butterflies.c File Reference

#include <windows.h>
#include <scrnsave.h>
#include <tchar.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glext.h>
#include "resource.h"

Include dependency graph for butterflies.c:

Go to the source code of this file.

Classes
struct	object

Functions
void	SetDefaults ()
void	ReadRegistry ()
void	WriteRegistry ()
void	SetObject (int loop)
void	LoadGLTextures ()
HGLRC	InitOGLWindow (HWND hWnd)
void	InitOpenGL (GLsizei width, GLsizei height)
void	Display ()
INT_PTR CALLBACK	AboutProc (HWND hdlg, UINT msg, WPARAM wpm, LPARAM lpm)
LRESULT WINAPI	ScreenSaverProc (HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
BOOL WINAPI	ScreenSaverConfigureDialog (HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
BOOL WINAPI	RegisterDialogClasses (HANDLE hInst)

Variables
HINSTANCE	hInstance
GLuint	texture [3]
HDC	hdcOpenGL
LPCTSTR	registryPath = _T("Software\\Microsoft\\ScreenSavers\\Butterflies")
BOOL	dRotate
struct object	obj [50]

Function Documentation

AboutProc()

INT_PTR CALLBACK AboutProc	(	HWND	hdlg,
		UINT	msg,
		WPARAM	wpm,
		LPARAM	lpm
	)

Definition at line 234 of file butterflies.c.

                                                                       {
 
    switch(msg){
    case WM_CTLCOLORSTATIC:
        if(((HWND)lpm == GetDlgItem(hdlg, WEBPAGE1)) || ((HWND)lpm == GetDlgItem(hdlg, WEBPAGE2)))
        {
            SetTextColor((HDC)wpm, RGB(0,0,255));
            SetBkColor((HDC)wpm, (COLORREF)GetSysColor(COLOR_3DFACE));
            return (INT_PTR)GetSysColorBrush(COLOR_3DFACE);
        }
        break;
    case WM_COMMAND:
        switch(LOWORD(wpm)){
        case IDOK:
            EndDialog(hdlg, LOWORD(wpm));
            break;
        case WEBPAGE1:
            ShellExecute(NULL, _T("open"), _T("http://nehe.gamedev.net"), NULL, NULL, SW_SHOWNORMAL);
            break;
        case WEBPAGE2:
            ShellExecute(NULL, _T("open"), _T("http://www.thaputer.com"), NULL, NULL, SW_SHOWNORMAL);
            break;
        }
    }
    return FALSE;
}

Referenced by ScreenSaverConfigureDialog().

Display()

void Display

(

)

Definition at line 185 of file butterflies.c.

{
    int loop;
    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);        // Clear Screen And Depth Buffer
 
    for (loop=0; loop<50; loop++)                           // Loop Of 50 (Draw 50 Objects)
    {
        glLoadIdentity ();                                      // Reset The Modelview Matrix
        glBindTexture(GL_TEXTURE_2D, texture[obj[loop].tex]);   // Bind Our Texture
        glTranslatef(obj[loop].x,obj[loop].y,obj[loop].z);      // Position The Object
        glRotatef(45.0f,1.0f,0.0f,0.0f);                        // Rotate On The X-Axis
        if (dRotate)
        {
            glRotatef((obj[loop].spinz),0.0f,0.0f,1.0f);            // Spin On The Z-Axis
        }
        glBegin(GL_TRIANGLES);                                  // Begin Drawing Triangles
            // First Triangle                                                           _____
            glTexCoord2f(1.0f,1.0f); glVertex3f( 1.0f, 1.0f, 0.0f);             //  (2)|    / (1)
            glTexCoord2f(0.0f,1.0f); glVertex3f(-1.0f, 1.0f, obj[loop].flap);   //     |  /
            glTexCoord2f(0.0f,0.0f); glVertex3f(-1.0f,-1.0f, 0.0f);             //  (3)|/
 
