OpenGLUT 0.6.3 development - OpenGLUT: one.c File Reference

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <GL/openglut.h>

#include <stdio.h>
#include <stdlib.h>

int g_LeaveGameMode = 0;
int g_InGameMode = 1;

/*
 * Call this function to have some text drawn at given coordinates
 */
void PrintText( int nX, int nY, char* pszText )
{
    int lines;
    char *p;

    /* Prepare the OpenGL state */
    glDisable( GL_LIGHTING );
    glDisable( GL_DEPTH_TEST );
    glMatrixMode( GL_PROJECTION );
    glPushMatrix();
    glLoadIdentity();

    /* Have an orthogonal projection matrix set */
    glOrtho( 0, glutGet( GLUT_WINDOW_WIDTH ),
             0, glutGet( GLUT_WINDOW_HEIGHT ),
             -1, +1
    );

    /* Now the matrix mode */
    glMatrixMode( GL_MODELVIEW );
    glPushMatrix();
    glLoadIdentity();

    /* Now the main text */
    glColor3ub( 0, 0, 0 );
    glRasterPos2i( nX, nY );

    for( p=pszText, lines=0; *p; p++ )
    {
        if( *p == '\n' )
        {
            lines++;
            glRasterPos2i( nX, nY-(lines*18) );
        }

        glutBitmapCharacter( GLUT_BITMAP_HELVETICA_18,  *p );
    }

    /* Revert to the old matrix modes */
    glMatrixMode( GL_PROJECTION );
    glPopMatrix();

    glMatrixMode( GL_MODELVIEW );
    glPopMatrix();

    /* Restore the old OpenGL states */
    glColor4f( 1.0f, 1.0f, 1.0f, 1.0f );
    glEnable( GL_DEPTH_TEST );
    glEnable( GL_LIGHTING );
}

/*
 * This is the display routine for our sample OpenGLUT windows
 */
static float g_fTime = 0.0f;

void SampleDisplay( void )
{
    /* Clear the screen */
    glClearColor( 0, 0.5, 1, 1 );
    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

    /* Have the cube rotated */
    glMatrixMode( GL_MODELVIEW );
    glPushMatrix();

    glRotatef( g_fTime, 0, 0, 1 );
    glRotatef( g_fTime, 0, 1, 0 );
    glRotatef( g_fTime, 1, 0, 0 );

    /* And then drawn... */
    glColor3f( 1, 1, 0 );
    /*glutWireCube( 20.0 );*/
    glutWireTeapot( 20.0 );
    /*glutWireSpher( 15.0, 15, 15 );*/
    /*glColor3f( 0, 1, 0 );*/
    /*glutWireCube( 30.0 );*/
    /*glutSolidCone( 10, 20, 10, 2 );*/

    /* Don't forget about the model-view matrix */
    glPopMatrix( );

    /* Draw a silly text */
    if( g_InGameMode == 0 )
        PrintText( 20, 20, "Hello there cruel world!" );
    else
        PrintText( 20, 20, "Press ESC to leave the game mode!" );

    /* And swap this context's buffers */
    glutSwapBuffers( );
}

/*
 * This is a sample idle function
 */
void SampleIdle( void )
{
    g_fTime += 0.5f;

    if( g_LeaveGameMode == 1 )
    {
        glutLeaveGameMode( );
        g_LeaveGameMode = 0;
        g_InGameMode = 0;
    }
}

/*
 * The reshape function
 */
void SampleReshape( int nWidth, int nHeight )
{
    GLfloat fAspect = (GLfloat) nHeight / (GLfloat) nWidth;
    GLfloat fPos[ 4 ] = { 0.0f, 0.0f, 10.0f, 0.0f };
    GLfloat fCol[ 4 ] = { 0.5f, 1.0f,  0.0f, 1.0f };

    /* Update the viewport first */
    glViewport( 0, 0, nWidth, nHeight );

    /* Then the projection matrix */
    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    glFrustum( -1.0, 1.0, -fAspect, fAspect, 1.0, 80.0 );

    /* Move back the camera a bit */
    glMatrixMode( GL_MODELVIEW );
    glLoadIdentity( );
    glTranslatef( 0.0, 0.0, -40.0f );

    /* Enable some features... */
    glEnable( GL_CULL_FACE );
    glEnable( GL_DEPTH_TEST );
    glEnable( GL_NORMALIZE );

    /* Set up some lighting */
    glLightfv( GL_LIGHT0, GL_POSITION, fPos );
    glEnable( GL_LIGHTING );
    glEnable( GL_LIGHT0 );

