C: / Documents and Settings / steve / My Documents / cvsroot / morepalmos / morepalmos / Source
MoreRect.c

00001 /******************************************************************************
00002  * MorePalmOS
00003  * Copyright (c) 2004 Steven Fisher
00004  *
00005  * Distributed under the Boost Software License, Version 1.0. See accompanying
00006  * license file License.txt or <http://www.boost.org/LICENSE_1_0.txt>.
00007  *
00008  * http://morepalmos.sourceforge.net
00009  *
00010  *   MorePalmOS is the humble begining of an attempt to provide a library for
00011  *   Palm OS development which works around system bugs, illustrate how to
00012  *   use system calls, and provide "glue code" for programming Palm OS
00013  *   applications in a more straightforward way while minimally impacting
00014  *   code size.
00015  *****************************************************************************/
00016 
00017 #include "MorePrefix.h"
00018 
00019 #include "MoreRect.h"
00020 
00021 #include "MorePrivate.h"
00022 
00023 void MPtAddPoints( const PointType* point1P, const PointType* point2P,
00024                 PointType* point3P )
00025 {
00026         *point3P = *point1P;
00027         point3P->x += point2P->x;
00028         point3P->y += point2P->y;
00029 }
00030 
00031 void MPtAddPoint( PointType* point1P, const PointType* point2P )
00032 {
00033         point1P->x += point2P->x;
00034         point1P->y += point2P->y;
00035 }
00036 
00037 void MPtSubtractPoint( PointType* point1P, const PointType* point2P )
00038 {
00039         point1P->x -= point2P->x;
00040         point1P->y -= point2P->y;
00041 }
00042 
00043 void MRctPtsToRect( const PointType* point1P, const PointType* point2P,
00044                                         RectangleType* resultRectP )
00045 {
00046         Coord leftMost;
00047         Coord rightMost;
00048         Coord topMost;
00049         Coord bottomMost;
00050         if ( point1P->x < point2P->x )
00051         {
00052                 leftMost = point1P->x;
00053                 rightMost = point2P->x;
00054         }
00055         else
00056         {
00057                 leftMost = point2P->x;
00058                 rightMost = point1P->x;
00059         }
00060         if ( point1P->y < point2P->y )
00061         {
00062                 topMost = point1P->y;
00063                 bottomMost = point2P->y;
00064         }
00065         else
00066         {
00067                 topMost = point1P->y;
00068                 bottomMost = point1P->y;
00069         }
00070         resultRectP->topLeft.x = leftMost;
00071         resultRectP->topLeft.y = topMost;
00072         resultRectP->extent.x = rightMost - leftMost;
00073         resultRectP->extent.y = bottomMost - topMost;
00074 }
00075 
00076 
00077 void MRctGetBottomRight( const RectangleType* rectP, PointType* bottomRight )
00078 {
00079         *bottomRight = rectP->topLeft;
00080         MPtAddPoint( bottomRight, &rectP->extent );
00081 }
00082 
00083 Coord MRctFindXCenter( const RectangleType* rectP )
00084 {
00085         return rectP->topLeft.x + (rectP->extent.x >> 1);
00086 }
00087 
00088 Coord MRctFindYCenter( const RectangleType* rectP )
00089 {
00090         return rectP->topLeft.y + (rectP->extent.y >> 1);
00091 }
00092 
00093 Coord MRctFindXCenterOf2( const RectangleType* rect1P,
00094                 const RectangleType* rect2P )
00095 {
00096         RectangleType rect3;
00097         MRctGetUnion( rect1P, rect2P, &rect3 );
00098         return rect3.topLeft.x + (rect3.extent.x >> 1);
00099 }
00100 
00101 Coord MRctFindYCenterOf2( const RectangleType* rect1P,
00102                 const RectangleType* rect2P )
00103 {
00104         RectangleType rect3;
00105         MRctGetUnion( rect1P, rect2P, &rect3 );
00106         return rect3.topLeft.y + (rect3.extent.y >> 1);
00107 }
00108 
00109 void MRctGetUnion( const RectangleType* rect1P, const RectangleType* rect2P,
00110                 RectangleType* rect3P )
00111 {
00112         AbsRectType absRect1, absRect2, absRect3;
00113         MRctRectToAbsRect( rect1P, &absRect1 );
00114         MRctRectToAbsRect( rect2P, &absRect2 );
00115         absRect3.left = _min( absRect1.left, absRect2.left );
00116         absRect3.top = _min( absRect1.top, absRect2.top );
00117         absRect3.right = _max( absRect1.right, absRect2.right );
00118         absRect3.bottom = _max( absRect1.bottom, absRect2.bottom );
00119         MRctAbsRectToRect( &absRect3, rect3P );
00120 }
00121 
00122 void MRctRectToAbsRect( const RectangleType* rectP, AbsRectType* absRectP )
00123 {
00124         absRectP->left = rectP->topLeft.x;
00125         absRectP->top = rectP->topLeft.y;
00126         absRectP->right = rectP->topLeft.x + rectP->extent.x;
00127         absRectP->bottom = rectP->topLeft.y + rectP->extent.y;
00128 }
00129 
00130 void MRctAbsRectToRect( const AbsRectType* absRectP, RectangleType* rectP )
00131 {
00132         rectP->topLeft.x = absRectP->left;
00133         rectP->topLeft.y = absRectP->top;
00134         rectP->extent.x = absRectP->right - absRectP->left;
00135         rectP->extent.y = absRectP->bottom - absRectP->top;
00136 }