Add new dimensions properties, helper creation function

Part of #3925

src/browser/renderer/shared/RendererUtils.ts

@@ -3,6 +3,8 @@
  * @license MIT
  */
 
+import { IDimensions, IOffset, IRenderDimensions } from 'browser/renderer/shared/Types';
+
 export function throwIfFalsy<T>(value: T | undefined | null): T {
   if (!value) {
     throw new Error('value must not be falsy');
@@ -28,3 +30,41 @@ function isBoxOrBlockGlyph(codepoint: number): boolean {
 export function excludeFromContrastRatioDemands(codepoint: number): boolean {
   return isPowerlineGlyph(codepoint) || isBoxOrBlockGlyph(codepoint);
 }
+
+export function createRenderDimensions(): IRenderDimensions {
+  return {
+    css: {
+      canvas: createDimension(),
+      cell: createDimension()
+    },
+    device: {
+      canvas: createDimension(),
+      cell: createDimension(),
+      char: {
+        width: 0,
+        height: 0,
+        left: 0,
+        top: 0
+      }
+    },
+    scaledCharWidth: 0,
+    scaledCharHeight: 0,
+    scaledCellWidth: 0,
+    scaledCellHeight: 0,
+    scaledCharLeft: 0,
+    scaledCharTop: 0,
+    scaledCanvasWidth: 0,
+    scaledCanvasHeight: 0,
+    canvasWidth: 0,
+    canvasHeight: 0,
+    actualCellWidth: 0,
+    actualCellHeight: 0
+  };
+}
+
+function createDimension(): IDimensions {
+  return {
+    width: 0,
+    height: 0
+  };
+}