Pro OpenGL ES for iOS

268 CHAPTER 8: Putting It All Together^

float distanceBetweenBodies=sqrt(delX*delX+delY*delY);

if((distanceBetweenBodies>vanishDist) && (distanceBetweenBodies<grazeDist))

{

percentVisible=(distanceBetweenBodies-vanishDist)/(2.0*sun_sr);

if(percentVisible>1.3) //9

percentVisible=1.3;

else if(percentVisible<0.2)

percentVisible=1.3;

}

else if(distanceBetweenBodies>grazeDist)

{

percentVisible=1.0;

}

else

{

percentVisible=0.0;

}

scale=STANDARD_FOV/m_FieldOfView;

if(percentVisible>0.0)

[m_LensFlare execute:[[UIScreen mainScreen]applicationFrame] //10

source:CGPointMake(sun_sx,sun_sy) scale:scale alpha:percentVisible];

}

}

//11

-(void)executePlanet:(Planet *)planet sx:(float *)sx sy:(float *)sy sz:(float *)sz

screenRadius:(float *)screenRadius render:(BOOL)render

{

static GLfloat angle=0.0;

GLKVector3 planetPos;

float temp;

float distance;

CGRect frame = [[UIScreen mainScreen] bounds];

glPushMatrix();

planetPos=[planet getPosition];

glTranslatef(planetPos.x,planetPos.y,planetPos.z);

if(render)

[planet execute]; //12

distance=GLKVector3Distance(m_Eyeposition, planetPos);

temp=(0.5*frame.size.width)/tanf(GLKMathDegreesToRadians(m_FieldOfView)/2.0);

*screenRadius=temp*[planet getRadius]/distance;