mieki256's diary

• greensquare.cpp
• icon.ico
• Makefile
• resource.h
• resource.rc

/* resource.rc */

#include <windows.h>
#include <scrnsave.h>
#include "resource.h"

#define IDC_STATIC_ICON     2300
#define IDC_STATIC_TEXT     2301

/* LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US */

/* Screensaver title */
STRINGTABLE
BEGIN
  IDS_DESCRIPTION       "Green Square Example Scr"
END

/* Icon */
ID_APP  ICON    "icon.ico"

/* Dialog */
DLG_SCRNSAVECONFIGURE DIALOG DISCARDABLE  0, 0, 186, 82
STYLE DS_MODALFRAME | WS_POPUP | WS_VISIBLE | WS_CAPTION | WS_SYSMENU
CAPTION "GreenSquare Setup"
 FONT 11, "Segoe UI"
BEGIN
  DEFPUSHBUTTON "OK", IDOK, 39, 61, 50, 14 
  PUSHBUTTON    "Cancel", IDCANCEL, 107, 61, 50, 14
  AUTOCHECKBOX  "Square tumbles as it revolves", IDC_TUMBLE, 25, 35, 137, 12
  LTEXT "One option... that's all you get.", IDC_STATIC_TEXT, 17, 15, 150, 13
END

#ifndef _RESOURCE_H_
#define _RESOURCE_H_

#define IDC_TUMBLE 1000

#define IDC_STATIC_ICON     2300
#define IDC_STATIC_TEXT     2301

#endif

// greensquare.cpp is an open-source example screensaver by Rachel Grey, lemming@alum.mit.edu.
// Paste into an IDE to compile if desired.
// I haven't chosen to include the resource file, so you'd need to provide a description string /and so forth.

#include <windows.h>
#include <scrnsave.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include "resource.h"

// get rid of these warnings: truncation from const double to float conversion from double to float
// #pragma warning(disable: 4305 4244)

//Define a Windows timer

#define TIMER 1

#define FPS 60

// globals for size of screen
static int Width, Height;

static bool bTumble = true;

// a global to keep track of the square's spinning
static GLfloat spin = 0;

/////////////////////////////////////////////////
////   INFRASTRUCTURE ENDS, SPECIFICS BEGIN   ///
////                                          ///
////    In a more complex scr, I'd put all    ///
////     the following into other files.      ///
/////////////////////////////////////////////////

// Initialize OpenGL
static void InitGL(HWND hWnd, HDC &hDC, HGLRC &hRC)
{
  PIXELFORMATDESCRIPTOR pfd;
  ZeroMemory(&pfd, sizeof pfd);
  pfd.nSize = sizeof pfd;
  pfd.nVersion = 1;
  //pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL; //blaine's
  pfd.dwFlags = PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
  pfd.iPixelType = PFD_TYPE_RGBA;
  pfd.cColorBits = 24;

  hDC = GetDC(hWnd);

  int i = ChoosePixelFormat(hDC, &pfd);
  SetPixelFormat(hDC, i, &pfd);

  hRC = wglCreateContext(hDC);
  wglMakeCurrent(hDC, hRC);
}

// Shut down OpenGL
static void CloseGL(HWND hWnd, HDC hDC, HGLRC hRC)
{
  wglMakeCurrent(NULL, NULL);
  wglDeleteContext(hRC);
  ReleaseDC(hWnd, hDC);
}


void SetupAnimation(int Width, int Height)
{
  //window resizing stuff
  glViewport(0, 0, (GLsizei) Width, (GLsizei) Height);

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();

  if (0)
    {
      glOrtho(-300, 300, -240, 240, 25, 75);
    }
  else
    {
      float w = 300;
      float h = ((w * 2) * Height / Width) / 2;
      glOrtho(-w, w, -h, h, 25, 75);
    }

  glMatrixMode(GL_MODELVIEW);

  glLoadIdentity();
  gluLookAt(0.0, 0.0, 50.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
  //camera xyz, the xyz to look at, and the up vector (+y is up)

  //background
  glClearColor(0.0, 0.0, 0.0, 0.0); //0.0s is black

  glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

  // glShadeModel(GL_FLAT);
  glShadeModel(GL_SMOOTH);
}

void OnTimer(HDC hDC) //increment and display
{
  float xvals[] = {-30.0, -30.0, 30.0,  30.0};
  float yvals[] = {-30.0,  30.0, 30.0, -30.0};

  spin = spin + 1;

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  glPushMatrix();

  glRotatef(spin, 0.0, 0.0, 1.0);
  glTranslatef(120, 0, 0);
  glRotatef(spin * ((bTumble) ? -4.0 : -1.0), 0.0, 0.0, 1.0);

  //draw the square (rotated to be a diamond)

  glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
  glColor3f(0.1, 1.0, 0.3); // set green color

  glBegin(GL_POLYGON);

  for (int i = 0; i < 4; i++)
    glVertex2f(xvals[i], yvals[i]);

  glEnd();

  glPopMatrix();

  glFlush();
  SwapBuffers(hDC);
}

void CleanupAnimation()
{
  // didn't create any objects, so no need to clean them up
}


/////////   REGISTRY ACCESS FUNCTIONS     ///////////

void GetConfig()
{
  if (0)
    {
      // get configuration from registry

      HKEY key;
      //DWORD lpdw;

      if (RegOpenKeyEx(HKEY_CURRENT_USER,
                       "Software\\GreenSquare", //lpctstr
                       0,                       //reserved
                       KEY_QUERY_VALUE,
                       &key) == ERROR_SUCCESS)
        {
          DWORD dsize = sizeof(bTumble);
          DWORD dwtype =  0;

