From da554cfef24b6a207db50507e7dae3513b36e59b Mon Sep 17 00:00:00 2001
From: Simon Robertshaw <simon@hardwired.org.uk>
Date: Sun, 18 Nov 2012 22:25:24 +0000
Subject: [PATCH] Allow resizing of custom brushes

---
 src/game/BitmapBrush.h | 64 ++++++++++++++++++++++++++++++++++--------
 1 file changed, 52 insertions(+), 12 deletions(-)

diff --git a/src/game/BitmapBrush.h b/src/game/BitmapBrush.h
index dd8dd92d9..e1c0445a9 100644
--- a/src/game/BitmapBrush.h
+++ b/src/game/BitmapBrush.h
@@ -14,9 +14,13 @@
 
 class BitmapBrush: public Brush
 {
+protected:
+	ui::Point origSize;
+	unsigned char * origBitmap;
 public:
 	BitmapBrush(std::vector<unsigned char> newBitmap, ui::Point rectSize_):
-		Brush(ui::Point(0, 0))
+		Brush(ui::Point(0, 0)),
+		origSize(0, 0)
 	{
 		ui::Point newSize = rectSize_;
 
@@ -28,28 +32,64 @@ public:
 
 		radius = (newSize-ui::Point(1, 1))/2;
 		size = newSize;
+		origSize = size;
 
-		if(bitmap)
-			delete[] bitmap;
-		bitmap = new unsigned char[size.X*size.Y];
-		std::fill(bitmap, bitmap+(size.X*size.Y), 0);
+		origBitmap = new unsigned char[size.X*size.Y];
+		std::fill(origBitmap, origBitmap+(size.X*size.Y), 0);
 		for(int y = 0; y < rectSize_.Y; y++)
 		{
 			for(int x = 0; x < rectSize_.X; x++)
 			{
-				bitmap[(y*size.X)+x] = newBitmap[(y*rectSize_.X)+x];
+				if(newBitmap[(y*rectSize_.X)+x] >= 128)
+					origBitmap[(y*size.X)+x] = newBitmap[(y*rectSize_.X)+x];
 			}	
 		}
 
-		updateOutline();
+		SetRadius(radius);
 	};
-	virtual void SetRadius(ui::Point radius)
-	{
-		//Do nothing... this brush is a fixed size
-	}
 	virtual void GenerateBitmap()
 	{
-		//Do nothing
+		if(origBitmap)
+		{
+			if(bitmap)
+				delete[] bitmap;
+			bitmap = new unsigned char[size.X*size.Y];
+			if(size == origSize)
+				std::copy(origBitmap, origBitmap+(origSize.X*origSize.Y), bitmap);
+			else
+			{
+				//Bilinear interpolation
+				float factorX = ((float)origSize.X)/((float)size.X);
+				float factorY = ((float)origSize.Y)/((float)size.Y);
+				for(int y = 0; y < size.Y; y++)
+				{
+					for(int x = 0; x < size.X; x++)
+					{
+						float originalY = ((float)y)*factorY;
+						float originalX = ((float)x)*factorX;
+
+						int lowerX = std::floor(originalX);
+						int upperX = std::min((float)(origSize.X-1), std::floor(originalX+1.0f));
+						int lowerY = std::floor(originalY);
+						int upperY = std::min((float)(origSize.Y-1), std::floor(originalY+1.0f));
+
+						unsigned char topRight = origBitmap[(lowerY*origSize.X)+upperX];
+						unsigned char topLeft = origBitmap[(lowerY*origSize.X)+lowerX];
+						unsigned char bottomRight = origBitmap[(upperY*origSize.X)+upperX];
+						unsigned char bottomLeft = origBitmap[(upperY*origSize.X)+lowerX];
+						float top = LinearInterpolate<float>(topLeft, topRight, lowerX, upperX, originalX);
+						float bottom = LinearInterpolate<float>(bottomLeft, bottomRight, lowerX, upperX, originalX);
+						float mid = LinearInterpolate<float>(top, bottom, lowerY, upperY, originalY);
+						bitmap[(y*size.X)+x] = mid > 128 ? 255 : 0;
+					}
+				}
+			}
+		}
+	}
+	virtual ~BitmapBrush()
+	{
+		if(origBitmap)
+			delete[] origBitmap;
 	}
 };