Html -> Rgb

**PsychoMark** · Jul 6th, 2001, 01:01 PM

Ok, I've got this piece of code to convert a color value to HTML coding (it's Delphi code, but it's fairly easy to understand for any VB coder):

Code:

  iRed := Color and $FF;
  iGreen := (Color and $FF00) div 256;
  iBlue := (Color and $FF0000) div 65536;

  Result := '#' + IntToHex(iRed, 2) + IntToHex(iGreen, 2) + IntToHex(iBlue, 2);

The only differences are that in VB $ = &H and IntToHex() is Hex()...

Ok, now that works perfectly, but my problem is, I want to reverse it. I've searched half the internet, but couldn't find it. Does anyone know how it works? The code doesn't have to be Delphi code, it can just be VB code...

Thanks!

**kedaman** · Jul 6th, 2001, 02:35 PM

since html color is bgr, it's just the reverse rgb, so bgr is rgb reversed.

**PsychoMark** · Jul 6th, 2001, 02:40 PM

HTML is RGB, but that's not really what I meant.

Say I have this value, "#FF0000" (Red), now I want to get the individual RGB values from this, which would be FF, 00 and 00, but how do I convert this to 0-255 range so I would get 255, 0, 0?

Offcourse I can do it manually with 100 if's, but I hate that

**kedaman** · Jul 6th, 2001, 02:52 PM

It looks like it's RGB but in fact the hi byte is in the left end, not the right.

type

?&hff0000

in immediate window and it'll result, 16711680. the code for blue, not red.

I'm not familiar with delphi, so you must excuse me. in vb you'd do val("&h" & hexvalue)
If there's no built in function for this, you don't need too many if's to accomplish the same tasks. loop trough each byte from hi to low, add up the ascii-48 and substract 7 for the range A-F. then you increment the byte pointer and multiply itself with the radix(16)

**PsychoMark** · Jul 6th, 2001, 02:57 PM

Mhhhh........I'll go for the if-approach

(not good at math)

But if anyone has some VB code I can understand (I understand things better when I look at code then when someone tries to explain it

), converting it shouldn't be a problem...

**kedaman** · Jul 6th, 2001, 03:20 PM

val() function knows what to do but as said i have no idea with delphi. some pseudo for what i was trying to say:

Code:

byte x, result y
loop x from hibyte to lowbyte
	if x<58
		y=y+x-48
	else
		y=y+x-55
	y*=16

**PsychoMark** · Jul 6th, 2001, 03:23 PM

Still don't quite understand it, but thanks anyways. I'll work something out...

**kedaman** · Jul 6th, 2001, 03:26 PM

just ask if you get stuck

denniswrenn · Jul 6th, 2001, 05:56 PM

Maybe you can convert this to Delphi... It uses quite a bit of If's, but not 100

VB Code:

Private Sub Form_Load()
    Dim a As Byte, b As Byte, c As Byte
    ToRGB "#FFFFFF", a, b, c
    MsgBox a
    MsgBox b
    MsgBox c
End Sub
 
Private Sub ToRGB(ByVal sHex As String, ByRef bR As Byte, ByRef bG As Byte, ByRef bB As Byte)
    Dim sR As String
    Dim sG As String
    Dim sB As String
    Dim sR1 As String
    Dim sR2 As String
    Dim sG1 As String
    Dim sG2 As String
    Dim sB1 As String
    Dim sB2 As String
 
    sHex = UCase(sHex)
    If Left(sHex, 1) = "#" And Len(sHex) = 7 Then
        sR = Mid(sHex, 2, 2)
        sG = Mid(sHex, 4, 2)
        sB = Mid(sHex, 6, 2)
    ElseIf Len(sHex) = 6 Then
        sR = Mid(sHex, 1, 2)
        sG = Mid(sHex, 3, 2)
        sB = Mid(sHex, 5, 2)
    End If
    
    sR1 = Chr(Asc(Left(sR, 1)))
    sR2 = Chr(Asc(Right(sR, 1)))
    sG1 = Chr(Asc(Left(sG, 1)))
    sG2 = Chr(Asc(Right(sG, 1)))
    sB1 = Chr(Asc(Left(sB, 1)))
    sB2 = Chr(Asc(Right(sB, 1)))
    'RED
    If IsNum(sR1) Then
        bR = (Asc(sR1) - 48) * 16
    Else
        bR = (Asc(sR1) - 55) * 16
    End If
    If IsNum(sR2) Then
        bR = bR + (Asc(sR2) - 48)
    Else
        bR = bR + (Asc(sR2) - 55)
    End If
    'GREEN
    If IsNum(sG1) Then
        bG = (Asc(sG1) - 48) * 16
    Else
        bG = (Asc(sG1) - 55) * 16
    End If
    If IsNum(sG2) Then
        bG = bG + (Asc(sG2) - 48)
    Else
        bG = bG + (Asc(sG2) - 55)
    End If
    'BLUE
    If IsNum(sB1) Then
        bB = (Asc(sB1) - 48) * 16
    Else
        bB = (Asc(sB1) - 55) * 16
    End If
    If IsNum(sB2) Then
        bB = bB + (Asc(sB2) - 48)
    Else
        bB = bB + (Asc(sB2) - 55)
    End If
End Sub
 
