73 lines
2.7 KiB
JavaScript
73 lines
2.7 KiB
JavaScript
|
game.system.GridSystem = ({ xDim, yDim, canvasWidth, canvasHeight }) => {
|
||
|
|
const entitiesGrid = Array(yDim).fill(null).map(() => Array(xDim).fill(null).map(() => new Map()));
|
||
|
|
|
||
|
|
const gridWidth = canvasWidth / xDim;
|
||
|
|
const gridHeight = canvasHeight / yDim;
|
||
|
|
|
||
|
|
const gameCoordsToGrid = ({ x, y }) => {
|
||
|
|
return { x: Math.floor((x+gridWidth/2) / canvasWidth * xDim), y: Math.floor((y+gridHeight/2) / canvasHeight * yDim) };
|
||
|
|
};
|
||
|
|
|
||
|
|
const gridCoordsToGame = ({ x, y }) => {
|
||
|
|
return { x: x * gridWidth, y: y * gridHeight };
|
||
|
|
};
|
||
|
|
|
||
|
|
const rebuildGrid = (entities) => {
|
||
|
|
let changedIds = new Set();
|
||
|
|
entities.map(entity => {
|
||
|
|
const { x, y } = entity.components.gridPosition;
|
||
|
|
if (!entitiesGrid[y][x].has(entity.id)) {
|
||
|
|
changedIds.add(entity.id);
|
||
|
|
}
|
||
|
|
});
|
||
|
|
entitiesGrid.forEach((row) => row.forEach((entitiesInCell) => {
|
||
|
|
for (let id of entitiesInCell.keys()) {
|
||
|
|
if (changedIds.has(id)) {
|
||
|
|
entitiesInCell.delete(id);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}));
|
||
|
|
changedIds.forEach(id => {
|
||
|
|
const entity = entities[id];
|
||
|
|
const { x, y } = entity.components.gridPosition;
|
||
|
|
entitiesGrid[y][x].set(entity.id, entity);
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
const update = (_elapsedTime, entities) => {
|
||
|
|
const gridEntities = Object.keys(entities).filter((x) => entities[x].hasComponent("gridPosition")).map((x) => entities[x]);
|
||
|
|
rebuildGrid(gridEntities);
|
||
|
|
gridEntities.map((entity) => {
|
||
|
|
if (entity.hasComponent("appearance")) {
|
||
|
|
entity.components.appearance.width = canvasWidth / xDim;
|
||
|
|
entity.components.appearance.height = canvasHeight / yDim;
|
||
|
|
}
|
||
|
|
if (entity.hasComponent("position")) {
|
||
|
|
const newGridCoords = gameCoordsToGrid(entity.components.position);
|
||
|
|
const oldGridCoords = entity.components.gridPosition;
|
||
|
|
if (!equivalence(newGridCoords, oldGridCoords)) {
|
||
|
|
const momentumVector = unitize({
|
||
|
|
dx: newGridCoords.x - oldGridCoords.x,
|
||
|
|
dy: newGridCoords.y - oldGridCoords.y,
|
||
|
|
});
|
||
|
|
|
||
|
|
// TODO: Loop in momentum direction until we find an entity that does not have "push" component
|
||
|
|
entity.components.gridPosition.x = entity.components.gridPosition.x + momentumVector.dx;
|
||
|
|
entity.components.gridPosition.y = entity.components.gridPosition.y + momentumVector.dy;
|
||
|
|
|
||
|
|
entity.components.position = {
|
||
|
|
...entity.components.position,
|
||
|
|
...gridCoordsToGame(entity.components.gridPosition)
|
||
|
|
};
|
||
|
|
|
||
|
|
if (entity.hasComponent("momentum")) {
|
||
|
|
entity.components.momentum.dx = 0;
|
||
|
|
entity.components.momentum.dy = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
});
|
||
|
|
};
|
||
|
|
|
||
|
|
return { entitiesGrid, gameCoordsToGrid, gridCoordsToGame, update, gridWidth, gridHeight };
|
||
|
|
};
|