}

// Add Resource
world.addResource(GameTime());

// Get Resource and Manipulate
final gameTime = world.getResource<GameTime>();
gameTime.seconds += 1;

// If you add same resource, it will replace the old one
world.addResource(GameTime()); // replace the old GameTime

// You can give tags to add the same resource type without replacing
world.addResource(GameTime(), tag: "menu");
final gameTime = world.getResource<GameTime>();
final gameTimeMenu = world.getResource<GameTime>(tag: "menu");

// Remove resource
world.removeResource<GameTime>(); // returns GameTime if the resource exists, null otherwise
world.removeResource<GameTime>(tag: "menu");
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