            // Second Triangle
            glTexCoord2f(1.0f,1.0f); glVertex3f( 1.0f, 1.0f, 0.0f);             //         /|(1)
            glTexCoord2f(0.0f,0.0f); glVertex3f(-1.0f,-1.0f, 0.0f);             //       /  |
            glTexCoord2f(1.0f,0.0f); glVertex3f( 1.0f,-1.0f, obj[loop].flap);   //  (2)/____|(3)
 
        glEnd();                                                // Done Drawing Triangles
 
        obj[loop].y-=obj[loop].yi;                              // Move Object Down The Screen
        obj[loop].spinz+=obj[loop].spinzi;                      // Increase Z Rotation By spinzi
        obj[loop].flap+=obj[loop].fi;                           // Increase flap Value By fi
 
        if (obj[loop].y<-18.0f)                                 // Is Object Off The Screen?
        {
            SetObject(loop);                                    // If So, Reassign New Values
        }
 
        if ((obj[loop].flap>1.0f) || (obj[loop].flap<-1.0f))    // Time To Change Flap Direction?
        {
            obj[loop].fi=-obj[loop].fi;                         // Change Direction By Making fi = -fi
        }
    }
 
    Sleep(15);                                                  // Create A Short Delay (15 Milliseconds)
 
    glFlush ();
 
}

Referenced by ScreenSaverProc().

InitOGLWindow()

HGLRC InitOGLWindow

(

HWND

hWnd

)

Definition at line 118 of file butterflies.c.

{
    HDC hDC = GetDC(hWnd);
    HGLRC hRC = 0;
    PIXELFORMATDESCRIPTOR pfd;
    int nFormat;
 
    ZeroMemory(&pfd, sizeof(PIXELFORMATDESCRIPTOR));
 
    pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
    pfd.nVersion = 1;
    pfd.dwFlags = PFD_SUPPORT_OPENGL | PFD_DRAW_TO_WINDOW | PFD_DOUBLEBUFFER;
    pfd.cColorBits = 24;
    pfd.cDepthBits = 24;
 
    nFormat = ChoosePixelFormat(hDC, &pfd);
    DescribePixelFormat(hDC, nFormat, sizeof(PIXELFORMATDESCRIPTOR), &pfd);
    SetPixelFormat(hDC, nFormat, &pfd);
 
    hRC = wglCreateContext(hDC);
    wglMakeCurrent(hDC, hRC);
 
    hdcOpenGL = hDC;
 
    return hRC;
}

Referenced by ScreenSaverProc().

InitOpenGL()

void InitOpenGL	(	GLsizei	width,
		GLsizei	height
	)

Definition at line 145 of file butterflies.c.

{
    int loop;
 
    if (height==0)                                      // Prevent A Divide By Zero By
    {
        height=1;                                       // Making Height Equal One
    }
 
    glViewport(0,0,width,height);                       // Reset The Current Viewport
 
    glMatrixMode(GL_PROJECTION);                        // Select The Projection Matrix
    glLoadIdentity();                                   // Reset The Projection Matrix
 
    // Calculate The Aspect Ratio Of The Window
    gluPerspective (45.0f, (GLfloat)(width)/(GLfloat)(height),1.0f, 1000.0f);
 
    glMatrixMode(GL_MODELVIEW);                         // Select The Modelview Matrix
    glLoadIdentity();
        // Start Of User Initialization
    LoadGLTextures();                                   // Load The Textures From Our Resource File
 
    glClearColor (0.0f, 0.0f, 0.0f, 0.5f);              // Black Background
    glClearDepth (1.0f);                                // Depth Buffer Setup
    glDepthFunc (GL_LEQUAL);                            // The Type Of Depth Testing (Less Or Equal)
    glDisable(GL_DEPTH_TEST);                           // Disable Depth Testing
    glShadeModel (GL_SMOOTH);                           // Select Smooth Shading
    glHint (GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // Set Perspective Calculations To Most Accurate
    glEnable(GL_TEXTURE_2D);                            // Enable Texture Mapping
    glBlendFunc(GL_ONE,GL_SRC_ALPHA);                   // Set Blending Mode (Cheap / Quick)
    glEnable(GL_BLEND);
 
 
    for (loop=0; loop<50; loop++)                   // Loop To Initialize 50 Objects
    {
        SetObject(loop);                                        // Call SetObject To Assign New Random Values
    }
 
}

Referenced by ScreenSaverProc().

