Moved the creation of random flames from mainform and into a seperate unit

2.10/Source/GradientHlpr.pas

@@ -3,7 +3,7 @@ unit GradientHlpr;
 interface
 
 uses
-  windows, Graphics;
+  windows, Graphics, Cmap;
 
 const
   PixelCountMax = 32768;
@@ -15,8 +15,10 @@ type
 type
   TGradientHelper = class
   private
+    procedure RGBBlend(a, b: integer; var Palette: TColorMap);
   public
     function GetGradientBitmap(Index: integer; const hue_rotation: double): TBitmap;
+    function RandomGradient: TColorMap;
   end;
 
 var
@@ -25,7 +27,7 @@ var
 implementation
 
 uses
-  Cmap;
+  Global;
 
 { TGradientHelper }
 
@@ -55,6 +57,82 @@ begin
   Result := BitMap;
 end;
 
+///////////////////////////////////////////////////////////////////////////////
+function TGradientHelper.RandomGradient: TColorMap;
+var
+  a, b, n, nodes: integer;
+  rgb: array[0..2] of double;
+  hsv: array[0..2] of double;
+  pal: TColorMap;
+begin
+  inc(MainSeed);
+  RandSeed := Mainseed;
+  nodes := random((MaxNodes - 1) - (MinNodes - 2)) + (MinNodes - 1);
+  n := 256 div nodes;
+  b := 0;
+  hsv[0] := (random(MaxHue - (MinHue - 1)) + MinHue) / 100;
+  hsv[1] := (random(MaxSat - (MinSat - 1)) + MinSat) / 100;
+  hsv[2] := (random(MaxLum - (MinLum - 1)) + MinLum) / 100;
+  hsv2rgb(hsv, rgb);
+  Pal[0][0] := Round(rgb[0] * 255);
+  Pal[0][1] := Round(rgb[1] * 255);
+  Pal[0][2] := Round(rgb[2] * 255);
+  repeat
+    a := b;
+    b := b + n;
+    hsv[0] := (random(MaxHue - (MinHue - 1)) + MinHue) / 100;
+    hsv[1] := (random(MaxSat - (MinSat - 1)) + MinSat) / 100;
+    hsv[2] := (random(MaxLum - (MinLum - 1)) + MinLum) / 100;
+    hsv2rgb(hsv, rgb);
+    if b > 255 then b := 255;
+    Pal[b][0] := Round(rgb[0] * 255);
+    Pal[b][1] := Round(rgb[1] * 255);
+    Pal[b][2] := Round(rgb[2] * 255);
+    RGBBlend(a, b, pal);
+  until b = 255;
+  Result := Pal;
+end;
+
+///////////////////////////////////////////////////////////////////////////////
+procedure TGradientHelper.RGBBlend(a, b: integer; var Palette: TColorMap);
+{ Linear blend between to indices of a palette }
+var
+  c, v: real;
+  vrange, range: real;
+  i: integer;
+begin
+  if a = b then
+  begin
+    Exit;
+  end;
+  range := b - a;
+  vrange := Palette[b mod 256][0] - Palette[a mod 256][0];
+  c := Palette[a mod 256][0];
+  v := vrange / range;
+  for i := (a + 1) to (b - 1) do
+  begin
+    c := c + v;
+    Palette[i mod 256][0] := Round(c);
+  end;
+  vrange := Palette[b mod 256][1] - Palette[a mod 256][1];
+  c := Palette[a mod 256][1];
+  v := vrange / range;
+  for i := a + 1 to b - 1 do
+  begin
+    c := c + v;
+    Palette[i mod 256][1] := Round(c);
+  end;
+  vrange := Palette[b mod 256][2] - Palette[a mod 256][2];
+  c := Palette[a mod 256][2];
+  v := vrange / range;
+  for i := a + 1 to b - 1 do
+  begin
+    c := c + v;
+    Palette[i mod 256][2] := Round(c);
+  end;
+end;
+
+///////////////////////////////////////////////////////////////////////////////
 initialization
   GradientHelper := TGradientHelper.create;
 finalization