232 lines
12 KiB
Python
232 lines
12 KiB
Python
#!/usr/bin/env python3
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'''
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Zoetrope maker.
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- prints disk of given diameter and number of images around the outside.
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Also includes a pulse trigger ring to trigger a strobe.
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- Width and phase of the pulse can be defined.
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Prints a distorted and undistorted image reference sizes
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- for use in a paint program to distort the source inages to fit onto the Disk.
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Neon22 - github 2016
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MIT license
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'''
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import inkex
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from lxml import etree
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from math import cos, sin, radians, pi
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__version__ = '0.2'
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def point_on_circle(radius, angle):
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" return xy coord of the point at distance radius from origin at angle "
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x = radius * cos(angle)
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y = radius * sin(angle)
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return (x, y)
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def draw_SVG_circle(parent, r, cx, cy, name, style):
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" structre an SVG circle entity under parent "
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circ_attribs = {'style': str(inkex.Style(style)),
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'cx': str(cx), 'cy': str(cy),
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'r': str(r),
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inkex.addNS('label','inkscape'): name}
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circle = etree.SubElement(parent, inkex.addNS('circle','svg'), circ_attribs )
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Black = '#000000'
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class Zoetrope(inkex.EffectExtension):
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def add_arguments(self, pars):
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pars.add_argument("-u", "--units", default='mm', help="Units this dialog is using")
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pars.add_argument("-d", "--diameter", type=float, default=1.0, help="Diameter of disk")
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pars.add_argument("-n", "--divisions", type=int, default=24, help="Number of divisions")
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pars.add_argument("-i", "--height", type=float, default=1.0, help="Image height")
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pars.add_argument("-t", "--trigger", type=inkex.Boolean, default=False, help="Trigger")
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pars.add_argument("-q", "--triggerradius", type=float, default=1.0, help="Height of trigger line")
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pars.add_argument("-e", "--thick", type=float, default=1.0, help="Thickness of trigger line")
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pars.add_argument("-r", "--ratio", type=float, default=0.5, help="Ratio of trigger pulse")
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pars.add_argument("-p", "--phase", type=float, default=0, help="Delay of trigger pulse")
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pars.add_argument("-w", "--stroke_width", type=float, default=0.1, help="Line thickness")
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pars.add_argument("-m", "--template", type=inkex.Boolean, default=False, help="Show Image Distortion template")
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pars.add_argument("-k", "--dpi", type=int, default=300, help="To calculate useful image size")
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pars.add_argument("--active-tab", default='', help="Active tab. Not used now.")
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def calc_unit_factor(self):
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""" return the scale factor for all dimension conversions.
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- Everything in inkscape is expected to be in 90dpi pixel units
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"""
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unit_factor = self.svg.unittouu(str(1.0) + self.options.units)
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return unit_factor
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def polar_to_cartesian(self, cx, cy, radius, angle):
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" So we can make arcs in the 'A' svg syntax. "
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angle_radians = radians(angle)
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return (cx + (radius * cos(angle_radians)),
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cy + (radius * sin(angle_radians)))
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def build_arc(self, x,y, start_angle, end_angle, radius, reverse=True):
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" Make a filled arc "
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# Not using internal arc rep - instead construct path A in svg style directly
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# so we can append lines to make single path
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start = self.polar_to_cartesian(x, y, radius, end_angle)
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end = self.polar_to_cartesian(x, y, radius, start_angle)
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arc_flag = 0 if reverse else 1
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sweep = 0 if (end_angle-start_angle) <=180 else 1
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path = 'M %s,%s' % (start[0], start[1])
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path += " A %s,%s 0 %d %d %s %s" % (radius, radius, sweep, arc_flag, end[0], end[1])
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return path
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def build_trigger_arc(self, angle, radius1, radius2):
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""" return path
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- using -ve angles to get pulse on CCW side of division line
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"""
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path = self.build_arc(0,0, -angle, 0, radius1)
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# shorten and reverse second arc to connect
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path += " L"+self.build_arc(0,0, 0, -angle, radius2, False)[1:]
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path += " Z" # close
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return path
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### -------------------------------------------------------------------
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### This is the main function and is called when the extension is run.
