rosapps/applications/screensavers/starfield/screensaver.c

   1 /*
   2  *  Copyright 2003 J Brown
   3  *  Copyright 2006 Eric Kohl
   4  *  Copyright 2007 Marc Piulachs (marc.piulachs@codexchange.net)
   5  *  Copyright 2015 Daniel Reimer
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  20  */
  21
  22 #include <windows.h>
  23 #include <tchar.h>
  24 #include <scrnsave.h>
  25 #include "resource.h"
  26
  27 #define RANDOM( min, max ) ((rand() % (int)(((max)+1) - (min))) + (min))
  28
  29 #define MAX_LOADSTRING 100
  30 #define MAX_STARS 1000
  31
  32 #define APPNAME            _T("Starfield")
  33 #define APP_TIMER          1
  34 #define APP_TIMER_INTERVAL 20
  35
  36 #define MAX_STARS 1000
  37
  38 // Details of each individual star
  39 typedef struct star
  40 {
  41     int m_nXPos, m_nYPos, m_nZPos;
  42     int m_nOldX, m_nOldY;
  43 } STAR;
  44
  45 STAR *stars;
  46
  47 int m_nTotStars;
  48 int m_nCenterX, m_nCenterY;
  49
  50 void DrawStarField (HDC pDC)
  51 {
  52     int nX, nY;
  53     int i;
  54     for (i = 0; i < m_nTotStars; i++)
  55     {
  56         // Clear last position of this star
  57         SetPixel (
  58             pDC,
  59             stars[i].m_nOldX,
  60             stars[i].m_nOldY,
  61             RGB (0, 0, 0));
  62
  63         nX = (int)((((long)stars[i].m_nXPos << 7) / (long)stars[i].m_nZPos) + m_nCenterX);
  64         nY = (int)((((long)stars[i].m_nYPos << 7) / (long)stars[i].m_nZPos) + m_nCenterY);
  65
  66         // Draw star
  67         SetPixel (
  68             pDC,
  69             nX,
  70             nY,
  71             RGB (255, 255, 255));
  72
  73         // Remember current position for clearing later
  74         stars[i].m_nOldX = nX;
  75         stars[i].m_nOldY = nY;
  76     }
  77 }
  78
  79 BOOL SetUpStars (int nNumStars)
  80 {
  81     int i;
  82     if (nNumStars > MAX_STARS)
  83     {
  84         MessageBox (0,
  85             _T("Too many stars! Aborting!"),
  86             _T("Error"),
  87             MB_OK | MB_ICONWARNING);
  88         return FALSE;
  89     }
  90
  91     if (stars)
  92         free (stars);
  93
  94     m_nTotStars = nNumStars;
  95
  96     stars = (STAR*)malloc(nNumStars * sizeof(STAR));
  97
  98     if (!stars)
  99     {
 100         MessageBox (0,
 101             _T("Unable to allocate memory! Aborting!"),
 102             _T("Error"),
 103             MB_OK | MB_ICONWARNING);
 104         return FALSE;
 105     }
 106
 107     for (i = 0; i < m_nTotStars; i++)
 108     {
 109         do
 110         {
 111             stars[i].m_nXPos = RANDOM (-320, 320);
 112             stars[i].m_nYPos = RANDOM (-200, 200);
 113             stars[i].m_nZPos = i+1;
 114             stars[i].m_nOldX = -1;
 115             stars[i].m_nOldY = -1;
 116         } while ((stars[i].m_nXPos == 0) || (stars[i].m_nYPos == 0));
 117     }
 118     return TRUE;
 119 }
 120
 121 void MoveStarField (int nXofs, int nYofs, int nZofs)
 122 {
 123     int i;
 124     for (i = 0; i < m_nTotStars; i++)
 125     {
 126         stars[i].m_nXPos += nXofs;
 127         stars[i].m_nYPos += nYofs;
 128         stars[i].m_nZPos += nZofs;
 129
 130         if (stars[i].m_nZPos > m_nTotStars)
 131             stars[i].m_nZPos -= m_nTotStars;
 132         if (stars[i].m_nZPos < 1)
 133             stars[i].m_nZPos += m_nTotStars;
 134     }
 135 }
 136
 137 void SetDimensions (int nWidth, int nHeight)
 138 {
 139     m_nCenterX = nWidth / 2;
 140     m_nCenterY = nHeight / 2;
 141 }
 142
 143 LRESULT WINAPI ScreenSaverProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 144 {
 145     static HDC pDC;
 146
 147     switch (msg)
 148     {
 149         case WM_CREATE:
 150         {
 151             SetTimer (
 152                 hwnd,
 153                 APP_TIMER,
 154                 APP_TIMER_INTERVAL,
 155                 NULL);
 156         }
 157         break;
 158         case WM_PAINT:
 159         {
 160             PAINTSTRUCT    PtStr;
 161             HDC pDC = BeginPaint (hwnd, &PtStr);
 162             DrawStarField (pDC);
 163             EndPaint (hwnd, &PtStr);
 164             SetUpStars(250);
 165             return (0);
 166         }
 167         break;
 168         case WM_TIMER:
 169         {
 170             if (wParam == APP_TIMER)
 171             {
 172                 MoveStarField (0, 0, -3);
 173                 pDC = GetDC(hwnd);
 174                 DrawStarField (pDC);
 175                 ReleaseDC(hwnd, pDC);
 176             }
 177         }
 178         break;
 179         case WM_SIZE:
 180         {
 181             // Change the center point of the starfield
 182             SetDimensions (
 183                 LOWORD(lParam),
 184                 HIWORD(lParam));
 185         }
 186         break;
 187         case WM_DESTROY:
 188         {
 189             KillTimer (hwnd, APP_TIMER);
 190             free(stars);
 191             ShowCursor(TRUE);
 192             PostQuitMessage (0);
 193             return 0;
 194         }
 195         break;
 196         default:
 197             return DefScreenSaverProc(hwnd, msg, wParam, lParam);
 198     }
 199     return 0;
 200 }
 201
 202 BOOL WINAPI ScreenSaverConfigureDialog(HWND hWnd, UINT message, WPARAM wparam, LPARAM lparam)
 203 {
 204     return FALSE;
 205 }
 206
 207 BOOL WINAPI RegisterDialogClasses(HANDLE hmodule)
 208 {
 209     TCHAR szTitle[256];
 210     TCHAR szText[256];
 211
 212     LoadString(hmodule,
 213             IDS_TITLE,
 214             szTitle,
 215             256);
 216
 217     LoadString(hmodule,
 218             IDS_TEXT,
 219             szText,
 220             256);
 221
 222     MessageBox(0,
 223             szText,
 224             szTitle,
 225             MB_OK | MB_ICONWARNING);
 226     return FALSE;
 227 }