johan.nel@[EMAIL PROTECTED]
wrote:
> Hi Paul,
>
> I hacked this from somewhere I cannot remember so not sure it work but
> you can try, sorry for no indentation:
> FUNCTION RGB2HSV(nR, nG, nB) AS ARRAY
> LOCAL nDelta, nMin, nV, nS, nH AS REAL8
> LOCAL aHSV AS ARRAY
> nMin := Min(nR, Min(nG, nB))
> nV := Max(nR, Max(nG, nB))
> nDelta := nV - nMin
> BEGIN SEQUENCE
> IF nV = 0.0
> nS := 0.0
> ELSE
> nS := nDelta / nV
> ENDIF
> IF nS = 0.0
> aHSV := {NIL, nS, nV}
> BREAK // nH undefined
> ELSEIF nR = nV
> nH := 60.0 * (nG - nB) / nDelta
> ELSEIF nG = nV
> nH := 120.0 + 60.0 * (nB - nR) / nDelta
> ELSEIF nB = nV
> nH := 240.0 + 60.0 * (nR - nG) / nDelta
> ENDIF
> IF nH < 0.0
> nH := nH + 360.0
> ENDIF
> aHSV := {nH, nS, nV}
> END SEQUENCE
> RETURN aHSV
>
> FUNCTION HSV2RGB(nH, nS, nV) AS ARRAY
> LOCAL nF, nHTemp, nP, nQ, nT, nR, nG, nB AS REAL8
> LOCAL aRGB AS ARRAY
> LOCAL nI AS INT
> BEGIN SEQUENCE
> IF nS = 0.0
> IF nH = NIL
> nR := nV
> nG := nV
> nB := nV
> ELSE
> aRGB := {NIL, NIL, NIL}
> BREAK
> ENDIF
> ELSE
> IF nH = 360.0
> nHTemp := 0.0
> ELSE
> nHTemp := nH
> ENDIF
> nHTemp := nHTemp / 60
> nI := Floor(nHTemp)
> nF := nHTemp - nI
> nP := nV * (1.0 - nS)
> nQ := nV * (1.0 - (nS * nF))
> nT := nV * (1.0 - (nS * (1.0 - nF)))
> DO CASE
> CASE nI = 0
> nR := nV; nG := nT; nB := nP
> CASE nI = 1
> nR := nQ; nG := nV; nB := nP
> CASE nI = 2
> nR := nP; nG := nV; nB := nT
> CASE nI = 3
> nR := nP; nG := nQ; nB := nV
> CASE nI = 4
> nR := nT; nG := nP; nB := nV
> CASE nI = 5
> nR := nV; nG := nP; nB := nQ
> ENDCASE
> ENDIF
> aRGB := {nR, nG, nB}
> END SEQUENCE
> RETURN aRGB
>
> HTH,
>
> Johan Nel
> Pretoria, South Africa.
Thanks Johan. But it doesn't work. When I convert a RGB color to HSV, do
nothing with it and just convert it back to HSV, I get 0,0,0 (black. ).
I'll play with it this afternoon to see what goes wrong.
--
Paul
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