implement lightning and smooth lightning

src/js/net/minecraft/client/Minecraft.js

@@ -84,6 +84,9 @@ window.Minecraft = class {
     }
 
     onTick() {
+        // Tick world
+        this.world.onTick();
+
         // Tick the player
         this.player.onTick();
     }

src/js/net/minecraft/client/render/BlockRenderer.js

@@ -1,5 +1,7 @@
 window.BlockRenderer = class {
 
+    static CLASSIC_LIGHTNING = false;
+
     constructor(worldRenderer) {
         this.worldRenderer = worldRenderer;
         this.tessellator = new Tessellator();
@@ -44,9 +46,11 @@ window.BlockRenderer = class {
         maxV = 1 - maxV;
 
         // Classic lightning
-        let brightness = 0.9 / 15.0 * 15 + 0.1;
-        let color = brightness * face.getShading();
-        this.tessellator.setColor(color, color, color);
+        if (BlockRenderer.CLASSIC_LIGHTNING) {
+            let brightness = 0.9 / 15.0 * 15 + 0.1;
+            let color = brightness * face.getShading();
+            this.tessellator.setColor(color, color, color);
+        }
 
         if (face === EnumBlockFace.BOTTOM) {
             this.addBlockCorner(world, face, minX, minY, maxZ, minU, maxV);
@@ -87,7 +91,49 @@ window.BlockRenderer = class {
     }
 
     addBlockCorner(world, face, x, y, z, u, v) {
+        // Smooth lightning
+        if (!BlockRenderer.CLASSIC_LIGHTNING) {
+            this.setAverageColor(world, face, x, y, z);
+        }
+
         this.tessellator.addVertexWithUV(x, y, z, u, v);
     }
 
+    setAverageColor(world, face, x, y, z) {
+        // Get the average light level of all 4 blocks at this corner
+        let lightLevelAtThisCorner = this.getAverageLightLevelAt(world, x, y, z);
+
+        // Convert light level from [0 - 15] to [0.1 - 1.0]
+        let brightness = 0.9 / 15.0 * lightLevelAtThisCorner + 0.1;
+        let color = brightness * face.getShading();
+
+        // Set color with shading
+        this.tessellator.setColor(color, color, color);
+    }
+
+    getAverageLightLevelAt(world, x, y, z) {
+        let totalLightLevel = 0;
+        let totalBlocks = 0;
+
+        // For all blocks around this corner
+        for (let offsetX = -1; offsetX <= 0; offsetX++) {
+            for (let offsetY = -1; offsetY <= 0; offsetY++) {
+                for (let offsetZ = -1; offsetZ <= 0; offsetZ++) {
+                    let typeId = world.getBlockAt(x + offsetX, y + offsetY, z + offsetZ);
+
+                    // Does it contain air?
+                    if (typeId === 0 || Block.getById(typeId).isTransparent()) {
+
+                        // Sum up the light levels
+                        totalLightLevel += world.getLightAt(x + offsetX, y + offsetY, z + offsetZ);
+                        totalBlocks++;
+                    }
+                }
+            }
+        }
+
+        // Calculate the average light level of all surrounding blocks
+        return totalBlocks === 0 ? 0 : totalLightLevel / totalBlocks;
+    }
+
 }

src/js/net/minecraft/client/world/ChunkSection.js

@@ -5,6 +5,7 @@ window.ChunkSection = class {
     constructor(world, chunk, x, y, z) {
         this.world = world;
         this.chunk = chunk;
+
         this.x = x;
         this.y = y;
         this.z = z;
@@ -22,10 +23,16 @@ window.ChunkSection = class {
         this.queuedForRebuild = true;
 
         this.blocks = [];
-        for (let x = 0; x < ChunkSection.SIZE; x++) {
-            for (let y = 0; y < ChunkSection.SIZE; y++) {
-                for (let z = 0; z < ChunkSection.SIZE; z++) {
-                    this.setBlockAt(x, y, z, 0);
+        this.blockLight = [];
+
+        // Fill chunk with air and light
+        for (let lightX = 0; lightX < ChunkSection.SIZE; lightX++) {
+            for (let lightY = 0; lightY < ChunkSection.SIZE; lightY++) {
+                for (let lightZ = 0; lightZ < ChunkSection.SIZE; lightZ++) {
+                    let index = lightY << 8 | lightZ << 4 | lightX;
+
+                    this.blocks[index] = 0;
+                    this.blockLight[index] = 15;
                 }
             }
         }
@@ -74,6 +81,30 @@ window.ChunkSection = class {
         this.blocks[index] = typeId;
     }
 
+    setLightAt(x, y, z, lightLevel) {
+        let index = y << 8 | z << 4 | x;
+        this.blockLight[index] = lightLevel;
+    }
+
+    getLightAt(x, y, z) {
+        let index = y << 8 | z << 4 | x;
+        return this.blockLight[index];
+    }
+
+    isEmpty() {
+        for (let x = 0; x < ChunkSection.SIZE; x++) {
+            for (let y = 0; y < ChunkSection.SIZE; y++) {
+                for (let z = 0; z < ChunkSection.SIZE; z++) {
+                    let index = y << 8 | z << 4 | x;
+                    if (this.blocks[index] !== 0) {
+                        return false;
+                    }
+                }
+            }
+        }
+        return true;
+    }
+
     queueForRebuild() {
         this.queuedForRebuild = true;
     }

