geometry.c

   1 /*******************************************************************************
   2 **3456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789
   3 **      10        20        30        40        50        60        70        80
   4 **
   5 ** file:
   6 **    geometry.c
   7 **
   8 ** author:
   9 **    Mirco "MacSlow" Mueller <macslow@bangang.de>
  10 **
  11 ** copyright (C) Mirco Mueller, July 2006, placed under the terms of the GPL
  12 **
  13 *******************************************************************************/
  14
  15 #include <stdio.h>
  16
  17 #include "geometry.h"
  18
  19 void
  20 advance (Point* pPoint)
  21 {
  22         if (pPoint == NULL)
  23                 return;
  24
  25         if (pPoint->iGrowX != 0)
  26         {
  27                 if (pPoint->fX + pPoint->fStepX < pPoint->fUpperLimitX)
  28                         pPoint->fX += pPoint->fStepX;
  29                 else
  30                 {
  31                         pPoint->iGrowX = 0;
  32                         pPoint->fX -= pPoint->fStepX;
  33                 }
  34         }
  35         else
  36         {
  37                 if (pPoint->fX - pPoint->fStepX > pPoint->fLowerLimitX)
  38                         pPoint->fX -= pPoint->fStepX;
  39                 else
  40                 {
  41                         pPoint->iGrowX = 1;
  42                         pPoint->fX += pPoint->fStepX;
  43                 }
  44         }
  45
  46         if (pPoint->iGrowY != 0)
  47         {
  48                 if (pPoint->fY + pPoint->fStepY < pPoint->fUpperLimitY)
  49                         pPoint->fY += pPoint->fStepY;
  50                 else
  51                 {
  52                         pPoint->iGrowY = 0;
  53                         pPoint->fY -= pPoint->fStepY;
  54                 }
  55         }
  56         else
  57         {
  58                 if (pPoint->fY - pPoint->fStepY > pPoint->fLowerLimitY)
  59                         pPoint->fY -= pPoint->fStepY;
  60                 else
  61                 {
  62                         pPoint->iGrowY = 1;
  63                         pPoint->fY += pPoint->fStepY;
  64                 }
  65         }
  66 }