Converting Hex RGB Strings to a DWORD
Author
Hello All
Could someone please tell me how to convert a hex RGB color value stored in a string to an DWORD value ?
Would I first have to seperate the color components?
Basically I just need to know how to convert from Hex String to Base 10 DWORD.
Thank You
Hi,
Hope this is not some kind of homework... :)
< edit: corrected a VERY BAD ERROR in the code... boys! why didn't anybody tell me about it! :'( >
< edit II: edit strikes back. Thanks to Enigma. He just pointed out how idiot i am... gosh, i'm a badass ;_;)
Yours,
[Edited by - Emmanuel Deloget on December 16, 2004 3:40:19 PM]
bool from_hex_to_int(const std::string& hex, int& result){ result = 0; for (int i=0; i<hex.size(); i++) { // value *= 16; <--- I'M BADA55 O_o result *= 16; if (hex >= '0' && hex <= '9') { result += int(hex - '0'); } else if (hex >= 'A' && hex <= 'F') { result += int(hex - 'A') + 10; } else if (hex >= 'a' && hex <= 'f') { result += int(hex - 'a') + 10; } else { return false; } } return true;}Hope this is not some kind of homework... :)
< edit: corrected a VERY BAD ERROR in the code... boys! why didn't anybody tell me about it! :'( >
< edit II: edit strikes back. Thanks to Enigma. He just pointed out how idiot i am... gosh, i'm a badass ;_;)
Yours,
[Edited by - Emmanuel Deloget on December 16, 2004 3:40:19 PM]
And to complete the collection (unless anyone has any more):
Enigma
#include <sstream>DWORD hexStringToDword(const std::string& string){ std::stringstream ss; unsigned int uint; ss << string; ss >> std::hex >> uint; if (ss.fail()) { throw std::runtime_error("hexadecimal string expected"); } return uint;}Enigma
about as obfuscated as I could get it, assumes the hex digit is always valid and only upper case.
string in;
int out=0;
for(int i=0;i<6;++){ out*=16; out+=( in>='0' && in<='9' || in>='A' && in<='F') ? ( (in>='A' && in<='F') ? in-'A'+10 : in-'0') : 0; }
string in;
int out=0;
for(int i=0;i<6;++){ out*=16; out+=( in>='0' && in<='9' || in>='A' && in<='F') ? ( (in>='A' && in<='F') ? in-'A'+10 : in-'0') : 0; }
I think I managed to get a little more obfuscated:
Same assumptions apply.
EDIT: A slight "improvement". Also nice neat line wrapping (required a few type changes):
I think I'll leave it at that.
Enigma
[Edited by - Enigma on December 16, 2004 1:09:43 PM]
DWORD out=0xFFFFFFF0;char t;while((out & 0xF0000000) && *in){ out<<=4; t = *(in++);out+=((t>47 & t<58) | (t>64 & t<71)) ? ( (t>57) ? t-55 : t-48) : 0;}DWORD mask=out>>28<<28;while(out & mask){out &= ~mask;mask>>=4;};return out;Same assumptions apply.
EDIT: A slight "improvement". Also nice neat line wrapping (required a few type changes):
long o=~15;int t;while(o>>31&&*i){o<<=4;t=*i++;o+=t>47&t<58|t>64&t<71?t>57?t-55:t-48:0;}long m=o>>28<<28;while(o&m){o&=~m;m>>=4;}return o;I think I'll leave it at that.
Enigma
[Edited by - Enigma on December 16, 2004 1:09:43 PM]
Author
Woah, all the replies!
Thanks Guys, you helped me out alot. This isn't a homework assignment,im just trying to read hex colors from an xml file for a gui system i'm creating.
Thanks Again
Thanks Guys, you helped me out alot. This isn't a homework assignment,im just trying to read hex colors from an xml file for a gui system i'm creating.
Thanks Again
Quote:Original post by Emmanuel Deloget
Hi,bool from_hex_to_int(const std::string& hex, int& result){ result = 0; for (int i=0; i<hex.size(); i++) { value *= 16; if (hex >= '0' && hex <= '9') { result += int(hex - '0'); } else if (hex >= 'A' && hex <= 'F') { result += int(hex - 'A') + 10; } else if (hex >= 'a' && hex <= 'f') { result += int(hex - 'a') + 10; } else { return false; } } return true;}
Hope this is not some kind of homework... :)
< edit: corrected a VERY BAD ERROR in the code... boys! why didn't anybody tell me about it! :'( >
Yours,
Sorry, I meant to mention it but forgot. By the way, you've still got an error.
Enigma
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