From f61366643d7e36eb80ecd2d946a4a7c8bfbf9714 Mon Sep 17 00:00:00 2001
From: Ken <kenny2minecraft@gmail.com>
Date: Thu, 31 Aug 2017 09:24:41 +0800
Subject: [PATCH] Clamp transparency value (at least for set)

---
 src/blocks/scratch3_pen.js | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/blocks/scratch3_pen.js b/src/blocks/scratch3_pen.js
index bac25ec3..91eaf290 100644
--- a/src/blocks/scratch3_pen.js
+++ b/src/blocks/scratch3_pen.js
@@ -382,8 +382,8 @@ class Scratch3PenBlocks {
      */
     changePenTransparencyBy (args, util) {
         const penState = this._getPenState(util.target);
-        
-        penState.penAttributes.color4f[3] = penState.penAttributes.color4f[3] + (args.TRANSPARENCY / 100);
+        const TRANSPARENCY = args.TRANSPARENCY / 100;
+        penState.penAttributes.color4f[3] = penState.penAttributes.color4f[3] + TRANSPARENCY;
         this._updatePenColor(penState);
     }
     
@@ -395,8 +395,8 @@ class Scratch3PenBlocks {
      */
     setPenTransparencyTo (args, util) {
         const penState = this._getPenState(util.target);
-        
-        penState.penAttributes.color4f[3] = args.TRANSPARENCY / 100;
+        const TRANSPARENCY = MathUtil.clamp(args.TRANSPARENCY, 0, 100) / 100;
+        penState.penAttributes.color4f[3] = TRANSPARENCY;
         this._updatePenColor(penState);
     }
 }