TheGameCreators - CodeBase

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Category: Basic 2D

Version: 1.0

Information

Uploaded: 23rd Dec 2006 12:01

Modified: 1st Jan 1970 01:00

Author: Nicholas Thompson

Summary

Function to convert HSV values to a DWORD (as produced by the RGB function)

Full Description

Sometimes you want to control the COLOUR of a colour without changing the saturation or the value/brightness. This is next to impossible to do with pure RGB values, but it is often quite a useful thing to do (for example creating random but equally visible colours for a game). DBP doesn't handle HSV internally (AFAIK) so here is a function with remarks to do just that. Provide a Hue in the range of 0.0 to 360.0 and a Saturation and Brightness in the range of 0.0 to 1.0 and it will return a DWORD of that colour. For more information on HSV, see:<br /> http://en.wikipedia.org/wiki/HSV_color_space

DarkBASIC Professional Source Code

` This code was downloaded from The Game Creators

` It is reproduced here with full permission

` http://www.thegamecreators.com

sync off

h as float : s as float : v as float

cls

h = rnd(360) : s = rnd(1000) * 0.001 : v = rnd(1000) * 0.001

ink hsv2dword(h, s , v), 0

print "H = " + str$(h)

print "S = " + str$(s)

print "V = " + str$(v)

box 0, 50, 50, 100

wait key

loop

end

remstart

h: 0.0 => 360.0

s: 0.0 => 1.0

v: 0.0 => 1.0

returns: Color as DWORD

remend

function hsv2dword(H as float, S as float, V as float)

`Sanitize the input...

if H < 0.0 then H = 0.0 else if H > 360.0 then H = 360.0

if S < 0.0 then S = 0.0 else if S >   1.0 then S =   1.0

if V < 0.0 then V = 0.0 else if V >   1.0 then V =   1.0

`Variable for returned Colour

returnCol as DWORD

`Section of the Hue

Hi as integer : Hi = (H / 60.0) mod 6

`f is a fraction of the section

f as float : f = (H / 60.0) - Hi

`p, q and t are temp variables used to work out the rgb values before we know where to put them

p as float : p = V * (1.0 - S)

q as float : q = V * (1.0 - (f * S))

t as float : t = V * (1.0 - ((1.0 - f) * S))

`Depending on the section worked out above, we store the rgb value appropriately...

R as float : G as float : B as float

select Hi

case 0 : R = V : G = t : B = p : endcase

case 1 : R = q : G = V : B = p : endcase

case 2 : R = p : G = V : B = t : endcase

case 3 : R = p : G = q : B = V : endcase

case 4 : R = t : G = p : B = V : endcase

case 5 : R = V : G = p : B = q : endcase

endselect

`Sanitize the output - just incase of floating point errors...

if R < 0.0 then R = 0.0 else if R > 1.0 then R = 1.0

if G < 0.0 then G = 0.0 else if G > 1.0 then G = 1.0

if B < 0.0 then B = 0.0 else if B > 1.0 then B = 1.0

`Convert to Bytes and then convert to a DWORD using the rgb() function

rByte as byte : rByte = R * 255

gByte as byte : gByte = G * 255

bByte as byte : bByte = B * 255

returnCol = rgb(rByte, gByte, bByte)

endfunction returnCol

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CodeBase - HSV 2 DWORD