Private Function IsNum(sNum As String) As Boolean
    If Len(sNum) <> 1 Then
        IsNum = False
    ElseIf Asc(sNum) >= 48 And Asc(sNum) <= 57 Then
        IsNum = True
    End If
End Function

**PsychoMark** · Jul 7th, 2001, 03:56 AM

Thank you!! That worked great!

I know this is a VB forum (really? I didn't even notice that? Wow...

), but here's the Delphi code anyways for anyone interested:

Code:

function IsNum(Value: Char): Boolean;
begin
  // Check ASCII value
  if (Ord(Value) >= 48) and (Ord(Value) <= 57) then
    Result := True
  else
    Result := False;
end;

function ConvertValue(Value: String): Byte;
var
  bResult: Byte;

begin
  // Check first character
  if IsNum(Value[1]) then
    bResult := (Ord(Value[1]) - 48) * 16
  else
    bResult := (Ord(Value[1]) - 55) * 16;

  // Check second character
  if IsNum(Value[2]) then
    bResult := bResult + (Ord(Value[2]) - 48)
  else
    bResult := bResult + (Ord(Value[2]) - 55);

  Result := bResult;
end;

function HTMLtoRGB(HTML: String): TColor;
var
  sHTML: String;
  sR,
  sG,
  sB: String;
  bR,
  bG,
  bB: Byte;
  iOffset: Integer;
  iLength: Integer;

begin
  // #ff0000 -> #FF0000 (necessary for ASCII operations)
  sHTML := UpperCase(HTML);

  // Check length
  iLength := Length(sHTML);

  if (iLength < 6) or (iLength > 7) then begin
    Result := 0;
    exit;
  end;

  if (sHTML[1] = '#') and (Length(sHTML) = 7) then
    iOffset := 2
  else
    iOffset := 1;

  // Get RGB values (using the 'string = array' rule)
  sR := sHTML[iOffset] + sHTML[iOffset + 1];
  sG := sHTML[iOffset + 2] + sHTML[iOffset + 3];
  sB := sHTML[iOffset + 4] + sHTML[iOffset + 5];

  // Convert RGB values
  bR := ConvertValue(sR);
  bG := ConvertValue(sG);
  bB := ConvertValue(sB);

  // Return color
  Result := RGB(bR, bG, bB);
end;

denniswrenn · Jul 7th, 2001, 04:07 AM

Wow, I must say, that is one effed up language

I'd prefer C++ anyday

Any particular reason you're coding in delphi rather than something like C++?(just curious)

**PsychoMark** · Jul 7th, 2001, 04:20 AM

Well, there are some reasons why I moved from VB to Delphi, and some why I didn't choose C++.

First of all, Delphi looks more like VB than C++. I initially did start to learn C++, created a DLL, but it takes a lot of code to create a window (unless you're using MFC, but that would still require a DLL, and that's the main reason I stopped using VB

). Delphi however still has the possibilities to create a Window using pure API, but also has a lot of standard components which are merged with the EXE (resulting in a 300 KB EXE file, but that isn't really that bad compared to the at least 2 MB of runtimes which VB needs)... but I created an OpenGL application recently which did create a window using only API, and it turned out to be 20 KB

Also, Delphi's IDE takes more time to load, but compiling a program is done within seconds (and that's on my P133

)...

And last but not least, the speed of Delphi compared to the speed of C++ is not that much. I wouldn't say it's just as fast, but it comes close... and if that's not enough, Delphi also supports inline assembly...

Now looking at the speed at which the programs run in both languages, compared to the time it takes to produce such a program, that made me choose Delphi...

(oh, and the help files which come with Delphi are incredible!! they're huge!! not only the Delphi help is included, but also a lot of MS SDK help files, like all the API function and OpenGL reference)

**PsychoMark** · Jul 7th, 2001, 04:23 AM

"Wow, I must say, that is one effed up language"

What did you mean with that anyways?

denniswrenn · Jul 7th, 2001, 04:24 AM

Well, you can use dialog's in C++.... MSVC++ has a dialog editor... it's like creating something in VB or Delphi(it's visual), but it results in an executable that is still horrifyingly small

But, I don't really like using dialogs... CreateWindowEx ==

**kedaman** · Jul 7th, 2001, 10:08 AM

Delphi looks much like pascal right? (begin and end everywhere) Isn't it even to pascal something VB to basic?