LoadGLTextures()

void LoadGLTextures

(

)

Definition at line 88 of file butterflies.c.

{
    HBITMAP hBMP;                                               // Handle Of The Bitmap
    BITMAP  BMP;                                                // Bitmap Structure
    int loop;
 
    // The ID Of The 3 Bitmap Images We Want To Load From The Resource File
    byte    Texture[]={ IDB_BUTTERFLY1, IDB_BUTTERFLY2, IDB_BUTTERFLY3 };
 
    glGenTextures(sizeof(Texture), &texture[0]);                // Generate 3 Textures (sizeof(Texture)=3 ID's)
    for (loop=0; loop<sizeof(Texture); loop++)              // Loop Through All The ID's (Bitmap Images)
    {
        hBMP=(HBITMAP)LoadImage(GetModuleHandle(NULL),MAKEINTRESOURCE(Texture[loop]), IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION);
        if (hBMP)                                               // Does The Bitmap Exist?
        {                                                       // If So...
            GetObject(hBMP,sizeof(BMP), &BMP);                  // Get The Object
                                                                // hBMP: Handle To Graphics Object
                                                                // sizeof(BMP): Size Of Buffer For Object Information
                                                                // Buffer For Object Information
            glPixelStorei(GL_UNPACK_ALIGNMENT,4);               // Pixel Storage Mode (Word Alignment / 4 Bytes)
            glBindTexture(GL_TEXTURE_2D, texture[loop]);        // Bind Our Texture
            glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR); // Linear Filtering
            glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_LINEAR); // Mipmap Linear Filtering
 
            // Generate Mipmapped Texture (3 Bytes, Width, Height And Data From The BMP)
            gluBuild2DMipmaps(GL_TEXTURE_2D, 3, BMP.bmWidth, BMP.bmHeight, GL_BGR_EXT, GL_UNSIGNED_BYTE, BMP.bmBits);
        }
    }
}

Referenced by InitOpenGL().

ReadRegistry()

void ReadRegistry

(

)

Definition at line 42 of file butterflies.c.

                   {
    LONG result;
    HKEY skey;
    DWORD valtype, valsize, val;
 
    SetDefaults();
 
    result = RegOpenKeyEx(HKEY_CURRENT_USER, registryPath, 0, KEY_READ, &skey);
    if(result != ERROR_SUCCESS)
        return;
 
    valsize=sizeof(val);
 
    result = RegQueryValueEx(skey, _T("Rotate"), 0, &valtype, (LPBYTE)&val, &valsize);
    if(result == ERROR_SUCCESS)
        dRotate = val;
    RegCloseKey(skey);
}

Referenced by ScreenSaverConfigureDialog(), and ScreenSaverProc().

RegisterDialogClasses()

BOOL WINAPI RegisterDialogClasses

(

HANDLE

hInst

)

Definition at line 327 of file butterflies.c.

{
    return TRUE;
}

ScreenSaverConfigureDialog()

BOOL WINAPI ScreenSaverConfigureDialog	(	HWND	hDlg,
		UINT	message,
		WPARAM	wParam,
		LPARAM	lParam
	)

Definition at line 298 of file butterflies.c.

{
    switch (message)
    {
        case WM_INITDIALOG:
            ReadRegistry();
            CheckDlgButton(hDlg, ROTATE, dRotate);
            return TRUE;
        case WM_COMMAND:
            switch (LOWORD(wParam))
            {
                case IDOK:
                    dRotate = (IsDlgButtonChecked(hDlg, ROTATE) == BST_CHECKED);
                    WriteRegistry();
                    EndDialog(hDlg, TRUE);
                    return TRUE;
                case IDCANCEL:
                    EndDialog(hDlg, TRUE);
                    break;
                case IDABOUT:
                    DialogBox(hInstance, MAKEINTRESOURCE(IDD_DLG_ABOUT), hDlg, AboutProc);
                    break;
            }
    }
 
    return FALSE;
}

ScreenSaverProc()

LRESULT WINAPI ScreenSaverProc	(	HWND	hWnd,
		UINT	message,
		WPARAM	wParam,
		LPARAM	lParam
	)

Definition at line 261 of file butterflies.c.

