Fixed weirdness when opening transparent images

jefff · Jul 9, 2013 · cbe407e · cbe407e
1 parent f947717
commit cbe407e
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Showing 2 changed files with 16 additions and 2 deletions.
diff --git a/AnimalCrossingQR/AnimalCrossingQR/AC/Color.cs b/AnimalCrossingQR/AnimalCrossingQR/AC/Color.cs
@@ -19,6 +19,16 @@ public Color(byte red, byte green, byte blue)
             Blue = blue;
         }
 
+        public Color(byte red, byte green, byte blue, byte alpha)
+            : this(LerpWhite(red, alpha), LerpWhite(green, alpha), LerpWhite(blue, alpha))
+        {
+        }
+
+        private static byte LerpWhite(byte color, byte alpha)
+        {
+            return (byte)(255.0 + (color - 255.0) * ((double)alpha / 255.0));
+        }
+
         public static double DistanceSquared(Color a, Color b)
         {
             return (a.Red - b.Red) * (a.Red - b.Red) +

diff --git a/AnimalCrossingQR/AnimalCrossingQR/AC/Pattern.cs b/AnimalCrossingQR/AnimalCrossingQR/AC/Pattern.cs
@@ -47,7 +47,7 @@ public Pattern(Image image)
                 gr.DrawImage(image, new Rectangle(0, 0, Width, Height));
             }
 
-            BitmapData bitmapData = resizedImage.LockBits(new Rectangle(0, 0, Width, Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
+            BitmapData bitmapData = resizedImage.LockBits(new Rectangle(0, 0, Width, Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
             byte[] imagePixelData = new byte[Math.Abs(bitmapData.Stride) * bitmapData.Height];
             Marshal.Copy(bitmapData.Scan0, imagePixelData, 0, imagePixelData.Length);
             resizedImage.UnlockBits(bitmapData);
@@ -68,7 +68,11 @@ private void LoadFromPixelData(byte[] data)
             Color[,] sourceImage = new Color[Width, Height];
             for (int i = 0; i < Width; i++)
                 for (int j = 0; j < Height; j++)
-                    sourceImage[i, j] = new Color(data[(j * Height + i) * 3 + 2], data[(j * Height + i) * 3 + 1], data[(j * Height + i) * 3 + 0]);
+                    sourceImage[i, j] = new Color(
+                        data[(j * Height + i) * 4 + 2],
+                        data[(j * Height + i) * 4 + 1],
+                        data[(j * Height + i) * 4 + 0],
+                        data[(j * Height + i) * 4 + 3]);
 
             HashSet<Color> bestPalette = CreateBestPalette(sourceImage);
             ColorPalette = new Palette();