OpenGL Superbible (2nd Edition)/OpenGL SuperBible e2.iso/book/Chap05/PERSPECT/Perspect.c

C/C++ Source or Header | 1999-08-31 | 17.0 KB | 653 lines

// Perspect.c
// Demonstrates Perspective Projection

#include <windows.h>            // Window defines
#include <gl\gl.h>              // OpenGL
#include <gl\glu.h>             // GLU library
#include "resource.h"           // About box resource identifiers.

#define glRGB(x, y, z)    glColor3ub((GLubyte)x, (GLubyte)y, (GLubyte)z)

HPALETTE hPalette = NULL;

// Application name and instance storeage
static LPCTSTR lpszAppName = "Perspective Projection Example";
static HINSTANCE hInstance;

// Rotation amounts
static GLfloat xRot = 0.0f;
static GLfloat yRot = 0.0f;


// Declaration for Window procedure
LRESULT CALLBACK WndProc(   HWND    hWnd,
                            UINT    message,
                            WPARAM  wParam,
                            LPARAM  lParam);

// Dialog procedure for about box
BOOL APIENTRY AboutDlgProc (HWND hDlg, UINT message, UINT wParam, LONG lParam);

// Set Pixel Format function - forward declaration
void SetDCPixelFormat(HDC hDC);




// Change viewing volume and viewport.  Called when window is resized
void ChangeSize(GLsizei w, GLsizei h)
    {
    GLfloat fAspect;

    // Prevent a divide by zero
    if(h == 0)
        h = 1;

    // Set Viewport to window dimensions
    glViewport(0, 0, w, h);

    fAspect = (GLfloat)w/(GLfloat)h;

    // Reset coordinate system
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    // Produce the perspective projection
    gluPerspective(60.0f, fAspect, 1.0, 400.0);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    }



// This function does any needed initialization on the rendering
// context.  Here it sets up and initializes the lighting for
// the scene.
void SetupRC()
    {
    // Light values and coordinates
    GLfloat  whiteLight[] = { 0.45f, 0.45f, 0.45f, 1.0f };
    GLfloat  sourceLight[] = { 0.25f, 0.25f, 0.25f, 1.0f };
    GLfloat     lightPos[] = { -50.f, 25.0f, 250.0f, 0.0f };

    glEnable(GL_DEPTH_TEST);    // Hidden surface removal
    glFrontFace(GL_CCW);        // Counter clock-wise polygons face out
    glEnable(GL_CULL_FACE);        // Do not calculate inside of jet

    // Enable lighting
    glEnable(GL_LIGHTING);

    // Setup and enable light 0
    glLightModelfv(GL_LIGHT_MODEL_AMBIENT,whiteLight);
    glLightfv(GL_LIGHT0,GL_AMBIENT,sourceLight);
    glLightfv(GL_LIGHT0,GL_DIFFUSE,sourceLight);
    glLightfv(GL_LIGHT0,GL_POSITION,lightPos);
    glEnable(GL_LIGHT0);

    // Enable color tracking
    glEnable(GL_COLOR_MATERIAL);

    // Set Material properties to follow glColor values
    glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);

    // Black blue background
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f );
    }




// Called to draw scene
void RenderScene(void)
    {
    float fZ,bZ;

    // Clear the window with current clearing color
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    fZ = 100.0f;
    bZ = -100.0f;

    // Save the matrix state and do the rotations
    glMatrixMode(GL_MODELVIEW);
    glPushMatrix();

    glTranslatef(0.0f, 0.0f, -300.0f);
    glRotatef(xRot, 1.0f, 0.0f, 0.0f);
    glRotatef(yRot, 0.0f, 1.0f, 0.0f);



    // Set material color, Red
    glRGB(192, 0, 0);

    // Front Face ///////////////////////////////////
    glBegin(GL_QUADS);
        // Pointing straight out Z
        glNormal3f(0.0f, 0.0f, 1.0f);

        // Left Panel
        glVertex3f(-50.0f, 50.0f, fZ);
        glVertex3f(-50.0f, -50.0f, fZ);
        glVertex3f(-35.0f, -50.0f, fZ);
        glVertex3f(-35.0f,50.0f,fZ);