Originally posted by PsychoMark
Delphi however still has the possibilities to create a Window using pure API, but also has a lot of standard components which are merged with the EXE (resulting in a 300 KB EXE file, but that isn't really that bad compared to the at least 2 MB of runtimes which VB needs)

Yeah, you can do that in VB too, I remember making a unattended execution dll which used createwindowex. The VB runtimes are part of windows scripting so there's no need to include them in your package. Anyways, C++ horrifying small executables rock

**PsychoMark** · Jul 7th, 2001, 10:27 AM

1. Delphi = Object Pascal + VCL (Visual Components Library, all the controls which are merged with the EXE)

2. VB can do that, but it would still require the runtime DLL's. Even though the runtimes are included with the OS more often, users running for example Win95 would still need them... (and I must say that the AddressOf thing in VB isn't exactly the most stable

)

3. Yeah, offcourse C++ is the king when it comes to small executables and high speeds, but like I said, I don't want to spent 20 minutes just to add a textbox...

4. I don't hate C++ or anything, I think it's a great language! It's just not my primary language...

denniswrenn · Jul 7th, 2001, 01:34 PM

*ahem*

>>>>Well, you can use dialog's in C++.... MSVC++ has a dialog editor... it's like creating something in VB or Delphi(it's visual), but it results in an executable that is still horrifyingly small

<<<<

**PsychoMark** · Jul 7th, 2001, 01:41 PM

Oops, didn't notice that one... anyways, I still like Delphi a little bit more

denniswrenn · Jul 7th, 2001, 01:44 PM

Originally posted by PsychoMark
"Wow, I must say, that is one effed up language"

What did you mean with that anyways?

effed = fed = f***ed

Was just kidding though

Well, kind of; pascal is wierd..

**kedaman** · Jul 7th, 2001, 06:45 PM

I agree with dennis, pascal is weird, but i've heard it's a very nice and well structured language. Can you use pointers? With Object Pascal, do you mean the objects are all COM? Is it ActiveX compatible?

**PsychoMark** · Jul 8th, 2001, 04:43 AM

Well, I don't think it's weird, but that's just a matter of getting used to it....

It is in my opinion very well structured. The way the objects are built, it's very well done. Delphi does support Pointers (really supports, not like VB). Delphi also supports COM and ActiveX, but I don't think that's what they mean with Object Pascal. I think it has something to do with the structure of the objects, they all use a base class which they inherit properties from. You can do some nice things with that btw...

Delphi also supports things like overloading functions, built-in message handling support (just add 'message WM_PAINT' for example after you've declared a function, and it reacts to it.... at least when you declare it in a form), and inline assembly (I already mentioned that, didn't I?

)

Name something that can be done in C++, and I'll bet it can be done in Delphi too...

Oops, one thing I like about C++: "X++" or "X *= 40". Delphi doesn't support that

. It does however has the "Inc(X)" function for integers, which the compilers optimizes a lot more than "X := X + 1"...

**PsychoMark** · Jul 8th, 2001, 04:48 AM

*looks at the other thread of denniswrenn*

...and Delphi also support threading, both using the API and the supplied TThread objecty

**kedaman** · Jul 8th, 2001, 01:55 PM

Sounds very nice, if you compare to vb6. templates? if not inheritance and polymorphism i guess templates. Inline asm sounds good, but other than that the variety of operators, some low level ones not only ++ and assignment operators, what about bitshifting (<< >> <<= >>=)? and operator overloading, maybe a bit unnessesary but cool feature, you can actually replace all methods and go wild on polymorphism with object only programming

Is there a preprocessor in object pascal? You know #include #define and company

Further on inheritance, multiple inhertinace? virtual inheritance? virtual functions? what about type structures, can they functions as objects like in c++, and I don't mean COM ones.

**PsychoMark** · Jul 8th, 2001, 02:10 PM

Wow, that's a lot of questions. Actually I don't really know, I've only worked with Delphi for about a month now, and I'm not really doing things like bitshifting

You should check out borland.com or something for those kind of questions, I just know I like Delphi and that it can do a lot more than VB at a much higher speed

**kedaman** · Jul 8th, 2001, 02:16 PM

maybe, or maybe i'll stay with c++. pascal just looks weird

denniswrenn · Jul 8th, 2001, 02:19 PM

C++ Rules..!

But I installed Delphi anyway(free copy of Ver. 4 standard with C++ Builder 5 pro) just incase garfield needs help

**Jotaf98** · Jul 9th, 2001, 02:33 PM

Hey, I have a question: what do you think is better, C++ or ASM?

Because I wanna learn one of them but I don't know which; also I don't know where to start learning it

**PsychoMark** · Jul 9th, 2001, 02:38 PM

I think C++. It's fast enough, allows for more rapid development, but still allows ASM to be used in case speed is really the top priority...

