ing.c

平面阴影技术。主要包括向量运算

#include<gl/glut.h>
#include <math.h>
float u=0;

#pragma comment( linker, "/subsystem:windows /entry:mainCRTStartup" )
float m[16]={10,0,0,0,
-10,0,-10,0,
0,0,10,0,
0,0,0,10};

void init(void)
{
	glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);
	glEnable(GL_DEPTH_TEST);
	glShadeModel(GL_SMOOTH);
	glEnable(GL_CULL_FACE);
	glCullFace(GL_BACK);
	glClearColor(0.2,0.2,0.7,1.0);

}

void render()
{
	glPushMatrix();
	  glTranslatef(-1.5,3.0,-3.0);
	  glutSolidSphere(1.0,16,20);
	glPopMatrix();

	glPushMatrix();	  
	  glTranslatef(1.5,3.0,-2.0);
	  glRotatef(55,1,3,4);
	  glutSolidCube(2.0);
	glPopMatrix();


}

void display(void)
{
	float pos[3];
	m[4]=14.12*cos(u);
	m[6]=14.12*sin(u)-15;
	m[7]=0;

	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	glTranslatef(0,-3,-5);

	
	pos[0]=-m[4];
	pos[1]=10;
	pos[2]=-m[6];
	glPushMatrix();
	glLightfv(GL_LIGHT0,GL_POSITION,pos);
	render();
	glMultMatrixf(m);
	glColor3f(0.7,0.11,0.11);
	glDisable(GL_LIGHTING);
	glEnable(GL_POLYGON_OFFSET_FILL);
	glPolygonOffset(-0.1,-0.1);
	render();
	glDisable(GL_POLYGON_OFFSET_FILL);
	glEnable(GL_LIGHTING);
	glPopMatrix();

	
	glDisable(GL_LIGHTING);
	glColor3f(0.9,0.1,0.1);
	glPushMatrix();
//	glTranslatef(0,-0.01,0);
	glBegin(GL_QUADS);
	glVertex3f(-20,0,0);
	glVertex3f(20,0,0);
	glVertex3f(0,0,-20);
	glVertex3f(-20,0,-20);
	glEnd();
	glPopMatrix();
	glEnable(GL_LIGHTING);

	glutSwapBuffers();

}

void special(int key, int x, int y)
{
	switch(key)
	{
    case GLUT_KEY_LEFT:
		u+=0.1;
		glutPostRedisplay();
		break;
	case GLUT_KEY_RIGHT:
		u-=0.1;
		glutPostRedisplay();
		break;
	}
}

void reshape(int w,int h)
{
	glViewport(0,0,(GLint)w,(GLint)h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(80,(GLfloat)w/(GLfloat)h,0.1,200.0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	
}	
int main(int argc,char**argv)
{
	glutInit(&argc,argv);
//	glutInitDisplayMode(GLUT_RGB);
    glutInitDisplayMode(GLUT_RGB|GLUT_DEPTH|GLUT_DOUBLE);
	glutInitWindowSize(500,500);
	glutCreateWindow(argv[0]);

	init();
	glutReshapeFunc(reshape);
	glutSpecialFunc(special);
	glutDisplayFunc(display);
	glutMainLoop();
	return 0;
}