Combine two colors
lazarus / 39-Graphics

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bigeno · 2018-12-01 16:55

I've some selection on spreadsheet and some cell colors. How to
combine selection color with colored cells ? example below. I simply
using canvas.brush.color for cell background.

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wp · 2018-12-01 18:08

Is this an fpspreadsheet question? The screenshot looks like that.

In fpspreadsheet the color of the selected cells is determined by this
function from the color c of the cell:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
CalcSelectionColor(c: TColor; ADelta: Byte) : TColor;type  TRGBA =
record R,G,B,A: Byte end;begin  c := ColorToRGB(c);  TRGBA(Result).A
:= 0;  if TRGBA(c).R < 128    then TRGBA(Result).R := TRGBA(c).R +
ADelta    else TRGBA(Result).R := TRGBA(c).R - ADelta;  if TRGBA(c).G
< 128    then TRGBA(Result).G := TRGBA(c).G + ADelta    else
TRGBA(Result).G := TRGBA(c).G - ADelta;  if TRGBA(c).B < 128    then
TRGBA(Result).B := TRGBA(c).B + ADelta    else TRGBA(Result).B :=
TRGBA(c).B - ADelta;end;This function adds ADelta to each dark color
component (i.e. makes it brigher) and subtracts ADelta from a bright
color component (i.e. makes it darker). ADelta should not be too
large, definitely less than 128; in the worksheet grid the value is
16.

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bigeno · 2018-12-01 19:46

No, thats screenshot from MS Excel, I work with TStringGrid.
Thank you, you right, I don't need mix two colors, darker will be ok
in that case

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Blaazen · 2018-12-01 20:13

I use this in ECControls:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
GetMergedColor(AColor, BColor: TColor; AProportion: Single):
TColor;var aR, bR, aG, bG, aB, bB: Integer;begin 
GetRGBIntValues(ColorToRGB(AColor), aR, aG, aB); 
GetRGBIntValues(ColorToRGB(BColor), bR, bG, bB);  aR := bR + trunc((aR
- bR)*AProportion);  aG := bG + trunc((aG - bG)*AProportion);  aB :=
bB + trunc((aB - bB)*AProportion);  Result := RGBToColor(aR, aG,
aB);end;
Parameter AProportion should be between 0..1, where 1 means AColor, 0
means BColor.