// TRANGLE.cpp : 定义控制台应用程序的入口点。

//

#include "stdafx.h"

#include<GL\glut.h>

#include<math.h>

#define PI 3.14

GLfloat Range=100.0f ;

bool DEPTH_TEST=false;

bool CULL_FACE=false;

bool OUTLINE_BACK=false;

static GLfloat xRot=0.0f;

static GLfloat yRot=0.0f;

bool STOP_DEPTHTEST=false;

void Init()

{

    glClearColor(0.0f,0.0f,0.0f,1.0f);

    glFrontFace(GL_CW);

    //单调着色

    glShadeModel(GL_FLAT);

}

void ChangeSize(int w,int h)

{

    if (h==)

    {

        h=;

    }

    glViewport(,,w,h);

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    if (w<=h)

    {

        glOrtho(-Range,Range,-Range*h/w,Range*h/w,-Range,Range);

    }

    else

    {

        glOrtho(-Range*w/h,Range*w/h,-Range,Range,-Range,Range);

    }

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

}

void MyMenu(int value)

{

    switch (value)

    {

    case :

        DEPTH_TEST=!DEPTH_TEST;

        break;

    case :

        CULL_FACE=!CULL_FACE;

        break;

    case :

        OUTLINE_BACK=!OUTLINE_BACK;

        break;

    case :

        STOP_DEPTHTEST=true;

    default:

        break;

    }

}

void MyspecialKey(int key,int x,int y)

{

    if (key==GLUT_KEY_LEFT)

    {

        yRot-=5.0f;

    }

    if (key==GLUT_KEY_RIGHT)

    {

        yRot+=5.0f;

    }

    if (key==GLUT_KEY_UP)

    {

        xRot-=5.0f;

    }

    if (key==GLUT_KEY_DOWN)

    {

        xRot+=5.0f;

    }

    if (xRot>355.0f)

    {

        xRot=0.0f;

    }

    if (xRot<=-5.0f)

    {

        xRot=355.0f;

    }

    if (yRot>355.0f)

    {

        yRot=0.0f;

    }

    if (yRot<=-5.0f)

    {

        yRot=355.0f;

    }

    glutPostRedisplay();

}

void Mydisplay()

{

    GLint color=;

    GLfloat angle=0.0f;

    GLfloat x,y;

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    if (DEPTH_TEST)

    {

        glEnable(GL_DEPTH_TEST);

    }

    else

    {

        glDisable(GL_DEPTH_TEST);

    }

    if (CULL_FACE)

    {

        glEnable(GL_CULL_FACE);

        glCullFace(GL_BACK);

    }

    else

    {

        glDisable(GL_CULL_FACE);

    }

    if (STOP_DEPTHTEST)

    {

        glDisable(GL_DEPTH_TEST);

    }

    if (OUTLINE_BACK)

    {

        glPolygonMode(GL_BACK,GL_LINE);

    }

    else

    {

        glPolygonMode(GL_BACK,GL_FILL);

    }

    glPushMatrix();

    glRotatef(xRot,1.0f,0.0f,0.0f);

    glRotatef(yRot,0.0f,1.0f,0.0f);

    glBegin(GL_TRIANGLE_FAN);

    glVertex3f(0.0f,0.0f,75.0f);

    for (angle = ;angle<PI*; angle+=(PI/))

    {

        x=50.0f*cos(angle);

        y=50.0f*sin(angle);

        if ((color%)==)

        {

            glColor3f(0.0f,1.0f,0.0f);

        }

        else

        {

            glColor3f(1.0f,0.0f,0.0f);

        }

        color++;

        glVertex3f(x,y,0.0f);

    }

    glEnd();

    glBegin(GL_TRIANGLE_FAN);

    glVertex3f(0.0f,0.0f,0.0f);

    for (angle = ;angle<PI*; angle+=(PI/))

    {

        x=50.0f*cos(angle);

        y=50.0f*sin(angle);

        if ((color%)==)

        {

            glColor3f(0.0f,1.0f,0.0f);

        }

        else

        {

            glColor3f(1.0f,0.0f,0.0f);

        }

        color++;

        glVertex3f(x,y,0.0f);

    }

    glEnd();

    glPopMatrix();

    glutSwapBuffers();

}

int main(int argc,char ** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE|GLUT_DEPTH);

    glutInitWindowPosition(,);

    glutInitWindowSize(,);

    glutCreateWindow("Trangle");

    Init();

    glutDisplayFunc(Mydisplay);

    glutReshapeFunc(ChangeSize);

    glutCreateMenu(MyMenu);

    glutAddMenuEntry("Depth Test",);

    glutAddMenuEntry("CullFace",);

    glutAddMenuEntry("Outline Back",);

    glutAddMenuEntry("STOP DEPTHTEST",);

    glutAttachMenu(GLUT_RIGHT_BUTTON);

    glutSpecialFunc(MyspecialKey);

    glutMainLoop();

}