contents of zip

scripts/startup_images_creator.js

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+// Use strict
+"use strict";
+
+
+// Classes
+
+// Startup images creator class
+class StartupImagesCreator {
+
+	// Public
+		
+		// Initialize
+		static initialize() {
+		
+			// Check if device pixel ratio is supported
+			if(typeof devicePixelRatio === "number") {
+		
+				// Create image
+				var image = new Image();
+				
+				// Image load event
+				image["onload"] = function() {
+				
+					// Get width, height, and pixel ratio
+					var width = screen["width"];
+					var height = screen["height"];
+					var pixelRatio = devicePixelRatio;
+					
+					// Create portrait and landscape startup images
+					StartupImagesCreator.createStartupImage(width, height, pixelRatio, image, (width < height) ? StartupImagesCreator.PORTRAIT_ORIENTATION : StartupImagesCreator.LANDSCAPE_ORIENTATION);
+					StartupImagesCreator.createStartupImage(height, width, pixelRatio, image, (height <= width) ? StartupImagesCreator.PORTRAIT_ORIENTATION : StartupImagesCreator.LANDSCAPE_ORIENTATION);
+				};
+				
+				// Set image's source
+				image["src"] = "." + getResource(StartupImagesCreator.LOGO_FILE_LOCATION);
+			}
+		}
+	
+	// Private
+	
+		// Add startup image
+		static createStartupImage(width, height, pixelRatio, image, orientation) {
+		
+			// Create canvas
+			var canvas = document.createElement("canvas");
+			
+			// Size canvas to be full screen on the device
+			canvas["width"] = width * pixelRatio;
+			canvas["height"] = height * pixelRatio;
+			
+			// Get canvas's context
+			var context = canvas.getContext("2d");
+			
+			// Set context's image smoothing
+			context["imageSmoothingEnabled"] = true;
+			context["mozImageSmoothingEnabled"] = true;
+			context["webkitImageSmoothingEnabled"] = true;
+			context["msImageSmoothingEnabled"] = true;
+			context["imageSmoothingQuality"] = "high";
+			
+			// Scale context to the pixel ratio
+			context.scale(pixelRatio, pixelRatio);
+			
+			// Create gradient
+			var gradient = context.createLinearGradient(0, 0, width, 0);
+			gradient.addColorStop(0, StartupImagesCreator.BACKGROUND_GRADIENT_START_COLOR);
+			gradient.addColorStop(1, StartupImagesCreator.BACKGROUND_GRADIENT_END_COLOR);
+			
+			// Fill context with the gradient
+			context["fillStyle"] = gradient;
+			context.fillRect(0, 0, width, height);
+			
+			// Draw image in the middle of the context
+			var imageWidth = image["width"] * Math.min(width, height) * StartupImagesCreator.IMAGE_SCALE_FACTOR;
+			var imageHeight = imageWidth * image["height"] / image["width"];
+			context.drawImage(image, (width - imageWidth) / 2, (height - imageHeight) / 2, imageWidth, imageHeight);
+			
+			// Create link from the context
+			var link = document.createElement("link");
+			link.setAttribute("rel", "apple-touch-startup-image");
+			link.setAttribute("media", "(orientation: " + orientation + ")");
+			link.setAttribute("href", canvas.toDataURL());
+			
+			// Add link to document
+			document["head"].appendChild(link);
+		}
+		
+		// Background gradient start color
+		static get BACKGROUND_GRADIENT_START_COLOR() {
+		
+			// Return background gradient start color
+			return "#9E00E7";
+		}
+		
+		// Background gradient end color
+		static get BACKGROUND_GRADIENT_END_COLOR() {
+		
+			// Return background gradient end color
+			return "#3600C9";
+		}
+		
+		// Image scale factor
+		static get IMAGE_SCALE_FACTOR() {
+		
+			// Return image scale factor
+			return 1 / 830;
+		}
+		
+		// Logo file location
+		static get LOGO_FILE_LOCATION() {
+		
+			// Return vertex shader file location
+			return "./images/logo_small.svg";
+		}
+		
+		// Portrait orientation
+		static get PORTRAIT_ORIENTATION() {
+		
+			// Return portrait orientation
+			return "portrait";
+		}
+		
+		// Landscape orientation
+		static get LANDSCAPE_ORIENTATION() {
+		
+			// Return landscape orientation
+			return "landscape";
+		}
+}
+
+
+// Main function
+
+// Set global object's startup images creator
+globalThis["StartupImagesCreator"] = StartupImagesCreator;
+
+// Ready event
+$(function() {
+
+	// Initialize startup images creator
+	StartupImagesCreator.initialize();
+});