diff options
Diffstat (limited to 'olpcgames/pangofont.py')
| -rwxr-xr-x | olpcgames/pangofont.py | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/olpcgames/pangofont.py b/olpcgames/pangofont.py new file mode 100755 index 0000000..ef2640a --- /dev/null +++ b/olpcgames/pangofont.py @@ -0,0 +1,293 @@ +"""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) + pygame (obviously) +""" +import pango +import logging +import cairo +import pangocairo +import pygame.rect, pygame.image +import gtk +import struct +from pygame import surface + +log = logging.getLogger( '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.""" + def __init__(self, family=None, size=None, bold=False, italic=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: + fd.set_size(size*1000) + + if bold: + fd.set_weight(pango.WEIGHT_BOLD) + if italic: + fd.set_style(pango.STYLE_OBLIQUE) + + self.fd = fd + + 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 ) + + # create layout + layout = pango.Layout(gtk.gdk.pango_context_get()) + layout.set_font_description(self.fd) + layout.set_text(text) + + # determine pixel size + (logical, ink) = layout.get_pixel_extents() + ink = pygame.rect.Rect(ink) + + # Create a new Cairo ImageSurface + csrf = cairo.ImageSurface(cairo.FORMAT_ARGB32, ink.w, ink.h) + cctx = pangocairo.CairoContext(cairo.Context(csrf)) + + # 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. + big_endian = struct.pack( '=i', 1 ) == struct.pack( '>i', 1 ) + if hasattr(csrf,'get_data'): + swap = True + else: + swap = False + log.debug( 'big_endian: %s swap: %s', big_endian, swap ) + def mangle_color(color): + """Mange a colour depending on endian-ness, and swap-necessity + + This implementation has only been tested on an AMD64 + machine with a get_data implementation (rather than + a get_data_as_rgba implementation). + """ + r,g,b = color[:3] + if len(color) > 3: + a = color[3] + else: + a = 255.0 + if swap and not big_endian: + return map(_fixColorBase, (b,g,r,a) ) + return map(_fixColorBase, (r,g,b,a) ) + + # render onto it + if background is not None: + background = mangle_color( background ) + cctx.set_source_rgba(*background) + cctx.paint() + + log.debug( 'incoming color: %s', color ) + color = 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 + if big_endian: + # You see, in big-endian-world, we can just use the RGB values + format = "ARGB" + else: + # But with little endian, we've already swapped R and B in + # mangle_color, so now just move the A + format = "RGBA" + if hasattr(csrf,'get_data'): + data = csrf.get_data() + else: + # XXX little-endian here, check on a big-endian machine + data = csrf.get_data_as_rgba() + format = 'RGBA' # XXX wrong, what's with all the silly swapping! + try: + data = str(data) + return pygame.image.fromstring(data, (ink.w,ink.h), format) + except ValueError, err: + err.args += (len(data), ink.w*ink.h*4,format ) + raise + +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 + +class Font(PangoFont): + """Abstract class, do not use""" + def __init__(self, *args, **kwargs): + raise NotImplementedError("PangoFont doesn't support Font directly, use SysFont or .fontByDesc") + +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 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 + +if __name__ == "__main__": + # Simple testing code... + logging.basicConfig() + from pygame import image,display, event, sprite + import pygame + import pygame.event + def main(): + display.init() + maxX,maxY = display.list_modes()[0] + screen = display.set_mode( (maxX/2, maxY/2 ) ) + background = pygame.Surface(screen.get_size()) + background = background.convert() + background.fill((255, 255,255)) + + screen.blit(background, (0, 0)) + display.flip() + + clock = pygame.time.Clock() + + font = PangoFont( size=30, family='monospace' ) + text1 = font.render( 'red', color=(255,0,0) , background=(255,255,255,0) ) + text2 = font.render( 'green', color=(0,255,0) ) + text3 = font.render( 'blue', color=(0,0,255) ) + text4 = font.render( 'blue-trans', color=(0,0,255,128) ) + text5 = font.render( 'cyan-trans', color=(0,255,255,128) ) + while 1: + clock.tick( 60 ) + for event in pygame.event.get(): + log.debug( 'event: %s', event ) + if event.type == pygame.QUIT: + return True + screen.blit( text1, (20,20 )) + screen.blit( text2, (20,80 )) + screen.blit( text3, (20,140 )) + screen.blit( text4, (200,20 )) + screen.blit( text5, (200,80 )) + display.flip() + main() + |