Graft pcb-tools-extension master onto gerbonara main

1 files changed, 796 insertions, 0 deletions

diff --git a/gerberex/dxf.py b/gerberex/dxf.py
new file mode 100644
index 0000000..2341092
--- /dev/null
+++ b/gerberex/dxf.py
@@ -0,0 +1,796 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2019 Hiroshi Murayama <opiopan@gmail.com>
+
+import io, sys
+from math import pi, cos, sin, tan, atan, atan2, acos, asin, sqrt
+import dxfgrabber
+from gerber.cam import CamFile, FileSettings
+from gerber.utils import inch, metric, write_gerber_value, rotate_point
+from gerber.gerber_statements import ADParamStmt
+from gerber.excellon_statements import ExcellonTool
+from gerber.excellon_statements import CoordinateStmt
+from gerberex.utility import is_equal_point, is_equal_value
+from gerberex.dxf_path import generate_paths, judge_containment
+from gerberex.excellon import write_excellon_header
+from gerberex.rs274x import write_gerber_header
+
+ACCEPTABLE_ERROR = 0.001
+
+def _normalize_angle(start_angle, end_angle):
+    angle = end_angle - start_angle
+    if angle > 0:
+        start = start_angle % 360
+    else:
+        angle = -angle
+        start = end_angle % 360
+    angle = min(angle, 360)
+    start = start - 360 if  start > 180 else start
+
+    regions = []
+    while angle > 0:
+        end = start + angle
+        if  end <= 180:
+            regions.append((start * pi / 180, end * pi / 180))
+            angle = 0
+        else:
+            regions.append((start * pi / 180, pi))
+            angle = end - 180
+            start = -180
+    return regions
+
+def _intersections_of_line_and_circle(start, end, center, radius, error_range):
+    x1 = start[0] - center[0]
+    y1 = start[1] - center[1]
+    x2 = end[0] - center[0]
+    y2 = end[1] - center[1]
+
+    dx = x2 - x1
+    dy = y2 - y1
+    dr = sqrt(dx * dx + dy * dy)
+    D = x1 * y2 - x2 * y1
+
+    distance = abs(dy * x1 - dx * y1) / dr
+
+    D2 = D * D
+    dr2 = dr * dr
+    r2 = radius * radius
+    delta = r2 * dr2 - D2
+    if distance > radius - error_range and distance < radius + error_range:
+        delta = 0
+    if delta < 0:
+        return None
+
+    sqrt_D = sqrt(delta)
+    E_x = -dx * sqrt_D if dy < 0 else dx * sqrt_D
+    E_y = abs(dy) * sqrt_D
+
+    p1_x = (D * dy + E_x) / dr2
+    p2_x = (D * dy - E_x) / dr2
+    p1_y = (-D * dx + E_y) / dr2
+    p2_y = (-D * dx - E_y) / dr2
+
+    p1_angle = atan2(p1_y, p1_x)
+    p2_angle = atan2(p2_y, p2_x)
+    if dx == 0: 
+        p1_t = (p1_y - y1) / dy
+        p2_t = (p2_y - y1) / dy
+    else:
+        p1_t = (p1_x - x1) / dx
+        p2_t = (p2_x - x1) / dx
+
+    if delta == 0:
+        return (
+            (p1_x + center[0], p1_y + center[1]),
+            None,
+            p1_angle, None,
+            p1_t, None
+        )
+    else:
+        return (
+            (p1_x + center[0], p1_y + center[1]),
+            (p2_x + center[0], p2_y + center[1]),
+            p1_angle, p2_angle,
+            p1_t, p2_t
+        )
+
+class DxfStatement(object):
+    def __init__(self, entity):
+        self.entity = entity
+        self.start = None
+        self.end = None
+        self.is_closed = False
+
+    def to_inch(self):
+        pass
+    
+    def to_metric(self):
+        pass
+
+    def is_equal_to(self, target, error_range=0):
+        return False
+
+    def reverse(self):
+        raise Exception('Not implemented')
+
+    def offset(self, offset_x, offset_y):
+        raise Exception('Not supported')
+    
+    def rotate(self, angle, center=(0, 0)):
+        raise Exception('Not supported')
+
+
+class DxfLineStatement(DxfStatement):
+    @classmethod
+    def from_entity(cls, entity):
+        start = (entity.start[0], entity.start[1])
+        end = (entity.end[0], entity.end[1])
+        return cls(entity, start, end)
+
+    @property
+    def bounding_box(self):
+        return (min(self.start[0], self.end[0]),
+                min(self.start[1], self.end[1]),
+                max(self.start[0], self.end[0]),
+                max(self.start[1], self.end[1]))
+
+    def __init__(self, entity, start, end):
+        super(DxfLineStatement, self).__init__(entity)
+        self.start = start
+        self.end = end
+
+    def to_inch(self):
+        self.start = (
