Improve text layouting (closes #1)

generate_map.py

@@ -241,11 +241,11 @@ def compute_bbox(ns):
 
 class BoundingBox:
 
-    def __init__(self, left, top, right, bottom, meta=None, base_weight=0):
+    def __init__(self, left, top, right=None, bottom=None, *, width=None, height=None, meta=None, base_weight=0):
         self.left = left
         self.top = top
-        self.right = right
-        self.bottom = bottom
+        self.right = right if width is None else left + width
+        self.bottom = bottom if height is None else top + height
         self.meta = meta
         self.base_weight = base_weight
         self.finished = False
@@ -270,7 +270,9 @@ class BoundingBox:
     def __add__(self, other):
         if not isinstance(other, tuple) and not isinstance(other, list):
             raise TypeError()
-        return BoundingBox(self.left + other[0], self.top + other[1], self.right + other[0], self.bottom + other[1], self.meta, self.base_weight)
+        return BoundingBox(self.left + other[0], self.top + other[1],
+                           self.right + other[0], self.bottom + other[1],
+                           width=None, height=None, meta=self.meta, base_weight=self.base_weight)
 
     def __iadd__(self, other):
         if not isinstance(other, tuple) and not isinstance(other, list):
@@ -284,7 +286,9 @@ class BoundingBox:
     def __sub__(self, other):
         if not isinstance(other, tuple) and not isinstance(other, list):
             raise TypeError()
-        return BoundingBox(self.left - other[0], self.top - other[1], self.right - other[0], self.bottom - other[1], self.meta, self.base_weight)
+        return BoundingBox(self.left - other[0], self.top - other[1],
+                           self.right - other[0], self.bottom - other[1],
+                           width=None, height=None, meta=self.meta, base_weight=self.base_weight)
 
     def __isub__(self, other):
         if not isinstance(other, tuple) and not isinstance(other, list):
@@ -314,7 +318,35 @@ class BoundingBox:
         return (c1[0] - c2[0])**2 + (c1[1] - c2[1])**2
 
     def with_margin(self, margin):
-        return BoundingBox(self.left - margin, self.top - margin, self.right + margin, self.bottom + margin, self.meta, self.base_weight)
+        return BoundingBox(self.left - margin, self.top - margin,
+                           self.right + margin, self.bottom + margin,
+                           width=None, height=None, meta=self.meta, base_weight=self.base_weight)
+
+    def chebyshev_distance(self, other): 
+        if other in self:
+            return 0
+        if isinstance(other, BoundingBox):
+            if other.left < self.left < other.right or other.left < self.right < other.right:
+                dh = 0
+            else:
+                dh = min(abs(self.left - other.right), abs(self.right - other.left))
+            if other.top < self.top < other.bottom or other.top < self.bottom < other.bottom:
+                dv = 0
+            else:
+                dv = min(abs(self.top - other.bottom), abs(self.bottom - other.top))
+            return max(dh, dv)
+        elif isinstance(other, tuple) or isinstance(other, list):
+            if self.left < other[0] < self.right:
+                dh = 0
+            else:
+                dh = min(abs(self.left - other[0]), abs(self.right - other[0]))
+            if self.top < other[1] < self.bottom:
+                dv = 0
+            else:
+                dv = min(abs(self.top - other[1]), abs(self.bottom - other[1]))
+            return max(dh, dv)            
+        else:
+            raise TypeError()
 
