ref: 2244f004403844e28440c956a3a073691845a6d0
dir: /python/demos/demo_keyboard.py/
#! /usr/bin/env python
def get_keyboard_edges(firstnote = 21, lastnote = 108):
octaves = 10
# build template of white notes
scalew = 12/7.
xw_temp = [i*scalew for i in range(0,7)]
# build template of black notes
scaleb = 6/7.
xb_temp = [i*scaleb for i in [1,3,7,9,11]]
xb,xw = [],[]
for octave in range(octaves-1):
for i in xb_temp:
curnote = i+12*octave
if curnote > firstnote-1 and curnote < lastnote+1:
xb = xb + [curnote]
for octave in range(octaves-1):
for i in xw_temp:
curnote = i+12*octave
if curnote > firstnote-1 and curnote < lastnote+1:
xw = xw + [curnote]
return xb, xw, 2/3. *scaleb, 1/2. * scalew
def create_keyboard_patches(firstnote, lastnote, ax = None):
import matplotlib.pyplot as plt
from matplotlib.path import Path
import matplotlib.patches as mpatches
blacks, whites, b_width, w_width = get_keyboard_edges(firstnote, lastnote)
if not ax:
fig = plt.figure()
ax = fig.add_subplot(111)
verts, codes = [], []
for white in whites:
verts += [ (white - w_width, 0), (white - w_width, 1), (white + w_width, 1), (white + w_width, 0) ]
verts += [ (white - w_width, 0) ]
codes += [Path.MOVETO] + [Path.LINETO] * 4
path = Path(verts, codes)
patch = mpatches.PathPatch(path, facecolor= 'white', edgecolor='black', lw=1)
ax.add_patch(patch)
verts, codes = [], []
for black in blacks:
verts += [ (black - b_width, 0.33), (black - b_width, 1), (black + b_width, 1), (black + b_width, 0.33) ]
verts += [ (black - b_width, 0.33) ]
codes += [Path.MOVETO] + [Path.LINETO] * 4
path = Path(verts, codes)
patch = mpatches.PathPatch(path, facecolor= 'black', edgecolor='black', lw=1)
ax.add_patch(patch)
ax.axis(xmin = firstnote, xmax = lastnote)
if __name__ == '__main__':
import matplotlib.pyplot as plt
create_keyboard_patches(firstnote = 58, lastnote = 84)
plt.show()