#include "stdafx.h"
#include "GL/glut.h"
#include "stdlib.h"
#include "stdio.h"
#include "math.h"
static int big = 0;
static bool isLeftEye = false;
#define PI 3.1415926
const GLfloat R = 8.0;
static GLfloat leftMatrix[16] = {1.0, 0.0, 0.0, 0.0,
0.0, 1.0, 0.0, 0.0,
0.0, 0.0, 1.0,  0.0,
0.0, 0.0, 0.0, 1.0};
static GLfloat rightMatrix[16] = {1.0, 0.0, 0.0, 0.0,
0.0, 1.0, 0.0, 0.0,
0.0, 0.0, 1.0, 0.0,
0.0, 0.0, 0.0, 1.0};
static GLfloat leftPersMatrix[16] = {1.0, 0.0, 0.0, 0.0,
0.0, 1.0, 0.0, 0.0,
0.0, 0.0, 1.0, 0.0,
0.0, 0.0, 0.0, 1.0};
static GLfloat rightPersMatrix[16] = {1.0, 0.0, 0.0, 0.0,
0.0, 1.0, 0.0, 0.0,
0.0, 0.0, 1.0, 0.0,
0.0, 0.0, 0.0, 1.0};
void init(void)
{ 
 const GLfloat SD = 0.06;
 GLfloat n = SD*R/2.0;
 //要是轉秩
 //n=0;
 leftMatrix[12] = n;
 rightMatrix[12] = -n;
 //這里假設眼到屏幕為一米，以米為單位
 GLfloat p = SD/(2*1*tan(PI/6)*1);
 //p = 0.0;
 leftPersMatrix[12] = -p;
 rightPersMatrix[12] = p;
 GLfloat mat_specular[] = {0.8, 0.8, 0.0, 1.0};
 GLfloat mat_shininess[] = {50.0};
 GLfloat light_position[] = {1.0, 1.0, 1.0, 0.0};
 GLfloat white_light[] = {1.0, 1.0, 1.0, 1.0};
 GLfloat yellow_light[] = {1.0, 1.0, 0.0, 1.0};
 GLfloat lmodel_ambient[] = {0.0, 0.7, 0.5, 1.0};
 glClearColor(1.0, 1.0, 1.0, 0.0);
 glShadeModel(GL_SMOOTH);
 glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
 glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
 glLightfv(GL_LIGHT0, GL_POSITION, light_position);
 glLightfv(GL_LIGHT0, GL_DIFFUSE, yellow_light);//主體的顏色
 glLightfv(GL_LIGHT0, GL_SPECULAR, white_light);//高光的顏色
 glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
 glEnable(GL_LIGHTING);
 glEnable(GL_LIGHT0);
 glEnable(GL_DEPTH_TEST);
}
void display(void)
{
 glColorMask(1.0, 1.0,1.0,1.0);
 glClearColor(0.0,0.0,0.0,1.0);
 glClearDepth(1.0);
 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 glColor3f(1.0, 1.0, 1.0);
 // 畫左眼
 glMatrixMode(GL_PROJECTION);
 glPushMatrix();
 float mat[16];
 glGetFloatv(GL_PROJECTION_MATRIX,mat);
 glLoadIdentity();
 glMultMatrixf(leftPersMatrix);
 glMultMatrixf(mat);
 glMatrixMode(GL_MODELVIEW);
 glPushMatrix();
 glGetFloatv(GL_MODELVIEW_MATRIX,mat);
 glLoadIdentity();
 glMultMatrixf(leftMatrix);
 glMultMatrixf(mat);
 glColorMask(1.0, 0.0,0.0,1.0);
 glRotatef((GLfloat) big, 0.0, 1.0, 0.0);
 glutSolidTeapot(2.0);
 glPopMatrix();
 glMatrixMode(GL_PROJECTION);
 glPopMatrix();
 glFlush();
 //畫右眼
 glClearDepth(1.0);
 glClear(GL_DEPTH_BUFFER_BIT);
 glMatrixMode(GL_PROJECTION);
 glPushMatrix();
 glGetFloatv(GL_PROJECTION_MATRIX,mat);
 glLoadIdentity();
 glMultMatrixf(rightPersMatrix);
 glMultMatrixf(mat);
 glMatrixMode(GL_MODELVIEW);
 glPushMatrix();
 glGetFloatv(GL_MODELVIEW_MATRIX,mat);
 glLoadIdentity();
 glMultMatrixf(rightMatrix);
 glMultMatrixf(mat);
 glColorMask(0.0, 1.0,1.0,1.0);
 glRotatef((GLfloat) big, 0.0, 1.0, 0.0);
 glutSolidTeapot(2.0);
 glPopMatrix();
 glMatrixMode(GL_PROJECTION);
 glPopMatrix();
 glFlush();
 //glPopMatrix();
 //if(isLeftEye)
 //{ 
 // glMatrixMode(GL_PROJECTION);
 // glMultMatrixf(leftPersMatrix);
 // glMatrixMode(GL_MODELVIEW);
 // glMultMatrixf(leftMatrix);
 // glColorMask(1.0, 0.0,0.0,1.0);
 // 
 // 
 // 
 // isLeftEye = false;
 //}else
 //{ 
 // 
 // glMatrixMode(GL_PROJECTION);
 // glMultMatrixf(rightPersMatrix);
 // glMatrixMode(GL_MODELVIEW);
 // glMultMatrixf(rightMatrix);
 // glColorMask(0.0, 1.0,1.0,1.0); 
 // isLeftEye = true;
 //}
 //glRotatef((GLfloat) big, 0.0, 1.0, 0.0);
 //glutSolidTeapot(1.0);
 //glRotatef((GLfloat) big, 0.0, 1.0, 0.0);
 //glTranslatef(3.0, 0.0, 0.0);
 //glutSolidTeapot(0.5);
 glutSwapBuffers();
}
void reshape(int w, int h)
{
 glViewport(0, 0, (GLsizei) w, (GLsizei) h);
 glMatrixMode(GL_PROJECTION);
 glLoadIdentity();
 gluPerspective(60, (GLfloat)w/(GLfloat)h, 0.01, 20.0);
 glMatrixMode(GL_MODELVIEW);
 glLoadIdentity();
 gluLookAt(0.0, 0.0, R, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0 );
}
void keyboard(unsigned char key, int x, int y)
{
 switch (key)
 {
 case 'b':
  big = (big + 1) % 360;
  glutPostRedisplay();
  break;
 case 'B':
  big = (big - 1) % 360;
  glutPostRedisplay();
  break;
 case 27:    // 按ESC鍵時退出程序
  exit (0);
  break;
 default:
  break;
 }
}
void spinDisplay(void)
{
 big = (big + 1) % 360;
 glutPostRedisplay();
}
int main (int argc, char** argv)
{
 glutInit(&argc, argv);
 glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
 glutInitWindowSize(500, 500);
 glutInitWindowPosition(100, 100);
 glutCreateWindow(argv[0]);
 init();
 glutDisplayFunc(display);
 glutReshapeFunc(reshape);
 glutKeyboardFunc(keyboard);
 glutIdleFunc(spinDisplay);
 glutMainLoop();
 return 0;
}