From 3abbe9b2c724c082713ee597781ec54a6542c715 Mon Sep 17 00:00:00 2001
From: fatchan <tom@69420.me>
Date: Sat, 29 Jun 2019 10:40:10 +0000
Subject: [PATCH] add distortion to captcha instead of wave using imagemagick
 and update dependency for gm fork

---
 helpers/captcha/captchagenerate.js | 51 ++++++++++++++++--------------
 package-lock.json                  | 26 +++++++++++++++
 package.json                       |  1 +
 3 files changed, 54 insertions(+), 24 deletions(-)

diff --git a/helpers/captcha/captchagenerate.js b/helpers/captcha/captchagenerate.js
index 40f6f8dc..b6a29b04 100644
--- a/helpers/captcha/captchagenerate.js
+++ b/helpers/captcha/captchagenerate.js
@@ -1,31 +1,36 @@
-const gm = require('@tohru/gm')
+const gm = require('gm').subClass({ imageMagick: true })
 	, rr = (min, max) => Math.floor(Math.random() * (max-min + 1) + min)
 	, width = 200
-	, height = 80;
-
-function getShape() {
-	const x1 = rr(width * 0.1, width * 0.9)
-		, y1 = rr(height * 0.1, height * 0.9)
-		, size = rr(15, 30)
-		, x2 = rr(x1, x1 + size)
-		, y2 = rr(y1, y1 + size);
-	return { x1, x2, y1, y2 };
-}
+	, height = 80
+	, distortion = 15
 
 module.exports = (text, captchaId) => {
 	return new Promise((resolve, reject) => {
-		text = text.split(''); //array of chars
-		const x = gm(200, 80, '#fff')
+		const recy = rr(35,45);
+		const distorts = [];
+		const numDistorts = rr(3,5);
+		const div = width/numDistorts;
+		for (let i = 0; i < numDistorts; i++) {
+			const originx = rr((div*i)+distortion, (div*(i+1))-distortion);
+			const originy = rr(distortion,height-distortion);
+			const destx = rr(Math.max(distortion,originx-distortion),Math.min(width-distortion,originx+distortion));
+			const desty = rr(Math.max(distortion,originy-distortion*2),Math.min(height-distortion,originy+distortion*2));
+			distorts.push([
+				{x:originx,y:originy}, //origin
+				{x:destx,y:desty} //dest
+			]);
+		}
+		const x = gm(width,height, '#fff')
 		.fill('#000')
-		.fontSize(70)
-		let lastx = 0;
+		.fontSize(65)
+		let lastx = 7;
 		for (let i = 0; i <6; i++) {
-			x.drawText(lastx, 45+rr(0,10), text[i])
+			x.drawText(lastx, 60, text[i])
 			switch (text[i]) {
 				case 'w':
 				case 'm':
-					lastx += 40;
-					break;
+						lastx += 45;
+						break;
 				case 'i':
 				case 'f':
 				case 'l':
@@ -35,14 +40,12 @@ module.exports = (text, captchaId) => {
 					break;
 				default:
 					lastx += 30;
-					break;
+				break;
 			}
 		}
-		const recy1 = rr(20,40)
-		x.drawRectangle(rr(5,10), recy1, rr(190,195), recy1+5)
-		.wave(10, rr(80,120))
-		.blur(1, 2)
-		.crop(200, 80, 0, 0)
+		//.drawText(5, 60, text)
+		x.drawRectangle(5, recy, 195, recy+4)
+		.distort(distorts, 'Shepards')
 		.quality(30)
 		.write(`./static/captcha/${captchaId}.jpg`, (err) => {
 			if (err) {
diff --git a/package-lock.json b/package-lock.json
index b436e973..1fad032a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2846,6 +2846,32 @@
         "sparkles": "^1.0.0"
       }
     },
+    "gm": {
+      "version": "github:fatchan/gm#07df8fbf131b6b18c32fa010a84e67964e132955",
+      "from": "github:fatchan/gm",
+      "requires": {
+        "array-parallel": "^0.1.3",
+        "array-series": "^0.1.5",
+        "cross-spawn": "^4.0.0",
+        "debug": "^3.1.0",
+        "tmp": "^0.0.33"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "3.2.6",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-3.2.6.tgz",
+          "integrity": "sha512-mel+jf7nrtEl5Pn1Qx46zARXKDpBbvzezse7p7LqINmdoIk8PYP5SySaxEmYv6TZ0JyEKA1hsCId6DIhgITtWQ==",
+          "requires": {
+            "ms": "^2.1.1"
+          }
+        },
+        "ms": {
+          "version": "2.1.2",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
+        }
+      }
+    },
     "graceful-fs": {
       "version": "4.1.15",
       "resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.1.15.tgz",
diff --git a/package.json b/package.json
index 9093f76c..d8b1315b 100644
--- a/package.json
+++ b/package.json
@@ -16,6 +16,7 @@
     "fluent-ffmpeg": "^2.1.2",
     "fs": "0.0.1-security",
     "fs-extra": "^7.0.1",
+    "gm": "github:fatchan/gm",
     "mongodb": "^3.2.7",
     "path": "^0.12.7",
     "pug": "^2.0.3",