+            inch(self.start[0]), inch(self.start[1]))
+        self.end = (
+            inch(self.end[0]), inch(self.end[1]))
+
+    def to_metric(self):
+        self.start = (
+            metric(self.start[0]), metric(self.start[1]))
+        self.end = (
+            metric(self.end[0]), metric(self.end[1]))
+
+    def is_equal_to(self, target, error_range=0):
+        if not isinstance(target, DxfLineStatement):
+            return False
+        return (is_equal_point(self.start, target.start, error_range) and \
+                is_equal_point(self.end, target.end, error_range)) or \
+               (is_equal_point(self.start, target.end, error_range) and \
+                is_equal_point(self.end, target.start, error_range))
+
+    def reverse(self):
+        pt = self.start
+        self.start = self.end
+        self.end = pt
+
+    def dots(self, pitch, width, offset=0):
+        x0, y0 = self.start
+        x1, y1 = self.end
+        y1 = self.end[1]
+        xp = x1 - x0
+        yp = y1 - y0
+        l = sqrt(xp * xp + yp * yp)
+        xd = xp * pitch / l
+        yd = yp * pitch / l
+        x0 += xp * offset / l
+        y0 += yp * offset / l
+
+        if offset > l +  width / 2:
+            return (None, offset - l)
+        else:
+            d = offset;
+            while d < l + width / 2:
+                yield ((x0, y0), d - l)
+                x0 += xd
+                y0 += yd
+                d += pitch
+
+    def offset(self, offset_x, offset_y):
+        self.start = (self.start[0] + offset_x, self.start[1] + offset_y)
+        self.end = (self.end[0] + offset_x, self.end[1] + offset_y)
+
+    def rotate(self, angle, center=(0, 0)):
+        self.start = rotate_point(self.start, angle, center)
+        self.end = rotate_point(self.end, angle, center)
+    
+    def intersections_with_halfline(self, point_from, point_to, error_range):
+        denominator = (self.end[0] - self.start[0]) * (point_to[1] - point_from[1]) - \
+                      (self.end[1] - self.start[1]) * (point_to[0] - point_from[0])
+        de = error_range * error_range
+        if denominator >= -de and denominator <= de:
+            return []
+        from_dx = point_from[0] - self.start[0]
+        from_dy = point_from[1] - self.start[1]
+        r = ((point_to[1] - point_from[1]) * from_dx - 
+             (point_to[0] - point_from[0]) * from_dy) / denominator
+        s = ((self.end[1] - self.start[1]) * from_dx -
+             (self.end[0] - self.start[0]) * from_dy) / denominator
+        dx = (self.end[0] - self.start[0])
+        dy = (self.end[1] - self.start[1])
+        le = error_range / sqrt(dx * dx + dy * dy)
+        if s < 0 or r < -le or r > 1 + le:
+            return []
+        
+        pt = (self.start[0] + (self.end[0] - self.start[0]) * r,
+              self.start[1] + (self.end[1] - self.start[1]) * r)
+        if is_equal_point(pt, self.start, error_range):
+            return []
+        else:
+            return [pt]
+
+    def intersections_with_arc(self, center, radius, angle_regions, error_range):
+        intersection = \
+            _intersections_of_line_and_circle(self.start, self.end, center, radius, error_range)
+        if intersection is None:
+            return []
+        else:
+            p1, p2, p1_angle, p2_angle, p1_t, p2_t = intersection
+
+        pts = []
+        if p1_t >= 0 and p1_t <= 1:
+            for region in angle_regions:
+                if p1_angle >= region[0] and p1_angle <= region[1]:
+                    pts.append(p1)
+                    break
+        if p2 is not None and p2_t >= 0 and p2_t <= 1:
+            for region in angle_regions:
+                if p2_angle >= region[0] and p2_angle <= region[1]:
+                    pts.append(p2)
+                    break
+
+        return pts
+
+class DxfArcStatement(DxfStatement):
+    def __init__(self, entity):
+        super(DxfArcStatement, self).__init__(entity)
+        if entity.dxftype == 'CIRCLE':
+            self.radius = self.entity.radius
+            self.center = (self.entity.center[0], self.entity.center[1])
+            self.start = (self.center[0] + self.radius, self.center[1])
+            self.end = self.start
+            self.start_angle = 0
+            self.end_angle = 360
