What's it all about, Alfie?

The graphs in Potentials are OK... but they are only interpolating between two colors. It's OK... but it's not as nice as I'd like it. What I wanted was to be able to have several colors in the mix - so I could come up with colors like Black Body Radiation. Then it came to me, that I could bracket the values with an array of colors, like:

  NSColor*    spectrum[] = {[NSColor redColor],
                            [NSColor orangeColor],
                            [NSColor yellowColor],
                            [NSColor cyanColor]};
  int         stages = 4;
  double      dc = 1.0/(stages - 1);

And then, for each point to plot:

  double      x = 0.0;
  int         ilow = 0;
  for (int r = 0; r < _rowCnt; r++) {
    for (int c = 0; c < _colCnt; c++) {
      x = _values[r][c];
      ilow = MIN((int)(x/dc), (stages-2));
      x -= ilow * dc;
      gc = [ResultsView interpolate:(x/dc)
                        withColorsBetween:spectrum[ilow]
                        and:spectrum[ilow+1]];

Where we're picking the value up, then finding the two bordering colors on that value, and then moving the value to the [0..1] range and then interpolating between those two colors.

In the end, it looks great:

It's a really nice improvement, and next we have to work on the Electric field.

This entry was posted on Sunday, May 5th, 2019 at 12:24 pm and is filed under Cocoa Coding. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.