HTML color -> PB color -> libxlsxwriter color

[the.weavster]

I have this procedure that turns a HTML color string into a PB color:

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Procedure.l ColorStringToNumber(col.s)
  Define.l ncol = 0
  Define.s xcol = ""
  If Left(col, 1) = "#"
    Define.s xcol = LSet(col, 7, "0")
    Define.a nR = Val("$" + Mid(xcol, 2, 2))
    Define.a nG = Val("$" + Mid(xcol, 4, 2))
    Define.a nB = Val("$" + Mid(xcol, 6, 2))
    ncol = RGB(nR, nG, nB)
  Else
    ncol = ColorStringToNumber(ColorNameToHex(col)) ; omitted for brevity
  EndIf
  ProcedureReturn ncol
EndProcedure

As PB's color has the RGB values in 3 bytes I actually thought it was going to work with libxlsxwriter straight off the bat which has its color values defined like this:

Throughout libxlsxwriter colors are specified using a Html style RGB integer value. For example with a Format object:

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// typedef uint32_t lxw_color_t
format_set_font_color(format, 0x3030E0);

Although I am getting a color in my spreadsheet cells it's not the color I expect. I have tried poking the RGB values into the last 3 bytes of a 32bit integer to see if that would work but again, I got a color but not the one I wanted

If somebody could point me in the right direction I'd be grateful

[SMaag]

It can't be that complicated.
What's the format of the col$
can you give me some examples of col$?

I have tried poking the RGB values into the last 3 bytes of a 32bit integer to see if that would work

you have to poke it in the first 3 Bytes

here is the Systens Colordefintion Structure for different Systems

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  CompilerIf #PB_Compiler_Processor = #PB_Processor_PowerPC
    ; ----------------------------------------------------------------------
    ; This is the exception Alpha first : Motorola PowerPC
    ; ----------------------------------------------------------------------
    Structure TSystemRGBA   ; here it's ABGR in Memory
      A.a
      B.a
      G.a
      R.a
    EndStructure
  CompilerElse    ; x86, x64; ARM32; ARM64
    ; ----------------------------------------------------------------------
    ; This is the standard Windows alignment RED=LoByte .. Alpha=HiByte
    ; In Memory RGBA but in Processor Register ABGR  
    ; ----------------------------------------------------------------------
    Structure TSystemRGBA   ; here it's RGBA in Memory
      R.a
      G.a
      B.a
      A.a
    EndStructure   
  CompilerEndIf
  
  Structure TSystemColor  ; The SystemColorStructure to have multiple access to the Color Channels!
    ; This is the trick how it works! TSystem RGBA is integrated as complete Structure, not as Pointer!
    ; This is a documented feature. See the PB help for Structure Union. There you will find the RGB example!
    ; IDENTICAL POINTERS FOR: 
    ;   @TSystemColor= @TSystemColor\col= @TSystemColor\RGB = @TSystemColor\RGB\R = @TSystemColor\ch[0]
    StructureUnion
      RGB.TSystemRGBA ; Access single color channels by name
      col.l           ; Access as 32Bit Color
      ch.a[4]         ; Access single color channels by number [0..3]                 
    EndStructureUnion
  EndStructure

[pfnuesu]

What about this?

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Define xcolor.s
xcolor = (ReplaceString("#3030E0","#","$"))
Debug Red(Val(xcolor))
Debug Blue(Val(xcolor))
Debug Green(Val(xcolor))

;And back to hex to verify...
Debug Hex(RGB(Red(Val(xcolor)),Green(Val(xcolor)),Blue(Val(xcolor))))

[RASHAD]

Your procedure works fine as expected
So probably libxlsxwriter using BGR not RGB

[SMaag]

converting is correct

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Procedure.l ColorStringToNumber(col.s)
  Protected.l ncol, nR, nG, nB
  Protected.s xcol
  
  col = Trim(col)
  
  If Asc(col) = '#'
    xcol = LSet(col, 7, "0")
    Debug "xcol = " + xcol
    
    nR = Val("$" + Mid(xcol, 2, 2))
    nG = Val("$" + Mid(xcol, 4, 2))
    nB = Val("$" + Mid(xcol, 6, 2))
        
    Debug "nR = " + Hex(nR) + " = " + Str(nR)
    Debug "nG = " + Hex(nG) + " = " + Str(nG)
    Debug "nG = " + Hex(nB) + " = " + Str(nB)
    
    ncol = RGB(nR, nG, nB)
  EndIf
  ProcedureReturn ncol
EndProcedure

#IndianRed 	= "#CD5C5C"   ;	RGB(205, 92, 92)
#LightCoral =	"#F08080" 	; RGB(240, 128, 128)
#Salmon 	=   "#FA8072" 	; RGB(250, 128, 114)
#DarkSalmon =	"#E9967A"   ;	RGB(233, 150, 122)
#LightSalmon ="#FFA07A"   ;	RGB(255, 160, 122)

Define mycol.l, mycol$

Debug "Test for HTML IndianRed =  #CD5C5C   ;	RGB(205, 92, 92)"

mycol = ColorStringToNumber(#IndianRed)
Debug "mycol = " + Hex(mycol)
Debug "R = " + Hex(Red(mycol))
Debug "G = " + Hex(Green(mycol))
Debug "B = " + Hex(Blue(mycol))

[the.weavster]

So probably libxlsxwriter using BGR not RGB

I don't think so as the declaration of cyan in libxlsxwriter's format.h header file is:

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LXW_COLOR_CYAN = 0x00FFFF

Which matches cyan in HTML: #00FFFF

I have tried using PB's RGB() directly, also poking to the first 3 bytes, poking to the last 3 bytes, reversing, etc... Whatever I've tried I never get the color I expect

[SMaag]

LXW_COLOR_CYAN = 0x00FFFF

Cyan = RGB(0,255,255)
so 0x00FFFF = RRGGBB is BigEndian and will reult in BBGGRR in the Memory of x68, x64, PB works with little Endian RRGGBB

https://libxlsxwriter.github.io/working ... olors.html
blue = 0x0000FF -> BigEndian Blue PB use LittleEndian blue = 0xFF0000
so libxlsxwriter use BGR from the view of PureBasic

[the.weavster]

Thank you both

I actually thought I had tried reversing RGB but I'd obviously slipped up doing it because that is working now

[AZJIO]

https://www.purebasic.fr/english/viewto ... 84#p628384