Put the Matrix class in a separate module

It avoids imports in functions and makes document.py a bit smaller.

weasyprint/document.py

@@ -27,6 +27,7 @@ from .images import get_image_from_uri as original_get_image_from_uri
 from .layout import LayoutContext, layout_document
 from .layout.percent import percentage
 from .logger import LOGGER, PROGRESS_LOGGER
+from .matrix import Matrix
 from .text.ffi import ffi, harfbuzz, pango
 from .text.fonts import FontConfiguration
 from .urls import URLFetchingError
@@ -596,56 +597,6 @@ def resolve_links(pages):
         yield page_links, paged_anchors.pop(0)
 
 
-class Matrix(list):
-    def __init__(self, a=1, b=0, c=0, d=1, e=0, f=0, matrix=None):
-        if matrix is None:
-            matrix = [[a, b, 0], [c, d, 0], [e, f, 1]]
-        super().__init__(matrix)
-
-    def __matmul__(self, other):
-        assert len(self[0]) == len(other) == len(other[0]) == 3
-        return Matrix(matrix=[
-            [sum(self[i][k] * other[k][j] for k in range(3)) for j in range(3)]
-            for i in range(len(self))])
-
-    @property
-    def invert(self):
-        d = self.determinant
-        return Matrix(matrix=[
-            [
-                (self[1][1] * self[2][2] - self[1][2] * self[2][1]) / d,
-                (self[0][1] * self[2][2] - self[0][2] * self[2][1]) / -d,
-                (self[0][1] * self[1][2] - self[0][2] * self[1][1]) / d,
-            ],
-            [
-                (self[1][0] * self[2][2] - self[1][2] * self[2][0]) / -d,
-                (self[0][0] * self[2][2] - self[0][2] * self[2][0]) / d,
-                (self[0][0] * self[1][2] - self[0][2] * self[1][0]) / -d,
-            ],
-            [
-                (self[1][0] * self[2][1] - self[1][1] * self[2][0]) / d,
-                (self[0][0] * self[2][1] - self[0][1] * self[2][0]) / -d,
-                (self[0][0] * self[1][1] - self[0][1] * self[1][0]) / d,
-            ],
-        ])
-
-    @property
-    def determinant(self):
-        assert len(self) == len(self[0]) == 3
-        return (
-            self[0][0] * (self[1][1] * self[2][2] - self[1][2] * self[2][1]) -
-            self[1][0] * (self[0][1] * self[2][2] - self[0][2] * self[2][1]) +
-            self[2][0] * (self[0][1] * self[1][2] - self[0][2] * self[1][1]))
-
-    def transform_point(self, x, y):
-        return (Matrix(matrix=[[x, y, 1]]) @ self)[0][:2]
-
-    @property
-    def values(self):
-        (a, b), (c, d), (e, f) = [column[:2] for column in self]
-        return a, b, c, d, e, f
-
-
 class Page:
     """Represents a single rendered page.
 

weasyprint/draw.py

@@ -13,6 +13,7 @@ from .formatting_structure import boxes
 from .images import RasterImage, SVGImage
 from .layout import replaced
 from .layout.background import BackgroundLayer
+from .matrix import Matrix
 from .stacking import StackingContext
 from .text.ffi import ffi, harfbuzz, pango, units_from_double, units_to_double
 from .text.line_break import get_last_word_end
@@ -357,8 +358,6 @@ def draw_table_backgrounds(stream, page, table):
 
 
 def draw_background_image(stream, layer, image_rendering):
-    from .document import Matrix
-
     if layer.image is None or 0 in layer.size:
         return
 
@@ -1028,8 +1027,6 @@ def draw_emojis(stream, font_size, x, y, emojis):
 def draw_first_line(stream, textbox, text_overflow, block_ellipsis, x, y,
                     angle=0):
     """Draw the given ``textbox`` line to the document ``stream``."""
-    from .document import Matrix
-
     pango.pango_layout_set_single_paragraph_mode(
         textbox.pango_layout.layout, True)
 

