/// <summary>
/// Calculates latitude/longitude for given screen coordinate.
/// </summary>
public virtual void PickingRayIntersection(
int screenX,
int screenY,
out Angle latitude,
out Angle longitude)
{
Vector3 v1 = new Vector3();
v1.X = screenX;
v1.Y = screenY;
v1.Z = viewPort.MinZ;
v1.Unproject(viewPort, m_absoluteProjectionMatrix, m_absoluteViewMatrix, m_absoluteWorldMatrix);
Vector3 v2 = new Vector3();
v2.X = screenX;
v2.Y = screenY;
v2.Z = viewPort.MaxZ;
v2.Unproject(viewPort, m_absoluteProjectionMatrix, m_absoluteViewMatrix, m_absoluteWorldMatrix);
Point3d p1 = new Point3d(v1.X, v1.Y, v1.Z);
Point3d p2 = new Point3d(v2.X, v2.Y, v2.Z);
double a = (p2.X - p1.X) * (p2.X - p1.X) + (p2.Y - p1.Y) * (p2.Y - p1.Y) + (p2.Z - p1.Z) * (p2.Z - p1.Z);
double b = 2.0 * ((p2.X - p1.X) * (p1.X) + (p2.Y - p1.Y) * (p1.Y) + (p2.Z - p1.Z) * (p1.Z));
double c = p1.X * p1.X + p1.Y * p1.Y + p1.Z * p1.Z - _worldRadius * _worldRadius;
double discriminant = b * b - 4 * a * c;
if (discriminant <= 0)
{
latitude = Angle.NaN;
longitude = Angle.NaN;
return;
}
// float t0 = ((-1.0f) * b + (float)Math.Sqrt(b*b - 4 * a * c)) / (2*a);
double t1 = ((-1.0) * b - Math.Sqrt(b * b - 4 * a * c)) / (2 * a);
// Vector3 i0 = new Vector3(p1.X + t0*(p2.X - p1.X), p1.Y + t0*(p2.Y - p1.Y), p1.Z + t0 *(p2.Z - p1.Z));
Point3d i1 = new Point3d(p1.X + t1 * (p2.X - p1.X), p1.Y + t1 * (p2.Y - p1.Y), p1.Z + t1 * (p2.Z - p1.Z));
// Vector3 i0t = MathEngine.CartesianToSpherical(i0.X, i0.Y, i0.Z);
Point3d i1t = MathEngine.CartesianToSphericalD(i1.X, i1.Y, i1.Z);
Point3d mousePointer = i1t;
latitude = Angle.FromRadians(mousePointer.Y);
longitude = Angle.FromRadians(mousePointer.Z);
}
/// <summary>
/// 1.绘制太阳
/// </summary>
/// <param name="drawArgs"></param>
private void RenderSun(DrawArgs drawArgs)
{
//根据时间计算太阳的位置
Point3d sunPosition = -SunCalculator.GetGeocentricPosition(TimeKeeper.CurrentTimeUtc);
Point3d sunSpherical = MathEngine.CartesianToSphericalD(sunPosition.X, sunPosition.Y, sunPosition.Z);
sunPosition = MathEngine.SphericalToCartesianD(
Angle.FromRadians(sunSpherical.Y),
Angle.FromRadians(sunSpherical.Z),
150000000000);
Vector3 sunVector = new Vector3((float)sunPosition.X, (float)sunPosition.Y, (float)sunPosition.Z);
Frustum viewFrustum = new Frustum();
float aspectRatio = (float)drawArgs.WorldCamera.Viewport.Width / drawArgs.WorldCamera.Viewport.Height;
Matrix projectionMatrix = Matrix.PerspectiveFovRH((float)drawArgs.WorldCamera.Fov.Radians, aspectRatio, 1.0f, 300000000000);
viewFrustum.Update(
Matrix.Multiply(drawArgs.WorldCamera.AbsoluteWorldMatrix,
Matrix.Multiply(drawArgs.WorldCamera.AbsoluteViewMatrix,
projectionMatrix)));
if (!viewFrustum.ContainsPoint(sunVector))
{
return;
}
Vector3 translationVector = new Vector3(
(float)(sunPosition.X - drawArgs.WorldCamera.ReferenceCenter.X),
(float)(sunPosition.Y - drawArgs.WorldCamera.ReferenceCenter.Y),
(float)(sunPosition.Z - drawArgs.WorldCamera.ReferenceCenter.Z));
Vector3 projectedPoint = drawArgs.WorldCamera.Project(translationVector);
if (m_sunTexture == null)
{
m_sunTexture = ImageHelper.LoadTexture(Path.Combine(((QRSTWorldGlobeControl)drawArgs.parentControl).DataDirectory, @"Space\sun.dds"));
m_sunSurfaceDescription = m_sunTexture.GetLevelDescription(0);
}
if (m_sprite == null)
{
m_sprite = new Sprite(drawArgs.device);
}
m_sprite.Begin(SpriteFlags.AlphaBlend);
// Render icon
float xscale = (float)m_sunWidth / m_sunSurfaceDescription.Width;
float yscale = (float)m_sunHeight / m_sunSurfaceDescription.Height;
m_sprite.Transform = Matrix.Scaling(xscale, yscale, 0);
m_sprite.Transform *= Matrix.Translation(projectedPoint.X, projectedPoint.Y, 0);
m_sprite.Draw(m_sunTexture,
new Vector3(m_sunSurfaceDescription.Width >> 1, m_sunSurfaceDescription.Height >> 1, 0),
Vector3.Empty,
System.Drawing.Color.FromArgb(253, 253, 200).ToArgb());
// Reset transform to prepare for text rendering later
m_sprite.Transform = Matrix.Identity;
m_sprite.End();
}