start #88 - image.contain

examples/contain.js

@@ -0,0 +1,16 @@
+/**
+ * Example for using LWIP to contain an image in a canvas.
+ */
+
+var path = require('path'),
+    lwip = require('../');
+
+lwip.open('lena.jpg', function(err, image) {
+    if (err) return console.log(err);
+    image.contain(400,700,'green',function(err, image){
+        image.writeFile('lena_contain.jpg', function(err){
+            if (err) return console.log(err);
+            console.log('done');
+        });
+    });
+});

index.js

@@ -1,3 +1,6 @@
 require('./lib/ImagePrototypeInit');
 require('./lib/BatchPrototypeInit');
+
+require('./lib/ImagePrototypeExtensions');
+
 module.exports = require('./lib/obtain');

lib/ImagePrototypeExtensions.js

@@ -0,0 +1,34 @@
+(function(undefined) {
+
+    var Image = require('./Image'),
+        decree = require('decree'),
+        defs = require('./defs');
+
+    var judges = {
+        contain: decree(defs.args.contain)
+    };
+
+    Image.prototype.contain = function() {
+        var that = this;
+        judges.contain(
+            arguments,
+            function(width, height, color, inter, callback) {
+                var s = Math.min(width / that.width(), height / that.height());
+                that.scale(s, s, inter, function(err){
+                    if (err) return callback(err);
+                    var padX = (width - that.width()) / 2,
+                        padY = (height - that.height()) / 2;
+                    that.pad(
+                        Math.ceil(padX),
+                        Math.ceil(padY),
+                        Math.floor(padX),
+                        Math.floor(padY),
+                        color,
+                        callback
+                    );
+                });
+            }
+        );
+    };
+
+})(void 0);

lib/defs.js

@@ -14,7 +14,8 @@
         GIF_DEF_INTERLACED: false,
         GIF_DEF_TRANSPARENT: 'auto',
         GIF_DEF_THRESHOLD: 50,
-        DEF_CREATE_COLOR: [0, 0, 0, 0]
+        DEF_CREATE_COLOR: [0, 0, 0, 0],
+        DEF_CONTAIN_COLOR: [0, 0, 0, 0]
     };
 
     var interpolations = exports.interpolations = {
@@ -365,7 +366,27 @@
         }, {
             name: 'callback',
             type: 'function'
-        }]
+        }],
+        contain: [{
+            name: 'width',
+            type: 'p-number'
+        }, {
+            name: 'height',
+            type: 'p-number'
+        }, {
+            name: 'color',
+            type: 'color',
+            optional: true,
+            default: defaults.DEF_CONTAIN_COLOR
+        }, {
+            name: 'interpolation',
+            type: 'interpolation',
+            optional: true,
+            default: interpolations[defaults.DEF_INTERPOLATION]
+        }, {
+            name: 'callback',
+            type: 'function'
+        }],
     };
 
 })();