private static void LoadCharsBlock(byte[] buffer, int block_size, FontData font_data)
{
const int char_line_block_size = 20;
int char_count = block_size / char_line_block_size;
font_data.Chars = new char[char_count];
font_data.GlyphOffsets = new SVec2[char_count];
font_data.GlyphRects = new SRect[char_count];
font_data.GlyphXAdvances = new float[char_count];
for (int i = 0; i < char_count; ++i)
{
int start = i * char_line_block_size;
int char_index = MemWordHelpers.MakeDWordLittleEndian(buffer, start);
font_data.Chars[i] = char_index >= 0 ? (char)char_index : '\0';
font_data.GlyphRects[i] = new SRect(
MemWordHelpers.MakeWordLittleEndian(buffer, start + 4),
MemWordHelpers.MakeWordLittleEndian(buffer, start + 6),
MemWordHelpers.MakeWordLittleEndian(buffer, start + 8),
MemWordHelpers.MakeWordLittleEndian(buffer, start + 10)
);
font_data.GlyphOffsets[i] = new SVec2(
MemWordHelpers.MakeWordLittleEndian(buffer, start + 12),
MemWordHelpers.MakeWordLittleEndian(buffer, start + 14)
);
font_data.GlyphXAdvances[i] = MemWordHelpers.MakeWordLittleEndian(buffer, start + 16);
}
}
public static void ParseAndFillData(FontData font_data, byte[] font_descr_content)
{
using var stream = new MemoryStream(font_descr_content);
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
var buffer = new byte[1024];
stream.Read(buffer, 0, 4);
if (buffer[0] != 66 || buffer[1] != 77 || buffer[2] != 70)
{
throw new InvalidDataException("Source steam does not contain BMFont data.");
}
if (buffer[3] != 3)
{
throw new InvalidDataException("Only BMFont version 3 format data is supported.");
}
// Following the first four bytes is a series of blocks with information. Each block starts with a one byte block type identifier, followed by a 4 byte integer that gives the size of the block, not including the block type identifier and the size value.
while (stream.Read(buffer, 0, 5) != 0)
{
byte block_type;
int block_size;
block_type = buffer[0];
block_size = MemWordHelpers.MakeDWordLittleEndian(buffer, 1);
if (block_size > buffer.Length)
{
buffer = new byte[block_size];
}
if (stream.Read(buffer, 0, block_size) != block_size)
{
throw new InvalidDataException("Failed to read enough data to fill block.");
}
switch (block_type)
{
case 1: // Block type 1: info
LoadInfoBlock(buffer, font_data);
break;
case 2: // Block type 2: common
LoadCommonBlock(buffer, font_data);
break;
case 3: // Block type 3: pages
break;
case 4: // Block type 4: chars
LoadCharsBlock(buffer, block_size, font_data);
break;
case 5: // Block type 5: kerning pairs
//LoadKerningsBlock(buffer, block_size);
break;
default: throw new InvalidDataException("Block type " + block_type + " is not a valid BMFont block");
}
}
}