src/js/net/minecraft/client/world/World.js

@@ -9,6 +9,28 @@ window.World = class {
 
         // Load world
         this.generator = new WorldGenerator(this, Date.now() % 100000);
+
+        this.lightUpdateQueue = [];
+    }
+
+    onTick() {
+        // Handle 128 light updates per tick
+         for (let i = 0; i < 128; i++) {
+
+             // Light updates
+             if (this.lightUpdateQueue.length !== 0) {
+
+                 // Get next position to update
+                 let positionIndex = this.lightUpdateQueue.shift();
+                 if (positionIndex != null) {
+                     let z = positionIndex >> 16;
+                     let x = positionIndex - (z << 16);
+                     this.updateBlockLightsAtXZ(x, z);
+                 } else {
+                     break;
+                 }
+             }
+         }
     }
 
     loadChunk(chunk) {
@@ -54,10 +76,17 @@ window.World = class {
         return typeId !== 0 && Block.getById(typeId).isSolid();
     }
 
+    isTransparentBlockAt(x, y, z) {
+        let typeId = this.getBlockAt(x, y, z);
+        return typeId === 0 || Block.getById(typeId).isTransparent();
+    }
+
     setBlockAt(x, y, z, type) {
         let chunkSection = this.getChunkAtBlock(x, y, z);
         if (chunkSection != null) {
             chunkSection.setBlockAt(x & 15, y & 15, z & 15, type);
+
+            this.updateBlockLightAt(x, y, z);
         }
 
         this.onBlockChanged(x, y, z);
@@ -95,6 +124,110 @@ window.World = class {
         return 0;
     }
 
+    updateBlockLightAt(x, y, z) {
+        // Calculate brightness for target block
+        let lightLevel = this.isHighestBlockAt(x, y, z) ? 15 : this.calculateLightAt(x, y, z);
+
+        // Update target block light
+        this.getChunkAtBlock(x, y, z).setLightAt(x & 15, y & 15, z & 15, lightLevel);
+
+        // Update block lights below the target block and the surrounding blocks
+        for (let offsetX = -1; offsetX <= 1; offsetX++) {
+            for (let offsetZ = -1; offsetZ <= 1; offsetZ++) {
+                this.updateBlockLightsAtXZ(x + offsetX, z + offsetZ);
+            }
+        }
+    }
+
+    updateBlockLightsAtXZ(x, z) {
+        let lightChanged = false;
+        let skyLevel = 15;
+
+        // Scan from the top to the bottom
+        for (let y = World.TOTAL_HEIGHT; y >= 0; y--) {
+            if (!this.isTransparentBlockAt(x, y, z)) {
+                // Sun is blocked because of solid block
+                skyLevel = 0;
+            } else {
+                // Get opacity of this block
+                let typeId = this.getBlockAt(x, y, z);
+                let translucence = typeId === 0 ? 1.0 : 1.0 - Block.getById(typeId).getOpacity();
+
+                // Decrease strength of the skylight by the opacity of the block
+                skyLevel *= translucence;
+
+                // Get previous block light
+                let prevBlockLight = this.getLightAt(x, y, z);
+
+                // Combine skylight with the calculated block light and decrease strength by the opacity of the block
+                let blockLight = Math.floor(Math.max(skyLevel, this.calculateLightAt(x, y, z)) * translucence);
+
+                // Did one of the light change inside of the range?
+                if (prevBlockLight !== blockLight) {
+                    lightChanged = true;
+                }
+
+                // Apply the new light to the block
+                this.setLightAt(x, y, z, blockLight);
+            }
+        }
+
+        // Chain reaction, update next affected blocks
+        if (lightChanged && this.lightUpdateQueue.length < 512) {
+            for (let offsetX = -1; offsetX <= 1; offsetX++) {
+                for (let offsetZ = -1; offsetZ <= 1; offsetZ++) {
+                    let positionIndex = (x + offsetX) + ((z + offsetZ) << 16);
+
+                    // Add block range to update queue
+                    if (!this.lightUpdateQueue.includes(positionIndex)) {
+                        this.lightUpdateQueue.push(positionIndex);
+                    }
+                }
+            }
+        }
+    }
+
+    setLightAt(x, y, z, light) {
+        let chunkSection = this.getChunkAtBlock(x, y, z);
+        if (chunkSection != null) {
+            chunkSection.setLightAt(x & 15, y & 15, z & 15, light);
+            chunkSection.queueForRebuild();
+        }
+    }
+
+    getLightAt(x, y, z) {
+        let chunkSection = this.getChunkAtBlock(x, y, z);
+        return chunkSection == null ? 15 : chunkSection.getLightAt(x & 15, y & 15, z & 15);
+    }
+
+    isHighestBlockAt(x, y, z) {
+        for (let i = y + 1; i < World.TOTAL_HEIGHT; i++) {
+            if (this.isSolidBlockAt(x, i, z)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    calculateLightAt(x, y, z) {
+        let maxBrightness = 0;
+
+        // Get maximal brightness of surround blocks
+        let values = EnumBlockFace.values();
+        for (let i in values) {
+            let face = values[i];
+
+            if (this.isTransparentBlockAt(x + face.x, y + face.y, z + face.z)) {
+                let brightness = this.getLightAt(x + face.x, y + face.y, z + face.z);
+
+                maxBrightness = Math.max(maxBrightness, brightness);
+            }
+        }
+
+        // Decrease maximum brightness by 6%
+        return Math.max(0, maxBrightness - 1);
+    }
+
     onBlockChanged(x, y, z) {
         this.queueForRebuildInRegion(x - 1, y - 1, z - 1, x + 1, y + 1, z + 1);
     }