     def compute_weight(self, other, erfas, chaostreffs, ns):
         w = 0
@@ -323,14 +355,18 @@ class BoundingBox:
         swc = self.with_margin(ns.dotsize_treff)
         swme = swm.with_margin(ns.dotsize_erfa)
         swmc = swm.with_margin(ns.dotsize_treff)
+        # I hope these weights are somewhat reasonably balanced...
         for o in other:
             if o.meta['city'] == self.meta['city']:
                 continue
             if o in self:
                 if o.finished:
+                    w += 1000
+                else:
                     w += 50
             else:
-                    w += 3
+                w += max(ns.font_distance*2 - swc.chebyshev_distance(o), 0)
+                continue
             if o in swm:
                 if o.finished:
                     w += 3
@@ -340,46 +376,16 @@ class BoundingBox:
             if city == self.meta['city']:
                 continue
             if location in swe:
-                w += 15
-            if location in swme:
-                w += 2
+                w += 1000
+            else:
+                w += max(ns.font_distance*2 - swe.chebyshev_distance(location), 0)
         for city, location in chaostreffs.items():
             if city == self.meta['city']:
                 continue
             if location in swc:
-                w += 5
-            if location in swmc:
-                w += 1
-        self._weight = w
-
-    def compute_finalized_weight(self, other, erfas, chaostreffs, ns):
-        w = 0
-        swm = self.with_margin(ns.font_distance)
-        swe = self.with_margin(ns.dotsize_erfa)
-        swc = self.with_margin(ns.dotsize_treff)
-        swme = swm.with_margin(ns.dotsize_erfa)
-        swmc = swm.with_margin(ns.dotsize_treff)
-        for o in other:
-            if o.meta['city'] == self.meta['city']:
-                continue
-            if o in self:
-                w += 100
-            if o in swm:
-                w += 15
-        for city, location in erfas.items():
-            if city == self.meta['city']:
-                continue
-            if location in swe:
-                w += 100
-            if location in swme:
-                w += 10
-        for city, location in chaostreffs.items():
-            if city == self.meta['city']:
-                continue
-            if location in swc:
-                w += 100
-            if location in swmc:
-                w += 5
+                w += 1000
+            else:
+                w += max(ns.font_distance*2 - swc.chebyshev_distance(location), 0)
         self._weight = w
 
     @property
@@ -390,43 +396,68 @@ class BoundingBox:
     def is_optimal(self):
         return self._weight == 0
 
+    def __str__(self):
+        return f'(({int(self.left)}, {int(self.top)}, {int(self.right)}, {int(self.bottom)}), weight={self.weight})'
+
 
 def optimize_text_layout(ns, erfas, chaostreffs, size, svg):
     font = ImageFont.truetype(ns.font, ns.font_size)
-    pil = ImageDraw(Image.new('P', size))
+    pil = ImageDraw(Image.new('P', (1, 1)))
+    xheight = -pil.textbbox((0,0), 'x', font=font, anchor='ls')[1]
+    capheight = -pil.textbbox((0,0), 'A', font=font, anchor='ls')[1]
+    voffset = - capheight / 2
 
     candidates = {}
     for city, location in erfas.items():
         text = city
+        erfax, erfay = location
         for rfrom, to in ns.rename:
             if rfrom == city:
                 text = to
                 break
-        rbox = pil.textbbox((location[0] + ns.font_distance, location[1] - ns.font_size/2), text, font=font, anchor='lt')
-        rbox = BoundingBox(*rbox, meta={'city': city, 'side': 'r', 'text': text})
-        rbox.right += 1.5 * ns.font_distance
-        lbox = pil.textbbox((location[0] - ns.font_distance, location[1] - ns.font_size/2), text, font=font, anchor='rt')
-        lbox = BoundingBox(*lbox, meta={'city': city, 'side': 'l', 'text': text})
-        lbox.left -= 1.5 * ns.font_distance
-        if location[0] > 0.8 * size[0]:
+
+        meta = {'city': city, 'text': text, 'baseline': capheight}
+        textbox = pil.textbbox((0, 0), text, font=font, anchor='ls')  # left, baseline at 0,0
+        mw, mh = textbox[2] - textbox[0], textbox[3] - textbox[1]
+        rbox = BoundingBox(erfax + ns.font_distance, erfay + voffset, width=mw, height=mh, meta=meta)
+        lbox = BoundingBox(erfax - ns.font_distance - mw, erfay + voffset, width=mw, height=mh, meta=meta)
+        if erfax > 0.8 * size[0]:
             rbox.base_weight += 0.001
         else:
             lbox.base_weight += 0.001
-        candidates[city] = [lbox, lbox + (0, ns.dotsize_erfa), lbox + (0, ns.dotsize_erfa*2), lbox - (0, ns.dotsize_erfa), lbox - (0, ns.dotsize_erfa*2), rbox, rbox + (0, ns.dotsize_erfa), rbox + (0, ns.dotsize_erfa*2), rbox - (0, ns.dotsize_erfa), rbox - (0, ns.dotsize_erfa*2)]
+        candidates[city] = [lbox, rbox]
+        for i in range(-2, 3):
+            if i == 0:
+                continue
+            candidates[city].append(lbox + (0, ns.dotsize_erfa*i))
+            candidates[city].append(rbox + (0, ns.dotsize_erfa*i))
+        candidates[city].extend([
+            BoundingBox(erfax - mw/2, erfay - ns.font_distance - mh, width=mw, height=mh, meta=meta, base_weight=0.001),
+            BoundingBox(erfax - mw/2, erfay + ns.font_distance, width=mw, height=mh, meta=meta, base_weight=0.001),
+            BoundingBox(erfax - ns.dotsize_erfa, erfay - ns.font_distance - mh, width=mw, height=mh, meta=meta, base_weight=0.002),
+            BoundingBox(erfax - ns.dotsize_erfa, erfay + ns.font_distance, width=mw, height=mh, meta=meta, base_weight=0.003),
+            BoundingBox(erfax + ns.dotsize_erfa - mw, erfay - ns.font_distance - mh, width=mw, height=mh, meta=meta, base_weight=0.001),
+            BoundingBox(erfax + ns.dotsize_erfa - mw, erfay + ns.font_distance, width=mw, height=mh, meta=meta, base_weight=0.001),
+        ])
         rbox.base_weight -= 0.003
         lbox.base_weight -= 0.003
 