        // Right Panel
        glVertex3f(50.0f, 50.0f, fZ);
        glVertex3f(35.0f, 50.0f, fZ);
        glVertex3f(35.0f, -50.0f, fZ);
        glVertex3f(50.0f,-50.0f,fZ);

        // Top Panel
        glVertex3f(-35.0f, 50.0f, fZ);
        glVertex3f(-35.0f, 35.0f, fZ);
        glVertex3f(35.0f, 35.0f, fZ);
        glVertex3f(35.0f, 50.0f,fZ);

        // Bottom Panel
        glVertex3f(-35.0f, -35.0f, fZ);
        glVertex3f(-35.0f, -50.0f, fZ);
        glVertex3f(35.0f, -50.0f, fZ);
        glVertex3f(35.0f, -35.0f,fZ);

        // Top length section ////////////////////////////
        // Normal points up Y axis
        glNormal3f(0.0f, 1.0f, 0.0f);
        glVertex3f(-50.0f, 50.0f, fZ);
        glVertex3f(50.0f, 50.0f, fZ);
        glVertex3f(50.0f, 50.0f, bZ);
        glVertex3f(-50.0f,50.0f,bZ);

        // Bottom section
        glNormal3f(0.0f, -1.0f, 0.0f);
        glVertex3f(-50.0f, -50.0f, fZ);
        glVertex3f(-50.0f, -50.0f, bZ);
        glVertex3f(50.0f, -50.0f, bZ);
        glVertex3f(50.0f, -50.0f, fZ);

        // Left section
        glNormal3f(1.0f, 0.0f, 0.0f);
        glVertex3f(50.0f, 50.0f, fZ);
        glVertex3f(50.0f, -50.0f, fZ);
        glVertex3f(50.0f, -50.0f, bZ);
        glVertex3f(50.0f, 50.0f, bZ);

        // Right Section
        glNormal3f(-1.0f, 0.0f, 0.0f);
        glVertex3f(-50.0f, 50.0f, fZ);
        glVertex3f(-50.0f, 50.0f, bZ);
        glVertex3f(-50.0f, -50.0f, bZ);
        glVertex3f(-50.0f, -50.0f, fZ);
    glEnd();


    glFrontFace(GL_CW);        // clock-wise polygons face out

    // Set material color, Red
    glBegin(GL_QUADS);
        // Back section
        // Pointing straight out Z
        glNormal3f(0.0f, 0.0f, -1.0f);

        // Left Panel
        glVertex3f(-50.0f, 50.0f, bZ);
        glVertex3f(-50.0f, -50.0f, bZ);
        glVertex3f(-35.0f, -50.0f, bZ);
        glVertex3f(-35.0f,50.0f,bZ);

        // Right Panel
        glVertex3f(50.0f, 50.0f, bZ);
        glVertex3f(35.0f, 50.0f, bZ);
        glVertex3f(35.0f, -50.0f, bZ);
        glVertex3f(50.0f,-50.0f,bZ);

        // Top Panel
        glVertex3f(-35.0f, 50.0f, bZ);
        glVertex3f(-35.0f, 35.0f, bZ);
        glVertex3f(35.0f, 35.0f, bZ);
        glVertex3f(35.0f, 50.0f,bZ);

        // Bottom Panel
        glVertex3f(-35.0f, -35.0f, bZ);
        glVertex3f(-35.0f, -50.0f, bZ);
        glVertex3f(35.0f, -50.0f, bZ);
        glVertex3f(35.0f, -35.0f,bZ);

    // Insides /////////////////////////////
        glRGB(192, 192, 192);

        // Normal points up Y axis
        glNormal3f(0.0f, 1.0f, 0.0f);
        glVertex3f(-35.0f, 35.0f, fZ);
        glVertex3f(35.0f, 35.0f, fZ);
        glVertex3f(35.0f, 35.0f, bZ);
        glVertex3f(-35.0f,35.0f,bZ);

        // Bottom section
        glNormal3f(0.0f, 1.0f, 0.0f);
        glVertex3f(-35.0f, -35.0f, fZ);
        glVertex3f(-35.0f, -35.0f, bZ);
        glVertex3f(35.0f, -35.0f, bZ);
        glVertex3f(35.0f, -35.0f, fZ);

