"""Implement Pygame's font interface using Pango for international support Depends on: pygtk (to get the pango context) pycairo (for the pango rendering context) python-pango (obviously) numpy (pygame) As soon as you import this module you have loaded *all* of the above. You can still use pygame.font until you decide to call install(), which will replace pygame.font with this module. Notes: * no ability to load TTF files, PangoFont uses the font files registered with GTK/X to render graphics, it cannot load an arbitrary TTF file. Most non-Sugar Pygame games use bundled TTF files, which means that you will likely need at least some changes to your font handling. Note, however, that the Pygame Font class is available to load the TTF files, so if you don't want to take advantage of PangoFont for already written code, but want to use it for "system font" operations, you can mix the two. * metrics are missing, Pango can provide the information, but the more involved metrics system means that translating to the simplified model in Pygame has as of yet not been accomplished. * better support for "exotic" languages and scripts (which is why we use it) The main problem with SDL_ttf is that it doesn't handle internationalization nearly as well as Pango (in fact, pretty much nothing does). However, it is fairly fast and it has a rich interface. You should avoid fonts where possible, prerender using Pango for internationalizable text, and use Pango or SDL_ttf for text that really needs to be rerendered each frame. (Use SDL_ttf if profiling demonstrates that performance is poor with Pango.) Note: Font -- is the original Pygame Font class, which allows you to load fonts from TTF files/filenames PangoFont -- is the Pango-specific rendering engine which allows for the more involved cross-lingual rendering operations. """ import pango import logging import pangocairo import pygame.rect, pygame.image import gtk import struct from pygame import surface from pygame.font import Font from olpcgames import _cairoimage log = logging.getLogger( 'olpcgames.pangofont' ) ##log.setLevel( logging.DEBUG ) # Install myself on top of pygame.font def install(): """Replace Pygame's font module with this module""" log.info( 'installing' ) from olpcgames import pangofont import pygame pygame.font = pangofont import sys sys.modules["pygame.font"] = pangofont class PangoFont(object): """Base class for a pygame.font.Font-like object drawn by Pango Attributes of note: fd -- instances Pango FontDescription object WEIGHT_* -- parameters for use with set_weight STYLE_* -- parameters for use with set_style """ WEIGHT_BOLD = pango.WEIGHT_BOLD WEIGHT_HEAVY = pango.WEIGHT_HEAVY WEIGHT_LIGHT = pango.WEIGHT_LIGHT WEIGHT_NORMAL = pango.WEIGHT_NORMAL WEIGHT_SEMIBOLD = pango.WEIGHT_SEMIBOLD WEIGHT_ULTRABOLD = pango.WEIGHT_ULTRABOLD WEIGHT_ULTRALIGHT = pango.WEIGHT_ULTRALIGHT STYLE_NORMAL = pango.STYLE_NORMAL STYLE_ITALIC = pango.STYLE_ITALIC STYLE_OBLIQUE = pango.STYLE_OBLIQUE def __init__(self, family=None, size=None, bold=False, italic=False, underline=False, fd=None): """If you know what pango.FontDescription (fd) you want, pass it in as 'fd'. Otherwise, specify any number of family, size, bold, or italic, and we will try to match something up for you.""" # Always set the FontDescription (FIXME - only set it if the user wants # to change something?) if fd is None: fd = pango.FontDescription() if family is not None: fd.set_family(family) if size is not None: log.debug( 'Pre-conversion size: %s', size ) size = int(size*1024) log.debug( 'Font size: %s', size, ) fd.set_size(size) # XXX magic number, pango's scaling self.fd = fd self.set_bold( bold ) self.set_italic( italic ) self.set_underline( underline ) def render(self, text, antialias=True, color=(255,255,255), background=None ): """Render the font onto a new Surface and return it. We ignore 'antialias' and use system settings. text -- (unicode) string with the text to render antialias -- attempt to antialias the text or not color -- three or four-tuple of 0-255 values specifying rendering colour for the text background -- three or four-tuple of 0-255 values specifying rendering colour for the background, or None for trasparent background returns a pygame image instance """ log.info( 'render: %r, antialias = %s, color=%s, background=%s', text, antialias, color, background ) layout = self._createLayout( text ) # determine pixel size (logical, ink) = layout.get_pixel_extents() ink = pygame.rect.Rect(ink) # Create a new Cairo ImageSurface csrf,cctx = _cairoimage.newContext( ink.w, ink.h ) cctx = pangocairo.CairoContext(cctx) # Mangle the colors on little-endian machines. The reason for this # is that Cairo writes native-endian 32-bit ARGB values whereas # Pygame expects endian-independent values in whatever format. So we # tell our users not to expect transparency here (avoiding the A issue) # and we swizzle all the colors around. # render onto it if background is not None: background = _cairoimage.mangle_color( background ) cctx.set_source_rgba(*background) cctx.paint() log.debug( 'incoming color: %s', color ) color = _cairoimage.mangle_color( color ) log.debug( ' translated color: %s', color ) cctx.new_path() cctx.layout_path(layout) cctx.set_source_rgba(*color) cctx.fill() # Create and return a new Pygame Image derived from the Cairo Surface return _cairoimage.asImage( csrf ) def set_bold( self, bold=True): """Set our font description's weight to "bold" or "normal" bold -- boolean, whether to set the value to "bold" weight or not """ if bold: self.set_weight( self.WEIGHT_BOLD ) else: self.set_weight( self.WEIGHT_NORMAL ) def set_weight( self, weight ): """Explicitly set our pango-style weight value""" self.fd.set_weight( weight ) return self.get_weight() def get_weight( self ): """Explicitly get our pango-style weight value""" return self.fd.get_weight() def get_bold( self ): """Return whether our font's weight is bold (or above)""" return self.fd.get_weight() >= pango.WEIGHT_BOLD def set_italic( self, italic=True ): """Set our "italic" value (style)""" if italic: self.set_style( self.STYLE_ITALIC ) else: self.set_style( self.STYLE_NORMAL ) def set_style( self, style ): """Set our font description's pango-style""" self.fd.set_style( style ) return self.fd.get_style() def get_style( self ): """Get our font description's pango-style""" return self.fd.get_style() def get_italic( self ): """Return whether we are currently italicised""" return self.fd.get_style() == self.STYLE_ITALIC # what about oblique? def set_underline( self, underline=True ): """Set our current underlining properly""" self.underline = underline def get_underline( self ): """Retrieve our current underline setting""" return self.underline def _createLayout( self, text ): """Produces a Pango layout describing this text in this font""" # create layout layout = pango.Layout(gtk.gdk.pango_context_get()) layout.set_font_description(self.fd) if self.underline: attrs = layout.get_attributes() if not attrs: attrs = pango.AttrList() attrs.insert(pango.AttrUnderline(pango.UNDERLINE_SINGLE, 0, 32767)) layout.set_attributes( attrs ) layout.set_text(text) return layout def size( self, text ): """Determine space required to render given text returns tuple of (width,height) """ layout = self._createLayout( text ) (logical, ink) = layout.get_pixel_extents() ink = pygame.rect.Rect(ink) return (ink.width,ink.height) ## def get_linesize( self ): ## """Determine inter-line spacing for the font""" ## font = self.get_context().load_font( self.fd ) ## metrics = font.get_metrics() ## return pango.PIXELS( metrics.get_ascent() ) ## def get_height( self ): ## def get_ascent( self ): ## def get_descent( self ): class SysFont(PangoFont): """Construct a PangoFont from a font description (name), size in pixels, bold, and italic designation. Similar to SysFont from Pygame.""" def __init__(self, name, size, bold=False, italic=False): fd = pango.FontDescription(name) fd.set_absolute_size(size*pango.SCALE) if bold: fd.set_weight(pango.WEIGHT_BOLD) if italic: fd.set_style(pango.STYLE_OBLIQUE) super(SysFont, self).__init__(fd=fd) # originally defined a new class, no reason for that... NotImplemented = NotImplementedError def match_font(name,bold=False,italic=False): """Stub, does not work, use fontByDesc instead""" raise NotImplementedError("PangoFont doesn't support match_font directly, use SysFont or .fontByDesc") def fontByDesc(desc="",bold=False,italic=False): """Constructs a FontDescription from the given string representation. The format of the fontByDesc string representation is passed directly to the pango.FontDescription constructor and documented at: http://www.pygtk.org/docs/pygtk/class-pangofontdescription.html#constructor-pangofontdescription Bold and italic are provided as a convenience. The format of the string representation is: "[FAMILY-LIST] [STYLE-OPTIONS] [SIZE]" where FAMILY-LIST is a comma separated list of families optionally terminated by a comma, STYLE_OPTIONS is a whitespace separated list of words where each WORD describes one of style, variant, weight, or stretch, and SIZE is an decimal number (size in points). For example the following are all valid string representations: "sans bold 12" "serif,monospace bold italic condensed 16" "normal 10" The commonly available font families are: Normal, Sans, Serif and Monospace. The available styles are: Normal the font is upright. Oblique the font is slanted, but in a roman style. Italic the font is slanted in an italic style. The available weights are: Ultra-Light the ultralight weight (= 200) Light the light weight (=300) Normal the default weight (= 400) Bold the bold weight (= 700) Ultra-Bold the ultra-bold weight (= 800) Heavy the heavy weight (= 900) The available variants are: Normal Small-Caps The available stretch styles are: Ultra-Condensed the smallest width Extra-Condensed Condensed Semi-Condensed Normal the normal width Semi-Expanded Expanded Extra-Expanded Ultra-Expanded the widest width """ fd = pango.FontDescription(name) if bold: fd.set_weight(pango.WEIGHT_BOLD) if italic: fd.set_style(pango.STYLE_OBLIQUE) return PangoFont(fd=fd) def get_init(): """Return boolean indicating whether we are initialised Always returns True """ return True def init(): """Initialise the module (null operation)""" pass def quit(): """De-initialise the module (null operation)""" pass def get_default_font(): """Return default-font specification to be passed to e.g. fontByDesc""" return "sans" def get_fonts(): """Return the set of all fonts available (currently just 3 generic types)""" return ["sans","serif","monospace"] def stdcolor(color): """Produce a 4-element 0.0-1.0 color value from input""" def fixlen(color): if len(color) == 3: return tuple(color) + (255,) elif len(color) == 4: return color else: raise TypeError("What sort of color is this: %s" % (color,)) return [_fixColorBase(x) for x in fixlen(color)] def _fixColorBase( v ): """Return a properly clamped colour in floating-point space""" return max((0,min((v,255.0))))/255.0