class Path(object):
'''
id : string, copied from the svg tag's id attribute, or an autogenerated
int if there is no id attr.
loops : a list of loops. A loop is a list of vertices. A vertex is a pair
of floats or ints.
color : triple of unsigned bytes, (r, g, b)
A Path corresponds to a single SVG path tag. It may contain many
independant loops which represent either disjoint polygons or holes.
'''
next_id = 1
def __init__(self, tag=None):
self.id = None
self.loops = []
self.color = (0, 0, 0)
self.bounds = Bounds()
self.triangles = None
if tag:
self.parse(tag)
def get_id(self, attributes):
if 'id' in attributes.keys():
return attributes['id'].value
else:
self.next_id += 1
return self.next_id - 1
def parse_color(self, color):
'''
color : string, eg: '#rrggbb' or 'none'
(where rr, gg, bb are hex digits from 00 to ff)
returns a triple of unsigned bytes, eg: (0, 128, 255)
'''
if color == 'none':
return None
return (
int(color[1:3], 16),
int(color[3:5], 16),
int(color[5:7], 16))
def parse_style(self, style):
'''
style : string, eg:
fill:#ff2a2a;fill-rule:evenodd;stroke:none;stroke-width:1px;
stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1
returns color as a triple of unsigned bytes: (r, g, b), or None
'''
style_elements = style.split(';')
while style_elements:
element = style_elements.pop()
if element.startswith('fill:'):
return self.parse_color(element[5:])
return None
def parse(self, tag):
self.id = self.get_id(tag.attributes)
if 'style' in tag.attributes.keys():
style_data = tag.attributes['style'].value
self.color = self.parse_style(style_data)
path_data = tag.attributes['d'].value
parser = PathDataParser()
path_tuple = parser.to_tuples(path_data)
tracer = SvgLoopTracer()
self.loops = tracer.to_loops(path_tuple)
self.bounds.add_bounds(tracer.bounds)
def offset(self, x, y):
for loop in self.loops:
for idx, vert in enumerate(loop):
loop[idx] = (vert[0] + x, vert[1] + y)
self.bounds.offset(x, y)
def tessellate(self):
if self.color:
self.triangles = tesselate(self.loops)
def _serialise_verts(self):
for vert in self.triangles:
yield vert[0]
yield vert[1]
def add_to_batch(self, batch):
'''
Adds itself to the given batch, as as single primitive of indexed
GL_TRIANGLES. Note that Batch will aggregate all such additions into
a single large primitive.
'''
if self.triangles:
num_verts = len(self.triangles)
serial_verts = list(self._serialise_verts())
colors = self.color * num_verts
indices = range(num_verts)
batch.add_indexed(
num_verts,
GL_TRIANGLES,
None,
indices,
('v2f/static', serial_verts),
('c3B/static', colors),
)
class SvgBatch(object):
'''
Maintains an ordered list of paths, each one corresponding to a path tag
from an SVG file. Creates a pylget Batch containing all these paths, for
rendering as a single OpenGL GL_TRIANGLES indexed vert primitive.
'''
def __init__(self, filename=None):
'''
filename: string, absolute or relative filename of an SVG file
'''
self.filename = filename
self.paths = []
self.path_by_id = {}
self.bounds = Bounds()
self.batch = None
@property
def width(self):
return self.bounds.width
@property
def height(self):
return self.bounds.height
def __getattr__(self, name):
if hasattr(self.path_by_id, name):
return getattr(self.path_by_id, name)
raise AttributeError(name)
def __getitem__(self, index):
return self.path_by_id[index]
def parse_svg(self):
'''
Populates self.paths from the <path> tags in the svg file.
'''
doc = xml.dom.minidom.parse(self.filename)
path_tags = doc.getElementsByTagName('path')
for path_tag in path_tags:
path = Path(path_tag)
self.paths.append(path)
self.path_by_id[path.id] = path
self.bounds.add_bounds(path.bounds)
def center(self):
'''
Offset all verts put center of svg at the origin
'''
center = self.bounds.get_center()
for path in self.paths:
path.offset(-center[0], -center[1])
self.bounds.offset(-center[0], -center[1])
def create_batch(self):
'''
Returns a new pyglet Batch object populated with indexed GL_TRIANGLES
'''
if self.batch is None:
self.batch = Batch()
self.parse_svg()
self.center()
for path in self.paths:
path.tessellate()
path.add_to_batch(self.batch)
return self.batch
