def calculate_metrics(self):
# It seems the only way to get the font's ascent and descent is to lay
# out some glyphs and measure them.
# fake ucs2 string
text = '\0a'
layout = c_void_p()
carbon.ATSUCreateTextLayout(byref(layout))
carbon.ATSUSetTextPointerLocation(layout, text, kATSUFromTextBeginning,
kATSUToTextEnd, 1)
carbon.ATSUSetRunStyle(layout, self.atsu_style, kATSUFromTextBeginning,
kATSUToTextEnd)
# determine the metrics for this font only
carbon.ATSUSetTransientFontMatching(layout, False)
value = ATSUTextMeasurement()
carbon.ATSUGetLineControl(layout, 0, kATSULineAscentTag, sizeof(value),
byref(value), None)
self.ascent = int(math.ceil(fix2float(value)))
carbon.ATSUGetLineControl(layout, 0, kATSULineDescentTag,
sizeof(value), byref(value), None)
self.descent = -int(math.ceil(fix2float(value)))
def render(self, text):
# Convert text to UCS2
text_len = len(text)
text_ucs2 = str_ucs2(text)
# Create layout override handler to extract device advance value.
override_spec = ATSULayoutOperationOverrideSpecifier()
override_spec.operationSelector = \
kATSULayoutOperationPostLayoutAdjustment
override_spec.overrideUPP = \
ATSUDirectLayoutOperationOverrideUPP(self._layout_callback)
# Create ATSU text layout for this text and font
layout = c_void_p()
carbon.ATSUCreateTextLayout(byref(layout))
set_layout_attributes(
layout, {
kATSUCGContextTag: self._bitmap_context,
kATSULayoutOperationOverrideTag: override_spec
})
carbon.ATSUSetTextPointerLocation(layout, text_ucs2,
kATSUFromTextBeginning,
kATSUToTextEnd, text_len)
carbon.ATSUSetRunStyle(layout, self.font.atsu_style,
kATSUFromTextBeginning, kATSUToTextEnd)
# Turning on transient font matching screws up font layout
# predictability when strange fonts are installed
# <ah> Don't believe this. Can't get foreign/special characters
# without transient on.
carbon.ATSUSetTransientFontMatching(layout, True)
# Get bitmap dimensions required
rect = Rect()
carbon.ATSUMeasureTextImage(layout, kATSUFromTextBeginning,
kATSUToTextEnd, 0, 0, byref(rect))
image_width = rect.right - rect.left + 2
image_height = rect.bottom - rect.top + 2
baseline = rect.bottom + 1
lsb = rect.left
# Resize Quartz context if necessary
if (image_width > self._bitmap_rect.size.width
or image_height > self._bitmap_rect.size.height):
self._create_bitmap_context(
int(max(image_width, self._bitmap_rect.size.width)),
int(max(image_height, self._bitmap_rect.size.height)))
set_layout_attributes(layout,
{kATSUCGContextTag: self._bitmap_context})
# Draw to the bitmap
carbon.CGContextClearRect(self._bitmap_context, self._bitmap_rect)
carbon.ATSUDrawText(layout, 0, kATSUToTextEnd, fixed(-lsb + 1),
fixed(baseline))
advance = self._glyph_advance
# Round advance to nearest int. It actually looks good with sub-pixel
# advance as well -- Helvetica at 12pt is more tightly spaced, but
# Times New Roman at 12pt is too light. With integer positioning
# overall look seems darker and perhaps more uniform. It's also more
# similar (programmatically) to Win32 and FreeType. Still, worth
# messing around with (comment out next line) if you're interested.
advance = int(round(advance))
# Fix advance for zero-width space
if text == u'\u200b':
advance = 0
# A negative pitch is required, but it is much faster to load the
# glyph upside-down and flip the tex_coords. Note region used
# to start at top of glyph image.
pitch = int(4 * self._bitmap_rect.size.width)
image = pyglet.image.ImageData(image_width,
self._bitmap_rect.size.height, 'RGBA',
self._bitmap, pitch)
skip_rows = int(self._bitmap_rect.size.height - image_height)
image = image.get_region(0, skip_rows, image.width, image_height)
glyph = self.font.create_glyph(image)
glyph.set_bearings(baseline, lsb - 1, int(advance))
t = list(glyph.tex_coords)
glyph.tex_coords = t[9:12] + t[6:9] + t[3:6] + t[:3]
return glyph
def render(self, text):
# Convert text to UCS2
text_len = len(text)
text = str_ucs2(text)
# Create ATSU text layout for this text and font
layout = c_void_p()
carbon.ATSUCreateTextLayout(byref(layout))
set_layout_attributes(layout,
{kATSUCGContextTag: self._bitmap_context})
carbon.ATSUSetTextPointerLocation(layout, text, kATSUFromTextBeginning,
kATSUToTextEnd, text_len)
carbon.ATSUSetRunStyle(layout, self.font.atsu_style,
kATSUFromTextBeginning, kATSUToTextEnd)
# Turning on transient font matching screws up font layout
# predictability when strange fonts are installed
carbon.ATSUSetTransientFontMatching(layout, False)
# Get bitmap dimensions required
rect = Rect()
carbon.ATSUMeasureTextImage(layout, kATSUFromTextBeginning,
kATSUToTextEnd, 0, 0, byref(rect))
image_width = rect.right - rect.left + 2
image_height = rect.bottom - rect.top + 2
baseline = rect.bottom + 1
lsb = rect.left
# Resize Quartz context if necessary
if (image_width > self._bitmap_rect.size.width
or image_height > self._bitmap_rect.size.height):
self._create_bitmap_context(
int(max(image_width, self._bitmap_rect.size.width)),
int(max(image_height, self._bitmap_rect.size.height)))
set_layout_attributes(layout,
{kATSUCGContextTag: self._bitmap_context})
# Get typographic box, which gives advance.
bounds_actual = c_uint32()
bounds = ATSTrapezoid()
carbon.ATSUGetGlyphBounds(layout, 0, 0, kATSUFromTextBeginning,
kATSUToTextEnd, kATSUseDeviceOrigins, 1,
byref(bounds), byref(bounds_actual))
advance = fix2float(bounds.lowerRight.x) - fix2float(
bounds.lowerLeft.x)
# Draw to the bitmap
carbon.CGContextClearRect(self._bitmap_context, self._bitmap_rect)
carbon.ATSUDrawText(layout, 0, kATSUToTextEnd, fixed(-lsb + 1),
fixed(baseline))
# A negative pitch is required, but it is much faster to load the
# glyph upside-down and flip the tex_coords. Note region used
# to start at top of glyph image.
pitch = int(4 * self._bitmap_rect.size.width)
image = pyglet.image.ImageData(image_width,
self._bitmap_rect.size.height, 'RGBA',
self._bitmap, pitch)
skip_rows = int(self._bitmap_rect.size.height - image_height)
image = image.get_region(0, skip_rows, image.width, image_height)
glyph = self.font.create_glyph(image)
glyph.set_bearings(baseline, lsb - 1, int(advance))
t = list(glyph.tex_coords)
glyph.tex_coords = t[9:12] + t[6:9] + t[3:6] + t[:3]
return glyph