    /* Set up a sample material */
    glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, fCol );
}

/*
 * A sample keyboard callback
 */
void SampleKeyboard( unsigned char cChar, int nMouseX, int nMouseY )
{
    printf( "SampleKeyboard(): keypress '%c' at (%i,%i)\n",
                    cChar, nMouseX, nMouseY );
}

/*
 * A sample keyboard callback (for game mode window)
 */
void SampleGameModeKeyboard( unsigned char cChar, int nMouseX, int nMouseY )
{
    if( cChar == 27 )
        g_LeaveGameMode = 1;
}


/*
 * A sample special callback
 */
void SampleSpecial( int nSpecial, int nMouseX, int nMouseY )
{
    printf( "SampleSpecial(): special keypress %i at (%i,%i)\n",
            nSpecial, nMouseX, nMouseY );
}

/*
 * A sample menu callback
 */
void SampleMenu( int menuID )
{
    /* Just print something funny */
    printf( "SampleMenu() callback executed, menuID is %i\n",
                    menuID );
}

/*
 * The sample's entry point
 */
int main( int argc, char** argv )
{
    int menuID, subMenuA, subMenuB;

    glutInitDisplayString( "stencil~2 rgb double depth>=16 samples" );
    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
    glutInitWindowPosition( 100, 100 );

    glutInit( &argc, argv );

    subMenuA = glutCreateMenu( SampleMenu );
    glutAddMenuEntry( "Sub menu A1 (01)", 1 );
    glutAddMenuEntry( "Sub menu A2 (02)", 2 );
    glutAddMenuEntry( "Sub menu A3 (03)", 3 );

    subMenuB = glutCreateMenu( SampleMenu );
    glutAddMenuEntry( "Sub menu B1 (04)", 4 );
    glutAddMenuEntry( "Sub menu B2 (05)", 5 );
    glutAddMenuEntry( "Sub menu B3 (06)", 6 );
    glutAddSubMenu( "Going to sub menu A", subMenuA );

    menuID = glutCreateMenu( SampleMenu );
    glutAddMenuEntry( "Entry one",   1 );
    glutAddMenuEntry( "Entry two",   2 );
    glutAddMenuEntry( "Entry three", 3 );
    glutAddMenuEntry( "Entry four",  4 );
    glutAddMenuEntry( "Entry five",  5 );
    glutAddSubMenu( "Enter sub menu A", subMenuA );
    glutAddSubMenu( "Enter sub menu B", subMenuB );

    glutCreateWindow( "Hello world!" );
    glutDisplayFunc( SampleDisplay );
    glutReshapeFunc( SampleReshape );
    glutKeyboardFunc( SampleKeyboard );
    glutSpecialFunc( SampleSpecial );
    glutIdleFunc( SampleIdle );
    glutAttachMenu( GLUT_LEFT_BUTTON );

    glutInitWindowPosition( 200, 200 );
    glutCreateWindow( "I am not Jan B." );
    glutDisplayFunc( SampleDisplay );
    glutReshapeFunc( SampleReshape );
    glutKeyboardFunc( SampleKeyboard );
    glutSpecialFunc( SampleSpecial );
    glutIdleFunc( SampleIdle );
    glutAttachMenu( GLUT_LEFT_BUTTON );

    printf( "Testing game mode string parsing, don't panic!\n" );
    glutGameModeString( "320x240:32@100" );
    glutGameModeString( "640x480:16@72" );
    glutGameModeString( "1024x768" );
    glutGameModeString( ":32@120" );
    glutGameModeString( "Toudi glupcze, Danwin bedzie moj!" );
    glutGameModeString( "640x480:16@72" );

    glutEnterGameMode();
    glutDisplayFunc( SampleDisplay );
    glutReshapeFunc( SampleReshape );
    glutKeyboardFunc( SampleGameModeKeyboard );
    glutIdleFunc( SampleIdle );
    glutAttachMenu( GLUT_LEFT_BUTTON );

    printf( "current window is %ix%i+%i+%i\n",
                    glutGet( GLUT_WINDOW_X ), glutGet( GLUT_WINDOW_Y ),
                    glutGet( GLUT_WINDOW_WIDTH ), glutGet( GLUT_WINDOW_HEIGHT )
    );

    /* Enter the main OpenGLUT processing loop */
    glutMainLoop();

    printf( "glutMainLoop() termination works fine!\n" );

    /* This is never reached in OpenGLUT. Is that good? */
    return EXIT_SUCCESS;
}
one.c File Reference

Detailed Description