+            self.is_closed = True
+        elif entity.dxftype == 'ARC':
+            self.start_angle = self.entity.start_angle
+            self.end_angle = self.entity.end_angle
+            self.radius = self.entity.radius
+            self.center = (self.entity.center[0], self.entity.center[1])
+            self.start = (
+                self.center[0] + self.radius * cos(self.start_angle / 180. * pi),
+                self.center[1] + self.radius * sin(self.start_angle / 180. * pi),
+            )
+            self.end = (
+                self.center[0] + self.radius * cos(self.end_angle / 180. * pi),
+                self.center[1] + self.radius * sin(self.end_angle / 180. * pi),
+            )
+            angle = self.end_angle - self.start_angle
+            self.is_closed = angle >= 360 or angle <= -360
+        else:
+            raise Exception('invalid DXF type was specified')
+        self.angle_regions = _normalize_angle(self.start_angle, self.end_angle)
+
+    @property
+    def bounding_box(self):
+        return (self.center[0] - self.radius, self.center[1] - self.radius,
+                self.center[0] + self.radius, self.center[1] + self.radius)
+
+    def to_inch(self):
+        self.radius = inch(self.radius)
+        self.center = (inch(self.center[0]), inch(self.center[1]))
+        self.start = (inch(self.start[0]), inch(self.start[1]))
+        self.end = (inch(self.end[0]), inch(self.end[1]))
+
+    def to_metric(self):
+        self.radius = metric(self.radius)
+        self.center = (metric(self.center[0]), metric(self.center[1]))
+        self.start = (metric(self.start[0]), metric(self.start[1]))
+        self.end = (metric(self.end[0]), metric(self.end[1]))
+
+    def is_equal_to(self, target, error_range=0):
+        if not isinstance(target, DxfArcStatement):
+            return False
+        aerror_range = error_range / pi * self.radius * 180
+        return is_equal_point(self.center, target.center, error_range) and \
+               is_equal_value(self.radius, target.radius, error_range) and \
+               ((is_equal_value(self.start_angle, target.start_angle, aerror_range) and 
+                 is_equal_value(self.end_angle, target.end_angle, aerror_range)) or
+                (is_equal_value(self.start_angle, target.end_angle, aerror_range) and
+                 is_equal_value(self.end_angle, target.end_angle, aerror_range)))
+
+    def reverse(self):
+        tmp = self.start_angle
+        self.start_angle = self.end_angle
+        self.end_angle = tmp
+        tmp = self.start
+        self.start = self.end
+        self.end = tmp
+
+    def dots(self, pitch, width, offset=0):
+        angle = self.end_angle - self.start_angle
+        afactor = 1 if angle > 0 else -1
+        aangle = angle * afactor
+        L = 2 * pi * self.radius
+        l = L * aangle / 360
+        pangle = pitch / L * 360
+        wangle = width / L * 360
+        oangle = offset / L * 360
+
+        if offset > l + width / 2:
+            yield (None, offset - l)
+        else:
+            da = oangle
+            while da < aangle + wangle / 2:
+                cangle = self.start_angle + da * afactor
+                x = self.radius * cos(cangle / 180 * pi) + self.center[0]
+                y = self.radius * sin(cangle / 180 * pi) + self.center[1]
+                remain = (da - aangle) / 360 * L
+                yield((x, y), remain)
+                da += pangle
+
+    def offset(self, offset_x, offset_y):
+        self.center = (self.center[0] + offset_x, self.center[1] + offset_y)
+        self.start = (self.start[0] + offset_x, self.start[1] + offset_y)
+        self.end = (self.end[0] + offset_x, self.end[1] + offset_y)
+
+    def rotate(self, angle, center=(0, 0)):
+        self.start_angle += angle
+        self.end_angle += angle
+        self.center = rotate_point(self.center, angle, center)
+        self.start = rotate_point(self.start, angle, center)
+        self.end = rotate_point(self.end, angle, center)
+        self.angle_regions = _normalize_angle(self.start_angle, self.end_angle)
+
+    def intersections_with_halfline(self, point_from, point_to, error_range):
+        intersection = \
+            _intersections_of_line_and_circle(
