mingw32.c

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/*
 * Demonstration program for Win32 GDI graphics.
 *
 *      @orignal
 *
 *      OpenGL Legacy Tutorials ： Lesson 01
 *
 *      This Code Was Created By Jeff Molofee 2000
 *      A HUGE Thanks To Fredric Echols For Cleaning Up
 *      And Optimizing This Code, Making It More Flexible!
 *      If You've Found This Code Useful, Please Let Me Know.
 *      Visit My Site At nehe.gamedev.net
 *
 *      @modified 2017-Aug-11
 *      @author Atmarkartworks t.m
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#undef UNICODE
#undef _UNICODE
 
#include <windows.h>
 
#include <GL/gl.h> 
#include <GL/gdi.h>
 
#include "ui.h"
 
 
 
/* ----------------------------------------------------------------------------------------------------------------------------- */
HDC         hDC=NULL;       // Private GDI Device Context
HWND        hWnd=NULL;      // Holds Our Window Handle
HINSTANCE   hInstance;      // Holds The Instance Of The Application
GDIContext cx;
 
 
BOOL    keys[256];          // Array Used For The Keyboard Routine
BOOL    active=TRUE;        // Window Active Flag Set To TRUE By Default
BOOL    fullscreen=TRUE;    // Fullscreen Flag Set To Fullscreen Mode By Default
 
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);   // Declaration For WndProc  s
 
#define GLvoid void
 
 
GLvoid ReSizeGLScene(GLsizei width, GLsizei height)     // Resize And Initialize The GL Window
{
    if (height==0)                                      // Prevent A Divide By Zero By
    {
        height=1;                                       // Making Height Equal One
    }
 
    reshape(width, height);
}
 
int InitGL(GLvoid)                                      // All Setup For OpenGL Goes Here
{
    init();
 
    return TRUE;                                        // Initialization Went OK
}
 
int DrawGLScene(GLvoid)                                 // Here's Where We Do All The Drawing
{
    draw();
 
    return TRUE;
}
 
GLvoid KillGLWindow(GLvoid)                             // Properly Kill The Window
{
    if (fullscreen)                                     // Are We In Fullscreen Mode?
    {
        ChangeDisplaySettings(NULL,0);                  // If So Switch Back To The Desktop
        ShowCursor(TRUE);                               // Show Mouse Pointer
    }
 
 
    if (hDC && !ReleaseDC(hWnd,hDC))                    // Are We Able To Release The DC
    {
        MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
        hDC=NULL;                                       // Set DC To NULL
    }
 
    if (hWnd && !DestroyWindow(hWnd))                   // Are We Able To Destroy The Window?
    {
        MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
        hWnd=NULL;                                      // Set hWnd To NULL
    }
 
    if (!UnregisterClass("OpenGL",hInstance))           // Are We Able To Unregister Class
    {
        MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
        hInstance=NULL;                                 // Set hInstance To NULL
    }
}
 
/*  This Code Creates Our OpenGL Window.  Parameters Are:                   *
 *  title           - Title To Appear At The Top Of The Window              *
 *  width           - Width Of The GL Window Or Fullscreen Mode             *
 *  height          - Height Of The GL Window Or Fullscreen Mode            *
 *  bits            - Number Of Bits To Use For Color (8/16/24/32)          *
 *  fullscreenflag  - Use Fullscreen Mode (TRUE) Or Windowed Mode (FALSE)   */
 
BOOL CreateGLWindow(char* title, int width, int height, int bits, BOOL fullscreenflag)
{
 
    GLuint      PixelFormat;            // Holds The Results After Searching For A Match
    WNDCLASS    wc;                     // Windows Class Structure
    DWORD       dwExStyle;              // Window Extended Style
    DWORD       dwStyle;                // Window Style
    RECT        WindowRect;             // Grabs Rectangle Upper Left / Lower Right Values
    WindowRect.left=(long)0;            // Set Left Value To 0
    WindowRect.right=(long)width;       // Set Right Value To Requested Width
    WindowRect.top=(long)0;             // Set Top Value To 0
    WindowRect.bottom=(long)height;     // Set Bottom Value To Requested Height
 
