ref: bcf47ea4a19444e2af92cfd25994e169a5b80a63
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 numpy as np 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()