Answer8.cpp

#include<GL/glut.h>
#include<stdio.h>
#include<stdlib.h>
#define MAX_CPTS  25
#define PI 3.14


GLfloat cpts[MAX_CPTS][3];
int ncpts = 0;
static int width = 500, height = 500;
float l, b;
int maxWidth, maxHeight;
int count = 0;

float scale = 1;

void addPoint(float l, float b) {

    cpts[ncpts][0] = (l * scale)/maxHeight;
    cpts[ncpts][1] = (b*scale)/maxWidth;
    cpts[ncpts][2] = 0.0;
    ncpts++;
}

void addIntitialPoints() {
    addPoint(0, 0);
    addPoint(b + b/2, l/4);
    addPoint(b + b/2, 3*(l/4));
    addPoint(0, l);
}
void drawCurves()
{
    int i;
    for(i=0; i<ncpts-3; i +=3)
    {
        /* draw the curve using OpenGL evaluators */

        glMap1f(GL_MAP1_VERTEX_3, 0.0, 1.0, 3, 4, cpts[i]);
        glMapGrid1f(30, 0.0, 1.0);
        glEvalMesh1(GL_LINE, 0, 30);
    }
    glFlush();
}


void drawPetal() {
    glPushMatrix();
        glScalef(-1, 1, 1);
        drawCurves();
    glPopMatrix();
    drawCurves();
}

float getRadians(float degree) {
    return (degree * PI)/180;
}

void drawPetalAtAngele(float angle) {
    //float angle = getRadians(degree);
    glPushMatrix();
        glRotatef(angle, 0, 0, 1);
        drawPetal();
    glPopMatrix();
}


void drawFlower(int n) {
    int angle = 0;
    int delta_angle = (360.0)/n;

    for(int i = 0; i < n; i++) {
        drawPetalAtAngele(angle + i * delta_angle);
    }
}


void display()
{
    int i;
    glClear(GL_COLOR_BUFFER_BIT);


    glBegin(GL_POINTS);
    for (i = 0; i < ncpts; i++)
        glVertex3fv(cpts[i]);
    glEnd();


    drawFlower(6);


    glFlush();
}

void reshape(int w, int h)
{
    width = w;
    height = h;

    maxWidth = w > h ? w : h;
    maxHeight = maxWidth;

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
    glMatrixMode(GL_MODELVIEW);
    glViewport(0, 0, w, h);

    ncpts = 0;
    addIntitialPoints();
    glutPostRedisplay();
}



void addReflection() {

}
void keyboard(unsigned char key, int x, int y)
{
    switch (key)
    {
        case 'q': case 'Q':
            exit(0);
            break;
        case 'c': case 'C':
            ncpts = 0;
            glutPostRedisplay();
            break;
        case 'r': case 'R':
            addIntitialPoints();
            addReflection();
            glutPostRedisplay();
            break;
        case 'd': case 'D':
            drawCurves();
            break;
        case 'i': case 'I':
            scale = scale * 2;
            ncpts = 0;
            addIntitialPoints();
            addReflection();
            glutPostRedisplay();
            drawCurves();
            break;

        case 'o': case 'O':
            scale = scale / 2;
            ncpts = 0;
            addIntitialPoints();
            addReflection();
            glutPostRedisplay();
            drawCurves();
            break;
    }
}

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

    printf("Enter the value of L and B");
    scanf("%f %f", &l, &b);

    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB);
    glutInitWindowSize(width, height);
    glutCreateWindow("curves");
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutKeyboardFunc(keyboard);
    glClearColor(1.0, 1.0, 1.0, 1.0);
    glColor3f(0.0, 0.0, 0.0);
    glPointSize(5.0);
    glEnable(GL_MAP1_VERTEX_3);
    glutMainLoop();
}