// OPEN_GL_test.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
static float rotAngle = 0.;
/* Initialize antialiasing for RGBA mode, including alpha
* blending, hint, and line width. Print out implementation
* specific info on line width granularity and width.
*/
void init(void)
{
GLfloat values[2];
glGetFloatv (GL_LINE_WIDTH_GRANULARITY, values);
printf ("GL_LINE_WIDTH_GRANULARITY value is %3.1f\n",
values[0]);
glGetFloatv (GL_LINE_WIDTH_RANGE, values);
printf ("GL_LINE_WIDTH_RANGE values are %3.1f %3.1f\n",
values[0], values[1]);
glEnable (GL_LINE_SMOOTH);
glEnable (GL_BLEND);
glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE);
glLineWidth (1.5);
glClearColor(0.0, 0.0, 0.0, 0.0);
}
/* Draw 2 diagonal lines to form an X */
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glColor3f (0.0, 1.0, 0.0);
glPushMatrix();
glRotatef(-rotAngle, 0.0, 0.0, 0.1);
glBegin (GL_LINES);
glVertex2f (-0.5, 0.5);
glVertex2f (0.5, -0.5);
glEnd ();
glPopMatrix();
glColor3f (0.0, 0.0, 1.0);
glPushMatrix();
glRotatef(rotAngle, 0.0, 0.0, 0.1);
glBegin (GL_LINES);
glVertex2f (0.5, 0.5);

glVertex2f (-0.5, -0.5);
glEnd ();
glPopMatrix();
glFlush();
}
void reshape(int w, int h)
{
glViewport(0, 0, (GLint) w, (GLint) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w <= h)
gluOrtho2D (-1.0, 1.0,
-1.0*(GLfloat)h/(GLfloat)w, 1.0*(GLfloat)h/(GLfloat)w);
else
gluOrtho2D (-1.0*(GLfloat)w/(GLfloat)h,
1.0*(GLfloat)w/(GLfloat)h, -1.0, 1.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void keyboard(unsigned char key, int x, int y)
{
switch (key) {
case 'r':
case 'R':
rotAngle += 20.;
if (rotAngle >= 360.) rotAngle = 0.;
glutPostRedisplay();
break;
case 27: /* Escape Key */
exit(0);
break;
default:
break;
}
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize (200, 200);
glutCreateWindow (argv[0]);
init();
glutReshapeFunc (reshape);
glutKeyboardFunc (keyboard);
glutDisplayFunc (display);
glutMainLoop();
return 0;
}

//
//#include <GL/gl.h>
//#include <GL/glu.h>
//#include <GL/glut.h>
//#include <stdlib.h>
//#define RAMPSIZE 16
//#define RAMP1START 32
//#define RAMP2START 48
//static float rotAngle = 0.;
///* Initialize antialiasing for color-index mode,
//* including loading a green color ramp starting
//* at RAMP1START, and a blue color ramp starting
//* at RAMP2START. The ramps must be a multiple of 16.
//*/
//void init(void)
//{
//int i;
//for (i = 0; i < RAMPSIZE; i++) {
//GLfloat shade;
//shade = (GLfloat) i/(GLfloat) RAMPSIZE;
//glutSetColor(RAMP1START+(GLint)i, 0., shade, 0.);
//glutSetColor(RAMP2START+(GLint)i, 0., 0., shade);
//}
//glEnable (GL_LINE_SMOOTH);
//glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE);
//glLineWidth (1.5);
//glClearIndex ((GLfloat) RAMP1START);
//}
///* Draw 2 diagonal lines to form an X */
//void display(void)
//{
//glClear(GL_COLOR_BUFFER_BIT);
//glIndexi(RAMP1START);
//glPushMatrix();
//glRotatef(-rotAngle, 0.0, 0.0, 0.1);
//glBegin (GL_LINES);
//glVertex2f (-0.5, 0.5);
//glVertex2f (0.5, -0.5);
//glEnd ();
//glPopMatrix();
//glIndexi(RAMP2START);
//glPushMatrix();
//glRotatef(rotAngle, 0.0, 0.0, 0.1);
//glBegin (GL_LINES);
//glVertex2f (0.5, 0.5);
//glVertex2f (-0.5, -0.5);
//glEnd ();
//glPopMatrix();
//glFlush();
//}
//void reshape(int w, int h)
//{
//glViewport(0, 0, (GLsizei) w, (GLsizei) h);
//glMatrixMode(GL_PROJECTION);
//glLoadIdentity();
//if (w <= h)
//gluOrtho2D (-1.0, 1.0,
//-1.0*(GLfloat)h/(GLfloat)w, 1.0*(GLfloat)h/(GLfloat)w);
//else
//gluOrtho2D (-1.0*(GLfloat)w/(GLfloat)h,
//1.0*(GLfloat)w/(GLfloat)h, -1.0, 1.0);
//glMatrixMode(GL_MODELVIEW);
//glLoadIdentity();
//}
//void keyboard(unsigned char key, int x, int y)
//{
//switch (key) {
//case `r':
//case `R':
//rotAngle += 20.;
//if (rotAngle >= 360.) rotAngle = 0.;
//glutPostRedisplay();
//break;
//case 27: /* Escape Key */
//exit(0);
//break;
//default:
//break;
//}
//}
//int main(int argc, char** argv)
//{
//glutInit(&argc, argv);
//glutInitDisplayMode (GLUT_SINGLE | GLUT_INDEX);
//glutInitWindowSize (200, 200);
//glutCreateWindow (argv[0]);
//init();
//glutReshapeFunc (reshape);
//glutKeyboardFunc (keyboard);
//glutDisplayFunc (display);
//glutMainLoop();
//return 0;
//}