Prevent WA scale manager from zooming too much

front/src/Phaser/Services/HdpiManager.ts

@@ -8,7 +8,12 @@ interface Size {
 export class HdpiManager {
     private _zoomModifier: number = 1;
 
-    public constructor(private minGamePixelsNumber: number) {
+    /**
+     *
+     * @param minRecommendedGamePixelsNumber The minimum number of pixels we want to display "by default" to the user
+     * @param absoluteMinPixelNumber The very minimum of game pixels to display. Below, we forbid zooming more
+     */
+    public constructor(private minRecommendedGamePixelsNumber: number, private absoluteMinPixelNumber: number) {
     }
 
     /**
@@ -24,7 +29,7 @@ export class HdpiManager {
         const realPixelNumber = realPixelScreenSize.width * realPixelScreenSize.height;
         // If the screen has not a definition small enough to match the minimum number of pixels we want to display,
         // let's make the canvas the size of the screen (in real pixels)
-        if (realPixelNumber <= this.minGamePixelsNumber) {
+        if (realPixelNumber <= this.minRecommendedGamePixelsNumber) {
             return {
                 game: realPixelScreenSize,
                 real: realPixelScreenSize
@@ -34,7 +39,7 @@ export class HdpiManager {
         let i = 1;
 
         while (true) {
-            if (realPixelNumber <= this.minGamePixelsNumber * i * i) {
+            if (realPixelNumber <= this.minRecommendedGamePixelsNumber * i * i) {
                 break;
             }
 
@@ -58,10 +63,34 @@ export class HdpiManager {
             }
         }
 
+        const gameWidth = Math.ceil(realPixelScreenSize.width / (i - 1) / this._zoomModifier);
+        const gameHeight = Math.ceil(realPixelScreenSize.height / (i - 1) / this._zoomModifier);
+
+        // Let's ensure we display a minimum of pixels, even if crazily zoomed in.
+        if (gameWidth * gameHeight < this.absoluteMinPixelNumber) {
+            const minGameHeight = Math.sqrt(this.absoluteMinPixelNumber * realPixelScreenSize.height / realPixelScreenSize.width);
+            const minGameWidth = Math.sqrt(this.absoluteMinPixelNumber * realPixelScreenSize.width / realPixelScreenSize.height);
+
+            // Let's reset the zoom modifier (WARNING this is a SIDE EFFECT in a getter)
+            this._zoomModifier = realPixelScreenSize.width / minGameWidth / (i - 1);
+
+            return {
+                game: {
+                    width: minGameWidth,
+                    height: minGameHeight,
+                },
+                real: {
+                    width: realPixelScreenSize.width,
+                    height: realPixelScreenSize.height,
+                }
+            }
+
+        }
+
         return {
             game: {
-                width: Math.ceil(realPixelScreenSize.width / (i - 1) / this._zoomModifier),
-                height: Math.ceil(realPixelScreenSize.height / (i - 1) / this._zoomModifier),
+                width: gameWidth,
+                height: gameHeight,
             },
             real: {
                 width: Math.ceil(realPixelScreenSize.width / (i - 1)) * (i - 1),

front/src/Phaser/Services/WaScaleManager.ts

@@ -7,8 +7,8 @@ class WaScaleManager {
     private hdpiManager: HdpiManager;
     private scaleManager!: ScaleManager;
 
-    public constructor(private minGamePixelsNumber: number) {
-        this.hdpiManager = new HdpiManager(minGamePixelsNumber);
+    public constructor(private minGamePixelsNumber: number, private absoluteMinPixelNumber: number) {
+        this.hdpiManager = new HdpiManager(minGamePixelsNumber, absoluteMinPixelNumber);
     }
 
     public setScaleManager(scaleManager: ScaleManager) {
@@ -44,4 +44,4 @@ class WaScaleManager {
     }
 }
 
-export const waScaleManager = new WaScaleManager(640*480);
+export const waScaleManager = new WaScaleManager(640*480, 196*196);

front/src/index.ts

@@ -69,7 +69,7 @@ switch (phaserMode) {
         throw new Error('phaserMode parameter must be one of "auto", "canvas" or "webgl"');
 }
 
-const hdpiManager = new HdpiManager(640*480);
+const hdpiManager = new HdpiManager(640*480, 196*196);
 const { game: gameSize, real: realSize } = hdpiManager.getOptimalGameSize({width, height});
 
 const config: GameConfig = {

front/tests/Phaser/Services/HdpiManagerTest.ts

@@ -3,7 +3,7 @@ import {HdpiManager} from "../../../src/Phaser/Services/HdpiManager";
 
 describe("Test HdpiManager", () => {
     it("should match screen size if size is too small.", () => {
-        const hdpiManager = new HdpiManager(640*480);
+        const hdpiManager = new HdpiManager(640*480, 64*64);
 
         const result = hdpiManager.getOptimalGameSize({ width: 320, height: 200 });
         expect(result.game.width).toEqual(320);
@@ -13,7 +13,7 @@ describe("Test HdpiManager", () => {
     });
 
     it("should match multiple just above.", () => {
-        const hdpiManager = new HdpiManager(640*480);
+        const hdpiManager = new HdpiManager(640*480, 64*64);
 
         let result = hdpiManager.getOptimalGameSize({ width: 960, height: 600 });
         expect(result.game.width).toEqual(960);
@@ -29,4 +29,27 @@ describe("Test HdpiManager", () => {
         expect(result.real.width).toEqual(result.game.width * 3);
         expect(result.real.height).toEqual(result.game.height * 3);
     });
+
+    it("should not zoom in too much.", () => {
+        const hdpiManager = new HdpiManager(640*480, 64*64);
+
+        hdpiManager.zoomModifier = 11;
+
+        let result = hdpiManager.getOptimalGameSize({ width: 640, height: 640 });
+        expect(result.game.width).toEqual(64);
+        expect(result.game.height).toEqual(64);
+        expect(hdpiManager.zoomModifier).toEqual(10);
+
+    });
+
+    it("should not zoom out too much.", () => {
+        const hdpiManager = new HdpiManager(640*480, 64*64);
+
+        hdpiManager.zoomModifier = 1/10;
+
+        let result = hdpiManager.getOptimalGameSize({ width: 1280, height: 768 });
+        expect(result.game.width).toEqual(1280);
+        expect(result.game.height).toEqual(768);
+        expect(hdpiManager.zoomModifier).toEqual(1);
+    });
 });