+                point_from, point_to, self.center, self.radius, error_range)
+        if intersection is None:
+            return []
+        else:
+            p1, p2, p1_angle, p2_angle, p1_t, p2_t = intersection
+        
+        if is_equal_point(p1, self.start, error_range):
+            p1 = None
+        elif p2 is not None and is_equal_point(p2, self.start, error_range):
+            p2 = None
+
+        def is_contained(angle, region, error):
+            if angle >= region[0] - error and angle <= region[1] + error:
+                return True
+            if angle < 0 and region[1] > 0:
+                angle = angle + 2 * pi
+            elif angle > 0 and region[0] < 0:
+                angle = angle - 2 * pi
+            return  angle >= region[0] - error and angle <= region[1] + error
+            
+        aerror = error_range * self.radius
+        pts = []
+        if p1 is not None and p1_t >= 0 and not is_equal_point(p1, self.start, error_range):
+            for region in self.angle_regions:
+                if is_contained(p1_angle, region, aerror):
+                    pts.append(p1)
+                    break
+        if p2 is not None and p2_t >= 0 and not is_equal_point(p2, self.start, error_range):
+            for region in self.angle_regions:
+                if is_contained(p2_angle, region, aerror):
+                    pts.append(p2)
+                    break
+
+        return pts
+
+    def intersections_with_arc(self, center, radius, angle_regions, error_range):
+        x1 = center[0] - self.center[0]
+        y1 = center[1] - self.center[1]
+        r1 = self.radius
+        r2 = radius
+        cd_sq = x1 * x1 + y1 * y1
+        cd = sqrt(cd_sq)
+        rd = abs(r1 - r2)
+
+        if (cd >= 0 and cd <= rd) or cd >= r1 + r2:
+            return []
+        
+        A = (cd_sq + r1 * r1 - r2 * r2) / 2
+        scale = sqrt(cd_sq * r1 * r1 - A * A) / cd_sq
+        xl = A * x1 / cd_sq
+        xr = y1 * scale
+        yl = A * y1 / cd_sq
+        yr = x1 * scale
+
+        pt1_x = xl + xr
+        pt1_y = yl - yr
+        pt2_x = xl - xr
+        pt2_y = yl + yr
+        pt1_angle1 = atan2(pt1_y, pt1_x)
+        pt1_angle2 = atan2(pt1_y - y1, pt1_x - x1)
+        pt2_angle1 = atan2(pt2_y, pt2_x)
+        pt2_angle2 = atan2(pt2_y - y1, pt2_x - x1)
+
+        aerror = error_range * self.radius
+        pts=[]
+        for region in self.angle_regions:
+            if pt1_angle1 >= region[0] and pt1_angle1 <= region[1]:
+                for region in angle_regions:
+                    if pt1_angle2 >= region[0] - aerror and pt1_angle2 <= region[1] + aerror:
+                        pts.append((pt1_x + self.center[0], pt1_y + self.center[1]))
+                        break
+                break
+        for region in self.angle_regions:
+            if pt2_angle1 >= region[0] and pt2_angle1 <= region[1]:
+                for region in angle_regions:
+                    if pt2_angle2 >= region[0] - aerror and pt2_angle2 <= region[1] + aerror:
+                        pts.append((pt2_x + self.center[0], pt2_y + self.center[1]))
+                        break
+                break
+        return pts
+
+class DxfPolylineStatement(DxfStatement):
+    def __init__(self, entity):
+        super(DxfPolylineStatement, self).__init__(entity)
+        self.start = (self.entity.points[0][0], self.entity.points[0][1])
+        self.is_closed = self.entity.is_closed
+        if self.is_closed:
+            self.end = self.start
+        else:
+            self.end = (self.entity.points[-1][0], self.entity.points[-1][1])
+
+    def disassemble(self):
+        class Item:
+            pass
+
+        def ptseq():
+            for i in range(1, len(self.entity.points)):
+                yield i
+            if self.entity.is_closed:
+                yield 0
+
+        x0 = self.entity.points[0][0]
+        y0 = self.entity.points[0][1]
+        b = self.entity.bulge[0]
+        for idx in ptseq():
+            pt = self.entity.points[idx]
+            x1 = pt[0]
+            y1 = pt[1]
+            if b == 0:
+                item = Item()
+                item.dxftype = 'LINE'
+                item.start = (x0, y0)
+                item.end = (x1, y1)
+                item.is_closed = False
