mightyscape-1.2/extensions/fablabchemnitz/zoetrope/zoetrope.py

232 lines
12 KiB
Python
Raw Normal View History

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