        // Left section
        glNormal3f(1.0f, 0.0f, 0.0f);
        glVertex3f(-35.0f, 35.0f, fZ);
        glVertex3f(-35.0f, 35.0f, bZ);
        glVertex3f(-35.0f, -35.0f, bZ);
        glVertex3f(-35.0f, -35.0f, fZ);

        // Right Section
        glNormal3f(-1.0f, 0.0f, 0.0f);
        glVertex3f(35.0f, 35.0f, fZ);
        glVertex3f(35.0f, -35.0f, fZ);
        glVertex3f(35.0f, -35.0f, bZ);
        glVertex3f(35.0f, 35.0f, bZ);
    glEnd();


    glFrontFace(GL_CCW);        // Counter clock-wise polygons face out

    // Restore the matrix state
    glPopMatrix();    // Modelview matrix

    // Flush drawing commands
    glFlush();
    }


// Select the pixel format for a given device context
void SetDCPixelFormat(HDC hDC)
    {
    int nPixelFormat;

    static PIXELFORMATDESCRIPTOR pfd = {
        sizeof(PIXELFORMATDESCRIPTOR),  // Size of this structure
        1,                                                              // Version of this structure
        PFD_DRAW_TO_WINDOW |                    // Draw to Window (not to bitmap)
        PFD_SUPPORT_OPENGL |                    // Support OpenGL calls in window
        PFD_DOUBLEBUFFER,                       // Double buffered
        PFD_TYPE_RGBA,                          // RGBA Color mode
        24,                                     // Want 24bit color
        0,0,0,0,0,0,                            // Not used to select mode
        0,0,                                    // Not used to select mode
        0,0,0,0,0,                              // Not used to select mode
        16,                                     // Size of depth buffer
        0,                                      // Not used to select mode
        0,                                      // Not used to select mode
        PFD_MAIN_PLANE,                         // Draw in main plane
        0,                                      // Not used to select mode
        0,0,0 };                                // Not used to select mode

    // Choose a pixel format that best matches that described in pfd
    nPixelFormat = ChoosePixelFormat(hDC, &pfd);

    // Set the pixel format for the device context
    SetPixelFormat(hDC, nPixelFormat, &pfd);
    }



// If necessary, creates a 3-3-2 palette for the device context listed.
HPALETTE GetOpenGLPalette(HDC hDC)
    {
    HPALETTE hRetPal = NULL;    // Handle to palette to be created
    PIXELFORMATDESCRIPTOR pfd;    // Pixel Format Descriptor
    LOGPALETTE *pPal;            // Pointer to memory for logical palette
    int nPixelFormat;            // Pixel format index
    int nColors;                // Number of entries in palette
    int i;                        // Counting variable
    BYTE RedRange,GreenRange,BlueRange;
                                // Range for each color entry (7,7,and 3)


    // Get the pixel format index and retrieve the pixel format description
    nPixelFormat = GetPixelFormat(hDC);
    DescribePixelFormat(hDC, nPixelFormat, sizeof(PIXELFORMATDESCRIPTOR), &pfd);

    // Does this pixel format require a palette?  If not, do not create a
    // palette and just return NULL
    if(!(pfd.dwFlags & PFD_NEED_PALETTE))
        return NULL;

    // Number of entries in palette.  8 bits yeilds 256 entries
    nColors = 1 << pfd.cColorBits;

    // Allocate space for a logical palette structure plus all the palette entries
    pPal = (LOGPALETTE*)malloc(sizeof(LOGPALETTE) +nColors*sizeof(PALETTEENTRY));

    // Fill in palette header
    pPal->palVersion = 0x300;        // Windows 3.0
    pPal->palNumEntries = nColors; // table size

    // Build mask of all 1's.  This creates a number represented by having
    // the low order x bits set, where x = pfd.cRedBits, pfd.cGreenBits, and
    // pfd.cBlueBits.
    RedRange = (1 << pfd.cRedBits) -1;
    GreenRange = (1 << pfd.cGreenBits) - 1;
    BlueRange = (1 << pfd.cBlueBits) -1;

