Method calcProjectedArea

src/cinder/Sphere.cpp:241–252

}

float Sphere::calcProjectedArea( float focalLength, vec2 screenSizePixels ) const
{
	vec3 o( mCenter );
	
    float r2 = mRadius * mRadius;
	float z2 = o.z * o.z;
	float l2 = dot( o, o );
	
	float area = -float( M_PI ) * focalLength * focalLength * r2 * sqrt( fabs((l2-r2)/(r2-z2)) ) / (r2-z2);
	float aspectRatio = screenSizePixels.x / screenSizePixels.y;
	return area * screenSizePixels.x * screenSizePixels.y * 0.25f / aspectRatio;
}

Sphere Sphere::transformed( const mat4 &transform ) const
{