          RegQueryValueEx(key, "Tumble", NULL, &dwtype,
                          (BYTE*)&bTumble, &dsize);

          //Finished with key
          RegCloseKey(key);
        }
      else //key isn't there yet--set defaults
        {
          bTumble = true;
        }
    }
  else
    {
      bTumble = true;
    }
}

void WriteConfig(HWND hDlg)
{
  if (0)
    {
      HKEY key;
      DWORD lpdw;

      const char* null_str = "";
      LPSTR str = const_cast<LPSTR>(null_str);

      if (RegCreateKeyEx(HKEY_CURRENT_USER,
                         "Software\\GreenSquare", // lpctstr
                         0,                       // reserved
                         str,                     // ptr to null-term string specifying the object type of this key
                         REG_OPTION_NON_VOLATILE,
                         KEY_WRITE,
                         NULL,
                         &key,
                         &lpdw) == ERROR_SUCCESS)

        {
          RegSetValueEx(key, "Tumble", 0, REG_DWORD,
                        (BYTE*)&bTumble, sizeof(bTumble));

          //Finished with keys
          RegCloseKey(key);
        }
    }
}

//////////////////////////////////////////////////
////   INFRASTRUCTURE -- THE THREE FUNCTIONS   ///
//////////////////////////////////////////////////

// Screen Saver Procedure
LRESULT WINAPI ScreenSaverProc(HWND hWnd, UINT message,
                               WPARAM wParam, LPARAM lParam)
{
  static HDC hDC;
  static HGLRC hRC;
  static RECT rect;

  switch (message)
    {
      case WM_CREATE:
        // get window dimensions
        GetClientRect(hWnd, &rect);
        Width = rect.right;
        Height = rect.bottom;

        // get configuration from registry
        GetConfig();

        // setup OpenGL, then animation
        InitGL(hWnd, hDC, hRC);
        SetupAnimation(Width, Height);

        // set timer to tick every 10 ms
        SetTimer(hWnd, TIMER, (int)(1000 / FPS), NULL);
        return 0;

      case WM_TIMER:
        OnTimer(hDC);       // animate!
        return 0;

      case WM_DESTROY:
        KillTimer(hWnd, TIMER);
        CleanupAnimation();
        CloseGL(hWnd, hDC, hRC);
        return 0;
    }

  return DefScreenSaverProc(hWnd, message, wParam, lParam);
}

BOOL WINAPI ScreenSaverConfigureDialog(HWND hDlg, UINT message,
                                       WPARAM wParam, LPARAM lParam)
{
  //InitCommonControls();
  //would need this for slider bars or other common controls

  HWND aCheck;

  switch (message)
    {
      case WM_INITDIALOG:
        LoadString(hMainInstance, IDS_DESCRIPTION, szAppName, 40);

        GetConfig();

        aCheck = GetDlgItem(hDlg, IDC_TUMBLE);
        SendMessage(aCheck, BM_SETCHECK, (bTumble) ? BST_CHECKED : BST_UNCHECKED, 0);
        return TRUE;

      case WM_COMMAND:
        switch (LOWORD(wParam))
          {
            case IDC_TUMBLE:
              bTumble = (IsDlgButtonChecked(hDlg, IDC_TUMBLE) == BST_CHECKED);
              return TRUE;

            //cases for other controls would go here

            case IDOK:
              WriteConfig(hDlg);  // get info from controls
              EndDialog(hDlg, LOWORD(wParam) == IDOK);
              return TRUE;

            case IDCANCEL:
              EndDialog(hDlg, LOWORD(wParam) == IDOK);
              return TRUE;
          }

        return FALSE;
    }  //end command switch

  return FALSE;
}

// needed for SCRNSAVE.LIB
BOOL WINAPI RegisterDialogClasses(HANDLE hInst)
{
  return TRUE;
}

greensquare.scr: greensquare.o resource.o
        g++ greensquare.o resource.o -o greensquare.scr -static -lstdc++ -lgcc -lscrnsave -lopengl32 -lglu32 -lgdi32 -lcomctl32 -lwinmm -mwindows

greensquare.o: greensquare.cpp resource.h
        g++ -c greensquare.cpp

resource.o: resource.rc resource.h icon.ico
        windres resource.rc resource.o

.PHONY: clean
clean:
        rm -f *.scr
        rm -f *.o

• windres resource.rc resource.o で、リソースファイル resource.rc を .o に変換する。
• g++ -c greensquare.cpp で、.cpp をコンパイルして .o を生成。
• g++ greensquare.o resource.o -o greensquare.scr ... で、.oファイル群をリンクして .scr を生成。

• -static : スタティックリンクを指定。
• -lstdc++ -lgcc : C言語の標準的なライブラリをリンク。
• -lscrnsave : スクリーンセーバ用ライブラリをリンク。libscrnsave.a (libscrnsavw.a) をリンクする。
• -lopengl32 -lglu32 : OpenGLのライブラリをリンク。
• -lgdi32 : GDIライブラリをリンク。
• -lcomctl32 : よく分かってないけれど、これをつけないと「*.dll が見つからない」と言われて .scr が動作しなかった。
• -lwinmm : Windowsのタイマー関係ライブラリ、らしい。
• -mwindows : Windows用アプリケーション(GUIアプリ)であることを指定。

• 「Test」を選ぶと、フルスクリーン表示の動作確認ができる。
• 「構成」を選ぶと、スクリーンセーバ設定画面で「設定」をクリックした時の設定ダイアログが表示される。