    fullscreen=fullscreenflag;          // Set The Global Fullscreen Flag
 
    hInstance           = GetModuleHandle(NULL);                // Grab An Instance For Our Window
    wc.style            = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;   // Redraw On Size, And Own DC For Window.
    wc.lpfnWndProc      = (WNDPROC) WndProc;                    // WndProc Handles Messages
    wc.cbClsExtra       = 0;                                    // No Extra Window Data
    wc.cbWndExtra       = 0;                                    // No Extra Window Data
    wc.hInstance        = hInstance;                            // Set The Instance
    wc.hIcon            = LoadIcon(NULL, IDI_WINLOGO);          // Load The Default Icon
    wc.hCursor          = LoadCursor(NULL, IDC_ARROW);          // Load The Arrow Pointer
    wc.hbrBackground    = NULL;                                 // No Background Required For GL
    wc.lpszMenuName     = NULL;                                 // We Don't Want A Menu
    wc.lpszClassName    = "OpenGL";                             // Set The Class Name
 
    if (!RegisterClass(&wc))                                    // Attempt To Register The Window Class
    {
        MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);
        return FALSE;                                           // Return FALSE
    }
 
    if (fullscreen)                                             // Attempt Fullscreen Mode?
    {
        DEVMODE dmScreenSettings;                               // Device Mode
        memset(&dmScreenSettings,0,sizeof(dmScreenSettings));   // Makes Sure Memory's Cleared
        dmScreenSettings.dmSize=sizeof(dmScreenSettings);       // Size Of The Devmode Structure
        dmScreenSettings.dmPelsWidth    = width;                // Selected Screen Width
        dmScreenSettings.dmPelsHeight   = height;               // Selected Screen Height
        dmScreenSettings.dmBitsPerPel   = bits;                 // Selected Bits Per Pixel
        dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;
 
        // Try To Set Selected Mode And Get Results.  NOTE: CDS_FULLSCREEN Gets Rid Of Start Bar.
        if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL)
        {
            // If The Mode Fails, Offer Two Options.  Quit Or Use Windowed Mode.
            if (MessageBox(NULL,"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?","NeHe GL",MB_YESNO|MB_ICONEXCLAMATION)==IDYES)
            {
                fullscreen=FALSE;       // Windowed Mode Selected.  Fullscreen = FALSE
            }
            else
            {
                // Pop Up A Message Box Letting User Know The Program Is Closing.
                MessageBox(NULL,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP);
                return FALSE;                                   // Return FALSE
            }
        }
    }
 
    if (fullscreen)                                             // Are We Still In Fullscreen Mode?
    {
        dwExStyle=WS_EX_APPWINDOW;                              // Window Extended Style
        dwStyle=WS_POPUP;                                       // Windows Style
        ShowCursor(FALSE);                                      // Hide Mouse Pointer
    }
    else
    {
        dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;           // Window Extended Style
        dwStyle=WS_OVERLAPPEDWINDOW;                            // Windows Style
    }
 
    AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);     // Adjust Window To True Requested Size
 
    // Create The Window
    if (!(hWnd=CreateWindowEx(  dwExStyle,                          // Extended Style For The Window
                                "OpenGL",                           // Class Name
                                title,                              // Window Title
                                dwStyle |                           // Defined Window Style
                                WS_CLIPSIBLINGS |                   // Required Window Style
                                WS_CLIPCHILDREN,                    // Required Window Style
                                0, 0,                               // Window Position
                                WindowRect.right-WindowRect.left,   // Calculate Window Width
                                WindowRect.bottom-WindowRect.top,   // Calculate Window Height
                                NULL,                               // No Parent Window
                                NULL,                               // No Menu
                                hInstance,                          // Instance
                                NULL)))                             // Dont Pass Anything To WM_CREATE
    {
        KillGLWindow();                             // Reset The Display
        MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);
        return FALSE;                               // Return FALSE
    }
 
 
    if (!(hDC=GetDC(hWnd)))                         // Did We Get A Device Context?
    {
        KillGLWindow();                             // Reset The Display
        MessageBox(NULL,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
        return FALSE;                               // Return FALSE
    }
 
    if (!(cx=gdiCreateContext(NULL, 0)))                // Are We Able To Get A Rendering Context?
    {
        KillGLWindow();                             // Reset The Display
        MessageBox(NULL,"Can't Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
        return FALSE;                               // Return FALSE
    }
 
    if(!gdiMakeCurrent(hWnd,cx, width, height))                 // Try To Activate The Rendering Context
    {
        KillGLWindow();                             // Reset The Display
        MessageBox(NULL,"Can't Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
        return FALSE;                               // Return FALSE
    }
 