+                yield DxfLineStatement.from_entity(item)
+            else:
+                ang = 4 * atan(b)
+                xm = x0 + x1
+                ym = y0 + y1
+                t = 1 / tan(ang / 2)
+                xc = (xm - t * (y1 - y0)) / 2
+                yc = (ym + t * (x1 - x0)) / 2
+                r = sqrt((x0 - xc)*(x0 - xc) + (y0 - yc)*(y0 - yc))
+                rx0 = x0 - xc
+                ry0 = y0 - yc
+                rc = max(min(rx0 / r, 1.0), -1.0)
+                start_angle = acos(rc) if ry0 > 0 else 2 * pi - acos(rc)
+                start_angle *= 180 / pi
+                end_angle = start_angle + ang * 180 / pi
+
+                item = Item()
+                item.dxftype = 'ARC'
+                item.start = (x0, y0)
+                item.end = (x1, y1)
+                item.start_angle = start_angle
+                item.end_angle = end_angle
+                item.radius = r
+                item.center = (xc, yc)
+                item.is_closed = end_angle - start_angle >= 360
+                yield DxfArcStatement(item)
+
+            x0 = x1
+            y0 = y1
+            b = self.entity.bulge[idx]
+
+    def to_inch(self):
+        self.start = (inch(self.start[0]), inch(self.start[1]))
+        self.end = (inch(self.end[0]), inch(self.end[1]))
+        for idx in range(0, len(self.entity.points)):
+            self.entity.points[idx] = (
+                inch(self.entity.points[idx][0]), inch(self.entity.points[idx][1]))
+
+    def to_metric(self):
+        self.start = (metric(self.start[0]), metric(self.start[1]))
+        self.end = (metric(self.end[0]), metric(self.end[1]))
+        for idx in range(0, len(self.entity.points)):
+            self.entity.points[idx] = (
+                metric(self.entity.points[idx][0]), metric(self.entity.points[idx][1]))
+    
+    def offset(self, offset_x, offset_y):
+        for idx in range(len(self.entity.points)):
+            self.entity.points[idx] = (
+                self.entity.points[idx][0] + offset_x, self.entity.points[idx][1] + offset_y)
+
+    def rotate(self, angle, center=(0, 0)):
+        for idx in range(len(self.entity.points)):
+            self.entity.points[idx] = rotate_point(self.entity.points[idx], angle, center)
+
+class DxfStatements(object):
+    def __init__(self, statements, units, dcode=10, draw_mode=None, fill_mode=None):
+        if draw_mode is None:
+            draw_mode = DxfFile.DM_LINE
+        if fill_mode is None:
+            fill_mode = DxfFile.FM_TURN_OVER
+        self._units = units
+        self.dcode = dcode
+        self.draw_mode = draw_mode
+        self.fill_mode = fill_mode
+        self.pitch = inch(1) if self._units == 'inch' else 1
+        self.width = 0
+        self.error_range = inch(ACCEPTABLE_ERROR) if self._units == 'inch' else ACCEPTABLE_ERROR
+        self.statements = list(filter(
+            lambda i: not (isinstance(i, DxfLineStatement) and \
+                          is_equal_point(i.start, i.end, self.error_range)),
+            statements
+        ))
+        self.close_paths, self.open_paths = generate_paths(self.statements, self.error_range)
+        self.sorted_close_paths = []
+        self.polarity = True # True means dark, False means clear
+
+    @property
+    def units(self):
+        return _units
+
+    def _polarity_command(self, polarity=None):
+        if polarity is None:
+            polarity = self.polarity
+        return '%LPD*%' if polarity else '%LPC*%'
+
+    def _prepare_sorted_close_paths(self):
+        if self.sorted_close_paths:
+            return
+        for i in range(0, len(self.close_paths)):
+            for j in range(i + 1, len(self.close_paths)):
+                containee, container = judge_containment(
+                    self.close_paths[i], self.close_paths[j], self.error_range)
+                if containee is not None:
+                    containee.containers.append(container)
+        self.sorted_close_paths = sorted(self.close_paths, key=lambda path: len(path.containers))
+
+    def to_gerber(self, settings=FileSettings()):
+        def gerbers():
+            yield 'G75*'
+            yield self._polarity_command()
+            yield 'D{0}*'.format(self.dcode)
+            if self.draw_mode == DxfFile.DM_FILL:
