*Added Grayscalefunction to the GuiImage Class

*Added svnrev.c to ignore list to avoid conflicts

source/libwiigui/gui.h

@@ -636,6 +636,8 @@ class GuiImage : public GuiElement
 		//!\param y Y coordinate
 		//!\param color Pixel color
 		void SetPixel(int x, int y, GXColor color);
+		//!Sets the image to grayscale
+		void SetGrayscale(void);
 		//!Directly modifies the image data to create a color-striped effect
 		//!Alters the RGB values by the specified amount
 		//!\param s Amount to increment/decrement the RGB values in the image

source/libwiigui/gui_image.cpp

@@ -288,6 +288,29 @@ void GuiImage::SetPixel(int x, int y, GXColor color)
 	*(image+offset+33) = color.b;
 }
 
+void GuiImage::SetGrayscale(void)
+{
+    LOCK(this);
+    GXColor color;
+    u32 offset, gray;
+
+    for(int x = 0; x < width; x++) {
+        for(int y = 0; y < height; y++) {
+            offset = (((y >> 2)<<4)*this->GetWidth()) + ((x >> 2)<<6) + (((y%4 << 2) + x%4 ) << 1);
+            color.r = *(image+offset+1);
+            color.g = *(image+offset+32);
+            color.b = *(image+offset+33);
+
+            gray = (77*color.r + 150*color.g + 28*color.b)/255;
+
+            *(image+offset+1) = gray;
+            *(image+offset+32) = gray;
+            *(image+offset+33) = gray;
+        }
+    }
+}
+
+
 void GuiImage::SetStripe(int s)
 {
 	LOCK(this);