New functions to return darker or lighter variations of a color.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/corelib/fpg_base.pas b/src/corelib/fpg_base.pas
index 196b820c..ddeaa227 100644
--- a/src/corelib/fpg_base.pas
+++ b/src/corelib/fpg_base.pas
@@ -743,6 +743,8 @@ function  fpgGetBlue(const AColor: TfpgColor): word;
 function  fpgGetAlpha(const AColor: TfpgColor): word;
 function  fpgGetAvgColor(const AColor1, AColor2: TfpgColor): TfpgColor;
 function  fpgColor(const ARed, AGreen, ABlue: byte): TfpgColor;
+function  fpgDarker(const AColor: TfpgColor; APercent: Byte = 50): TfpgColor;
+function  fpgLighter(const AColor: TfpgColor; APercent: Byte = 50): TfpgColor;
 
 
 { Points }
@@ -1036,6 +1038,32 @@ begin
   Result := ABlue or (AGreen shl 8) or (ARed shl 16);
 end;
 
+function fpgDarker(const AColor: TfpgColor; APercent: Byte): TfpgColor;
+var
+  lColor: TFPColor;
+begin
+  lColor.Red := fpgGetRed(AColor);
+  lColor.Green := fpgGetGreen(AColor);
+  lColor.Blue := fpgGetBlue(AColor);
+  lColor.Red := Round(lColor.Red*APercent/100);
+  lColor.Green := Round(lColor.Green*APercent/100);
+  lColor.Blue := Round(lColor.Blue*APercent/100);
+  Result := FPColorTofpgColor(lColor);
+end;
+
+function fpgLighter(const AColor: TfpgColor; APercent: Byte): TfpgColor;
+var
+  lColor: TFPColor;
+begin
+  lColor.Red := fpgGetRed(AColor);
+  lColor.Green := fpgGetGreen(AColor);
+  lColor.Blue := fpgGetBlue(AColor);
+  lColor.Red := Round((lColor.Red*APercent/100) + (255 - APercent/100*255));
+  lColor.Green := Round((lColor.Green*APercent/100) + (255 - APercent/100*255));
+  lColor.Blue := Round((lColor.Blue*APercent/100) + (255 - APercent/100*255));
+  Result := FPColorTofpgColor(lColor);
+end;
+
 function PtInRect(const ARect: TfpgRect; const APoint: TPoint): Boolean;
 begin
   Result := (APoint.x >= ARect.Left) and