private System.Drawing.Color ArbitraryRedshiftBasedColor(CoordinateEngine.RelativisticObject dude, CoordinateEngine.RelativisticObject reference)
{
//Get z from the two objects
//for information about z, see http://en.wikipedia.org/wiki/Redshift
//z==0 means no shift
//1+z = wavelength(observed)/wavelength(emitted)
//so multiply the object's wavelength by (1+z)
//the shift from pure green to pure red or pure blue to pure green is about z=0.17, so this would not be the most dynamic scale for large z
double z = CoordinateEngine.calculateRedshiftZ(dude, universe.bro);
//"Accurate" values
const double upperlimit = 0.17;
const double lowerlimit = -0.146;
//Way to "soften" the quick and hard transition between colors. The 1/exponent roughly multiplies the visible spectrum window...
z = -1.0 + Math.Pow(1.0 + z, 1.0 / 1.0);
if (z > upperlimit)//receding fast
{
return(System.Drawing.Color.FromArgb(127, 5, 10));
}
else if (z < lowerlimit)//approaching fast
{
return(System.Drawing.Color.FromArgb(127, 0, 255));
}
else if (z > 0.0)
{
return(System.Drawing.Color.FromArgb((int)(z / upperlimit * 255), (int)(255 * (1 - z / upperlimit)), 0));
}
else //z<0.0
{
return(System.Drawing.Color.FromArgb(0, (int)(255 * (1 - z / lowerlimit)), (int)(z / lowerlimit * 255)));
}
}
//Populates the dudes, as a hard-coded demo
public void InitDemo()
{
for (int i=0; i<DemoConsts.array_size_x; i++) {
for (int j=0; j<DemoConsts.array_size_y; j++) {
for (int k=0; k<DemoConsts.array_size_z; k++) {
//This mess of things at 0,0,0 sorts itself out after a few frames using UpdateDudes(), don't worry
CoordinateEngine.RelativisticObject new_guy = new CoordinateEngine.RelativisticObject(0,0,0);
new_guy.vrms = DemoConsts.speed;
double new_gamma = double.PositiveInfinity;
if(DemoConsts.speed<1.0){
new_gamma = CoordinateEngine.computeGamma(DemoConsts.speed);
}
new_guy.gamma = new_gamma;
dudes.Add(new_guy);
}
}
}
}
//Populates the dudes, as a hard-coded demo
public void InitDemo()
{
for (int i = 0; i < DemoConsts.array_size_x; i++)
{
for (int j = 0; j < DemoConsts.array_size_y; j++)
{
for (int k = 0; k < DemoConsts.array_size_z; k++)
{
//This mess of things at 0,0,0 sorts itself out after a few frames using UpdateDudes(), don't worry
CoordinateEngine.RelativisticObject new_guy = new CoordinateEngine.RelativisticObject(0, 0, 0);
new_guy.vrms = DemoConsts.speed;
double new_gamma = double.PositiveInfinity;
if (DemoConsts.speed < 1.0)
{
new_gamma = CoordinateEngine.computeGamma(DemoConsts.speed);
}
new_guy.gamma = new_gamma;
dudes.Add(new_guy);
}
}
}
}
/// <summary>
/// Draw a single RelativisticObject to the screen.
/// </summary>
/// <param name="ro">The RelativisticObject to draw.</param>
/// <param name="issilver">Whether that object should be silver I guess</param>
/// <remarks>
/// What? You want to choose a color? Get off my lawn!
/// </remarks>
private void DrawRelativisticObject(CoordinateEngine.RelativisticObject ro, bool issilver = true)
{
double x;
double y;
double z;
if (SHOULD_LORENTZ_TRANSFORM_IMAGE)
{
double[] apparent_position = CoordinateEngine.ApparentPosition(ro.x, universe.bro.x, universe.bro.v);
x = apparent_position[_x];
y = apparent_position[_y];
z = apparent_position[_z];
}
else
{
x = ro.x[_x];
y = ro.x[_y];
z = ro.x[_z];
}
//double size = .01*Math.Sqrt (CoordinateEngine.RMS(universe.bro.x));
double size = 0.042; //Diameter of the Earth if t=seconds
size /= 2; //Turns size into the side length of the cube
GL.Begin(BeginMode.Quads);
if (issilver)
{
GL.Color3(ArbitraryRedshiftBasedColor(ro, universe.bro));
}
else
{
GL.Color3(Color.Blue);
}
// front
GL.Vertex3(x - size, y - size, z + size);
GL.Vertex3(x - size, y + size, z + size);
GL.Vertex3(x + size, y + size, z + size);
GL.Vertex3(x + size, y - size, z + size);
// right
GL.Vertex3(x + size, y - size, z + size);
GL.Vertex3(x + size, y + size, z + size);
GL.Vertex3(x + size, y + size, z - size);
GL.Vertex3(x + size, y - size, z - size);
// bottom
GL.Vertex3(x + size, y - size, z - size);
GL.Vertex3(x + size, y - size, z + size);
GL.Vertex3(x - size, y - size, z + size);
GL.Vertex3(x - size, y - size, z - size);
// left
GL.Vertex3(x - size, y - size, z - size);
GL.Vertex3(x - size, y - size, z + size);
GL.Vertex3(x - size, y + size, z + size);
GL.Vertex3(x - size, y + size, z - size);
// top
GL.Vertex3(x - size, y + size, z - size);
GL.Vertex3(x - size, y + size, z + size);
GL.Vertex3(x + size, y + size, z + size);
GL.Vertex3(x + size, y + size, z - size);
// back
GL.Vertex3(x + size, y + size, z - size);
GL.Vertex3(x + size, y - size, z - size);
GL.Vertex3(x - size, y - size, z - size);
GL.Vertex3(x - size, y + size, z - size);
GL.End();
}