Class-ify touchscreen

mattgodbolt · Dec 24, 2023 · 42079a0 · 42079a0
1 parent 027c0cf
commit 42079a0
Showing 1 changed file with 55 additions and 48 deletions.
diff --git a/touchscreen.js b/touchscreen.js
@@ -2,24 +2,63 @@
 
 import * as utils from "./utils.js";
 
-export function TouchScreen(scheduler) {
-    const self = this;
-    const PollHz = 8; // Made up
-    const PollCycles = (2 * 1000 * 1000) / PollHz;
-    this.scheduler = scheduler;
-    this.mouse = [];
-    this.outBuffer = new utils.Fifo(16);
-    this.delay = 0;
-    this.mode = 0;
-    this.onMouse = function (x, y, button) {
-        this.mouse = { x: x, y: y, button: button };
-    };
-    this.poll = function () {
+const PollHz = 8; // Made up
+const PollCycles = (2 * 1000 * 1000) / PollHz;
+
+function doScale(val, scale, margin) {
+    val = (val - margin) / (1 - 2 * margin);
+    return val * scale;
+}
+
+export class TouchScreen {
+    constructor(scheduler) {
+        this.scheduler = scheduler;
+        this.mouse = [];
+        this.outBuffer = new utils.Fifo(16);
+        this.delay = 0;
+        this.mode = 0;
+        this.pollTask = this.scheduler.newTask(this.poll);
+    }
+
+    tryReceive(rts) {
+        if (self.outBuffer.size && rts) return self.outBuffer.get();
+        return -1;
+    }
+
+    doRead() {
+        const scaleX = 120,
+            marginX = 0.13;
+        const scaleY = 100,
+            marginY = 0.03;
+        const scaledX = doScale(self.mouse.x, scaleX, marginX);
+        const scaledY = doScale(1 - self.mouse.y, scaleY, marginY);
+        const toSend = [0x4f, 0x4f, 0x4f, 0x4f];
+        const x = Math.min(255, Math.max(0, scaledX)) | 0;
+        const y = Math.min(255, Math.max(0, scaledY)) | 0;
+        if (self.mouse.button) {
+            toSend[0] = 0x40 | ((x & 0xf0) >>> 4);
+            toSend[1] = 0x40 | (x & 0x0f);
+            toSend[2] = 0x40 | ((y & 0xf0) >>> 4);
+            toSend[3] = 0x40 | (y & 0x0f);
+        }
+        for (let i = 0; i < 4; ++i) self.store(toSend[i]);
+        self.store(".".charCodeAt(0));
+    }
+
+    poll() {
         self.doRead();
         self.pollTask.reschedule(PollCycles);
-    };
-    this.pollTask = this.scheduler.newTask(this.poll);
-    this.onTransmit = function (val) {
+    }
+
+    store(byte) {
+        self.outBuffer.put(byte);
+    }
+
+    onMouse(x, y, button) {
+        this.mouse = { x: x, y: y, button: button };
+    }
+
+    onTransmit(val) {
         switch (String.fromCharCode(val)) {
             case "M":
                 self.mode = 0;
@@ -43,37 +82,5 @@ export function TouchScreen(scheduler) {
                 break;
         }
         self.pollTask.ensureScheduled(self.mode === 129 || self.mode === 130, PollCycles);
-    };
-    this.tryReceive = function (rts) {
-        if (self.outBuffer.size && rts) return self.outBuffer.get();
-        return -1;
-    };
-    this.store = function (byte) {
-        self.outBuffer.put(byte);
-    };
-
-    function doScale(val, scale, margin) {
-        val = (val - margin) / (1 - 2 * margin);
-        return val * scale;
     }
-
-    this.doRead = function () {
-        const scaleX = 120,
-            marginX = 0.13;
-        const scaleY = 100,
-            marginY = 0.03;
-        const scaledX = doScale(self.mouse.x, scaleX, marginX);
-        const scaledY = doScale(1 - self.mouse.y, scaleY, marginY);
-        const toSend = [0x4f, 0x4f, 0x4f, 0x4f];
-        const x = Math.min(255, Math.max(0, scaledX)) | 0;
-        const y = Math.min(255, Math.max(0, scaledY)) | 0;
-        if (self.mouse.button) {
-            toSend[0] = 0x40 | ((x & 0xf0) >>> 4);
-            toSend[1] = 0x40 | (x & 0x0f);
-            toSend[2] = 0x40 | ((y & 0xf0) >>> 4);
-            toSend[3] = 0x40 | (y & 0x0f);
-        }
-        for (let i = 0; i < 4; ++i) self.store(toSend[i]);
-        self.store(".".charCodeAt(0));
-    };
 }