Sim screen canvas implementation and _setPixel.

sim/state/screen.ts

@@ -0,0 +1,34 @@
+
+namespace pxsim {
+
+    export class EV3ScreenState {
+        points: {[x: number]: {[y: number]: number}};
+        constructor() {
+            this.points = {};
+        }
+
+        setPixel(x: number, y: number, v: number) {
+            if (x < 0 || x > 178) return;
+            if (y < 0 || y > 128) return;
+
+            const xPoints = this.points[x]
+            if (!xPoints) this.points[x] = {};
+            this.points[x][y] = v;
+        }
+    }
+}
+
+
+namespace pxsim.screen {
+
+    export function _setPixel(x: number, y: number, mode: Draw) {
+        const screenState = (board() as DalBoard).screenState;
+        screenState.setPixel(x, y, mode);
+        runtime.queueDisplayUpdate();
+    }
+
+
+    export function _blitLine(xw: number, y: number, buf: number, mode: Draw) {
+        
+    }
+}