+                yield 'G36*'
+                if self.fill_mode == DxfFile.FM_TURN_OVER:
+                    self._prepare_sorted_close_paths()
+                    polarity = self.polarity
+                    level = 0
+                    for path in self.sorted_close_paths:
+                        if len(path.containers) > level:
+                            level = len(path.containers)
+                            polarity = not polarity
+                            yield 'G37*'
+                            yield self._polarity_command(polarity)
+                            yield 'G36*'
+                        yield path.to_gerber(settings)
+                else:
+                    for path in self.close_paths:
+                        yield path.to_gerber(settings)
+                yield 'G37*'
+            else:
+                pitch = self.pitch if self.draw_mode == DxfFile.DM_MOUSE_BITES else 0
+                for path in self.open_paths:
+                    yield path.to_gerber(settings, pitch=pitch, width=self.width)
+                for path in self.close_paths:
+                    yield path.to_gerber(settings, pitch=pitch, width=self.width)
+
+        return '\n'.join(gerbers())
+
+    def to_excellon(self, settings=FileSettings()):
+        if self.draw_mode == DxfFile.DM_FILL:
+            return
+        def drills():
+            pitch = self.pitch if self.draw_mode == DxfFile.DM_MOUSE_BITES else 0
+            for path in self.open_paths:
+                yield path.to_excellon(settings, pitch=pitch, width=self.width)
+            for path in self.close_paths:
+                yield path.to_excellon(settings, pitch=pitch, width=self.width)
+        return '\n'.join(drills())
+
+    def to_inch(self):
+        if self._units == 'metric':
+            self._units = 'inch'
+            self.pitch = inch(self.pitch)
+            self.width = inch(self.width)
+            self.error_range = inch(self.error_range)
+            for path in self.open_paths:
+                path.to_inch()
+            for path in self.close_paths:
+                path.to_inch()
+
+    def to_metric(self):
+        if self._units == 'inch':
+            self._units = 'metric'
+            self.pitch = metric(self.pitch)
+            self.width = metric(self.width)
+            self.error_range = metric(self.error_range)
+            for path in self.open_paths:
+                path.to_metric()
+            for path in self.close_paths:
+                path.to_metric()
+    
+    def offset(self, offset_x, offset_y):
+        for path in self.open_paths:
+            path.offset(offset_x, offset_y)
+        for path in self.close_paths:
+            path.offset(offset_x, offset_y)
+
+    def rotate(self, angle, center=(0, 0)):
+        for path in self.open_paths:
+            path.rotate(angle, center)
+        for path in self.close_paths:
+            path.rotate(angle, center)
+
+class DxfFile(CamFile):
+    DM_LINE = 0
+    DM_FILL = 1
+    DM_MOUSE_BITES = 2
+
+    FM_SIMPLE = 0
+    FM_TURN_OVER = 1
+
+    FT_RX274X = 0
+    FT_EXCELLON = 1
+
+    @classmethod
+    def from_dxf(cls, dxf, settings=None, draw_mode=None, filename=None):
+        fsettings = settings if settings else \
+            FileSettings(zero_suppression='leading')
+
+        if dxf.header['$INSUNITS'] == 1:
+            fsettings.units = 'inch'
+            if not settings:
+                fsettings.format = (2, 5)
+        else:
+            fsettings.units = 'metric'
+            if not settings:
+                fsettings.format = (3, 4)
+
+        statements = []
+        for entity in dxf.entities:
+            if entity.dxftype == 'LWPOLYLINE':
+                statements.append(DxfPolylineStatement(entity))
+            elif entity.dxftype == 'LINE':
+                statements.append(DxfLineStatement.from_entity(entity))
+            elif entity.dxftype == 'CIRCLE':
+                statements.append(DxfArcStatement(entity))
+            elif entity.dxftype == 'ARC':
+                statements.append(DxfArcStatement(entity))
+        
+        return cls(statements, fsettings, draw_mode, filename)
+    
+    @classmethod
+    def rectangle(cls, width, height, left=0, bottom=0, units='metric', draw_mode=None, filename=None):
