Thread: OpenGL Stipple

I'm trying to stipple the red part of this tetrahedron with "fly" but the stipple doesn't show up. What am I missing?

Code:

#include <stdlib.h>
#include <GL/glut.h>

/* initial tetrahedron */

GLfloat v[4][3]={{0.0, 0.0, 1.0}, {0.0, 0.942809, -0.33333},
      {-0.816497, -0.471405, -0.333333}, {0.816497, -0.471405, -0.333333}};

GLfloat colors[4][3] = {{1.0, 0.0, 0.0}, {0.0, 1.0, 0.0},
                        {0.0, 0.0, 1.0}, {0.0, 0.0, 0.0}};

int n;

void triangle(GLfloat *va, GLfloat *vb, GLfloat *vc)
{
	   glVertex3fv(va);
       glVertex3fv(vb);
       glVertex3fv(vc);
}

void tetra(GLfloat *a, GLfloat *b, GLfloat *c, GLfloat *d)
{
		GLubyte fly[] = {
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x03, 0x80, 0x01, 0xC0, 0x06, 0xC0, 0x03, 0x60, 
      0x04, 0x60, 0x06, 0x20, 0x04, 0x30, 0x0C, 0x20, 
      0x04, 0x18, 0x18, 0x20, 0x04, 0x0C, 0x30, 0x20,
      0x04, 0x06, 0x60, 0x20, 0x44, 0x03, 0xC0, 0x22, 
      0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22, 
      0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22,
      0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22, 
      0x66, 0x01, 0x80, 0x66, 0x33, 0x01, 0x80, 0xCC, 
      0x19, 0x81, 0x81, 0x98, 0x0C, 0xC1, 0x83, 0x30,
      0x07, 0xe1, 0x87, 0xe0, 0x03, 0x3f, 0xfc, 0xc0, 
      0x03, 0x31, 0x8c, 0xc0, 0x03, 0x33, 0xcc, 0xc0, 
      0x10, 0x63, 0xC6, 0x08, 0x10, 0x30, 0x0c, 0x08, 
      0x10, 0x18, 0x18, 0x08, 0x10, 0x00, 0x00, 0x08};

	glClear (GL_COLOR_BUFFER_BIT);
	
    glColor3fv(colors[0]);
	
	glEnable (GL_POLYGON_STIPPLE);
	glPolygonStipple (fly);	
    triangle(a, b, c);
	
	glDisable (GL_POLYGON_STIPPLE);
    
	glColor3fv(colors[1]);
    triangle(a, c, d);
    
	glColor3fv(colors[2]);
    triangle(a, d, b);
    
	glColor3fv(colors[3]);
    triangle(b, d, c);
}
void mouse(int btn, int state, int x, int y)
{
    if(btn==GLUT_RIGHT_BUTTON && state==GLUT_DOWN)   exit(0);
}
void divide_tetra(GLfloat *a, GLfloat *b, GLfloat *c, GLfloat *d, int m)
{

	tetra(a,b,c,d);
}


void display()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glBegin(GL_TRIANGLES);
    divide_tetra(v[0], v[1], v[2], v[3], n);
    glEnd();
    glFlush();
}


void myReshape(int w, int h)
{
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if (w <= h)
        glOrtho(-2.0, 2.0, -2.0 * (GLfloat) h / (GLfloat) w,
            2.0 * (GLfloat) h / (GLfloat) w, -10.0, 10.0);
    else
        glOrtho(-2.0 * (GLfloat) w / (GLfloat) h,
            2.0 * (GLfloat) w / (GLfloat) h, -2.0, 2.0, -10.0, 10.0);
    glMatrixMode(GL_MODELVIEW);
    glutPostRedisplay();
}
void init (void) 
{
   glClearColor (0.0, 0.0, 0.0, 0.0);
   glShadeModel (GL_FLAT);    
}


void main(int argc, char **argv)
{

    n=4; /* or enter number of subdivision steps here */
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(800, 600);
    glutCreateWindow("3D TetraHedron");
	init ();
    glutReshapeFunc(myReshape);
	glutMouseFunc (mouse);
    glutDisplayFunc(display);
    glEnable(GL_DEPTH_TEST);
    glClearColor (1.0, 1.0, 1.0, 1.0);
    glutMainLoop();
}

Thanks
Rogue

No replies?
Surely someone knows whats going on?

