ngryman/ribs

/*!
 * ribs
 * Copyright (c) 2013-2014 Nicolas Gryman <ngryman@gmail.com>
 * LGPL Licensed
 */

'use strict';

/**
 * Module dependencies.
 */

var bindings = require('./bindings'),
    Image = bindings.Image;

/**
 * Used by console.log and friends.
 *
 * @returns {string}
 */
Image.prototype.inspect = function() {
    return 'Image {width: ' + this.width +
        ', height: ' + this.height +
        ', channels: ' + this.channels +
        ', length: ' + this.length +
        ', originalFormat: ' + this.originalFormat + '}';
};

/**
 * Iterate over each pixel in left-right, top-bottom direction.
 *
 * @param callback - Callback invoked with each color.
 */
Image.prototype.each = function(callback) {
    for (var i = 0, len = this.length; i < len; i++)
        callback(this[i], i, this);
};

/**
 *
 * @param callback
 */
Image.prototype.eachPixel = function(callback) {
    var pixel = {};
    for (var i = 0, len = this.length, channels = this.channels; i < len; i += channels) {
        pixel.r = this[i + 0];
        pixel.g = this[i + 1];
        pixel.b = this[i + 2];
        if (4 == channels)
            pixel.a = this[i + 3];

        callback(pixel, i, this);
    }
};

/**
 * Map over each pixel in left-right, top-bottom direction.
 *
 * @param callback - Callback invoked with each color. The return value will be assigned to the
 * current pixel.
 */
Image.prototype.map = function(callback) {
    for (var i = 0, len = this.length; i < len; i++)
        this[i] = callback(this[i], i, this) || this[i];
};

/**
 *
 * @param callback
 */
Image.prototype.mapPixel = function(callback) {
    var pixel = {};
    for (var i = 0, len = this.length, channels = this.channels; i < len; i += channels) {
        pixel.r = this[i + 0];
        pixel.g = this[i + 1];
        pixel.b = this[i + 2];
        if (4 == channels)
            pixel.a = this[i + 3];

        callback(pixel, i, this);

        this[i + 0] = pixel.r;
        this[i + 1] = pixel.g;
        this[i + 2] = pixel.b;
        if (4 == channels)
            this[i + 3] = pixel.a;
    }
};

/**
 * Export.
 */

module.exports = Image;