Merge pull request #7 from yahoo/add_rotate

Add rotation methods

CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+v0.11.1 - 04/20/15
+* Add rotateCW/rotateCCW methods
+* Add experimental feature
+  * Add synchronous PNG loader (readImageSync)
+
 v0.11.0 - 04/19/15
 * Add experimental features:
   * Add PNG decoder supporting true-color (+alpha) and index-color (with palette); supports auxiliary chunk tRNS

examples/loadFromMemory.js

@@ -25,7 +25,7 @@ var image = PNGImage.loadImage(blob, function (err, image) {
 		red: 0, green: 0, blue: 0, alpha: 255
 	});
 
-	console.log('modified!');
+	console.log('Modified!');
 
 	// Export it
 	image.writeImage(__dirname + '/export.png', function (err) {

examples/rotate.js

@@ -0,0 +1,20 @@
+// Copyright 2015, Yahoo! Inc.
+// Copyrights licensed under the Mit License. See the accompanying LICENSE file for terms.
+
+var PNGImage = require('../index');
+
+PNGImage.readImage(__dirname + '/squirrel.png', function (err, image) {
+
+	if (err) {
+		throw err;
+	}
+
+	image = image.rotateCCW();
+	//image = image.rotateCW();
+
+	image.writeImage(__dirname + '/rotatedSquirrel.png', function (err) {
+		if (err) throw err;
+
+		console.log('Done');
+	});
+});

examples/synchonous.js

@@ -0,0 +1,17 @@
+// Copyright 2015, Yahoo! Inc.
+// Copyrights licensed under the Mit License. See the accompanying LICENSE file for terms.
+
+var PNGImage = require('../index');
+
+var image = PNGImage.readImageSync(__dirname + '/eye.png');
+
+// Black-out an area
+image.fillRect(17, 10, 15, 20, {
+	red: 0, green: 0, blue: 0, alpha: 255
+});
+
+console.log('Modified!');
+
+image.writeImageSync(__dirname + '/eye_ouput.png');
+
+console.log('Done');

index.js

@@ -5,6 +5,7 @@ var fs = require('fs'),
 	_ = require('underscore'),
 	PNG = require('pngjs').PNG,
 	pixel = require('./lib/pixel'),
+	modify = require('./lib/modify'),
 	conversion = require('./lib/conversion'),
 	filters = require('./lib/filters'),
 	streamBuffers = require("stream-buffers");
@@ -78,6 +79,7 @@ PNGImage.createImage = function (width, height) {
 	return new PNGImage(image);
 };
 
+
 /**
  * Copies an already existing image
  *
@@ -92,6 +94,7 @@ PNGImage.copyImage = function (image) {
 	return newImage;
 };
 
+
 /**
  * Reads an image from the filesystem
  *
@@ -120,6 +123,19 @@ PNGImage.readImage = function (filename, fn) {
 	return resultImage;
 };
 
+/**
+ * Reads an image from the filesystem synchronously
+ *
+ * @static
+ * @method readImageSync
+ * @param {string} filename
+ * @return {PNGImage}
+ */
+PNGImage.readImageSync = function (filename) {
+	return this.loadImageSync(fs.readFileSync(filename));
+};
+
+
 /**
  * Loads an image from a blob
  *
@@ -415,6 +431,7 @@ PNGImage.prototype.constructor = PNGImage;
 
 // Add standard methods to the prototype
 _.extend(PNGImage.prototype, pixel);
+_.extend(PNGImage.prototype, modify);
 _.extend(PNGImage.prototype, conversion);
 
 

lib/modify.js

@@ -0,0 +1,55 @@
+// Copyright 2015 Yahoo! Inc.
+// Copyrights licensed under the Mit License. See the accompanying LICENSE file for terms.
+
+/**
+ * Image manipulation functions
+ *
+ * @class PNGImage
+ * @type {object}
+ */
+module.exports = {
+
+	/**
+	 * Rotates the current image 90 degree counter-clockwise
+	 *
+	 * @method rotateCCW
+	 * @return {PNGImage} Rotated image
+	 */
+	rotateCCW: function () {
+		var Class = this.constructor,
+			x, y,
+			width = this.getWidth(),
+			height = this.getHeight(),
+			image = Class.createImage(height, width);
+
+		for (x = 0; x < width; x++) {
+			for (y = 0; y < height; y++) {
+				image.setPixel(y, width - x - 1, this.getPixel(x, y));
+			}
+		}
+
+		return image;
+	},
+
+	/**
+	 * Rotates the current image 90 degree clockwise
+	 *
+	 * @method rotateCW
+	 * @return {PNGImage} Rotated image
+	 */
+	rotateCW: function () {
+		var Class = this.constructor,
+			x, y,
+			width = this.getWidth(),
+			height = this.getHeight(),
+			image = Class.createImage(height, width);
+
+		for (x = 0; x < width; x++) {
+			for (y = 0; y < height; y++) {
+				image.setPixel(height - y - 1, x, this.getPixel(x, y));
+			}
+		}
+
+		return image;
+	}
+};

lib/pixel.js

@@ -52,18 +52,25 @@ module.exports = {
 	 *
 	 * @method setAtIndex
 	 * @param {int} idx Index of pixel
-	 * @param {object} color
+	 * @param {object|int} color
 	 * @param {int} [color.red] Red value for pixel
 	 * @param {int} [color.green] Green value for pixel
 	 * @param {int} [color.blue] Blue value for pixel
 	 * @param {int} [color.alpha] Alpha value for pixel
 	 * @param {number} [color.opacity] Opacity of color
 	 */
 	setAtIndex: function (idx, color) {
-		if (color.red !== undefined) this.setRed(idx, color.red, color.opacity);
-		if (color.green !== undefined) this.setGreen(idx, color.green, color.opacity);
-		if (color.blue !== undefined) this.setBlue(idx, color.blue, color.opacity);
-		if (color.alpha !== undefined) this.setAlpha(idx, color.alpha, color.opacity);
+		if (typeof color === 'object') {
+			if (color.red !== undefined) this.setRed(idx, color.red, color.opacity);
+			if (color.green !== undefined) this.setGreen(idx, color.green, color.opacity);
+			if (color.blue !== undefined) this.setBlue(idx, color.blue, color.opacity);
+			if (color.alpha !== undefined) this.setAlpha(idx, color.alpha, color.opacity);
+		} else {
+			this.setRed(idx, color & 0xff);
+			this.setGreen(idx, (color & 0xff00) >> 8);
+			this.setBlue(idx, (color & 0xff0000) >> 16);
+			this.setAlpha(idx, (color & 0xff000000) >> 24);
+		}
 	},
 
 	/**

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pngjs-image",
-  "version": "0.11.0",
+  "version": "0.11.1",
   "description": "Native PNG image manipulation",
   "license": "MIT",
   "main": "index.js",