panda3d/panda/src/text/dynamicTextFont.cxx
2002-02-11 15:07:11 +00:00

327 lines
11 KiB
C++

// Filename: dynamicTextFont.cxx
// Created by: drose (08Feb02)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001, Disney Enterprises, Inc. All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license. You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://www.panda3d.org/license.txt .
//
// To contact the maintainers of this program write to
// panda3d@yahoogroups.com .
//
////////////////////////////////////////////////////////////////////
#include "dynamicTextFont.h"
#ifdef HAVE_FREETYPE
#include "config_text.h"
#include "config_util.h"
FT_Library DynamicTextFont::_ft_library;
bool DynamicTextFont::_ft_initialized = false;
bool DynamicTextFont::_ft_ok = false;
TypeHandle DynamicTextFont::_type_handle;
// This constant determines how big a particular point size font
// appears. By convention, 10 points is 1 foot high.
static const float points_per_unit = 10.0f;
// A universal convention.
static const float points_per_inch = 72.0f;
////////////////////////////////////////////////////////////////////
// Function: DynamicTextFont::Constructor
// Access: Published
// Description: The constructor expects the name of some font file
// that FreeType can read, along with face_index,
// indicating which font within the file to load
// (usually 0).
////////////////////////////////////////////////////////////////////
DynamicTextFont::
DynamicTextFont(const Filename &font_filename, int face_index) {
_texture_margin = 2;
_poly_margin = 1.0f;
_page_x_size = 256;
_page_y_size = 256;
_point_size = 10.0f;
_pixels_per_unit = 40.0f;
if (!_ft_initialized) {
initialize_ft_library();
}
if (!_ft_ok) {
text_cat.error()
<< "Unable to read font " << font_filename << ": FreeType library not available.\n";
return;
}
Filename path(font_filename);
if (!path.resolve_filename(get_model_path())) {
text_cat.error()
<< "Unable to find font file " << font_filename << "\n";
} else {
string os_specific = path.to_os_specific();
int error = FT_New_Face(_ft_library,
os_specific.c_str(),
face_index,
&_face);
if (error == FT_Err_Unknown_File_Format) {
text_cat.error()
<< "Unable to read font " << font_filename << ": unknown file format.\n";
} else if (error) {
text_cat.error()
<< "Unable to read font " << font_filename << ": invalid.\n";
} else {
string name = _face->family_name;
if (_face->style_name != NULL) {
name += " ";
name += _face->style_name;
}
set_name(name);
text_cat.info()
<< "Loaded font " << get_name() << "\n";
_is_valid = true;
reset_scale();
}
}
}
////////////////////////////////////////////////////////////////////
// Function: DynamicTextFont::get_num_pages
// Access: Published
// Description: Returns the number of pages associated with the font.
// Initially, the font has zero pages; when the first
// piece of text is rendered with the font, it will add
// additional pages as needed. Each page is a Texture
// object that contains the images for each of the
// glyphs currently in use somewhere.
////////////////////////////////////////////////////////////////////
int DynamicTextFont::
get_num_pages() const {
return _pages.size();
}
////////////////////////////////////////////////////////////////////
// Function: DynamicTextFont::get_page
// Access: Published
// Description: Returns the nth page associated with the font.
// Initially, the font has zero pages; when the first
// piece of text is rendered with the font, it will add
// additional pages as needed. Each page is a Texture
// object that contains the images for each of the
// glyphs currently in use somewhere.
////////////////////////////////////////////////////////////////////
DynamicTextPage *DynamicTextFont::
get_page(int n) const {
nassertr(n >= 0 && n < (int)_pages.size(), (DynamicTextPage *)NULL);
return _pages[n];
}
////////////////////////////////////////////////////////////////////
// Function: DynamicTextFont::clear
// Access: Published
// Description: Drops all the glyphs out of the cache and frees any
// association with any previously-generated pages.
//
// Calling this frequently can result in wasted texture
// memory, as any previously rendered text will still
// keep a pointer to the old, previously-generated
// pages. As long as the previously rendered text
// remains around, the old pages will also remain
// around.
////////////////////////////////////////////////////////////////////
void DynamicTextFont::
clear() {
_pages.clear();
_cache.clear();
}
////////////////////////////////////////////////////////////////////
// Function: DynamicTextFont::write
// Access: Published, Virtual
// Description:
////////////////////////////////////////////////////////////////////
void DynamicTextFont::
write(ostream &out, int indent_level) const {
indent(out, indent_level)
<< "DynamicTextFont " << get_name() << ", "
<< _cache.size() << " glyphs, "
<< get_num_pages() << " pages.\n";
}
////////////////////////////////////////////////////////////////////
// Function: DynamicTextFont::get_glyph
// Access: Public, Virtual
// Description: Returns the glyph associated with the given character
// code, or NULL if there is no such glyph.
////////////////////////////////////////////////////////////////////
const TextGlyph *DynamicTextFont::
get_glyph(int character) {
Cache::iterator ci = _cache.find(character);
if (ci != _cache.end()) {
return (*ci).second;
}
if (!_is_valid) {
return (TextGlyph *)NULL;
}
DynamicTextGlyph *glyph = make_glyph(character);
_cache.insert(Cache::value_type(character, glyph));
return glyph;
}
////////////////////////////////////////////////////////////////////
// Function: DynamicTextFont::reset_scale
// Access: Private
// Description: Resets the font to use the current _point_size and
// _pixels_per_unit. Returns true if successful, false
// otherwise.
