更新

2026-08-11 17:41:36 +08:00
parent cfe4c82c90
commit 03fe4ddf9d
18771 changed files with 3617239 additions and 0 deletions
@@ -0,0 +1,81 @@
+var isFn = require('./isFn');
+var loadImg = require('./loadImg');
+var noop = require('./noop');
+var defaults = require('./defaults');
+var createUrl = require('./createUrl');
+var isStr = require('./isStr');
+exports = function(file, options, cb) {
+    if (isFn(options)) {
+        cb = options;
+        options = {};
+    }
+    cb = cb || noop;
+    options = options || {};
+    defaults(options, defOptions);
+    options.mimeType = options.mimeType || file.type;
+    if (isStr(file)) {
+        options.isUrl = true;
+    } else {
+        file = createUrl(file);
+    }
+    loadImg(file, function(err, img) {
+        if (err) return cb(err);
+        compress(img, options, cb);
+    });
+};
+function compress(img, options, cb) {
+    var canvas = document.createElement('canvas');
+    var ctx = canvas.getContext('2d');
+    var width = img.width;
+    var height = img.height;
+    var ratio = width / height;
+    var maxWidth = options.maxWidth;
+    var maxHeight = options.maxHeight;
+    if (options.width || options.height) {
+        if (options.width) {
+            width = options.width;
+            height = width / ratio;
+        } else if (options.height) {
+            height = options.height;
+            width = height * ratio;
+        }
+    } else {
+        if (width > maxWidth) {
+            width = maxWidth;
+            height = width / ratio;
+        }
+        if (height > maxHeight) {
+            height = maxHeight;
+            width = height * ratio;
+        }
+    }
+    width = floor(width);
+    height = floor(height);
+    canvas.width = width;
+    canvas.height = height;
+    ctx.drawImage(img, 0, 0, width, height);
+    if (URL && options.isUrl) URL.revokeObjectURL(img.src);
+    if (canvas.toBlob) {
+        try {
+            canvas.toBlob(
+                function(file) {
+                    cb(null, file);
+                },
+                options.mimeType,
+                options.quality
+            );
+        } catch (e) {
+            cb(e);
+        }
+    } else {
+        cb(new Error('Canvas toBlob is not supported'));
+    }
+}
+var defOptions = {
+    maxWidth: Infinity,
+    maxHeight: Infinity,
+    quality: 0.8
+};
+var floor = Math.floor;
+
+module.exports = exports;