Added management and drawing functions for ellipses and polygons.

include/SDL_ellipse.h

@@ -0,0 +1,92 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 2010 Eli Gottlieb
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    Eli Gottlieb
+    eligottlieb@gmail.com
+*/
+
+/**
+ *  \file SDL_ellipse.h
+ *  
+ *  Header file for SDL_ellipse definition and management functions.
+ */
+
+#ifndef _SDL_ellipse_h
+#define _SDL_ellipse_h
+
+#include "SDL_stdinc.h"
+#include "SDL_error.h"
+#include "SDL_pixels.h"
+#include "SDL_rwops.h"
+
+#include "begin_code.h"
+/* Set up for C function definitions, even when using C++ */
+#ifdef __cplusplus
+/* *INDENT-OFF* */
+extern "C" {
+/* *INDENT-ON* */
+#endif
+
+/**
+ *  \brief  The structure that defines an ellipse.
+ *
+ *  \sa SDL_EllipseEmpty
+ *  \sa SDL_EllipseEquals
+ *  \sa SDL_EllipsesIntersect
+ *  \sa SDL_IntersectEllipseAndLine
+ */
+typedef struct SDL_Ellipse {
+	int x,y;
+	int a,b;
+	int r;
+} SDL_Ellipse;
+
+/**
+ *  \brief Returns true if the ellipse has no area.
+ */
+#define SDL_EllipseEmpty(X)    ((X)->r <= 0)
+
+/**
+ *  \brief Returns true if the two ellipses are equal.
+ */
+#define SDL_EllipseEquals(A, B)   (((A)->x == (B)->x) && ((A)->y == (B)->y) && \
+                                ((A)->a == (B)->a) && ((A)->b == (B)->b) && ((A)->r == (B)->r))
+
+/**
+ *  \brief Determine whether two ellipses intersect.
+ *  
+ *  \return SDL_TRUE if there is an intersection, SDL_FALSE otherwise.
+ */
+extern DECLSPEC SDL_bool SDLCALL SDL_EllipsesIntersect(const SDL_Ellipse * A,const SDL_Ellipse * B);
+
+/**
+ *  \brief Calculate the intersection of an ellipse and line segment.
+ *  
+ *  \return SDL_TRUE if there is an intersection, SDL_FALSE otherwise.
+ */
+extern DECLSPEC SDL_bool SDLCALL SDL_IntersectEllipseAndLine(const SDL_Ellipse *ellipse,int *X1,int *Y1,int *X2,int *Y2);
+
+/* Ends C function definitions when using C++ */
+#ifdef __cplusplus
+/* *INDENT-OFF* */
+}
+/* *INDENT-ON* */
+#endif
+#include "close_code.h"
+
+#endif /* _SDL_ellipse_h */