From 61d3d67df06529eddff701ac0a0cc12913b33f96 Mon Sep 17 00:00:00 2001
From: Paul Mathieu <paulmathieu@google.com>
Date: Sun, 26 Dec 2021 11:00:32 -0800
Subject: [PATCH] Small refactor in face creation

---
 world.js | 73 +++++++++++++++++++++++---------------------------------
 1 file changed, 30 insertions(+), 43 deletions(-)

diff --git a/world.js b/world.js
index 2d8d9c5..1344bc4 100644
--- a/world.js
+++ b/world.js
@@ -279,7 +279,7 @@ class ChunkMap {
 
 /** Makes a brave new (empty) world */
 export function makeWorld() {
-    return {chunks: [], chunkMap: new ChunkMap()};
+    return {chunkMap: new ChunkMap()};
 }
 
 function makeFaces(chunk, blocks, neighbors) {
@@ -404,7 +404,6 @@ export function generateMissingChunks(world, z, x, timeLimit = 10000) {
                 }
 
                 const chunk = makeChunk(i * 16, j * 16);
-                world.chunks.push(chunk);
                 world.chunkMap.set(i, j, chunk);
 
                 updateMissingFaces(world, chunk);
@@ -414,27 +413,6 @@ export function generateMissingChunks(world, z, x, timeLimit = 10000) {
     return world;
 }
 
-function addFace(chunk, block, dir) {
-    const face = createChunkFace(block, dir);
-    if (isTransparent(block.type)) {
-        chunk.transparentFaces.push(face);
-    } else {
-        chunk.faces.push(face);
-    }
-}
-
-function createChunkFace(block, dir, center = null) {
-    center = center ?? faceCenter(block.centerPosition, dir);
-    if (block.type === BlockType.WATER && dir === '+y') {
-        center[1] -= 0.15;
-    }
-    return {
-        dir,
-        blockIndex: block.blockIndex,
-        face: makeFace(dir, faceTexture(block.type, dir), faceCenter(block.centerPosition, dir)),
-    };
-}
-
 /** Generates geometry for all visible chunks. */
 export function updateWorldGeometry(gl, world, z, x, timeLimit = 10000) {
     const ic = Math.floor(z / 16);
@@ -613,6 +591,13 @@ export function markBlock(world, cameraPosition, direction, maxDistance) {
     }
 }
 
+function blockIndex2Ijk(bi) {
+    const blocki = Math.floor(bi / (256 * 16));
+    const blockj = Math.floor((bi % (256 * 16)) / 256);
+    const blockk = bi % 256;
+
+    return [blocki, blockj, blockk];
+}
 
 export function destroyBlock(world, block) {
     const trimFaces = chunk => {
@@ -642,7 +627,13 @@ export function destroyBlock(world, block) {
         .filter(({ block }) => block.type !== BlockType.AIR &&
             block.type !== BlockType.UNDEFINED)
         .forEach(({ block, dir }) => {
-            addFace(block.chunk, block, dir);
+            makeFaces(block.chunk,
+                () => [blockIndex2Ijk(block.blockIndex)],
+                () => [{
+                    block: BlockType.AIR,
+                    dir,
+                    faceCenter: faceCenter(block.centerPosition, dir),
+                }]);
             trimFaces(block.chunk);
 
             if (block.chunk.buffer !== undefined) {
@@ -670,29 +661,25 @@ export function makeBlock(world, position, type) {
         { block: blockLookup(world, bx, by, bz + 1), dir: '+z', ndir: '-z' },
     ];
 
-    const refresh = chunk => {
-        if (chunk.buffer !== undefined) {
-            chunk.buffer.delete();
-            delete chunk.buffer;
-        }
-    }
-
     neighbors
         .filter(({ block }) => block.type !== BlockType.UNDEFINED)
         .forEach(({ block: nblock, dir, ndir }) => {
-            if (nblock.type  === BlockType.AIR ||
-                nblock.type === BlockType.WATER) {
-                addFace(block.chunk, block, dir);
-            }// else {
-                nblock.chunk.faces = nblock.chunk.faces.filter(f => (
-                    f.blockIndex !== nblock.blockIndex ||
-                    f.dir !== ndir
-                ));
-                refresh(nblock.chunk);
-            //}
+            makeFaces(block.chunk,
+                () => [blockIndex2Ijk(block.blockIndex)],
+                () => [{
+                    block: BlockType.AIR,
+                    dir,
+                    faceCenter: faceCenter(block.centerPosition, dir),
+                }]);
+            nblock.chunk.faces = nblock.chunk.faces.filter(f => (
+                f.blockIndex !== nblock.blockIndex ||
+                f.dir !== ndir
+            ));
+            nblock.chunk.transparentFaces = nblock.chunk.transparentFaces.filter(f => (
+                f.blockIndex !== nblock.blockIndex ||
+                f.dir !== ndir
+            ));
         });
-
-    refresh(block.chunk);
 }
 
 export async function initWorldGl(gl) {