From 6de09834cfa376d3ecd70fe55f729c0c52696b37 Mon Sep 17 00:00:00 2001
From: Alexander Parshin <parshin.alexander@gmail.com>
Date: Sat, 25 Apr 2015 10:02:44 +0300
Subject: [PATCH] Optimize getImageData()

Mostly for fully transparent pixels
---
 src/PixelArray.cc | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/PixelArray.cc b/src/PixelArray.cc
index 0a773cc..4838eee 100644
--- a/src/PixelArray.cc
+++ b/src/PixelArray.cc
@@ -114,10 +114,16 @@ PixelArray::PixelArray(Canvas *canvas, int sx, int sy, int width, int height):
       uint8_t g = *pixel >> 8;
       uint8_t b = *pixel;
       dst[bx + 3] = a;
-      float alpha = (float) a / 255;
-      dst[bx + 0] = (int)((float) r / alpha);
-      dst[bx + 1] = (int)((float) g / alpha);
-      dst[bx + 2] = (int)((float) b / alpha);
+      if (a != 0 && a != 255) {
+          float alpha = (float) a / 255;
+          dst[bx + 0] = (int)((float) r / alpha);
+          dst[bx + 1] = (int)((float) g / alpha);
+          dst[bx + 2] = (int)((float) b / alpha);
+      } else {
+          dst[bx + 0] = r;
+          dst[bx + 1] = g;
+          dst[bx + 2] = b;
+      }
     }
     dst += dstStride;
   }