    ShowWindow(hWnd,SW_SHOW);                       // Show The Window
    SetForegroundWindow(hWnd);                      // Slightly Higher Priority
    SetFocus(hWnd);                                 // Sets Keyboard Focus To The Window
    ReSizeGLScene(width, height);                   // Set Up Our Perspective GL Screen
 
    if (!InitGL())                                  // Initialize Our Newly Created GL Window
    {
        KillGLWindow();                             // Reset The Display
        MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);
        return FALSE;                               // Return FALSE
    }
 
    return TRUE;                                    // Success
}
 
LRESULT CALLBACK WndProc(   HWND    hWnd,           // Handle For This Window
                            UINT    uMsg,           // Message For This Window
                            WPARAM  wParam,         // Additional Message Information
                            LPARAM  lParam)         // Additional Message Information
{
 
    switch (uMsg)                                   // Check For Windows Messages
    {
        case WM_ACTIVATE:                           // Watch For Window Activate Message
        {
            if (!HIWORD(wParam))                    // Check Minimization State
            {
                active=TRUE;                        // Program Is Active
 
            }
            else
            {
                active=FALSE;                       // Program Is No Longer Active
            }
 
            return 0;                               // Return To The Message Loop
        }
 
        case WM_SYSCOMMAND:                         // Intercept System Commands
        {
            switch (wParam)                         // Check System Calls
            {
                case SC_SCREENSAVE:                 // Screensaver Trying To Start?
                case SC_MONITORPOWER:               // Monitor Trying To Enter Powersave?
                return 0;                           // Prevent From Happening
            }
            break;                                  // Exit
        }
 
        case WM_CLOSE:                              // Did We Receive A Close Message?
        {
            gdiDestroyContext(cx);
            PostQuitMessage(0);                     // Send A Quit Message
            return 0;                               // Jump Back
        }
 
        case WM_KEYDOWN:                            // Is A Key Being Held Down?
        {
            keys[wParam] = TRUE;                    // If So, Mark It As TRUE
            return 0;                               // Jump Back
        }
 
        case WM_KEYUP:                              // Has A Key Been Released?
        {
            keys[wParam] = FALSE;                   // If So, Mark It As FALSE
            return 0;                               // Jump Back
        }
 
        case WM_SIZE:                               // Resize The OpenGL Window
        {
            ReSizeGLScene(LOWORD(lParam),HIWORD(lParam));  // LoWord=Width, HiWord=Height
            return 0;                               // Jump Back
        }
    }
 
    // Pass All Unhandled Messages To DefWindowProc
    return DefWindowProc(hWnd,uMsg,wParam,lParam);
}
 
 
void tkSwapBuffers(void)
{
    gdiSwapBuffers(hWnd);
}
 
int ui_loop(int argc,char **argv, const char *name)
{
    MSG     msg;                                    // Windows Message Structure
    BOOL    done=FALSE;                             // Bool Variable To Exit Loop
    GDIContext cx;
    int width, height, k;
 
    width = 640;
    height = 480;
 
    // Ask The User Which Screen Mode They Prefer
    if (MessageBox(NULL,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDNO)
    {
        fullscreen=FALSE;                           // Windowed Mode
    }
 
    // Create Our OpenGL Window
    if (!CreateGLWindow("TinyGL MinGW32",width,height,16,fullscreen))
    {
        return 0;                                   // Quit If Window Was Not Created
    }
 
 
    while(!done)                                    // Loop That Runs While done=FALSE
    {
        if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))   // Is There A Message Waiting?
        {
            if (msg.message==WM_QUIT)               // Have We Received A Quit Message?
            {
                done=TRUE;                          // If So done=TRUE
            }
            else                                    // If Not, Deal With Window Messages
            {
                TranslateMessage(&msg);             // Translate The Message
                DispatchMessage(&msg);              // Dispatch The Message
            }
        }
        else                                        // If There Are No Messages
        {
            idle();
 
            // Draw The Scene.  Watch For ESC Key And Quit Messages From DrawGLScene()
            if ((active && !DrawGLScene()) || keys[VK_ESCAPE])  // Active?  Was There A Quit Received?
            {
                done=TRUE;                          // ESC or DrawGLScene Signalled A Quit
            }
            else                                    // Not Time To Quit, Update Screen
            {
                SwapBuffers(hDC);                   // Swap Buffers (Double Buffering)
            }
 
            if (keys[VK_F1])                        // Is F1 Being Pressed?
            {
                keys[VK_F1]=FALSE;                  // If So Make Key FALSE
                KillGLWindow();                     // Kill Our Current Window
                fullscreen=!fullscreen;             // Toggle Fullscreen / Windowed Mode
                // Recreate Our OpenGL Window
                if (!CreateGLWindow("NeHe's First Polygon Tutorial",640,480,16,fullscreen))
                {
                    return 0;                       // Quit If Window Was Not Created
                }
            }
        }
    }
 
    // Shutdown
    KillGLWindow();                                 // Kill The Window
    return (msg.wParam);                            // Exit The Program
}