/*avance ejercicio reflejo*/
#include "stdafx.h"

/*
*  double.c
*  This program demonstrates double buffering for
*  flicker-free animation.  The left and middle mouse
*  buttons start and stop the spinning motion of the square.
*/

/* E. Angel, Interactive Computer Graphics */
/* A Top-Down Approach with OpenGL, Third Edition */
/* Addison-Wesley Longman, 2003 */

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

static GLfloat spin = 0.0;
int singleb, doubleb;

void displayd(void)
{
	glClear(GL_COLOR_BUFFER_BIT);

	glRectf(-25.0, -25.0, 25.0, 25.0);

	glutSwapBuffers();
}
#define GL_PI 3.14159

void displays(void)
{
	glClear(GL_COLOR_BUFFER_BIT);

	//glRectf(-25.0, -25.0, 25.0, 25.0);

	glBegin(GL_LINES); // All lines lie in the xy plane. 

	GLfloat z = 0.0f;

	for (GLfloat angle = 0.0f; angle <= GL_PI; angle += (GL_PI / 20.0f))
	{                     // Top half of the circle 
		GLfloat x = 25.0f*sin(angle), y = 25.0f*cos(angle);
		glVertex3f(x, y, z);                    // First endpoint of line 

												// Bottom half of the circle 
		x = 25.0f*sin(angle + GL_PI); y = 25.0f*cos(angle + GL_PI);
		glVertex3f(x, y, z);                  // Second endpoint of line 
	}                        // Done drawing points 

	glEnd();


	glFlush();
}

void spinDisplay(void)
{
	spin = spin + .02;
	if (spin > 360.0)
		spin = spin - 360.0;
	glutSetWindow(singleb);
	glLoadIdentity();
	glRotatef(spin, 0.0, 0.0, 1.0);
	glutPostRedisplay();
	glutSetWindow(doubleb);
	glLoadIdentity();
	glRotatef(spin, 0.0, 0.0, 1.0);
	glutPostRedisplay();
}

void myinit(void)
{
	glClearColor(0.0, 0.0, 0.0, 1.0);
	glColor3f(1.0, 1.0, 1.0);
	glShadeModel(GL_FLAT);
	glLineStipple(1., 0x00FF);
	glEnable(GL_LINE_STIPPLE);
}

void mouse(int btn, int state, int x, int y)
{
	if (btn == GLUT_LEFT_BUTTON && state == GLUT_DOWN)  glutIdleFunc(spinDisplay);
	if (btn == GLUT_MIDDLE_BUTTON && state == GLUT_DOWN)   glutIdleFunc(NULL);
}

void myReshape(int w, int h)
{
	glViewport(0, 0, w, h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	if (w <= h)
		glOrtho(-50.0, 50.0, -50.0*(GLfloat)h / (GLfloat)w,
			50.0*(GLfloat)h / (GLfloat)w, -1.0, 1.0);
	else
		glOrtho(-50.0*(GLfloat)w / (GLfloat)h,
			50.0*(GLfloat)w / (GLfloat)h, -50.0, 50.0, -1.0, 1.0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}

/*  Main Loop
*  Open window with initial window size, title bar,
*  RGBA display mode, and handle input events.
*/
int main(int argc, char** argv)
{

	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	singleb = glutCreateWindow("single buffered");
	myinit();
	glutDisplayFunc(displays);
	glutReshapeFunc(myReshape);
	glutIdleFunc(spinDisplay);
	glutMouseFunc(mouse);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
	doubleb = glutCreateWindow("double buffered");
	myinit();
	glutDisplayFunc(displayd);
	glutReshapeFunc(myReshape);
	glutIdleFunc(spinDisplay);
	glutMouseFunc(mouse);

	glutMainLoop();

}