implement crosshair

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

@@ -23,7 +23,7 @@ window.Minecraft = class {
         this.pickedBlock = 1;
 
         // Create current screen and overlay
-        this.ingameOverlay = new IngameOverlay();
+        this.ingameOverlay = new IngameOverlay(this.window);
         this.currentScreen = null;
 
         // Initialize

src/js/net/minecraft/client/gui/Gui.js

@@ -7,4 +7,20 @@ window.Gui = class {
         stack.globalAlpha = alpha;
     }
 
+    drawTexture(stack, texture, x, y, width, height, alpha = 1.0) {
+        this.drawSprite(stack, texture, 0, 0, 256, 256, x, y, width, height, alpha);
+    }
+
+    drawSprite(stack, texture, spriteX, spriteY, spriteWidth, spriteHeight, x, y, width, height, alpha = 1.0) {
+        stack.globalAlpha = alpha;
+        stack.drawImage(texture, spriteX, spriteY, spriteWidth, spriteHeight, x, y, width, height);
+        stack.globalAlpha = 1.0;
+    }
+
+    loadTexture(path) {
+        let img = new Image();
+        img.src = path;
+        return img;
+    }
+
 }

src/js/net/minecraft/client/gui/IngameOverlay.js

@@ -1,7 +1,19 @@
 window.IngameOverlay = class extends Gui {
 
+    constructor(window) {
+        super();
+        this.window = window;
+
+        this.textureCrosshair = this.loadTexture("icons.png");
+    }
+
     render(stack, mouseX, mouseY, partialTicks) {
-        this.drawRect(stack, 0, 0, 500, 500, '#0000FF');
+        this.renderCrosshair(stack, this.window.width / 2, this.window.height / 2)
+    }
+
+    renderCrosshair(stack, x, y) {
+        let size = 15 * 4;
+        this.drawSprite(stack, this.textureCrosshair, 0, 0, 15, 15, x - size / 2, y - size / 2, size, size, 0.6);
     }
 
 }

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

@@ -70,6 +70,7 @@ window.WorldRenderer = class {
 
         // Get context stack of 2d canvas
         this.stack2d = this.canvas2d.getContext('2d');
+        this.stack2d.imageSmoothingEnabled = false;
 
         // Create texture from rendered graphics.
         this.frameBuffer = new THREE.Texture(this.canvas2d)
@@ -110,6 +111,10 @@ window.WorldRenderer = class {
         let cameraChunkZ = Math.floor(player.z >> 4);
         this.renderChunks(cameraChunkX, cameraChunkZ);
 
+        // Clear frame buffer for 2d screen
+        this.stack2d.clearRect(0, 0, this.window.width, this.window.height);
+        this.frameBuffer.needsUpdate = true;
+
         // Render in-game overlay
         let mouseX = this.minecraft.window.mouseX;
         let mouseY = this.minecraft.window.mouseY;