         if ns.debug:
             for c in candidates[city]:
+                di = etree.Element('rect', x=str(c.left), y=str(c.top + capheight - xheight), width=str(c.width), height=str(xheight))
+                di.set('class', 'debugright')
                 dr = etree.Element('rect', x=str(c.left), y=str(c.top), width=str(c.width), height=str(c.height))
                 dr.set('class', 'debugleft')
+                svg.append(di)
                 svg.append(dr)
 
     
     unfinished = {c for c in erfas.keys()}
     finished = {}
 
+    with tqdm.tqdm(total=len(erfas)) as progress:
         while len(unfinished) > 0:
+            progress.update(len(erfas) - len(unfinished))
 
             all_boxes = set(finished.values())
             unfinished_boxes = set()
@@ -460,7 +491,7 @@ def optimize_text_layout(ns, erfas, chaostreffs, size, svg):
         for city in order:
             all_boxes = set(finished.values())
             for box in candidates[city]:
-                box.compute_finalized_weight(all_boxes, erfas, chaostreffs, ns)
+                box.compute_weight(all_boxes, erfas, chaostreffs, ns)
             minbox = min(candidates[city], key=lambda box: box.weight)
             if minbox is not finished[city]:
                 changed = True
@@ -607,10 +638,7 @@ def create_svg(ns, bbox):
     print('Layouting labels')
     texts = optimize_text_layout(ns, erfas, chaostreffs, (int(svg_box[0]), int(svg_box[1])), svg)
     for city, box in texts.items():
-        if box.meta['side'] == 'l':
-            box += (1.5 * ns.font_distance, 0)
-        text = etree.Element('text', x=str(box.left), y=str(box.top))
-        text.set('alignment-baseline', 'hanging')
+        text = etree.Element('text', x=str(box.left), y=str(box.top + box.meta['baseline']))
         text.set('class', 'erfalabel')
         text.set('data-erfa', city)
         text.text = box.meta['text']
@@ -635,8 +663,8 @@ def main():
     ap.add_argument('--bbox-margin', type=float, default=0.3, help='Margin around the inferred bounding box.  Ignored with --bbox')
     ap.add_argument('--stylesheet', type=str, default='style/erfamap.css', help='Stylesheet for the generated SVG')
     ap.add_argument('--font', type=str, default='style/concertone-regular.ttf', help='Name of the font used in the stylesheet.')
-    ap.add_argument('--font-size', type=int, default=40, help='Size of the font used in the stylesheet.')
-    ap.add_argument('--font-distance', type=int, default=15, help='Distance of labels from their dots center')
+    ap.add_argument('--font-size', type=int, default=45, help='Size of the font used in the stylesheet.')
+    ap.add_argument('--font-distance', type=int, default=18, help='Distance of labels from their dots center')
     ap.add_argument('--dotsize-erfa', type=float, default=13, help='Radius of Erfa dots')
     ap.add_argument('--dotsize-treff', type=float, default=8, help='Radius of Chaostreff dots')
     ap.add_argument('--rename', type=str, action='append', nargs=2, metavar=('FROM', 'TO'), default=[], help='Rename a city with an overly long name (e.g. "Rothenburg ob der Tauber" to "Rothenburg")')

style/erfamap.css

@@ -29,7 +29,7 @@ circle.erfa, circle.chaostreff {
 
 text.erfalabel {
     font-family: concertone;
-    font-size: 40px;
+    font-size: 45px;
 }
 
 rect.debugleft {