/// <summary>
/// Map over the fraction of the sun's disk visible times Cos(theta) - theta is the angle between the sun and normal
/// </summary>
/// <param name="line"></param>
/// <param name="sample"></param>
/// <param name="start"></param>
/// <param name="stop"></param>
/// <param name="step"></param>
/// <param name="action"></param>
/// <returns></returns>
public bool MapOverSunContribution(int line, int sample, DateTime start, DateTime stop, TimeSpan step, Action <DateTime, float> action)
{
var id = TerrainPatch.LineSampleToId(line, sample);
var patch = GetPatch(id);
if (patch == null)
{
return(false);
}
var cross = GetSurfaceNormal(line, sample);
var y_offset = line - patch.Line;
var x_offset = sample - patch.Sample;
var mat = patch.Matrices[y_offset][x_offset];
var horizon = patch.Horizons[y_offset][x_offset];
if (!horizon.IsDegrees)
{
lock (horizon)
horizon.ConvertSlopeToDegrees();
}
var cache = SunVectorCache.GetSingleton();
var temp = new Vector3d();
for (var time = start; time <= stop; time += step)
{
var sunvec = cache.SunPosition(time);
TerrainPatch.Transform(ref sunvec, ref mat, ref temp);
var sun_x = temp[0];
var sun_y = temp[1];
var sun_z = temp[2];
var azimuth_rad = Math.Atan2(sun_y, sun_x) + Math.PI; // [0,2PI]
var azimuth_deg = (float)(azimuth_rad * 180d / Math.PI);
var alen = Math.Sqrt(sun_x * sun_x + sun_y * sun_y);
var slope = sun_z / alen;
var elevation_deg = ((float)Math.Atan(slope)) * 180f / 3.141592653589f;
var sunfrac = horizon.SunFraction2(azimuth_deg, elevation_deg);
//if (line == 17522 && sample == 12388)
//{
// Console.WriteLine($"{line},{sample}, time={time} elevation_deg={elevation_deg} sun={sunfrac}");
//}
sunvec.NormalizeFast(); // Normalize before calculating surface temp
var dot = Vector3d.Dot(sunvec, cross);
var sun_contrib = dot < 0d ? 0d : sunfrac * dot;
//if (sun_contrib > 0)
// Console.WriteLine(sun_contrib);
action(time, (float)sun_contrib);
}
return(true);
}
void FillAzimuthElevation()
{
var center_patch = GetCenterPatch();
var center_pt = center_patch.PointInPatch(new Point(TerrainPatch.DEM_size / 2, TerrainPatch.DEM_size / 2));
var mat = center_patch.Matrices[center_pt.Y][center_pt.X];
const int per_degree = 4;
const int count = 360 * per_degree;
var slope_array = Enumerable.Range(0, count).Select(i => float.MinValue).ToArray();
var vec_array = new PointF[count];
var stop = TileLightingProductManager.MetonicCycleStop;
var step = TileLightingProductManager.MetonicCycleStep;
var temp = new Vector3d();
for (var time = TileLightingProductManager.MetonicCycleStart; time <= stop; time += step)
{
var sun = CSpice.SunPosition(time);
TerrainPatch.Transform(ref sun, ref mat, ref temp);
var sun_x = temp[0];
var sun_y = temp[1];
var sun_z = temp[2];
var azimuth_rad = Math.Atan2(sun_y, sun_x) + Math.PI; // [0,2PI]
var azimuth_deg = azimuth_rad * 180d / Math.PI;
var index = (int)(azimuth_deg * per_degree);
var alen = Math.Sqrt(sun_x * sun_x + sun_y * sun_y);
var slope = (float)(sun_z / alen);
if (slope > slope_array[index])
{
slope_array[index] = slope;
vec_array[index] = new PointF((float)(sun_x / alen), (float)(sun_y / alen));
}
}
var slope_list = new List <float>();
var vec_list = new List <PointF>();
for (var i = 0; i < slope_array.Length; i++)
{
var s = slope_array[i];
if (s > float.MinValue)
{
slope_list.Add(s);
vec_list.Add(vec_array[i]);
}
}
cpu_slope = slope_array.ToArray();
cpu_vector_x = vec_list.Select(p => p.X).ToArray();
cpu_vector_y = vec_list.Select(p => p.Y).ToArray();
}
public void MapOverLightCurve(int line, int sample, DateTime start, DateTime stop, TimeSpan step, Action <DateTime, float> action)
{
var id = TerrainPatch.LineSampleToId(line, sample);
var patch = GetPatch(id);
if (patch == null)
{
return;
}
var y_offset = line - patch.Line;
var x_offset = sample - patch.Sample;
var mat = patch.Matrices[y_offset][x_offset];
var horizon = patch.Horizons[y_offset][x_offset];
if (!horizon.IsDegrees)
{
lock (horizon)
horizon.ConvertSlopeToDegrees();
}
var cache = SunVectorCache.GetSingleton();
var temp = new Vector3d();
for (var time = start; time <= stop; time += step)
{
var sunvec = cache.SunPosition(time);
TerrainPatch.Transform(ref sunvec, ref mat, ref temp);
var sun_x = temp[0];
var sun_y = temp[1];
var sun_z = temp[2];
var azimuth_rad = Math.Atan2(sun_y, sun_x) + Math.PI; // [0,2PI]
var azimuth_deg = (float)(azimuth_rad * 180d / Math.PI);
var alen = Math.Sqrt(sun_x * sun_x + sun_y * sun_y);
var slope = sun_z / alen;
var elevation_deg = ((float)Math.Atan(slope)) * 180f / 3.141592653589f;
var sun = horizon.SunFraction2(azimuth_deg, elevation_deg);
//Console.WriteLine($"time={time} elevation_deg={elevation_deg} sun={sun}");
action(time, sun);
}
}
protected override void OnPaint(PaintEventArgs e)
{
if (!ReadyToRender())
{
return;
}
if (_bitmap == null || _bitmap.Width != Width || _bitmap.Height != Height)
{
_bitmap?.Dispose();
_bitmap = new Bitmap(Width, Height, PixelFormat.Format32bppArgb);
}
Patch.FillPointsAndMatrices(Terrain);
var m = Patch.Matrices[PointInPatch.Y][PointInPatch.X];
var temp = new Vector3d();
TerrainPatch.Transform(ref ShadowCaster, ref m, ref temp);
var x = temp[0];
var y = temp[1];
var z = temp[2];
var azimuth_rad = Math.Atan2(y, x) + Math.PI; // [0,2PI]
var alen = Math.Sqrt(x * x + y * y);
var slope = z / alen;
var elevation_deg = ((float)Math.Atan(slope)) * 180f / 3.141592653589f;
var normalized_azimuth = azimuth_rad / (2d * Math.PI); // range [0,1)
var horizon_index_f = (float)(Horizon.HorizonSamplesD * normalized_azimuth);
var buf = Patch.Horizons[PointInPatch.Y][PointInPatch.X].Buffer;
var width = _bitmap.Width;
var height = _bitmap.Height;
var sunCenter = new Point(width / 2, height / 2);
var sunRadius = 8; // was 20
// The width of a single slat in pixels
const float sun_width_deg = .25f;
var slat_width = sunRadius; // .25 deg
var slat_width2 = slat_width / 2;
// The index of the slat that 'covers' the sun's center
var index_center = (int)horizon_index_f;
var center_slat_left = (int)((sunCenter.X - (horizon_index_f - index_center) * sunRadius) + 0.5f);
//Console.WriteLine($"caster render idx={index_center} horizon_elev={LookupHorizon(buf, index_center)} sun_elev={elevation_deg}");
var span = (width / 2) / sunRadius + 1;
var span2 = 2 * span;
using (var g = Graphics.FromImage(_bitmap))
{
g.FillRectangle(Brushes.White, 0, 0, _bitmap.Width, _bitmap.Height);
g.FillEllipse(Brushes.Yellow, sunCenter.X - sunRadius, sunCenter.Y - sunRadius, sunRadius * 2, sunRadius * 2);
for (var slat_offset = -span; slat_offset <= span2; slat_offset++)
{
var slat_left = center_slat_left + slat_offset * slat_width;
var slat_index = index_center + slat_offset;
var slat_angle1 = LookupHorizon(buf, slat_index);
var slat_angle2 = LookupHorizon(buf, slat_index - 1);
var slat_top1 = sunCenter.Y + ((elevation_deg - slat_angle1) / sun_width_deg) * sunRadius;
var slat_top2 = sunCenter.Y + ((elevation_deg - slat_angle2) / sun_width_deg) * sunRadius;
//Console.WriteLine($" slat_top={slat_top1} slat_angle={slat_angle1}");
var top = Math.Max(0, slat_top1);
g.FillRectangle(_grayBrush, slat_left, top, slat_width, height);
g.DrawRectangle(Pens.DarkGray, slat_left, top, slat_width, height);
g.DrawLine(Pens.Red, slat_left - slat_width2, slat_top2, slat_left + slat_width2, slat_top1);
}
var azimuth_deg = azimuth_rad * 180d / Math.PI;
var frac = SunFraction2(g, sunCenter, sunRadius, buf, (float)azimuth_deg, elevation_deg);
Console.WriteLine($"sun frac={frac}");
}
e.Graphics.DrawImage(_bitmap, 0, 0);
}