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Thread: Three dimensional blending program shows white screen

  1. #1
    Junior Member Newbie
    Join Date
    Jan 2013
    Posts
    23

    Three dimensional blending program shows white screen

    I am trying the alpha3D.c program from the OpenGL red book which demonstarte drawing opaque and translucent 3D objects . I have attached the code. I can compile it. But when I run the program, I just see the white screen. I need to know what the problem is. Please help me figure it out.

    Code :
    #include <stdlib.h>
    #include <stdio.h>
     
    #include <GL/glut.h>
     
    #define MAXZ 8.0
    #define MINZ -8.0
    #define ZINC 0.4
     
    static float solidZ = MAXZ;
    static float transparentZ = MINZ;
    static GLuint sphereList, cubeList;
     
    static void init(void)
    {
    GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 0.15 };
    GLfloat mat_shininess[] = { 100.0 };
    GLfloat position[] = { 0.5, 0.5, 1.0, 0.0 };
    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
    glLightfv(GL_LIGHT0, GL_POSITION, position);
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_DEPTH_TEST);
    sphereList = glGenLists(1);
    glNewList(sphereList, GL_COMPILE);
    glutSolidSphere (0.4, 16, 16);
    glEndList();
    cubeList = glGenLists(1);
    glNewList(cubeList, GL_COMPILE);
    glutSolidCube (0.6);
    glEndList();
    }
     
    void display(void)
    {
     
    GLfloat mat_solid[] = { 0.75, 0.75, 0.0, 1.0 };
    GLfloat mat_zero[] = { 0.0, 0.0, 0.0, 1.0 };
    GLfloat mat_transparent[] = { 0.0, 0.8, 0.8, 0.6 };
    GLfloat mat_emission[] = { 0.0, 0.3, 0.3, 0.6 };
    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glPushMatrix ();
    glTranslatef (-0.15, -0.15, solidZ);
    glMaterialfv(GL_FRONT, GL_EMISSION, mat_zero);
    glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_solid);
    glCallList (sphereList);
    glPopMatrix ();
    glPushMatrix ();
    glTranslatef (0.15, 0.15, transparentZ);
    glRotatef (15.0, 1.0, 1.0, 0.0);
    glRotatef (30.0, 0.0, 1.0, 0.0);
    glMaterialfv(GL_FRONT, GL_EMISSION, mat_emission);
    glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_transparent);
    glEnable (GL_BLEND);
    glDepthMask (GL_FALSE);
    glBlendFunc (GL_SRC_ALPHA, GL_ONE);
    glCallList (cubeList);
    glDepthMask (GL_TRUE);
    glDisable (GL_BLEND);
    glPopMatrix ();
    glutSwapBuffers();
    }
     
    void reshape(int w, int h)
    {
    glViewport(0, 0, (GLint) w, (GLint) h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if (w <= h)
       glOrtho (-1.5, 1.5, -1.5*(GLfloat)h/(GLfloat)w,1.5*(GLfloat)h/(GLfloat)w, -10.0, 10.0);
    else
    	glOrtho (-1.5*(GLfloat)w/(GLfloat)h,1.5*(GLfloat)w/(GLfloat)h, -1.5, 1.5, -10.0, 10.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    }
     
    void animate(void)
    {
    if (solidZ <= MINZ || transparentZ >= MAXZ)
    glutIdleFunc(NULL);
    else {
    solidZ -= ZINC;
    transparentZ += ZINC;
    glutPostRedisplay();
    }
    }
     
    void keyboard(unsigned char key, int x, int y)
    {
    switch (key) {
    case 'a':
    case 'A':
    solidZ = MAXZ;
    transparentZ = MINZ;
    glutIdleFunc(animate);
    break;
    case 'r':
    case 'R':
    solidZ = MAXZ;
    transparentZ = MINZ;
    glutPostRedisplay();
    break;
    case 27:
    exit(0);
    }
    }
     
    int main(int argc, char** argv)
    {
    glutInit(&argc, argv);
    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(500, 500);
    glutCreateWindow(argv[0]);
    init();
    glutReshapeFunc(reshape);
    glutKeyboardFunc(keyboard);
    glutDisplayFunc(display);
    glutMainLoop();
    return 0;
    }

  2. #2
    Newbie Newbie
    Join Date
    Jun 2013
    Posts
    1
    The same problem with you~~

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