sandsim/js/physics.js

89 lines
3.2 KiB
JavaScript

// Physics simulation functions
function updatePhysics(timestamp) {
// Check if we should update physics based on the update rate
if (timestamp && lastPhysicsTime && timestamp - lastPhysicsTime < physicsUpdateRate) {
return;
}
lastPhysicsTime = timestamp || 0;
// Update physics objects
if (typeof updatePhysicsObjects === 'function') {
updatePhysicsObjects();
}
// Update entities
if (typeof updateEntities === 'function') {
updateEntities();
}
// Get visible chunks
const visibleChunks = getVisibleChunks();
// Increment fire update counter
fireUpdateCounter++;
// Process each visible chunk
for (const { chunkX, chunkY, isVisible } of visibleChunks) {
// Skip physics calculations for chunks that are not visible
if (!isVisible) continue;
const chunk = getOrCreateChunk(chunkX, chunkY);
let chunkModified = false;
// Process from bottom to top, right to left for correct gravity simulation
for (let y = CHUNK_SIZE - 1; y >= 0; y--) {
// Alternate direction each row for more natural flow
const startX = y % 2 === 0 ? 0 : CHUNK_SIZE - 1;
const endX = y % 2 === 0 ? CHUNK_SIZE : -1;
const step = y % 2 === 0 ? 1 : -1;
for (let x = startX; x !== endX; x += step) {
const index = y * CHUNK_SIZE + x;
const type = chunk[index];
if (type === EMPTY || type === STONE || type === WOOD || type === LEAF) continue;
const worldX = chunkX * CHUNK_SIZE + x;
const worldY = chunkY * CHUNK_SIZE + y;
// Use a lookup table for faster element updates
const updateFunctions = {
[SAND]: updateSand,
[WATER]: updateWater,
[DIRT]: updateDirt,
[GRASS]: updateGrass,
[SEED]: updateSeed,
[GRASS_BLADE]: updateGrassBlade,
[FLOWER]: updateFlower,
[TREE_SEED]: updateTreeSeed,
[FIRE]: updateFire,
[LAVA]: updateLava
};
const updateFunction = updateFunctions[type];
if (updateFunction) {
const wasModified = updateFunction(worldX, worldY);
if (wasModified) {
chunkModified = true;
}
}
}
}
// Mark chunk as dirty if it was modified
if (chunkModified) {
dirtyChunks.add(getChunkKey(chunkX, chunkY));
}
}
// Adaptive physics rate based on FPS
if (fps < 30 && physicsUpdateRate < 32) {
// If FPS is low, update physics less frequently
physicsUpdateRate = Math.min(32, physicsUpdateRate + 2);
} else if (fps > 50 && physicsUpdateRate > 16) {
// If FPS is high, update physics more frequently
physicsUpdateRate = Math.max(16, physicsUpdateRate - 2);
}
}