weasyprint/matrix.py

@@ -0,0 +1,51 @@
+"""Transformation matrix."""
+
+
+class Matrix(list):
+    def __init__(self, a=1, b=0, c=0, d=1, e=0, f=0, matrix=None):
+        if matrix is None:
+            matrix = [[a, b, 0], [c, d, 0], [e, f, 1]]
+        super().__init__(matrix)
+
+    def __matmul__(self, other):
+        assert len(self[0]) == len(other) == len(other[0]) == 3
+        return Matrix(matrix=[
+            [sum(self[i][k] * other[k][j] for k in range(3)) for j in range(3)]
+            for i in range(len(self))])
+
+    @property
+    def invert(self):
+        d = self.determinant
+        return Matrix(matrix=[
+            [
+                (self[1][1] * self[2][2] - self[1][2] * self[2][1]) / d,
+                (self[0][1] * self[2][2] - self[0][2] * self[2][1]) / -d,
+                (self[0][1] * self[1][2] - self[0][2] * self[1][1]) / d,
+            ],
+            [
+                (self[1][0] * self[2][2] - self[1][2] * self[2][0]) / -d,
+                (self[0][0] * self[2][2] - self[0][2] * self[2][0]) / d,
+                (self[0][0] * self[1][2] - self[0][2] * self[1][0]) / -d,
+            ],
+            [
+                (self[1][0] * self[2][1] - self[1][1] * self[2][0]) / d,
+                (self[0][0] * self[2][1] - self[0][1] * self[2][0]) / -d,
+                (self[0][0] * self[1][1] - self[0][1] * self[1][0]) / d,
+            ],
+        ])
+
+    @property
+    def determinant(self):
+        assert len(self) == len(self[0]) == 3
+        return (
+            self[0][0] * (self[1][1] * self[2][2] - self[1][2] * self[2][1]) -
+            self[1][0] * (self[0][1] * self[2][2] - self[0][2] * self[2][1]) +
+            self[2][0] * (self[0][1] * self[1][2] - self[0][2] * self[1][1]))
+
+    def transform_point(self, x, y):
+        return (Matrix(matrix=[[x, y, 1]]) @ self)[0][:2]
+
+    @property
+    def values(self):
+        (a, b), (c, d), (e, f) = [column[:2] for column in self]
+        return a, b, c, d, e, f

weasyprint/svg/defs.py

@@ -11,6 +11,7 @@ from math import ceil, hypot
 
 import pydyf
 
+from ..matrix import Matrix
 from .bounding_box import is_valid_bounding_box
 from .utils import color, parse_url, size, transform
 
@@ -80,8 +81,6 @@ def draw_gradient_or_pattern(svg, node, name, font_size, opacity, stroke):
 def draw_gradient(svg, node, gradient, font_size, opacity, stroke):
     """Draw given gradient node."""
     # TODO: merge with Gradient.draw
-    from ..document import Matrix
-
     positions = []
     colors = []
     for child in gradient:
@@ -455,7 +454,6 @@ def spread_radial_gradient(spread, positions, colors, fx, fy, fr, cx, cy, r,
 
 def draw_pattern(svg, node, pattern, font_size, opacity, stroke):
     """Draw given gradient node."""
-    from ..document import Matrix
     from . import Pattern
 
     pattern._etree_node.tag = 'svg'

weasyprint/svg/path.py

@@ -2,6 +2,7 @@
 
 from math import atan2, cos, isclose, pi, radians, sin, tan
 
+from ..matrix import Matrix
 from .utils import normalize, point
 
 PATH_LETTERS = 'achlmqstvzACHLMQSTVZ'
@@ -14,8 +15,6 @@ def _rotate(x, y, angle):
 
 def path(svg, node, font_size):
     """Draw path node."""
-    from ..document import Matrix
-
     string = node.get('d', '')
 
     for letter in PATH_LETTERS:

weasyprint/svg/utils.py

@@ -12,6 +12,8 @@ from urllib.parse import urlparse
 
 from tinycss2.color3 import parse_color
 
+from ..matrix import Matrix
+
 
 class PointError(Exception):
     """Exception raised when parsing a point fails."""
@@ -144,8 +146,6 @@ def transform(transform_string, font_size, normalized_diagonal):
     """Get a matrix corresponding to the transform string."""
     # TODO: merge with Page._gather_links_and_bookmarks and
     # css.validation.properties.transform
-    from ..document import Matrix
-
     transformations = re.findall(
         r'(\w+) ?\( ?(.*?) ?\)', normalize(transform_string))
     matrix = Matrix()