[psCharStrings] Shorten output of encodeFloat

Lib/fontTools/misc/psCharStrings.py

@@ -275,6 +275,24 @@ def encodeFloat(f):
         s = s[1:]
     elif s[:3] == "-0.":
         s = "-" + s[2:]
+    elif s.endswith("000"):
+        significantDigits = s.rstrip("0")
+        s = "%sE%d" % (significantDigits, len(s) - len(significantDigits))
+    else:
+        dotIndex = s.find(".")
+        eIndex = s.find("E")
+        if dotIndex != -1 and eIndex != -1:
+            integerPart = s[:dotIndex]
+            fractionalPart = s[dotIndex + 1 : eIndex]
+            exponent = int(s[eIndex + 1 :])
+            newExponent = exponent - len(fractionalPart)
+            if newExponent == 1:
+                s = "%s%s0" % (integerPart, fractionalPart)
+            else:
+                s = "%s%sE%d" % (integerPart, fractionalPart, newExponent)
+    if s.startswith((".0", "-.0")):
+        sign, s = s.split(".", 1)
+        s = "%s%sE-%d" % (sign, s.lstrip("0"), len(s))
     nibbles = []
     while s:
         c = s[0]
@@ -286,6 +304,8 @@ def encodeFloat(f):
                 c = "E-"
             elif c2 == "+":
                 s = s[1:]
+            if s.startswith("0"):
+                s = s[1:]
         nibbles.append(realNibblesDict[c])
     nibbles.append(0xF)
     if len(nibbles) % 2:

Tests/misc/psCharStrings_test.py

@@ -87,9 +87,22 @@ class T2CharStringTest(unittest.TestCase):
             (1.0, "1e 1f"),  # 1
             (-1.0, "1e e1 ff"),  # -1
             (98765.37e2, "1e 98 76 53 7f"),  # 9876537
-            (1234567890.0, "1e 1a 23 45 67 9b 09 ff"),  # 1234567890
-            (9.876537e-4, "1e a0 00 98 76 53 7f"),  # 9.876537e-24
-            (9.876537e4, "1e 98 76 5a 37 ff"),  # 9.876537e+24
+            (1234567890.0, "1e 12 34 56 79 b2 ff"),  # 12345679E2
+            (9.876537e-4, "1e 98 76 53 7c 10 ff"),  # 9876537E-10
+            (9.876537e4, "1e 98 76 5a 37 ff"),  # 98765.37
+            (1000.0, "1e 1b 3f"),  # 1E3
+            (-1000.0, "1e e1 b3 ff"),  # -1E3
+            (1e8, "1e 1b 8f"),  # 1E8
+            (1e-5, "1e 1c 5f"),  # 1E-5
+            (1.2e8, "1e 12 b7 ff"),  # 12E7
+            (1.2345e-5, "1e 12 34 5c 9f"),  # 12345E-9
+            (9.0987654e8, "1e 90 98 76 54 0f"),  # 909876540
+            (0.1, "1e a1 ff"),  # .1
+            (-0.1, "1e ea 1f"),  # -.1
+            (0.01, "1e 1c 2f"),  # 1e-2
+            (-0.01, "1e e1 c2 ff"),  # -1e-2
+            (0.0123, "1e 12 3c 4f"),  # 123e-4
+            (-0.0123, "1e e1 23 c4 ff"),  # -123e-4
         ]
 
         for sample in testNums: