OPENGL 观察者漫游程序

最新推荐文章于 2024-02-04 17:44:42 发布

转载最新推荐文章于 2024-02-04 17:44:42 发布 · 631 阅读

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#colors #button #buffer #include #360 #c

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本文介绍了一个使用OpenGL和GLUT库实现的彩色立方体绘制程序。该程序通过定义顶点坐标和颜色来绘制一个由六个不同颜色面组成的立方体，并允许用户通过鼠标旋转立方体和键盘调整观察者位置。

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

GLfloat vertices[][3]={{-1.0,-1.0,-1.0},{1.0,-1.0,-1.0},{1.0,1.0,-1.0},{-1.0,1.0,-1.0},
{-1.0,-1.0,1.0},{1.0,-1.0,1.0},{1.0,1.0,1.0},{-1.0,1.0,1.0}};

GLfloat colors[][3]={{0.0,0.0,0.0},{1.0,0.0,0.0},{1.0,1.0,0.0},{0.0,1.0,0.0},
{0.0,0.0,1.0},{1.0,0.0,1.0},{1.0,1.0,1.0},{0.0,1.0,1.0}};

void polygon(int a,int b,int c,int d)
{
glBegin(GL_POLYGON);
glColor3fv(colors[a]);
glVertex3fv(vertices[a]);
glVertex3fv(vertices[b]);
glVertex3fv(vertices[c]);
glVertex3fv(vertices[d]);
glEnd();
}

void colorcube()
{
polygon(0,3,2,1);
polygon(2,3,7,6);
polygon(0,4,7,3);
polygon(1,2,6,5);
polygon(4,5,6,7);
polygon(0,1,5,4);
}

static GLfloat theta[]={0.0,0.0,0.0};
static GLint axis=2;
static GLdouble viewer[]={0.0,0.0,5.0};

void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
gluLookAt(viewer[0],viewer[1],viewer[2],0.0,0.0,0.0,0.0,1.0,0.0);

glRotatef(theta[0],1.0,0.0,0.0);
glRotatef(theta[1],0.0,1.0,0.0);
glRotatef(theta[2],0.0,0.0,1.0);
colorcube();

glFlush();
glutSwapBuffers();
}

void mouse(int btn, int state, int x, int y)
{
if (btn==GLUT_LEFT_BUTTON&&state==GLUT_DOWN) axis=0;
if(btn==GLUT_MIDDLE_BUTTON && state== GLUT_DOWN) axis=1;
if(btn==GLUT_RIGHT_BUTTON && state==GLUT_DOWN) axis=2;
theta[axis] +=2.0;
if (theta[axis]>360.0) theta[axis]-=360.0;
display();
}

void keys(unsigned char key,int x, int y)
{
if(key=='x') viewer[0]-=1.0;
if(key=='X') viewer[0]+=1.0;
if(key=='y') viewer[1]-=1.0;
if(key=='Y') viewer[1]+=1.0;
if(key=='z') viewer[2]-=1.0;
if(key=='Z') viewer[2]+=1.0;
display();
}

void myReshape(int w,int h)
{
glViewport(0,0,w,h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if(w<=h)
glFrustum(-2.0,2.0,-2.0*(GLfloat) h/(GLfloat) w,2.0*(GLfloat) h/(GLfloat) w,2.0,20.0);
else
glFrustum(-2.0,2.0,-2.0*(GLfloat) w/(GLfloat) h,2.0*(GLfloat) w/(GLfloat) h,2.0,20.0);

glMatrixMode(GL_MODELVIEW);
}

void main(int argc ,char **argv)
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_DOUBLE |GLUT_RGB |GLUT_DEPTH);
glutInitWindowSize(500,500);
glutCreateWindow("colorcube");
glutReshapeFunc(myReshape);
glutDisplayFunc(display);
glutMouseFunc(mouse);
glutKeyboardFunc(keys);
glEnable(GL_DEPTH_TEST);
glutMainLoop();
}