Support for square line cap

TODO.md

@@ -13,10 +13,8 @@ Features:
  - [x] "use" element
  - [x] stroke-dasharray
  - [ ] stroke-linecap ("butt", "round", "square")
- - [ ] stroke-linejoin
+ - [x] stroke-linejoin ("miter", "round", "bevel")
  - [x] Draw lines as triangle strip (instead of triangle fan)
-
-
  - [*] Patterns
    - [ ] userSpaceOnUse
    - [x] objectBoundingBox

glsvg/lines.py

@@ -16,6 +16,10 @@ def __init__(self, startp, endp, w=0):
         self.lower_join = None
         self.connector = []
 
+    @property
+    def direction(self):
+        return (self.end-self.start).normalized()
+
     @property
     def upper_edge(self):
         return LineSegment(self.start + self.up_normal,
@@ -189,7 +193,7 @@ def split_line_by_pattern(points, pattern):
     return lines
 
 
-def calc_polyline(points, w, join_type='miter', miter_limit=4, closed=False):
+def calc_polyline(points, w, line_cap='butt', join_type='miter', miter_limit=4, closed=False):
 
     miter_length = w * miter_limit
     points = [vec2(p) for p in points]
@@ -204,6 +208,11 @@ def calc_polyline(points, w, join_type='miter', miter_limit=4, closed=False):
     lines[0].upper_join = lines[0].upper_edge.start
     lines[0].lower_join = lines[0].lower_edge.start
 
+    if line_cap == 'square':
+        ext = lines[0].direction * w * -0.5
+        lines[0].upper_join = lines[0].upper_join + ext
+        lines[0].lower_join = lines[0].lower_join + ext
+
     for i in range(1, len(lines)):
         ln, pln = lines[i], lines[i-1]
         _process_joint(ln, pln, miter_length, join_type=='round')
@@ -238,15 +247,27 @@ def calc_polyline(points, w, join_type='miter', miter_limit=4, closed=False):
             ll.lower_v.append(lower_join)
 
     else:
-        ll.upper_v.append(ll.upper_join)
-        ll.upper_v.append(ll.upper_edge.end)
-        ll.lower_v.append(ll.lower_join)
-        ll.lower_v.append(ll.lower_edge.end)
+        if line_cap == 'butt':
+            ll.upper_v.append(ll.upper_join)
+            ll.upper_v.append(ll.upper_edge.end)
+            ll.lower_v.append(ll.lower_join)
+            ll.lower_v.append(ll.lower_edge.end)
+        elif line_cap == 'square':
+            ext = ll.direction * w*0.5
+            ll.upper_v.append(ll.upper_join)
+            ll.upper_v.append(ll.upper_edge.end + ext)
+            ll.lower_v.append(ll.lower_join)
+            ll.lower_v.append(ll.lower_edge.end + ext)
+        elif line_cap == 'round':
+            ll.upper_v.append(ll.upper_join)
+            ll.upper_v.append(ll.upper_edge.end)
+            ll.lower_v.append(ll.lower_join)
+            ll.lower_v.append(ll.lower_edge.end)
 
     return lines
 
 
-def draw_polyline(points, w, color, join_type='miter', miter_limit=4, closed=False, debug=False):
+def draw_polyline(points, w, color, line_cap='butt', join_type='miter', miter_limit=4, closed=False, debug=False):
     if len(points) == 0:
         return
 
@@ -265,7 +286,7 @@ def draw_polyline(points, w, color, join_type='miter', miter_limit=4, closed=Fal
     if points[0] == points[-1]:
         closed = True
 
-    lines = calc_polyline(points, w, join_type, miter_limit, closed)
+    lines = calc_polyline(points, w, line_cap, join_type, miter_limit, closed)
     swap = False
     vertices = []
 

glsvg/svg_path.py

@@ -204,10 +204,10 @@ def _render_stroke(self):
                 ls = lines.split_line_by_pattern(loop_plus, self.style.stroke_dasharray)
 
                 for l in ls:
-                    lines.draw_polyline(l, stroke_width, color=strokes[0], join_type=self.style.stroke_linejoin, miter_limit=miter_limit)
+                    lines.draw_polyline(l, stroke_width, color=strokes[0], line_cap=self.style.stroke_linecap, join_type=self.style.stroke_linejoin, miter_limit=miter_limit)
 
             else:
-                lines.draw_polyline(loop_plus, stroke_width, color=strokes[0], join_type=self.style.stroke_linejoin, miter_limit=miter_limit)
+                lines.draw_polyline(loop_plus, stroke_width, color=strokes[0], line_cap=self.style.stroke_linecap, join_type=self.style.stroke_linejoin, miter_limit=miter_limit)
 
     def _render_stroke_stencil(self):
         if not self.outline:

glsvg/svg_style.py

@@ -44,6 +44,7 @@ def from_element(self, element):
         self.stroke_opacity = float(element.get('stroke-opacity', 1))
         self.stroke_linejoin = element.get('stroke-linejoin', 'miter')
         self.stroke_miterlimit = float(element.get('stroke-miterlimit', 4))
+        self.stroke_linecap = element.get('stroke-linecap', 'butt')
 
         dash_array = element.get('stroke-dasharray', None)
         if dash_array:
@@ -69,6 +70,8 @@ def from_element(self, element):
                     self.stroke_dasharray = [float(x.strip()) for x in dash_array.split(',')]
             if 'stroke-linejoin' in style_dict:
                 self.stroke_linejoin = style_dict['stroke-linejoin']
+            if 'stroke-linecap' in style_dict:
+                self.stroke_linecap = style_dict['stroke-linecap']
             if 'opacity' in style_dict:
                 self.fill_opacity *= float(style_dict['opacity'])
                 self.stroke_opacity *= float(style_dict['opacity'])

setup.py

@@ -3,7 +3,7 @@
 setup(
     name = "glsvg",
     packages = ["glsvg"],
-    version = "0.2",
+    version = "0.3",
     description = "OpenGL SVG Renderer",
     author = "Ian Overgard",
     author_email = "ian.overgard@gmail.com",