{
    static HGLRC hRC;
    static DWORD timer = 1;
    HDC hDC;
    RECT WindowRect;
    int width;
    int height;
 
    switch (message)
    {
    case WM_CREATE:
        ReadRegistry();
        hRC = InitOGLWindow(hWnd);
        GetClientRect (hWnd, &WindowRect);
        width = WindowRect.right - WindowRect.left;
        height = WindowRect.bottom - WindowRect.top;
        InitOpenGL(width,height);
        SetTimer(hWnd, timer, 5, NULL);
        break;
    case WM_TIMER:
        hDC = GetDC(hWnd);
        Display();
        SwapBuffers(hDC);
        ReleaseDC(hWnd, hDC);
        break;
    case WM_DESTROY:
        wglMakeCurrent(NULL, NULL);
        wglDeleteContext(hRC);
        ReleaseDC(hWnd, hdcOpenGL);
        break;
    }
 
    return DefScreenSaverProc(hWnd, message, wParam, lParam);
}

SetDefaults()

void SetDefaults

(

)

Definition at line 37 of file butterflies.c.

{
    dRotate = TRUE;
}

Referenced by DECLARE_INTERFACE_(), and ReadRegistry().

SetObject()

void SetObject

(

int

loop

)

Definition at line 76 of file butterflies.c.

{
    obj[loop].tex=rand()%3;                                     // Texture Can Be One Of 3 Textures
    obj[loop].x=rand()%34-17.0f;                                // Random x Value From -17.0f To 17.0f
    obj[loop].y=18.0f;                                          // Set y Position To 18 (Off Top Of Screen)
    obj[loop].z=-((rand()%30000/1000.0f)+10.0f);                // z Is A Random Value From -10.0f To -40.0f
    obj[loop].spinzi=(rand()%10000)/5000.0f-1.0f;               // spinzi Is A Random Value From -1.0f To 1.0f
    obj[loop].flap=0.0f;                                        // flap Starts Off At 0.0f;
    obj[loop].fi=0.05f+(rand()%100)/1000.0f;                    // fi Is A Random Value From 0.05f To 0.15f
    obj[loop].yi=0.001f+(rand()%1000)/10000.0f;                 // yi Is A Random Value From 0.001f To 0.101f
}

Referenced by DECLARE_INTERFACE_(), Display(), and InitOpenGL().

WriteRegistry()

void WriteRegistry

(

)

Definition at line 61 of file butterflies.c.

                    {
    LONG result;
    HKEY skey;
    DWORD val, disp;
 
    result = RegCreateKeyEx(HKEY_CURRENT_USER, registryPath, 0, NULL, REG_OPTION_NON_VOLATILE, KEY_WRITE, NULL, &skey, &disp);
    if(result != ERROR_SUCCESS)
        return;
 
    val = dRotate;
    RegSetValueEx(skey, _T("Rotate"), 0, REG_DWORD, (CONST BYTE*)&val, sizeof(val));
 
    RegCloseKey(skey);
}

Referenced by ScreenSaverConfigureDialog().

Variable Documentation

dRotate

BOOL dRotate

Definition at line 18 of file butterflies.c.

Referenced by Display(), ReadRegistry(), ScreenSaverConfigureDialog(), SetDefaults(), and WriteRegistry().

hdcOpenGL

HDC hdcOpenGL

Definition at line 15 of file butterflies.c.

Referenced by InitOGLWindow(), and ScreenSaverProc().

hInstance

HINSTANCE hInstance

Definition at line 12 of file butterflies.c.

Referenced by ScreenSaverConfigureDialog().

obj

struct object obj[50]

Definition at line 34 of file butterflies.c.

registryPath

LPCTSTR registryPath = _T("Software\\Microsoft\\ScreenSavers\\Butterflies")

Definition at line 17 of file butterflies.c.

Referenced by DriverEntry(), FreeBT_DriverUnload(), ReadRegistry(), WdfDeleteKmdfVersionFromRegistry(), and WriteRegistry().

texture

GLuint texture[3]

Definition at line 14 of file butterflies.c.