    // Loop through all the palette entries
    for(i = 0; i < nColors; i++)
        {
        // Fill in the 8-bit equivalents for each component
        pPal->palPalEntry[i].peRed = (i >> pfd.cRedShift) & RedRange;
        pPal->palPalEntry[i].peRed = (unsigned char)(
            (double) pPal->palPalEntry[i].peRed * 255.0 / RedRange);

        pPal->palPalEntry[i].peGreen = (i >> pfd.cGreenShift) & GreenRange;
        pPal->palPalEntry[i].peGreen = (unsigned char)(
            (double)pPal->palPalEntry[i].peGreen * 255.0 / GreenRange);

        pPal->palPalEntry[i].peBlue = (i >> pfd.cBlueShift) & BlueRange;
        pPal->palPalEntry[i].peBlue = (unsigned char)(
            (double)pPal->palPalEntry[i].peBlue * 255.0 / BlueRange);

        pPal->palPalEntry[i].peFlags = (unsigned char) NULL;
        }


    // Create the palette
    hRetPal = CreatePalette(pPal);

    // Go ahead and select and realize the palette for this device context
    SelectPalette(hDC,hRetPal,FALSE);
    RealizePalette(hDC);

    // Free the memory used for the logical palette structure
    free(pPal);

    // Return the handle to the new palette
    return hRetPal;
    }


// Entry point of all Windows programs
int APIENTRY WinMain(   HINSTANCE       hInst,
                        HINSTANCE       hPrevInstance,
                        LPSTR           lpCmdLine,
                        int                     nCmdShow)
    {
    MSG                     msg;            // Windows message structure
    WNDCLASS        wc;                     // Windows class structure
    HWND            hWnd;           // Storeage for window handle

    hInstance = hInst;

    // Register Window style
    wc.style                = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
    wc.lpfnWndProc          = (WNDPROC) WndProc;
    wc.cbClsExtra           = 0;
    wc.cbWndExtra           = 0;
    wc.hInstance            = hInstance;
    wc.hIcon                        = NULL;
    wc.hCursor                      = LoadCursor(NULL, IDC_ARROW);

    // No need for background brush for OpenGL window
    wc.hbrBackground        = NULL;

    wc.lpszMenuName         = MAKEINTRESOURCE(IDR_MENU);
    wc.lpszClassName        = lpszAppName;

    // Register the window class
    if(RegisterClass(&wc) == 0)
        return FALSE;


    // Create the main application window
    hWnd = CreateWindow(
                lpszAppName,
                lpszAppName,

                // OpenGL requires WS_CLIPCHILDREN and WS_CLIPSIBLINGS
                WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN | WS_CLIPSIBLINGS,

                // Window position and size
                50, 50,
                400, 400,
                NULL,
                NULL,
                hInstance,
                NULL);

    // If window was not created, quit
    if(hWnd == NULL)
        return FALSE;


    // Display the window
    ShowWindow(hWnd,SW_SHOW);
    UpdateWindow(hWnd);

    // Process application messages until the application closes
    while( GetMessage(&msg, NULL, 0, 0))
        {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
        }

    return msg.wParam;
    }




// Window procedure, handles all messages for this program
LRESULT CALLBACK WndProc(       HWND    hWnd,
                            UINT    message,
                            WPARAM  wParam,
                            LPARAM  lParam)
    {
    static HGLRC hRC;               // Permenant Rendering context
    static HDC hDC;                 // Private GDI Device context

    switch (message)
        {
        // Window creation, setup for OpenGL
        case WM_CREATE:
            // Store the device context
            hDC = GetDC(hWnd);

            // Select the pixel format
            SetDCPixelFormat(hDC);

            hPalette = GetOpenGLPalette(hDC);

            // Create the rendering context and make it current
            hRC = wglCreateContext(hDC);
            wglMakeCurrent(hDC, hRC);
            SetupRC();

            break;

        // Window is being destroyed, cleanup
        case WM_DESTROY:
            // Deselect the current rendering context and delete it
            wglMakeCurrent(hDC,NULL);
            wglDeleteContext(hRC);

            if(hPalette != NULL)
                DeleteObject(hPalette);

            // Tell the application to terminate after the window
            // is gone.
            PostQuitMessage(0);
            break;

        // Window is resized.
        case WM_SIZE:
            // Call our function which modifies the clipping
            // volume and viewport
            ChangeSize(LOWORD(lParam), HIWORD(lParam));
            break;