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def effect(self):
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""" Calculate Zoetrope from inputs.
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- Make gropups for each drawn entity type.
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- add explanatory text
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- Show trigger pulse ring, distortion and image templates
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"""
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# convert import options
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unit_factor = self.calc_unit_factor()
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path_stroke_width = self.options.stroke_width * unit_factor
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diameter = self.options.diameter * unit_factor
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divisions = self.options.divisions
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image_height = self.options.height * unit_factor
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triggerradius = self.options.triggerradius * unit_factor
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thick = self.options.thick * unit_factor
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cross = diameter/50
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# This finds center of current view in inkscape
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t = 'translate(%s,%s)' % (self.svg.namedview.center[0], self.svg.namedview.center[1] )
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# Make a nice useful name
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g_attribs = { inkex.addNS('label','inkscape'): 'Zoetrope',
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'transform': t,
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'info':'N: '+str(divisions)+';' }
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# add the group to the document's current layer
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topgroup = etree.SubElement(self.svg.get_current_layer(), 'g', g_attribs )
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# Group for pulse triggers
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g_attr = { inkex.addNS('label','inkscape'): 'Pulse track'}
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pulsegroup = etree.SubElement(topgroup, 'g', g_attr )
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# Group for Labels
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t = 'translate(%s,%s)' % (0, diameter/1.9 )
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g_attr = { inkex.addNS('label','inkscape'): 'Label', 'transform': t }
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labelgroup = etree.SubElement(topgroup, 'g', g_attr )
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# Center cross
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line_style = { 'stroke': Black, 'fill': 'none', 'stroke-width': path_stroke_width }
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fill_style = { 'stroke': 'none', 'fill': Black, 'stroke-width': 'none' }
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d = 'M {0},0 L {1},0 M 0,{0} L 0,{1}'.format(-cross,cross)
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cross_attribs = { inkex.addNS('label','inkscape'): 'Center cross',
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'style': str(inkex.Style(line_style)), 'd': d }
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cross_path = etree.SubElement(topgroup, inkex.addNS('path','svg'), cross_attribs )
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# Main Disk
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draw_SVG_circle(topgroup, diameter/2, 0, 0, 'outer_ring', line_style)
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draw_SVG_circle(topgroup, diameter/2-image_height, 0, 0, 'image_ring', line_style)
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# radials
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trigger_angle = (360.0/divisions) * self.options.ratio
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angle = 360.0/divisions
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angle_radians = radians(angle)
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arc_path = self.build_trigger_arc(trigger_angle, triggerradius, triggerradius + thick)
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for i in range(divisions):
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startpt = point_on_circle(cross*2, angle_radians*i)
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if self.options.trigger:
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endpt = point_on_circle(triggerradius, angle_radians*i)
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else:
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endpt = point_on_circle(diameter/2, angle_radians*i)
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path = "M%s,%s L%s,%s"%(startpt[0], startpt[1], endpt[0], endpt[1])
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radial_attr = {inkex.addNS('label','inkscape'): 'radial',
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'style': str(inkex.Style(line_style)), 'd': path }
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etree.SubElement(topgroup, inkex.addNS('path','svg'), radial_attr )
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# second part of radial line (and trigger ring) if needed
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if self.options.trigger:
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# radial lines
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startpt = point_on_circle(triggerradius + thick, angle_radians*i)
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endpt = point_on_circle(diameter/2, angle_radians*i)
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path = "M%s,%s L%s,%s"%(startpt[0], startpt[1], endpt[0], endpt[1])
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radial_attr = {inkex.addNS('label','inkscape'): 'radial',
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'style': str(inkex.Style(line_style)), 'd': path }
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etree.SubElement(topgroup, inkex.addNS('path','svg'), radial_attr )
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# add the arcs # CCW rotation
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arc_offset = angle*i - (angle-trigger_angle)*self.options.phase
