opengl实现太阳系天体运动(4)

#include

// Rotation amounts

static GLfloat xRot = 0.0f; static GLfloat yRot = 0.0f;

void SpecialKeys(int key, int x, int y); void ChangeSize( GLsizei w, GLsizei h ); void DrawAxis(); void SetupRC();

void RenderScene() {

//清空颜色缓冲区，填充的颜色由 glClearColor( 0, 0.0, 0.0, 1 ); 指定为黑色

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

// Save matrix state and do the rotation

glPushMatrix();

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

DrawAxis();

//绘制太阳

glColor3f( 1.0f, 1.0f, 1.0f );//白色

glutSolidSphere( 50.f, 15, 15 );

//绘制地球

static GLfloat earthAngle = 0; const GLfloat RADIUS = 100.f; glRotatef( earthAngle, 0, 0, 1 ); glTranslatef( RADIUS, RADIUS, 0 ); glColor3f( 0.0f, 1.0f, 0.0f );//绿色

glutSolidSphere( 20.f, 15, 15 );

// 绘制黄色的“月亮”

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

glRotatef(earthAngle/30.0*360.0 - earthAngle/360.0*360.0, 0.0f, 0.0f, -1.0f);

glTranslatef(RADIUS/2, 0.0f, 0.0f); glutSolidSphere(7, 20, 20);

earthAngle += 1;

if ( earthAngle >= 360 ) {

earthAngle -= 360; }

printf( \, earthAngle );

// Restore transformations

glPopMatrix();

glutSwapBuffers(); }

int main(int argc, char* argv[]) {

glutInit(&argc, argv);

glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH); glutInitWindowSize (800, 600); glutInitWindowPosition (100, 100); glutCreateWindow( \ ); glutDisplayFunc( RenderScene );

glutIdleFunc (RenderScene); //glutIdleFunc 表示在CPU空闲的时间调用某一函数

glutReshapeFunc( ChangeSize ); glutSpecialFunc( SpecialKeys ); SetupRC(); glutMainLoop();

return 1; }

void SetupRC() {

glClearColor( 0, 0.0, 0.0, 1 ); glShadeModel( GL_SMOOTH );

glEnable(GL_DEPTH_TEST);//被遮住的部分不绘制 }

void ChangeSize( GLsizei w, GLsizei h ) {

GLfloat nRange = 200.0f;

// Prevent a divide by zero

if(h == 0) h = 1;

// Set Viewport to window dimensions

glViewport(0, 0, w, h);

// Reset projection matrix stack

glMatrixMode(GL_PROJECTION); glLoadIdentity();

// Establish clipping volume (left, right, bottom, top, near, far)

if (w <= h)

glOrtho (-nRange, nRange, -nRange*h/w, nRange*h/w, -nRange, nRange); else

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

// Reset Model view matrix stack

glMatrixMode(GL_MODELVIEW); glLoadIdentity(); }

void SpecialKeys(int key, int x, int y) {

if(key == GLUT_KEY_UP) xRot -= 5.0f;

if(key == GLUT_KEY_DOWN) xRot += 5.0f;

if(key == GLUT_KEY_LEFT) yRot -= 5.0f;

if(key == GLUT_KEY_RIGHT) yRot += 5.0f;

if(xRot > 356.0f) xRot = 0.0f;