OpenGLEAN 0.6 development - OpenGLEAN: one.c File Reference

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

#include <GL/openglean.h>

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

int LeaveGameMode = 0;
int 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, 1, 1, 1);
    glEnable (GL_DEPTH_TEST);
    glEnable (GL_LIGHTING);
}

/*
 * This is the display routine for our sample OpenGLEAN windows
 */
static float fTime = 0;

void SampleDisplay (void)
{
    /* Clear the screen */
    glClearColor (0, .5, 1, 1);
    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

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

    glRotatef (fTime, 0, 0, 1);
    glRotatef (fTime, 0, 1, 0);
    glRotatef (fTime, 1, 0, 0);

    /* And then drawn... */
    glColor3f (1, 1, 0);
    /* glutWireCube( 20.0 ); */
    glutWireTeapot (20.0);
    /* glutWireSpher( 15, 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 (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)
{
    fTime += 0.5;

    if (LeaveGameMode == 1)
    {
        glutLeaveGameMode ();
        LeaveGameMode = 0;
        InGameMode = 0;
    }
}

/*
 * The reshape function
 */
void SampleReshape (int nWidth, int nHeight)
{
    GLfloat fAspect = nHeight / (GLfloat) nWidth;
    GLfloat fPos [4] = {0, 0, 10, 0};
    GLfloat fCol [4] = {.5, 1, 0, 1};

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

    /* Then the projection matrix */
    glMatrixMode (GL_PROJECTION);
    glLoadIdentity ();
    glFrustum (-1, 1, -fAspect, fAspect, 1, 80);

    /* Move back the camera a bit */
    glMatrixMode (GL_MODELVIEW);
    glLoadIdentity ();
    glTranslatef (0, 0, -40);

    /* 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 key, int x, int y)
{
    (void) x;  /* XXX Reference at least once to placate GCC */
    (void) y;

    if (27 == key)
        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 OpenGLEAN processing loop */
    glutMainLoop ();

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

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

Detailed Description
