Moved files into meaningful folders

src/common/subImage.js

@@ -0,0 +1,90 @@
+/**
+ * Construct representing a part of another {ImageWrapper}. Shares data
+ * between the parent and the child.
+ * @param from {ImageRef} The position where to start the {SubImage} from. (top-left corner)
+ * @param size {ImageRef} The size of the resulting image
+ * @param I {ImageWrapper} The {ImageWrapper} to share from
+ * @returns {SubImage} A shared part of the original image
+ */
+function SubImage(from, size, I) {
+    if (!I) {
+        I = {
+            data: null,
+            size: size
+        };
+    }
+    this.data = I.data;
+    this.originalSize = I.size;
+    this.I = I;
+
+    this.from = from;
+    this.size = size;
+}
+
+/**
+ * Displays the {SubImage} in a given canvas
+ * @param canvas {Canvas} The canvas element to write to
+ * @param scale {Number} Scale which is applied to each pixel-value
+ */
+SubImage.prototype.show = function(canvas, scale) {
+    var ctx,
+        frame,
+        data,
+        current,
+        y,
+        x,
+        pixel;
+
+    if (!scale) {
+        scale = 1.0;
+    }
+    ctx = canvas.getContext('2d');
+    canvas.width = this.size.x;
+    canvas.height = this.size.y;
+    frame = ctx.getImageData(0, 0, canvas.width, canvas.height);
+    data = frame.data;
+    current = 0;
+    for (y = 0; y < this.size.y; y++) {
+        for (x = 0; x < this.size.x; x++) {
+            pixel = y * this.size.x + x;
+            current = this.get(x, y) * scale;
+            data[pixel * 4 + 0] = current;
+            data[pixel * 4 + 1] = current;
+            data[pixel * 4 + 2] = current;
+            data[pixel * 4 + 3] = 255;
+        }
+    }
+    frame.data = data;
+    ctx.putImageData(frame, 0, 0);
+};
+
+/**
+ * Retrieves a given pixel position from the {SubImage}
+ * @param x {Number} The x-position
+ * @param y {Number} The y-position
+ * @returns {Number} The grayscale value at the pixel-position
+ */
+SubImage.prototype.get = function(x, y) {
+    return this.data[(this.from.y + y) * this.originalSize.x + this.from.x + x];
+};
+
+/**
+ * Updates the underlying data from a given {ImageWrapper}
+ * @param image {ImageWrapper} The updated image
+ */
+SubImage.prototype.updateData = function(image) {
+    this.originalSize = image.size;
+    this.data = image.data;
+};
+
+/**
+ * Updates the position of the shared area
+ * @param from {x,y} The new location
+ * @returns {SubImage} returns {this} for possible chaining
+ */
+SubImage.prototype.updateFrom = function(from) {
+    this.from = from;
+    return this;
+};
+
+export default (SubImage);