def test_methods():
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, 10, 10)
context = cairo.Context(surface)
extents = context.glyph_extents([cairo.Glyph(0, 0, 0)])
assert isinstance(extents, cairo.TextExtents)
extents = context.text_extents("foo")
assert isinstance(extents, cairo.TextExtents)
sf = context.get_scaled_font()
extents = sf.text_extents("foo")
assert isinstance(extents, cairo.TextExtents)
extents = sf.glyph_extents([cairo.Glyph(0, 0, 0)])
assert isinstance(extents, cairo.TextExtents)
def test_glyph(index, x, y):
try:
g = cairo.Glyph(index, x, y)
except OverflowError:
pass
else:
assert g.index == index
assert g.x == x
assert g.y == y
def layout_line(self, ctx, mastis, font_size, dpi=72):
# First, cut the mastis line into kerning pairs in the order of the
# utterance.
kpairs = []
for i in range(len(mastis)):
if (i + 1 < len(mastis)):
kpairs.append((mastis[i], mastis[i + 1]))
else:
kpairs.append((mastis[i], None))
#print(f"kpairs = {kpairs}")
# Walk down the pairs converting to a list of:
# [glyph_id, x_px, y_px] lists that indicate where to place
# the glyph relative to the location of the current pen.
glayout = []
dx_ems = 0
dy_ems = 0
dpi_scale = dpi / 72.0 # NOTE: Validate this equation
font_scale = font_size * dpi_scale
x_pen, y_pen = ctx.get_current_point()
for pair in kpairs:
if (pair[1] is not None):
kern_val_ems = self.get_kerning_for_pair(pair[0], pair[1])
else:
kern_val_ems = 0
kern_val_ems = 0
current_glyph_index = self.get_glyph_index(pair[0])
current_glyph_name = self.get_glyph_name(pair[0])
current_glyph_width_ems = self.get_glyph_width(current_glyph_name)
#print(f"cglyph[{pair[0]}] width: {current_glyph_width_ems}, kerning: {pair[0]}:{pair[1]}/{kern_val_ems}, dx_ems: {dx_ems}, dy_ems: {dy_ems}, kvems: {kern_val_ems}")
# convert from em space to pixel space relative to the pen location.
# Note: specifically written this way to minimize floating error.
x_px = (dx_ems * font_scale) / self.units_per_em
y_px = (dy_ems * font_scale) / self.units_per_em
#print(f" '{pair[0]}': x_px: {x_px} y_px: {y_px}")
glyph = cairo.Glyph(current_glyph_index, x_pen + x_px,
y_pen + y_px)
#print(f" glyph: {glyph}")
glayout.append(glyph)
# Now, figure out the advance and subtract the kerning for the
# placement of the next glyph in em space. NOTE: that kerning
# values are positive or negative as appropriate, so we simply
# add it all together.
dx_ems += current_glyph_width_ems + kern_val_ems
# We don't handle vertical scripts, so ignore dy_ems.
dy_ems = 0
# TODO: Need to also return extents of line (which include the kerning)
# as another value, that will make all kinds of other things easier.
# Like computing the proper image width, etc, etc.
return glayout
def kern_test():
WIDTH = 475
HEIGHT = 128
FONT_SIZE = 30
kilta_text = "Këkketë rin in tuirachún nútokolsa li"
kilta_text = "rin rin rin"
kilta_text = "rin rin rin rin rin rin rin rin rin"
kt = ku.KiltaTokenizer()
mastis_text = kt.romanized_to_mastis(kilta_text.strip())
kf = KiltaFont("./KiThree.ttf")
face = kf.get_cairo_font_face()
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, WIDTH, HEIGHT)
ctx = cairo.Context(surface)
ctx.set_font_face(face)
ctx.set_font_size(FONT_SIZE)
# font_extents is (ascent, descent, height, max_x_advance, max_y_advance)
font_extents = ctx.font_extents()
# fill background with white
ctx.rectangle(0, 0, WIDTH, HEIGHT)
ctx.set_source_rgba(1.0, 1.0, 1.0, 1.0) # white
ctx.fill()
# Draw unkerned text
ctx.set_source_rgba(0.0, 0.0, 0.0, 1.0) # black
ctx.move_to(0, HEIGHT / 2.0 - FONT_SIZE - font_extents[1]) # descender
ctx.show_text(mastis_text)
line_extent = ctx.text_extents(mastis_text)
print(f"Unkerned Glyph extents: {line_extent}")
# Draw kerned text
ctx.move_to(0, HEIGHT / 2.0)
mastis_glyphs = kf.layout_line(ctx, mastis_text, FONT_SIZE)
ctx.show_glyphs(mastis_glyphs)
line_extent = ctx.glyph_extents(mastis_glyphs)
print(f"Kerned Glyph extents: {line_extent}")
# DEBUGGING
ctx.move_to(WIDTH / 2.0, HEIGHT / 2.0)
debug_text = kt.romanized_to_mastis("k")
debug_mastis = kf.get_glyph_index(debug_text[0])
debug_glyph = [cairo.Glyph(debug_mastis, WIDTH / 2.0, HEIGHT / 2.0 + 40)]
ctx.show_glyphs(debug_glyph)
ext = ctx.glyph_extents(debug_glyph)
print(f"ext of mastis 'k' is {ext}")
# Cleanup
del ctx
surface.write_to_png("hello.png")
del surface
print("Wrote image to hello.png")
def test_context():
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, 10, 10)
context = cairo.Context(surface)
assert context.glyph_extents([(0, 0, 0)])
context.glyph_path([(0, 0, 0)])
context.show_glyphs([(0, 0, 0)])
g = cairo.Glyph(0, 0.5, 0.25)
assert context.glyph_extents([g])
context.glyph_path([g])
context.show_glyphs([(0, 0, 0)])
def test_type():
assert cairo.Glyph
assert issubclass(cairo.Glyph, tuple)
with pytest.raises(TypeError):
cairo.Glyph()
g = cairo.Glyph(0, 0.5, 0.25)
assert hash(g) == hash(cairo.Glyph(0, 0.5, 0.25))
assert isinstance(g, tuple)
assert g == (0, 0.5, 0.25)
assert g == cairo.Glyph(0, 0.5, 0.25)
assert g[1] == 0.5
assert g.index == 0
assert g.x == 0.5
assert g.y == 0.25
with pytest.raises(AttributeError):
assert g.z
assert repr(cairo.Glyph(0, 0, 0)) == \
"cairo.Glyph(index=0, x=0.0, y=0.0)"
assert str(cairo.Glyph(0, 0, 0)) == \
"cairo.Glyph(index=0, x=0.0, y=0.0)"
assert eval(repr(g)) == g
def test_context():
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, 10, 10)
context = cairo.Context(surface)
assert context.glyph_extents([(0, 0, 0)])
context.glyph_path([(0, 0, 0)])
context.show_glyphs([(0, 0, 0)])
g = cairo.Glyph(0, 0.5, 0.25)
assert context.glyph_extents([g])
context.glyph_path([g])
context.show_glyphs([(0, 0, 0)])
with pytest.raises(TypeError):
context.glyph_path([object()])