initial checkin of C++ port (in progress)

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@2 0fc631ac-6414-0410-93d0-97cfa31319b6

src/gfx/rotate_image.cpp

@@ -0,0 +1,96 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include "../util/prec.hpp"
+#include "gfx.hpp"
+
+// ----------------------------------------------------------------------------- : Implementation
+
+// Rotates an image
+// 'Rotater' is a function object that knows how to 'rotate' a pixel coordinate
+template <class Rotater>
+Image rotateImageImpl(Image img) {
+	UInt width = img.GetWidth(), height = img.GetHeight();
+	// initialize the return image
+	Image ret;
+	Rotater::init(ret, width, height);
+	Byte* in = img.GetData(), *out = ret.GetData();
+	// rotate each pixel
+	for (UInt y = 0 ; y < height ; ++y) {
+		for (UInt x = 0 ; x < width ; ++x) {
+			memcpy(out + 3 * Rotater::offset(x, y, width, height), in, 3);
+			in += 3;
+		}
+	}
+	// don't forget alpha
+	if (img.HasAlpha()) {
+		ret.InitAlpha();
+		in  = img.GetAlpha();
+		out = ret.GetAlpha();
+		for (UInt y = 0 ; y < height ; ++y) {
+			for (UInt x = 0 ; x < width ; ++x) {
+				out[Rotater::offset(x, y, width, height)] = *in;
+				in += 1;
+			}
+		}
+	}
+	// ret is rotated image
+	return ret;
+}
+
+// ----------------------------------------------------------------------------- : Rotations
+
+// Function object to handle rotation
+struct Rotate90 {
+	/// Init a rotated image, where the source is w * h pixels
+	inline static void init(Image& img, UInt w, UInt h) {
+		img.Create(h, w, false);
+	}
+	/// Offset in the target data, x, y, w, h are SOURCE coordintes
+	inline static int offset(UInt x, UInt y, UInt w, UInt h) {
+		int mx = y;
+		int my = w - x - 1;
+		return h * my + mx; // note: h, since that is the width of the target image
+	}
+};
+
+struct Rotate180 {
+	inline static void init(Image& img, UInt w, UInt h) {
+		img.Create(w, h, false);
+	}
+	inline static int offset(UInt x, UInt y, UInt w, UInt h) {
+		UInt mx = w - x - 1;
+		UInt my = h - y - 1;
+		return w * my + mx;
+	}
+};
+
+struct Rotate270 {
+	inline static void init(Image& img, UInt w, UInt h) {
+		img.Create(h, w, false);
+	}
+	inline static int offset(UInt x, UInt y, UInt w, UInt h) {
+		UInt mx = h - y - 1;
+		UInt my = x;
+		return h * my + mx;
+	}
+};
+
+// ----------------------------------------------------------------------------- : Interface
+
+Image rotateImageBy(const Image& image, int angle) {
+	if (angle == 90) {
+		return rotateImageImpl<Rotate90>(image);
+	} else if (angle == 180){
+		return rotateImageImpl<Rotate180>(image);
+	} else if (angle == 270){
+		return rotateImageImpl<Rotate270>(image);
+	} else{
+		return image;
+	}
+}