ifstream f(filename);
f.seekg(4);
char blocktype;
int blocksize;
while (!f.eof()) {
f.read(&blocktype, sizeof(blocktype));
f.read((char*) &blocksize, sizeof(blocksize));
switch (blocktype) {
case 1: //info
f.read((char*) &infob, blocksize);
break;
case 2: //common
f.read((char*) &commonb, blocksize);
break;
case 3: //pages
f.read((char*) &pagesb, blocksize);
break;
case 4: //chars
f.read((char*) &charsb, blocksize);
break;
case 5: //kerning pairs
f.read((char*) &kerningpairsb, blocksize);
break;
}
}
BMFont binary format reading
Author
hello, i have a problem when reading the binary format of bmfont.
this is how i do it:
this works fine for the first block, however blocktype and blocksize for the second block are 0 and some high integer...
From the documentation:
"Each block starts with a one byte block type identifier, followed by a 4 byte integer that gives the size of the block, including the 4 byte size value, but not the block type identifier."
I suspect you missed this phrase in the documentation. When reading the block, you should only read the rest of the block, since you've already read the first 4 bytes in the block.
Simply add "blocksize -= 4;" after the "f.read((char*) &blocksize, sizeof(blocksize));" line, and you should be fine.
Regards,
Andreas
"Each block starts with a one byte block type identifier, followed by a 4 byte integer that gives the size of the block, including the 4 byte size value, but not the block type identifier."
I suspect you missed this phrase in the documentation. When reading the block, you should only read the rest of the block, since you've already read the first 4 bytes in the block.
Simply add "blocksize -= 4;" after the "f.read((char*) &blocksize, sizeof(blocksize));" line, and you should be fine.
Regards,
Andreas
Author
thanks. i already thought so, that i am 4 bytes off. but why is the blocksize part of the struct then? because i have to comment it out now, since otherwise the read operation will start filling the struct at struct.blocksize which is off by 4 bytes again.
another question:
why does the charsBlock declare an array of size 1 of chars? shouldnt it declare a pointer of chars, since the size of that array should be the number characters later on?
thanks!
[Edited by - ehmdjii on January 6, 2008 7:59:37 AM]
another question:
why does the charsBlock declare an array of size 1 of chars? shouldnt it declare a pointer of chars, since the size of that array should be the number characters later on?
thanks!
[Edited by - ehmdjii on January 6, 2008 7:59:37 AM]
I need to change the documentation to not describe the structure with C structures. It confuses too many people.
As the charsBlock is inlined in the structure it must be declared as an array, rather than a pointer. Since you don't know the size of the array before hand it is common to declare it with size 1. With C and C++ there's no boundscheck anyway so there is no problem accessing elements beyond this first element.
As the charsBlock is inlined in the structure it must be declared as an array, rather than a pointer. Since you don't know the size of the array before hand it is common to declare it with size 1. With C and C++ there's no boundscheck anyway so there is no problem accessing elements beyond this first element.
Author
thanks a lot for your help.
however i have still problems reading the binary format, namely reading the chars-block. if i understand it correctly, then this is one large block with the size of sizeof(charsBlock::charInfo)*numberOfCharacters
reading the characters into the struct works fine until a certain character is reached. after that all further fstream.read() operations only read 0s. (all of the struct is 0). which also means there is no kerningBlock found. if i look at the text-version or the xml-version of the same font, it looks fine. there are no zeros and there is also the kerning-part.
which character it is, depends on the font itself. but it mostly reads between 30 and 60 characters after which it only reads 0s.
edit: ok i just found out, that eof has been reached on the fstream. could it be that the file ends too early?
edit: ok it turned out that i forgot to set the std::ios::binary flag on the fstream. sorry my bad.
[Edited by - ehmdjii on January 9, 2008 3:14:59 PM]
however i have still problems reading the binary format, namely reading the chars-block. if i understand it correctly, then this is one large block with the size of sizeof(charsBlock::charInfo)*numberOfCharacters
reading the characters into the struct works fine until a certain character is reached. after that all further fstream.read() operations only read 0s. (all of the struct is 0). which also means there is no kerningBlock found. if i look at the text-version or the xml-version of the same font, it looks fine. there are no zeros and there is also the kerning-part.
which character it is, depends on the font itself. but it mostly reads between 30 and 60 characters after which it only reads 0s.
edit: ok i just found out, that eof has been reached on the fstream. could it be that the file ends too early?
edit: ok it turned out that i forgot to set the std::ios::binary flag on the fstream. sorry my bad.
[Edited by - ehmdjii on January 9, 2008 3:14:59 PM]
OK.
I'll have to update my acGraphics::CFont class to be able to load the font in binary format as well. That way people will have a reference implementation to look at, while they implement their own.
Regards,
Andreas
I'll have to update my acGraphics::CFont class to be able to load the font in binary format as well. That way people will have a reference implementation to look at, while they implement their own.
Regards,
Andreas
This topic is closed to new replies.
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