**parksie** · Jul 9th, 2001, 02:49 PM

C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++!
BURN IN HELL ALL NON-C++ USERS!!!!! BWAHAHAHAHAHAHA

I hate Pascal

I don't like the way it has keywords for things you don't need (begin/end) and also the separation of variables from code is nasty.

**PsychoMark** · Jul 9th, 2001, 02:53 PM

Is Parksie trying to make a point?

(burn in hell all you "burn in hell people who don't use [your language here]" !!

)

**parksie** · Jul 9th, 2001, 02:55 PM

Me? Point? Naaaaahhhh

**kedaman** · Jul 9th, 2001, 02:59 PM

Originally posted by parksie
C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++! C++!
BURN IN HELL ALL NON-C++ USERS!!!!! BWAHAHAHAHAHAHA

I hate Pascal I don't like the way it has keywords for things you don't need (begin/end) and also the separation of variables from code is nasty.

exactly, being and end all the time instead of {} makes you sick

C++ for the real pro's, VB for kids and pascal for other weirdos

**parksie** · Jul 9th, 2001, 03:04 PM

The neat thing with C++ or C is that you can really strip it down to the bare limit - you can get a 32-bit C program in under a kilobyte by using no standard libraries and implementing all the code yourself (including _mainCRTStartup).

**Jotaf98** · Jul 9th, 2001, 06:17 PM

Hehe I tricked you all, I've been learning ASM for a long time to optimize my special effects module (it's getting kinda hard now hehe) and it rocks, check this out

**Jotaf98** · Jul 9th, 2001, 06:23 PM

Btw look at the size of the EXE, it's HIGHLY optimized!

**PsychoMark** · Jul 10th, 2001, 01:57 AM

Originally posted by kedaman
exactly, being and end all the time instead of {} makes you sick C++ for the real pro's, VB for kids and pascal for other weirdos

Well, in that case I'm a weirdo!

To Jotaf98, can you post the code used to do the messagebox?

I tried to get a program as small as possible in Delphi too, it turned out to be 16 kb (mainly because of the System unit Delphi automatically adds), but at least the code was readible:

Code:

program msgbox;

const
  { MessageBox constants }
  MB_OK = $00000000;
  MB_ICONINFORMATION = $00000040;

{ MessageBox API }
function MessageBox(hWnd: LongWord; lpText, lpCaption: PChar; uType: LongWord): Integer; 
    stdcall; external 'user32.dll' name 'MessageBoxA';

begin
  MessageBox(0, 'Delphi kicks ass!', ':p', MB_OK or MB_ICONINFORMATION);
end.

(btw, the program to color the code, made that in Delphi, took me 2 hours, including preview option and nice looking interface, now try that in ASM

)

Btw, where did you learn ASM? Since Delphi supports the 'asm' keyword, I would sure like to try it out some time...

[edit] note to self: add line-break option for code [/edit]

**PsychoMark** · Jul 10th, 2001, 09:54 AM

Oops, nevermind the "I want to learn ASM part"...

Just looked at a tutorial to show a MessageBox...

*runs away screaming and pulling his hair out*

I'll stick with Delphi for a while

(just finished my first OpenGL test, OpenGL rules!!

)

**Jotaf98** · Jul 11th, 2001, 05:50 PM

Hehe, in fact, that's the program that comes with the sample winzip file, modified a bit with my Hex Editor

Do you know any good books about C++? Whenever someone reccomends me a book, someone else says that book s*cks...

And the only part that I wanna learn is DLLs and dynamic 2 and 3 dimensioned arrays

**kedaman** · Jul 12th, 2001, 02:27 PM

If that's the only thing you want to learn, that's probably not where you'll end up.
There's no built in "arrays" in C++, you use pointers, and you'll learn to love them or you'll just quit C++. There are of course array classes but I think they suck. exporting DLL functions shouldn't be that hard, in fact that was the first thing I wanted to do when I started C++ and now it's the last thing I want to learn

I still do recommend Sam's teach yourself C++ in 21 days, it took about 5 days for me to read trough.

**PsychoMark** · Jul 12th, 2001, 02:58 PM

*cough* Delphi *cough*

Well, actually, that's exactly what I wanted to use C++ for too. I only looked at the sample at DirectX4VB, and did get it working, but that's about it... still addicted to pointers though

I did download a tutorial for C++ (CyberCarsten's site if I'm correct), which wasn't specifically about DLL's and arrays, but it does help learning the language, so I'll go with kedaman's advice...

Thread: Html -> Rgb

Thread Tools

Display

Html -> Rgb

use the same function

Illusion

I knew it, those := was looking very pascalish to me

Posting Permissions