Code:

#include <stdlib.h>
#include <GL/glut.h>

/* initial tetrahedron */

GLfloat v[4][3]={{0.0, 0.0, 1.0}, {0.0, 0.942809, -0.33333},
      {-0.816497, -0.471405, -0.333333}, {0.816497, -0.471405, -0.333333}};

GLfloat colors[4][3] = {{1.0, 0.0, 0.0}, {0.0, 1.0, 0.0},
                        {0.0, 0.0, 1.0}, {0.0, 0.0, 0.0}};

int n;

	GLubyte fly[] = {								//fly stipple pattern
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x03, 0x80, 0x01, 0xC0, 0x06, 0xC0, 0x03, 0x60, 
      0x04, 0x60, 0x06, 0x20, 0x04, 0x30, 0x0C, 0x20, 
      0x04, 0x18, 0x18, 0x20, 0x04, 0x0C, 0x30, 0x20,
      0x04, 0x06, 0x60, 0x20, 0x44, 0x03, 0xC0, 0x22, 
      0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22, 
      0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22,
      0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22, 
      0x66, 0x01, 0x80, 0x66, 0x33, 0x01, 0x80, 0xCC, 
      0x19, 0x81, 0x81, 0x98, 0x0C, 0xC1, 0x83, 0x30,
      0x07, 0xe1, 0x87, 0xe0, 0x03, 0x3f, 0xfc, 0xc0, 
      0x03, 0x31, 0x8c, 0xc0, 0x03, 0x33, 0xcc, 0xc0, 
      0x10, 0x63, 0xC6, 0x08, 0x10, 0x30, 0x0c, 0x08, 
      0x10, 0x18, 0x18, 0x08, 0x10, 0x00, 0x00, 0x08};


void triangle(GLfloat *va, GLfloat *vb, GLfloat *vc)
{
       glVertex3fv(va);
       glVertex3fv(vb);
       glVertex3fv(vc);
}

void tetra(GLfloat *a, GLfloat *b, GLfloat *c, GLfloat *d)
{

	glColor3fv(colors[0]);//sets color to red
    glEnable (GL_POLYGON_STIPPLE);//sets to enable polygon stipple
	glPolygonStipple (fly);//sets the polygon stipple to fly[]

	glBegin(GL_POLYGON);//starts the polygon draw, has to be polygon so polygon stipple will work

	glVertex2fv(v[0]);
	glVertex2fv(v[1]);
	glVertex2fv(v[2]);

	glEnd();//ends polygon
	glDisable (GL_POLYGON_STIPPLE);//ends the stipple

	glBegin(GL_TRIANGLES);//starts triangles

	glColor3fv(colors[1]);
    triangle(a, c, d);
    glColor3fv(colors[2]);
    triangle(a, d, b);
    glColor3fv(colors[3]);
    triangle(b, d, c);

	glEnd();
	
}

void divide_tetra(GLfloat *a, GLfloat *b, GLfloat *c, GLfloat *d, int m)
{

    //GLfloat mid[6][3];
    
    tetra(a,b,c,d); //calls the tetra draw function
}

void mouse(int btn, int state, int x, int y)//function that exits upon right mouse button in down state
{
    if(btn==GLUT_RIGHT_BUTTON && state==GLUT_DOWN)   exit(0);
}


void display()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    
    divide_tetra(v[0], v[1], v[2], v[3], n);
    
    glFlush();
}


void myReshape(int w, int h)
{
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if (w <= h)
        glOrtho(-2.0, 2.0, -2.0 * (GLfloat) h / (GLfloat) w,
            2.0 * (GLfloat) h / (GLfloat) w, -10.0, 10.0);
    else
        glOrtho(-2.0 * (GLfloat) w / (GLfloat) h,
            2.0 * (GLfloat) w / (GLfloat) h, -2.0, 2.0, -10.0, 10.0);
    glMatrixMode(GL_MODELVIEW);
    glutPostRedisplay();
}


void main(int argc, char **argv)
{
    n=4; /* or enter number of subdivision steps here */
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(500, 500);
    glutCreateWindow("Attack of the fly Tetrahedron!!");
    glutReshapeFunc(myReshape);
	glutMouseFunc (mouse);//This function calls mouse which closes upon clicking right mouse button
    glutDisplayFunc(display);
    glEnable(GL_DEPTH_TEST);
    glClearColor (1.0, 1.0, 1.0, 1.0);
    glutMainLoop();
}

You don't need to post the code twice. Bumping is frowned on. Please try posting in the gamedevelopment forum.

Same code alright - just some things in it are redone. Possibly for speed.