Unicode char comparison puzzle

[tcab]

Thanks for the responses.

So the problem is that I want to filter out all the unicode chars/codepoints that cannot be rendered. I just want to see all the "juicy" characters that the Prime is capable of rendering, and none of the noise viz. I dont want:

I want:


I stumbled upon this post about comparing the bitmaps of characters, and managed to write the Prime code to do it. My new character comparison function renders the character as a bitmap, which I then convert into a list of 1' s and 0's and can use this information to compare characters, as rendered.

Code:


EXPORT bit_signature_for_char(c)
BEGIN
  local result={}, x, y, pix;
  TEXTOUT_P(c,G1,0,0,2,#000000,100,#FFFFFF);
  for y from 0 to 5 do  // should probably compare more rows of pixels
    for x from 0 to 100 do
      if GETPIX_P(G1,x, y) = #FFFFFF then
        pix := 0;
      else
        pix := 1;
      end;
      result := concat(result, pix);
    end;
  end;
  return result;
END;

EXPORT same_char(c1, c2)
BEGIN
  return string(bit_signature_for_char(c1)) = string(bit_signature_for_char(c2));
END;

EXPORT UNIFUN()
BEGIN
LOCAL cp, S:="";
PRINT();
FOR cp FROM #2600h TO #26FFh DO
  //IF CHAR(cp) ≠ "⛾" THEN  // doesn't work 
  IF NOT same_char(CHAR(cp), CHAR(#2600)) THEN  // works :-)
    S := S + CHAR(cp);
  END;
END;
PRINT(S);
END;

Running across a longer range of chars takes time, but gives:


A couple of programming issues I ran into:

• I used the offscreen bitmap G1 but for some reason couldn't use G2 to do the textout renderings of bitmaps?
• I couldn't find a function to compare lists, so had to convert the lists to strings in order to compare them.