+        if units == 'metric':
+            settings = FileSettings(units=units, zero_suppression='leading', format=(3,4))
+        else:
+            settings = FileSettings(units=units, zero_suppression='leading', format=(2,5))
+        statements = [
+            DxfLineStatement(None, (left, bottom), (left + width, bottom)),
+            DxfLineStatement(None, (left + width, bottom), (left + width, bottom + height)),
+            DxfLineStatement(None, (left + width, bottom + height), (left, bottom + height)),
+            DxfLineStatement(None, (left, bottom + height), (left, bottom)),
+        ]
+        return cls(statements, settings, draw_mode, filename)
+
+    def __init__(self, statements, settings=None, draw_mode=None, filename=None):
+        if not settings:
+            settings = FileSettings(units='metric', format=(3,4), zero_suppression='leading')
+        if draw_mode == None:
+            draw_mode = self.DM_LINE
+
+        super(DxfFile, self).__init__(settings=settings, filename=filename)
+        self._draw_mode = draw_mode
+        self._fill_mode = self.FM_TURN_OVER
+        
+        self.aperture = ADParamStmt.circle(dcode=10, diameter=0.0)
+        if settings.units == 'inch':
+            self.aperture.to_inch()
+        else:
+            self.aperture.to_metric()
+        self.statements = DxfStatements(
+            statements, self.units, dcode=self.aperture.d, draw_mode=self.draw_mode, fill_mode=self.filename)
+
+    @property
+    def dcode(self):
+        return self.aperture.dcode
+
+    @dcode.setter
+    def dcode(self, value):
+        self.aperture.d = value
+        self.statements.dcode = value
+
+    @property
+    def width(self):
+        return self.aperture.modifiers[0][0]
+
+    @width.setter
+    def width(self, value):
+        self.aperture.modifiers = ([float(value),],)
+        self.statements.width = value
+
+    @property
+    def draw_mode(self):
+        return self._draw_mode
+    
+    @draw_mode.setter
+    def draw_mode(self, value):
+        self._draw_mode = value
+        self.statements.draw_mode = value
+
+    @property
+    def fill_mode(self):
+        return self._fill_mode
+    
+    @fill_mode.setter
+    def fill_mode(self, value):
+        self._fill_mode = value
+        self.statements.fill_mode = value
+
+    @property
+    def pitch(self):
+        return self.statements.pitch
+    
+    @pitch.setter
+    def pitch(self, value):
+        self.statements.pitch = value
+    
+    def write(self, filename=None, filetype=FT_RX274X):
+        self.settings.notation = 'absolute'
+        self.settings.zeros = 'trailing'
+        filename = filename if filename is not None else self.filename
+        with open(filename, 'w') as f:
+            if filetype == self.FT_RX274X:
+                write_gerber_header(f, self.settings)
+                f.write(self.aperture.to_gerber(self.settings) + '\n')
+                f.write(self.statements.to_gerber(self.settings) + '\n')
+                f.write('M02*\n')
+            else:
+                tools = [ExcellonTool(self.settings, number=1, diameter=self.width)]
+                write_excellon_header(f, self.settings, tools)
+                f.write('T01\n')
+                f.write(self.statements.to_excellon(self.settings) + '\n')
+                f.write('M30\n')
+
+
+    def to_inch(self):
+        if self.units == 'metric':
+            self.aperture.to_inch()
+            self.statements.to_inch()
+            self.pitch = inch(self.pitch)
+            self.units = 'inch'
+
+    def to_metric(self):
+        if self.units == 'inch':
+            self.aperture.to_metric()
+            self.statements.to_metric()
+            self.pitch = metric(self.pitch)
+            self.units = 'metric'
+
+    def offset(self, offset_x, offset_y):
+        self.statements.offset(offset_x, offset_y)
+    
+    def rotate(self, angle, center=(0, 0)):
+        self.statements.rotate(angle, center)
+
+    def negate_polarity(self):
+        self.statements.polarity = not self.statements.polarity
+
+def loads(data, filename=None):
+    if sys.version_info.major == 2:
+        data = unicode(data)
+    stream = io.StringIO(data)
+    dxf = dxfgrabber.read(stream)
+    return DxfFile.from_dxf(dxf)