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Fixed missing alpha blending and optimized performance.

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git-svn-id: http://svn.code.sf.net/p/greenshot/code/trunk@1718 7dccd23d-a4a3-4e1f-8c07-b4c1b4018ab4
This commit is contained in:
RKrom 2012-03-21 13:12:19 +00:00
parent 4a5e04ae23
commit 64bc855652
2 changed files with 34 additions and 40 deletions
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32
GreenshotPlugin/Core/BitmapBuffer.cs
View file

@ -33,6 +33,22 @@ namespace GreenshotPlugin.Core {
private static log4net.ILog LOG = log4net.LogManager.GetLogger(typeof(BitmapBuffer));
private bool clone;
private Bitmap bitmap;
private static int[] factors = new int[256];
private static int[] remainings = new int[256];
static BitmapBuffer() {
// Pre calculate for alpha blending
for (int i = 0; i < 256; i++) {
int factor = 0x10000 * i / 255;
factors[i] = factor;
remainings[i] = (0x10000 * 255) - factor;
}
}
public static Color BackgroundBlendColor {
get;
set;
}
/// <summary>
/// Get the bitmap, you will always need to dispose the returned bitmap!!
@ -309,7 +325,7 @@ namespace GreenshotPlugin.Core {
}
/// <summary>
/// Retrieve the color, without alpha, at location x,y
/// Retrieve the color, without alpha (is blended), at location x,y
/// Before the first time this is called the Lock() should be called once!
/// </summary>
/// <param name="x">X coordinate</param>
@ -318,7 +334,19 @@ namespace GreenshotPlugin.Core {
public Color GetColorAtWithoutAlpha(int x, int y) {
if (x >= 0 && y >= 0 && x < rect.Width && y < rect.Height) {
int offset = x * bytesPerPixel + y * stride;
return Color.FromArgb(255, pointer[rIndex+offset], pointer[gIndex+offset], pointer[bIndex+offset]);
int a = (aIndex == -1) ? (byte)255 : pointer[aIndex + offset];
int red = pointer[rIndex + offset];
int green = pointer[gIndex + offset];
int blue = pointer[bIndex + offset];
if (a < 255) {
int aMult = factors[a];
int rem = remainings[a];
red = (red * rem + BackgroundBlendColor.R * aMult) >> 16;
green = (green * rem + BackgroundBlendColor.G * aMult) >> 16;
blue = (blue * rem + BackgroundBlendColor.B * aMult) >> 16;
}
return Color.FromArgb(255, red, green, blue);
} else {
return Color.Empty;
}

38
GreenshotPlugin/Core/QuantizerHelper.cs
View file

@ -71,8 +71,6 @@ namespace GreenshotPlugin.Core {
public class WuQuantizer {
private static log4net.ILog LOG = log4net.LogManager.GetLogger(typeof(WuQuantizer));
private static readonly Color BackgroundColor;
private static readonly Double[] Factors;
private const Int32 MAXCOLOR = 512;
private const Int32 RED = 2;
@ -102,14 +100,6 @@ namespace GreenshotPlugin.Core {
private Bitmap sourceBitmap;
private Bitmap resultBitmap;
static WuQuantizer() {
BackgroundColor = Color.White;
Factors = new Double[256];
for (Int32 value = 0; value < 256; value++) {
Factors[value] = value / 255.0;
}
}
/// <summary>
/// See <see cref="IColorQuantizer.Prepare"/> for more details.
/// </summary>
@ -157,8 +147,7 @@ namespace GreenshotPlugin.Core {
bbbDest.Lock();
for (int y = 0; y < bbbSrc.Height; y++) {
for (int x = 0; x < bbbSrc.Width; x++) {
Color color = bbbSrc.GetColorAt(x, y);
color = ConvertAlpha(color);
Color color = bbbSrc.GetColorAtWithoutAlpha(x, y);
// To count the colors
int index = color.ToArgb() & 0x00ffffff;
// Check if we already have this color
@ -270,8 +259,7 @@ namespace GreenshotPlugin.Core {
byte bestMatch;
for (int y = 0; y < bbbSrc.Height; y++) {
for (int x = 0; x < bbbSrc.Width; x++) {
Color color = bbbSrc.GetColorAt(x, y);
Color color = bbbSrc.GetColorAtWithoutAlpha(x, y);
// Check if we already matched the color
if (!lookup.ContainsKey(color)) {
// If not we need to find the best match
@ -329,28 +317,6 @@ namespace GreenshotPlugin.Core {
return resultBitmap;
}
/// <summary>
/// Converts the alpha blended color to a non-alpha blended color.
/// </summary>
/// <param name="color">The alpha blended color (ARGB).</param>
/// <returns>The non-alpha blended color (RGB).</returns>
private static Color ConvertAlpha(Color color) {
Color result = color;
if (color.A < 255) {
// performs a alpha blending (second color is BackgroundColor, by default a Control color)
Double colorFactor = Factors[color.A];
Double backgroundFactor = Factors[255 - color.A];
Int32 red = (Int32)(color.R * colorFactor + BackgroundColor.R * backgroundFactor);
Int32 green = (Int32)(color.G * colorFactor + BackgroundColor.G * backgroundFactor);
Int32 blue = (Int32)(color.B * colorFactor + BackgroundColor.B * backgroundFactor);
Int32 argb = 255 << 24 | red << 16 | green << 8 | blue;
result = Color.FromArgb(argb);
}
return result;
}
/// <summary>
/// Converts the histogram to a series of moments.
/// </summary>