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t = 'rotate(%s)' % (arc_offset)
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attribs = { inkex.addNS('label','inkscape'): 'trigger',
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'style': str(inkex.Style(fill_style)), 'd': arc_path , 'transform': t,}
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etree.SubElement(pulsegroup, inkex.addNS('path','svg'), attribs )
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# Add animation of bouncing ball
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# Add pale grid on each image so can draw directly on template
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#
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if self.options.trigger:
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draw_SVG_circle(pulsegroup, triggerradius, 0, 0, 'trigger_ring', line_style)
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draw_SVG_circle(pulsegroup, triggerradius + thick, 0, 0, 'trigger_ring', line_style)
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# text Label
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font_height = min(32, max( 8, int(diameter/50.0)))
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text_style = { 'font-size': str(font_height),
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'font-family': 'sans-serif',
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'text-anchor': 'middle',
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'text-align': 'center',
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'fill': Black }
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text_atts = {'style':str(inkex.Style(text_style)),
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'x': '0', 'y': '0' }
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text = etree.SubElement(labelgroup, 'text', text_atts)
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text.text = "Zoetrope"
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text_atts = {'style':str(inkex.Style(text_style)),
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'x': '0', 'y': str(font_height*1.2) }
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text = etree.SubElement(labelgroup, 'text', text_atts)
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text.text = "Diameter = %4.2f%s. Divisions = %d" % (self.options.diameter, self.options.units, divisions)
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text_atts = {'style':str(inkex.Style(text_style)),
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'x': '0', 'y': str(font_height*2.4) }
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if self.options.trigger:
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text = etree.SubElement(labelgroup, 'text', text_atts)
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text.text = "Pulse Duty = %4.2f, Phase = %4.2f" % (self.options.ratio, self.options.phase)
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# Distortion pattern
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if self.options.template:
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# Group for Labels
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t = 'translate(%s,%s)' % (0, -image_height-font_height*5 )
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g_attr = { inkex.addNS('label','inkscape'): 'Template', 'transform': t }
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templategroup = etree.SubElement(topgroup, 'g', g_attr )
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# Draw template
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arc_path = self.build_trigger_arc(angle, diameter/2, diameter/2-image_height)
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t = 'rotate(%s)' % (-90+angle/2)
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attribs = { inkex.addNS('label','inkscape'): 'distorted image',
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'style': str(inkex.Style(line_style)), 'd': arc_path , 'transform': t}
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image = etree.SubElement(templategroup, inkex.addNS('path','svg'), attribs )
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# Draw Image info
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image_width = pi*diameter/divisions
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ystart = -diameter/2.0 + image_height
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image_ratio = image_width / image_height
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text_atts = {'style':str(inkex.Style(text_style)),
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'x': '0', 'y': str(ystart + font_height*2) }
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text = etree.SubElement(templategroup, 'text', text_atts)
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text.text = "Aspect ratio=1:%4.2f" % (image_ratio)
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# template rect
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attr = {'x':str(-image_width*1.8), 'y':str(-diameter/2),
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'width':str(image_width),
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'height':str(image_height),
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'style':str(inkex.Style(line_style))}
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template_sq = etree.SubElement(templategroup, 'rect', attr)
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# suggested sizes
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# image_height is in 90dpi pixels
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dpi_factor = self.svg.unittouu('1in')/float(self.options.dpi)
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h = int(image_height / float(dpi_factor))
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w = int(h*image_ratio)
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text_atts = {'style':str(inkex.Style(text_style)),
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'x': '0', 'y': str(ystart + font_height*3.2) }
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text = etree.SubElement(templategroup, 'text', text_atts)
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text.text = "At %d dpi. Image = %d x %d pixels" % (self.options.dpi, w, h)
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if __name__ == '__main__':
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Zoetrope().run() |