Added another similar variant for Question7

Answer7aliter.cpp

@@ -0,0 +1,149 @@
+#include <GL/glut.h>
+
+float ver_angle = 90, rotangle=-90;
+float theta=90.001;
+int click=0;
+
+float rate=0.05;
+void display(void) {
+    double base,height;
+    int slicesCols,ringsRows;
+    base = 0.7;
+    height = 1;
+    slicesCols = 30;
+    ringsRows = 50;
+
+
+    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
+    glClearColor(0.4f,0.4f,0.4f,1.0f);
+
+
+
+    glEnable(GL_DEPTH_TEST);
+
+    glColor3f(1.0f,.7f,0.0f);
+
+    glLoadIdentity();
+
+    gluLookAt(5.0f, 3.0f, 3.0f,
+              4.0f, 1.5f, 0.0f,
+              0.0f, 1.0f, 0.0f);
+    glTranslatef(0.0, 0, -12);
+
+    glLineWidth(3.0f);
+    glColor3f(0.0, 1.0, 1.0);
+    glBegin(GL_LINES);
+
+        glVertex3f(0.0f,0.0f, -3.0f);
+        glVertex3f(0.0f, 0.0f, 7.0f);
+
+        glVertex3f(0.0f,0.0f, -3.0f);
+        glVertex3f(2.5f, -4.0f, -3.0f);
+
+        glVertex3f(0.0f,0.0f, 7.0f);
+        glVertex3f(2.5f, -4.0f, 7.0f);
+
+        glVertex3f(0.0f,0.0f, -3.0f);
+        glVertex3f(-2.5f, -4.0f, -3.0f);
+
+        glVertex3f(0.0f,0.0f, 7.0f);
+        glVertex3f(-2.5f, -4.0f, 7.0f);
+
+
+    glEnd();
+
+    glRotatef(rotangle, 0.0, 0.0, 1.0);
+
+    glColor3f(0.0, 1.0, 1.0);
+    glBegin(GL_LINES);
+
+    glVertex3f(0.0f, -2.5f, 2.0f);
+    glVertex3f(0.0f, 0.0f, 2.0f);
+
+    glVertex3f(0.0f, -2.5f, -2.0f);
+    glVertex3f(0.0f, 0.0f, -2.0f);
+
+
+
+    glVertex3f(-1.0f, -3.5f, 2.0f);
+    glVertex3f(0.0f, -2.5f, 2.0f);
+
+    glVertex3f(-1.0f, -3.5f, -2.0f);
+    glVertex3f(0.0f, -2.5f, -2.0f);
+
+    glVertex3f(1.0f, -3.5f, -2.0f);
+    glVertex3f(0.0f, -2.5f, -2.0f);
+
+    glVertex3f(1.0f, -3.5f, 2.0f);
+    glVertex3f(0.0f, -2.5f, 2.0f);
+
+    glEnd();
+
+    glColor3f( 1, 0, 0 );
+    glBegin(GL_POLYGON);
+
+    glVertex3f(-1.0,-3.5,2);
+    glVertex3f( 1.0,-3.5 ,2);
+    glVertex3f( 1.0, -3.5 ,-2);
+    glVertex3f(-1.0,-3.5 ,-2);
+
+    glEnd();
+
+
+    glutSwapBuffers();
+}
+
+void reshape(int x, int y)
+{
+    glViewport(0, 0, (GLsizei)x,(GLsizei)y);
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    gluPerspective(60, x/(double)y, 2, 20.0);
+    glMatrixMode(GL_MODELVIEW);
+}
+void idle(void)
+{
+    if(click){
+
+        theta-=0.005;
+        rotangle+=rate;
+        if(rotangle>=theta)
+            rate=-rate;
+
+        if(rotangle<=-theta)
+            rate=-rate;
+
+        if(theta<=2)
+            rate=0;
+    }
+    display();
+}
+void timer(int){
+    glutPostRedisplay();
+    glutTimerFunc(1000/60,timer,0);
+}
+void mouse(int btn, int state, int x, int y) {  
+    if(btn==GLUT_LEFT_BUTTON && state == GLUT_DOWN) {  
+        click=1;
+    }
+}
+int main(int argc, char *argv[]) {
+    glutInit(&argc, argv);
+    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);
+
+    glutInitWindowSize(1000, 750);
+    glutInitWindowPosition(100, 100);
+    glutCreateWindow("SWING");
+
+    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+
+    glutDisplayFunc(display);
+    glutIdleFunc(idle);
+
+    glutReshapeFunc(reshape);
+    glutTimerFunc(0,timer,0);
+    glutMouseFunc(mouse);
+    glutMainLoop();
+    return 0;
+}
+