/* This program displays a funky curve through the unit cube.  This
   program aims to be as simple as possible.

Scott D. Anderson
Fall 2003
*/

#include <tw.h>

void draw_bezier_curve(GLfloat* cp) {
    int steps = 16;
    // glMap1f(target, u_min, u_max, stride, order, point_array);
    glMap1f(GL_MAP1_VERTEX_3, 0, 1, 3, 4, cp);
    glEnable(GL_MAP1_VERTEX_3);
    glMapGrid1f(steps,0.0,1.0);
    glEvalMesh1(GL_LINE,0,steps);
}

void draw_funky_curve() {
    GLfloat curveCP[] = {-1,-1,-1,
                         +0.7,-1,-1,
                         1,-0.7,1,
                         1,1,1};
    const int stride=3;

    glPushAttrib(GL_ALL_ATTRIB_BITS);
    glPointSize(5);
    twColorName(TW_CYAN);
    glBegin(GL_POINTS);
    for(int i=0; i<4*stride; i+=stride) 
        glVertex3f(curveCP[i],curveCP[i+1],curveCP[i+2]);
    glEnd();
    glLineWidth(3);
    twColorName(TW_YELLOW);
    draw_bezier_curve(curveCP);
    glPopAttrib();
}

void display(void) {
    twDisplayInit();
    twCamera();

    draw_funky_curve();

    glFlush();
    glutSwapBuffers();
}

int main(int argc, char** argv) {
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(500,500);
    glutCreateWindow(argv[0]);
    glutDisplayFunc(display);
    twBoundingBox(-1,1,-1,1,-1,1);
    twMainInit();
    glutMainLoop();
}