        // The painting function.  This message sent by Windows
        // whenever the screen needs updating.
        case WM_PAINT:
            {
            // Call OpenGL drawing code
            RenderScene();

            SwapBuffers(hDC);

            // Validate the newly painted client area
            ValidateRect(hWnd,NULL);
            }
            break;

        // Windows is telling the application that it may modify
        // the system palette.  This message in essance asks the
        // application for a new palette.
        case WM_QUERYNEWPALETTE:
            // If the palette was created.
            if(hPalette)
                {
                int nRet;

                // Selects the palette into the current device context
                SelectPalette(hDC, hPalette, FALSE);

                // Map entries from the currently selected palette to
                // the system palette.  The return value is the number
                // of palette entries modified.
                nRet = RealizePalette(hDC);

                // Repaint, forces remap of palette in current window
                InvalidateRect(hWnd,NULL,FALSE);

                return nRet;
                }
            break;


        // This window may set the palette, even though it is not the
        // currently active window.
        case WM_PALETTECHANGED:
            // Don't do anything if the palette does not exist, or if
            // this is the window that changed the palette.
            if((hPalette != NULL) && ((HWND)wParam != hWnd))
                {
                // Select the palette into the device context
                SelectPalette(hDC,hPalette,FALSE);

                // Map entries to system palette
                RealizePalette(hDC);

                // Remap the current colors to the newly realized palette
                UpdateColors(hDC);
                return 0;
                }
            break;

        // Key press, check for arrow keys to do cube rotation.
        case WM_KEYDOWN:
            {
            if(wParam == VK_UP)
                xRot-= 5.0f;

            if(wParam == VK_DOWN)
                xRot += 5.0f;

            if(wParam == VK_LEFT)
                yRot -= 5.0f;

            if(wParam == VK_RIGHT)
                yRot += 5.0f;

            xRot = (GLfloat)((const int)xRot % 360);
            yRot = (GLfloat)((const int)yRot % 360);

            InvalidateRect(hWnd,NULL,FALSE);
            }
            break;

        // A menu command
        case WM_COMMAND:
            {
            switch(LOWORD(wParam))
                {
                // Exit the program
                case ID_FILE_EXIT:
                    DestroyWindow(hWnd);
                    break;

                // Display the about box
                case ID_HELP_ABOUT:
                    DialogBox (hInstance,
                        MAKEINTRESOURCE(IDD_DIALOG_ABOUT),
                        hWnd,
                        AboutDlgProc);
                    break;
                }
            }
            break;


    default:   // Passes it on if unproccessed
        return (DefWindowProc(hWnd, message, wParam, lParam));

    }

    return (0L);
    }




// Dialog procedure.
BOOL APIENTRY AboutDlgProc (HWND hDlg, UINT message, UINT wParam, LONG lParam)
    {

    switch (message)
    {
        // Initialize the dialog box
        case WM_INITDIALOG:
            {
            int i;
            GLenum glError;

            // glGetString demo
            SetDlgItemText(hDlg,IDC_OPENGL_VENDOR,glGetString(GL_VENDOR));
            SetDlgItemText(hDlg,IDC_OPENGL_RENDERER,glGetString(GL_RENDERER));
            SetDlgItemText(hDlg,IDC_OPENGL_VERSION,glGetString(GL_VERSION));
            SetDlgItemText(hDlg,IDC_OPENGL_EXTENSIONS,glGetString(GL_EXTENSIONS));

            // gluGetString demo
            SetDlgItemText(hDlg,IDC_GLU_VERSION,gluGetString(GLU_VERSION));
            SetDlgItemText(hDlg,IDC_GLU_EXTENSIONS,gluGetString(GLU_EXTENSIONS));


            // Display any recent error messages
            i = 0;
            do {
                glError = glGetError();
                SetDlgItemText(hDlg,IDC_ERROR1+i,gluErrorString(glError));
                i++;
                }
            while(i < 6 && glError != GL_NO_ERROR);


            return (TRUE);
            }
            break;

        // Process command messages
        case WM_COMMAND:
            {
            // Validate and Make the changes
            if(LOWORD(wParam) == IDOK)
                EndDialog(hDlg,TRUE);
            }
            break;

        // Closed from sysbox
        case WM_CLOSE:
            EndDialog(hDlg,TRUE);
            break;
        }

    return FALSE;
    }