1 files changed, 62 insertions, 0 deletions
diff --git a/python/demos/demo_keyboard.py b/python/demos/demo_keyboard.py
new file mode 100755
index 0000000..63786b9
--- /dev/null
+++ b/python/demos/demo_keyboard.py
@@ -0,0 +1,62 @@
+#! /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()