feat: add SvgRoundedModuleDrawer class for SVG QR codes with rounded corners

Author: tobiasploetz

qrcode/image/styles/moduledrawers/svg.py

@@ -137,3 +137,138 @@ def subpath(self, box) -> str:
         # x,y is the point the arc is drawn to
 
         return f"M{x0},{yh}A{h},{h} 0 0 0 {x1},{yh}A{h},{h} 0 0 0 {x0},{yh}z"
+
+
+class SvgRoundedModuleDrawer(SvgPathQRModuleDrawer):
+    """
+    Draws the modules with all 90 degree corners replaced with rounded edges.
+
+    radius_ratio determines the radius of the rounded edges - a value of 1
+    means that an isolated module will be drawn as a circle, while a value of 0
+    means that the radius of the rounded edge will be 0 (and thus back to 90
+    degrees again).
+    """
+    needs_neighbors = True
+
+    def __init__(self, radius_ratio: Decimal = Decimal(1), **kwargs):
+        super().__init__(**kwargs)
+        self.radius_ratio = radius_ratio
+
+    def initialize(self, *args, **kwargs) -> None:
+        super().initialize(*args, **kwargs)
+        self.corner_radius = self.box_half * self.radius_ratio
+
+    def drawrect(self, box, is_active):
+        if not is_active:
+            return
+        
+        # Check if is_active has neighbor information (ActiveWithNeighbors object)
+        if hasattr(is_active, 'N'):
+            # Neighbor information is available
+            self.img._subpaths.append(self.subpath(box, is_active))
+        else:
+            # No neighbor information available, draw a square with all corners rounded
+            self.img._subpaths.append(self.subpath_all_rounded(box))
+
+    def subpath_all_rounded(self, box) -> str:
+        """Draw a module with all corners rounded."""
+        coords = self.coords(box)
+        x0 = self.img.units(coords.x0, text=False)
+        y0 = self.img.units(coords.y0, text=False)
+        x1 = self.img.units(coords.x1, text=False)
+        y1 = self.img.units(coords.y1, text=False)
+        r = self.img.units(self.corner_radius, text=False)
+        
+        # Build the path with all corners rounded
+        path = []
+        
+        # Start at top-left after the rounded part
+        path.append(f"M{x0 + r},{y0}")
+        
+        # Top edge to top-right corner
+        path.append(f"H{x1 - r}")
+        # Top-right rounded corner
+        path.append(f"A{r},{r} 0 0 1 {x1},{y0 + r}")
+        
+        # Right edge to bottom-right corner
+        path.append(f"V{y1 - r}")
+        # Bottom-right rounded corner
+        path.append(f"A{r},{r} 0 0 1 {x1 - r},{y1}")
+        
+        # Bottom edge to bottom-left corner
+        path.append(f"H{x0 + r}")
+        # Bottom-left rounded corner
+        path.append(f"A{r},{r} 0 0 1 {x0},{y1 - r}")
+        
+        # Left edge to top-left corner
+        path.append(f"V{y0 + r}")
+        # Top-left rounded corner
+        path.append(f"A{r},{r} 0 0 1 {x0 + r},{y0}")
+        
+        # Close the path
+        path.append("z")
+        
+        return "".join(path)
+
+    def subpath(self, box, is_active) -> str:
+        """Draw a module with corners rounded based on neighbor information."""
+        # Determine which corners should be rounded
+        nw_rounded = not is_active.W and not is_active.N
+        ne_rounded = not is_active.N and not is_active.E
+        se_rounded = not is_active.E and not is_active.S
+        sw_rounded = not is_active.S and not is_active.W
+        
+        coords = self.coords(box)
+        x0 = self.img.units(coords.x0, text=False)
+        y0 = self.img.units(coords.y0, text=False)
+        x1 = self.img.units(coords.x1, text=False)
+        y1 = self.img.units(coords.y1, text=False)
+        r = self.img.units(self.corner_radius, text=False)
+        
+        # Build the path
+        path = []
+        
+        # Start at top-left and move clockwise
+        if nw_rounded:
+            # Start at top-left corner, after the rounded part
+            path.append(f"M{x0 + r},{y0}")
+        else:
+            # Start at the top-left corner
+            path.append(f"M{x0},{y0}")
+        
+        # Top edge to top-right corner
+        if ne_rounded:
+            path.append(f"H{x1 - r}")
+            # Top-right rounded corner
+            path.append(f"A{r},{r} 0 0 1 {x1},{y0 + r}")
+        else:
+            path.append(f"H{x1}")
+        
+        # Right edge to bottom-right corner
+        if se_rounded:
+            path.append(f"V{y1 - r}")
+            # Bottom-right rounded corner
+            path.append(f"A{r},{r} 0 0 1 {x1 - r},{y1}")
+        else:
+            path.append(f"V{y1}")
+        
+        # Bottom edge to bottom-left corner
+        if sw_rounded:
+            path.append(f"H{x0 + r}")
+            # Bottom-left rounded corner
+            path.append(f"A{r},{r} 0 0 1 {x0},{y1 - r}")
+        else:
+            path.append(f"H{x0}")
+        
+        # Left edge back to start
+        if nw_rounded:
+            path.append(f"V{y0 + r}")
+            # Top-left rounded corner
+            path.append(f"A{r},{r} 0 0 1 {x0 + r},{y0}")
+        else:
+            path.append(f"V{y0}")
+        
+        # Close the path
+        path.append("z")
+        
+        return "".join(path)

qrcode/tests/test_qrcode_svg.py

@@ -2,6 +2,8 @@
 
 import qrcode
 from qrcode.image import svg
+from qrcode.image.styles.moduledrawers.svg import SvgRoundedModuleDrawer
+from decimal import Decimal
 from qrcode.tests.consts import UNICODE_TEXT
 
 
@@ -52,3 +54,29 @@ def test_svg_circle_drawer():
     qr.add_data(UNICODE_TEXT)
     img = qr.make_image(image_factory=svg.SvgPathImage, module_drawer="circle")
     img.save(io.BytesIO())
+
+
+def test_svg_rounded_module_drawer():
+    """Test that the SvgRoundedModuleDrawer works correctly."""
+    qr = qrcode.QRCode()
+    qr.add_data(UNICODE_TEXT)
+    
+    # Test with default parameters
+    module_drawer = SvgRoundedModuleDrawer()
+    img = qr.make_image(image_factory=svg.SvgPathImage, module_drawer=module_drawer)
+    img.save(io.BytesIO())
+    
+    # Test with custom radius_ratio
+    module_drawer = SvgRoundedModuleDrawer(radius_ratio=Decimal('0.5'))
+    img = qr.make_image(image_factory=svg.SvgPathImage, module_drawer=module_drawer)
+    img.save(io.BytesIO())
+    
+    # Test with custom size_ratio
+    module_drawer = SvgRoundedModuleDrawer(size_ratio=Decimal('0.8'))
+    img = qr.make_image(image_factory=svg.SvgPathImage, module_drawer=module_drawer)
+    img.save(io.BytesIO())
+    
+    # Test with both custom parameters
+    module_drawer = SvgRoundedModuleDrawer(radius_ratio=Decimal('0.3'), size_ratio=Decimal('0.9'))
+    img = qr.make_image(image_factory=svg.SvgPathImage, module_drawer=module_drawer)
+    img.save(io.BytesIO())