void GlFont::InitialiseFont(const unsigned char* ttf_buffer, float pixel_height, int tex_w, int tex_h)
{
font_height_px = pixel_height;
this->tex_w = tex_w;
this->tex_h = tex_h;
font_bitmap = new unsigned char[tex_w*tex_h];
const int offset = 0;
stbtt_fontinfo f;
if (!stbtt_InitFont(&f, ttf_buffer, offset)) {
throw std::runtime_error("Unable to initialise font");
}
float scale = stbtt_ScaleForPixelHeight(&f, pixel_height);
STBTT_memset(font_bitmap, 0, tex_w*tex_h);
int x = 1;
int y = 1;
int bottom_y = 1;
// Generate bitmap and char indices
for (int i=0; i < NUM_CHARS; ++i) {
int advance, lsb, x0,y0,x1,y1,gw,gh;
int g = stbtt_FindGlyphIndex(&f, FIRST_CHAR + i);
stbtt_GetGlyphHMetrics(&f, g, &advance, &lsb);
stbtt_GetGlyphBitmapBox(&f, g, scale,scale, &x0,&y0,&x1,&y1);
gw = x1-x0;
gh = y1-y0;
if (x + gw + 1 >= tex_w)
y = bottom_y, x = 1; // advance to next row
if (y + gh + 1 >= tex_h) // check if it fits vertically AFTER potentially moving to next row
throw std::runtime_error("Unable to initialise font");
STBTT_assert(x+gw < tex_w);
STBTT_assert(y+gh < tex_h);
stbtt_MakeGlyphBitmap(&f, font_bitmap+x+y*tex_w, gw,gh,tex_w, scale,scale, g);
// Adjust offset for edges of pixels
chardata[i] = GlChar(tex_w,tex_h, x, y, gw, gh, scale*advance, x0 -0.5, -y0 -0.5);
x = x + gw + 1;
if (y+gh+1 > bottom_y)
bottom_y = y+gh+1;
}
// Generate kern table
for (int i=0; i < NUM_CHARS; ++i) {
for (int j=0; j < NUM_CHARS; ++j) {
kern_table[i*NUM_CHARS+j] = scale * stbtt_GetCodepointKernAdvance(&f,i,j);
}
}
}
bool GlFont::LoadFontFromText(char* xml_text)
{
rapidxml::xml_document<> doc;
doc.parse<0>(xml_text);
rapidxml::xml_node<>* node_font = doc.first_node("font");
if(node_font) {
rapidxml::xml_node<>* node_info = node_font->first_node("info");
rapidxml::xml_node<>* node_common = node_font->first_node("common");
rapidxml::xml_node<>* node_pages = node_font->first_node("pages");
rapidxml::xml_node<>* node_chars = node_font->first_node("chars");
rapidxml::xml_node<>* node_kerns = node_font->first_node("kernings");
if(node_info && node_common && node_chars) {
sName = node_info->first_attribute_value<std::string>("face");
sCharset = node_info->first_attribute_value<std::string>("charset");
nSize = node_info->first_attribute_value<int>("size");
nStretchHeight = node_info->first_attribute_value<int>("stretchH");
nOutline = node_info->first_attribute_value<int>("outline");
bBold = node_info->first_attribute_value<bool>("bold");
bItalic = node_info->first_attribute_value<bool>("italic");
bUnicode = node_info->first_attribute_value<bool>("unicode");
bSmooth = node_info->first_attribute_value<bool>("smooth");
bAntiAliasing = node_info->first_attribute_value<bool>("aa");
nBase = node_common->first_attribute_value<int>("base");
nScaleWidth = node_common->first_attribute_value<int>("scaleW");
nScaleHeight = node_common->first_attribute_value<int>("scaleH");
nLineHeight = node_common->first_attribute_value<int>("lineHeight");
nPages = node_common->first_attribute_value<int>("pages");
if(node_pages) {
for( rapidxml::xml_node<>* xml_page = node_pages->first_node();
xml_page; xml_page = xml_page->next_sibling() )
{
const std::string filename = xml_page->first_attribute_value<std::string>( "file" );
LoadGlImage(mTex, filename, false );
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
}
}else{
mTex.Reinitialise(nScaleWidth, nScaleHeight, GL_ALPHA,false,0,GL_ALPHA,GL_UNSIGNED_BYTE,font_image_data );
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
}
if( nPages < 1) {
std::cerr << "Incorrect number of font pages loaded." << std::endl;
}
for( rapidxml::xml_node<>* xml_char = node_chars->first_node();
xml_char; xml_char = xml_char->next_sibling() )
{
char id = xml_char->first_attribute_value<int>("id");
int x = xml_char->first_attribute_value<int>("x");
int y = xml_char->first_attribute_value<int>("y");
int width = xml_char->first_attribute_value<int>("width");
int height = xml_char->first_attribute_value<int>("height");
int xOffset = xml_char->first_attribute_value<int>("xoffset");
int yOffset = xml_char->first_attribute_value<int>("yoffset");
int xAdvance = xml_char->first_attribute_value<int>("xadvance");
int page = xml_char->first_attribute_value<int>("page");
if(page != 0) {
std::cerr << "Multi-page font not supported" << std::endl;
page = 0;
}
mmCharacters[id] = GlChar(nScaleWidth, nScaleHeight,
x,y,width, height,xAdvance,
xOffset,nBase - yOffset);
}
if(node_kerns) {
for( rapidxml::xml_node<>* xml_kern = node_kerns->first_node();
xml_kern; xml_kern = xml_kern->next_sibling() )
{
char first = xml_kern->first_attribute_value<char>("first");
char second = xml_kern->first_attribute_value<char>("second");
int amount = xml_kern->first_attribute_value<int>("amount");
mmCharacters[second].SetKern(first,amount);
}
}
}
}
return false;
}
