better text handling

axi/drawing.py

@@ -243,7 +243,7 @@ class Drawing(object):
                 paths.append(path)
         return Drawing(paths)
 
-    def render(self, scale=109, margin=1, line_width=0.5/25.4,
+    def render(self, scale=109, margin=1, line_width=0.35/25.4,
             bounds=None, show_bounds=True,
             use_axi_bounds=False, show_axi_bounds=False):
         if cairo is None:

axi/hershey.py

@@ -1,3 +1,5 @@
+from __future__ import division
+
 from .hershey_fonts import *
 
 def text(string, font=FUTURAL, spacing=0, extra=0):
@@ -18,29 +20,67 @@ def text(string, font=FUTURAL, spacing=0, extra=0):
             x += extra
     return result
 
-def text_width(string, font=FUTURAL, spacing=0):
-    x = 0
-    for ch in string:
-        index = ord(ch) - 32
-        if index < 0 or index >= 96:
-            x += spacing
-            continue
-        lt, rt, coords = font[index]
-        x += rt - lt + spacing
-    return x
+def _word_wrap(text, width, measure_func):
+    result = []
+    for line in text.split('\n'):
+        fields = itertools.groupby(line, lambda x: x.isspace())
+        fields = [''.join(g) for _, g in fields]
+        if len(fields) % 2 == 1:
+            fields.append('')
+        x = ''
+        for a, b in zip(fields[::2], fields[1::2]):
+            w, _ = measure_func(x + a)
+            if w > width:
+                if x == '':
+                    result.append(a)
+                    continue
+                else:
+                    result.append(x)
+                    x = ''
+            x += a + b
+        if x != '':
+            result.append(x)
+    result = [x.strip() for x in result]
+    return result
 
-def justify_text(lines, font=FUTURAL, spacing=0):
-    widths = [text_width(x, font, spacing) for x in lines]
-    max_width = max(widths)
-    extras = []
-    for i, (line, width) in enumerate(zip(lines, widths)):
-        spaces = line.count(' ')
-        if spaces == 0:
-            e = 0
-        else:
-            e = float(max_width - width) / spaces
-        if i == len(lines) - 1:
-            e = 0
-        extras.append(e)
-        print width, max_width, spaces, e
-    return [text(line, font, spacing, extra) for line, extra in zip(lines, extras)]
+class Font(object):
+    def __init__(self, font, point_size):
+        self.font = font
+        self.max_height = axi.Drawing(axi.text(string.printable, font)).height
+        self.scale = (point_size / 72) / self.max_height
+    def text(self, text):
+        d = axi.Drawing(axi.text(text, self.font))
+        d = d.scale(self.scale)
+        return d
+    def justify_text(self, text, width):
+        d = self.text(text)
+        w = d.width
+        spaces = text.count(' ')
+        if spaces == 0 or w >= width:
+            return d
+        e = ((width - w) / spaces) / self.scale
+        d = axi.Drawing(axi.text(text, self.font, extra=e))
+        d = d.scale(self.scale)
+        return d
+    def measure(self, text):
+        return self.text(text).size
+    def wrap(self, text, width, line_spacing=1, align=0, justify=False):
+        lines = _word_wrap(text, width, self.measure)
+        ds = [self.text(line) for line in lines]
+        max_width = max(d.width for d in ds)
+        if justify:
+            jds = [self.justify_text(line, max_width) for line in lines]
+            ds = jds[:-1] + [ds[-1]]
+        spacing = line_spacing * self.max_height * self.scale
+        result = axi.Drawing()
+        y = 0
+        for d in ds:
+            if align == 0:
+                x = 0
+            elif align == 1:
+                x = max_width - d.width
+            else:
+                x = max_width / 2 - d.width / 2
+            result.add(d.translate(x, y))
+            y += spacing
+        return result

examples/text.py

@@ -81,8 +81,8 @@ class Font(object):
         return result
 
 def main():
-    font = Font(axi.FUTURAL, 18)
-    d = font.wrap(TEXT * 2, 12, 1.5, justify=True)
+    font = Font(axi.FUTURAL, 14)
+    d = font.wrap(TEXT, 11.5, 1.5, justify=True)
     d = d.center(12, 8.5)
     d.render(bounds=axi.V3_BOUNDS).write_to_png('out.png')