////////////////////////////////////////////////////////////////////
bool DynamicTextFont::
reset_scale() {
float units_per_inch = (points_per_inch / points_per_unit);
int dpi = (int)(_pixels_per_unit * units_per_inch);
int error = FT_Set_Char_Size(_face,
(int)(_point_size * 64), (int)(_point_size * 64),
dpi, dpi);
if (error) {
text_cat.warning()
<< "Unable to set " << get_name()
<< " to " << _point_size << "pt at " << dpi << " dpi.\n";
_line_height = 1.0f;
return false;
}
// The face's height is only relevant for scalable fonts,
// according to FreeType. How should we determine whether we
// have a scalable font or otherwise?
float pixel_size = _point_size * (_pixels_per_unit / points_per_unit);
_line_height = (float)_face->height * pixel_size / ((float)_face->units_per_EM * 64.0f);
return true;
}
////////////////////////////////////////////////////////////////////
// Function: DynamicTextFont::make_glyph
// Access: Private
// Description: Slots a space in the texture map for the new
// character and renders the glyph, returning the
// newly-created TextGlyph object, or NULL if the
// glyph cannot be created for some reason.
////////////////////////////////////////////////////////////////////
DynamicTextGlyph *DynamicTextFont::
make_glyph(int character) {
int error = FT_Load_Char(_face, character, FT_LOAD_RENDER);
if (error) {
text_cat.error()
<< "Unable to render character " << character << "\n";
return (DynamicTextGlyph *)NULL;
}
FT_GlyphSlot slot = _face->glyph;
FT_Bitmap &bitmap = slot->bitmap;
if (bitmap.pixel_mode != ft_pixel_mode_grays) {
text_cat.error()
<< "Unexpected pixel mode in bitmap: " << (int)bitmap.pixel_mode << "\n";
return (DynamicTextGlyph *)NULL;
}
if (bitmap.num_grays != 256) {
// We expect 256 levels of grayscale to come back from FreeType,
// since that's what we asked for.
text_cat.warning()
<< "Expected 256 levels of gray, got " << bitmap.num_grays << "\n";
}
DynamicTextGlyph *glyph = slot_glyph(bitmap.width, bitmap.rows);
// Now copy the rendered glyph into the texture.
unsigned char *buffer_row = bitmap.buffer;
for (int yi = 0; yi < bitmap.rows; yi++) {
unsigned char *texture_row = glyph->get_row(yi);
nassertr(texture_row != (unsigned char *)NULL, (DynamicTextGlyph *)NULL);
memcpy(texture_row, buffer_row, bitmap.width);
buffer_row += bitmap.pitch;
}
glyph->_page->mark_dirty(Texture::DF_image);
float advance = slot->advance.x / 64.0;
glyph->make_geom(slot->bitmap_top, slot->bitmap_left, advance,
_poly_margin, _pixels_per_unit);
return glyph;
}
////////////////////////////////////////////////////////////////////
// Function: DynamicTextFont::slot_glyph
// Access: Private
// Description: Chooses a page that will have room for a glyph of the
// indicated size (after expanding the indicated size by
// the current margin). Returns the newly-allocated
// glyph on the chosen page; the glyph has not been
// filled in yet except with its size.
////////////////////////////////////////////////////////////////////
DynamicTextGlyph *DynamicTextFont::
slot_glyph(int x_size, int y_size) {
// Increase the indicated size by the current margin.
x_size += _texture_margin * 2;
y_size += _texture_margin * 2;
Pages::iterator pi;
for (pi = _pages.begin(); pi != _pages.end(); ++pi) {
DynamicTextPage *page = (*pi);
DynamicTextGlyph *glyph = page->slot_glyph(x_size, y_size, _texture_margin);
if (glyph != (DynamicTextGlyph *)NULL) {
return glyph;
}
if (page->is_empty()) {
// If we couldn't even put in on an empty page, we're screwed.
text_cat.error()
<< "Glyph of size " << x_size << " by " << y_size
<< " won't fit on an empty page.\n";
return (DynamicTextGlyph *)NULL;
}
}
// We need to make a new page.
PT(DynamicTextPage) page = new DynamicTextPage(this);
_pages.push_back(page);
return page->slot_glyph(x_size, y_size, _texture_margin);
}
////////////////////////////////////////////////////////////////////
// Function: DynamicTextFont::initialize_ft_library
// Access: Private, Static
// Description: Should be called exactly once to initialize the
// FreeType library.
////////////////////////////////////////////////////////////////////
void DynamicTextFont::
initialize_ft_library() {
if (!_ft_initialized) {
int error = FT_Init_FreeType(&_ft_library);
_ft_initialized = true;
if (error) {
text_cat.error()
<< "Unable to initialize FreeType; DynamicTextFonts will not load.\n";
} else {
_ft_ok = true;
}
}
}
#endif // HAVE_FREETYPE