屏幕坐标到OpenGL世界坐标的转换

worldPos screen2world(int x, int y)

{

GLint viewport[4];

GLdouble modelview[16];

GLdouble projection[16];

GLfloat winX, winY, winZ;

GLdouble posX, posY, posZ;

glGetDoublev(GL_MODELVIEW_MATRIX, modelview);

glGetDoublev(GL_PROJECTION_MATRIX, projection);

glGetIntegerv(GL_VIEWPORT, viewport);

winX = (float)x;

winY = (float)viewport[3] - (float)y;

glReadPixels(x, int(winY), 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &winZ);

gluUnProject(winX, winY, winZ, modelview, projection, viewport, &posX, &posY, &posZ);

worldPos v;

v.posX = posX;

v.posY = posY;

v.posZ = posZ;

return v;

}