public void UpdateTerrainElevation(TerrainAccessor terrainAccessor)
{
// Update camera terrain elevation
if (terrainAccessor != null)
{
if (Altitude < 300000)
{
if (System.DateTime.Now - this.lastElevationUpdate > TimeSpan.FromMilliseconds(500))
{
float elevation;
// Under camera target
elevation = terrainAccessor.GetCachedElevationAt(Latitude.Degrees, Longitude.Degrees);
TerrainElevation = float.IsNaN(elevation) ? (short)0 : (short)elevation;
// Under the camera itself
Vector3 cameraPos = Position;
Vector3 cameraCoord = MathEngine.CartesianToSpherical(cameraPos.X, cameraPos.Y, cameraPos.Z);
double camLat = MathEngine.RadiansToDegrees(cameraCoord.Y);
double camLon = MathEngine.RadiansToDegrees(cameraCoord.Z);
elevation = terrainAccessor.GetCachedElevationAt(camLat, camLon);
TerrainElevationUnderCamera = float.IsNaN(elevation) ? (short)0 : (short)elevation;
if (TerrainElevationUnderCamera < 0 && !World.Settings.AllowNegativeAltitude)
{
TerrainElevationUnderCamera = 0;
}
// reset timer
this.lastElevationUpdate = System.DateTime.Now;
}
}
else
{
TerrainElevation = 0;
TerrainElevationUnderCamera = 0;
}
}
else
{
TerrainElevation = 0;
TerrainElevationUnderCamera = 0;
}
}
/// <summary>
/// This is where we do our rendering
/// Called from UI thread = UI code safe in this function
/// </summary>
public override void Render(DrawArgs drawArgs)
{
if (!isInitialized || (this.world.Name == "Earth" && World.Settings.EnableAtmosphericScattering))
{
return;
}
// Camera & Device shortcuts ;)
CameraBase camera = drawArgs.WorldCamera;
Device device = drawArgs.device;
//if(camera.Altitude > 200e3) return;
Vector3 cameraPos = camera.Position;
double distToCenterOfPlanet = (camera.Altitude + camera.WorldRadius);
// Create or refresh SkyGradient dome
if (mesh == null || lastAltitude != camera.Altitude)
{
// Compute distance to horizon and dome radius
double tangentalDistance = Math.Sqrt(distToCenterOfPlanet * distToCenterOfPlanet - camera.WorldRadius * camera.WorldRadius);
double domeRadius = tangentalDistance;
// horizon latitude
double horizonLat = (-Math.PI / 2 + Math.Acos(tangentalDistance / distToCenterOfPlanet)) * 180 / Math.PI;
// zenith latitude
double zenithLat = 90;
if (camera.Altitude >= thickness)
{
double tangentalDistanceZenith = Math.Sqrt(distToCenterOfPlanet * distToCenterOfPlanet - (camera.WorldRadius + thickness) * (camera.WorldRadius + thickness));
zenithLat = (-Math.PI / 2 + Math.Acos(tangentalDistanceZenith / distToCenterOfPlanet)) * 180 / Math.PI;
}
if (camera.Altitude < thickness && camera.Altitude > thickness * 0.8)
{
zenithLat = (thickness - camera.Altitude) / (thickness - thickness * 0.8) * 90;
}
// new mesh
if (mesh != null)
{
mesh.Dispose();
}
mesh = ColoredSphere(device, (float)domeRadius, horizonLat, zenithLat, 128, 24);
lastAltitude = camera.Altitude;
}
// set texture to null
device.SetTexture(0, null);
device.TextureState[0].ColorOperation = TextureOperation.BlendCurrentAlpha;
device.VertexFormat = CustomVertex.PositionColored.Format;
// save world and projection transform
Matrix origWorld = device.Transform.World;
Matrix origProjection = device.Transform.Projection;
// move SkyGradient dome
Matrix SkyGradientTrans;
Vector3 cameraCoord = MathEngine.CartesianToSpherical(cameraPos.X, cameraPos.Y, cameraPos.Z);
float camLat = cameraCoord.Y;
float camLon = cameraCoord.Z;
SkyGradientTrans = Matrix.Translation(0, 0, (float)distToCenterOfPlanet);
SkyGradientTrans = Matrix.Multiply(SkyGradientTrans, Matrix.RotationY(-camLat + (float)Math.PI / 2));
SkyGradientTrans = Matrix.Multiply(SkyGradientTrans, Matrix.RotationZ(camLon));
device.Transform.World = SkyGradientTrans;
// Recenter
Recenter(drawArgs);
// Save fog status
bool origFog = device.RenderState.FogEnable;
device.RenderState.FogEnable = false;
// Set new one (to avoid being clipped) - probably better ways of doing this?
float aspectRatio = (float)device.Viewport.Width / device.Viewport.Height;
device.Transform.Projection = Matrix.PerspectiveFovRH((float)camera.Fov.Radians, aspectRatio, 1, float.MaxValue);
// draw
//device.RenderState.FillMode = FillMode.WireFrame;
mesh.DrawSubset(0);
// Restore device states
device.RenderState.FillMode = FillMode.Solid;
device.Transform.World = origWorld;
device.Transform.Projection = origProjection;
device.RenderState.FogEnable = origFog;
device.RenderState.ZBufferEnable = true;
// Fog effect
if (useFog)
{
// Compute distance to horizon and camera altitude
double tangentalDistance = Math.Sqrt(distToCenterOfPlanet * distToCenterOfPlanet - camera.WorldRadius * camera.WorldRadius);
float a = (float)camera.Altitude;
device.RenderState.FogEnable = true;
device.RenderState.FogColor = horizonColor;
device.RenderState.FogTableMode = FogMode.Linear;
device.RenderState.FogStart = a * nearFactor;
device.RenderState.FogEnd = (float)tangentalDistance * farFactor;
}
}
