Have Image objects "render themselves" on a cairo Context.

weasyprint/draw.py

@@ -24,14 +24,6 @@ from .stacking import StackingContext
 from .text import show_first_line
 from .compat import xrange
 
-# Map values of the image-rendering property to cairo FILTER values:
-# Values are normalized to lower case.
-IMAGE_RENDERING_TO_FILTER = dict(
-    optimizespeed=cairo.FILTER_FAST,
-    auto=cairo.FILTER_GOOD,
-    optimizequality=cairo.FILTER_BEST,
-)
-
 
 @contextlib.contextmanager
 def stacked(context):
@@ -304,12 +296,9 @@ def draw_background_image(context, layer):
     sub_surface = cairo.PDFSurface(None, repeat_width, repeat_height)
     sub_context = cairo.Context(sub_surface)
     sub_context.rectangle(0, 0, image_width, image_height)
-    sub_context.scale(image_width / intrinsic_width,
-                      image_height / intrinsic_height)
-    sub_pattern = layer.image.get_pattern()
-    sub_pattern.set_filter(IMAGE_RENDERING_TO_FILTER[layer.image_rendering])
-    sub_context.set_source(sub_pattern)
-    sub_context.fill()
+    sub_context.clip()
+    layer.image.draw(
+        sub_context, image_width, image_height, layer.image_rendering)
     pattern = cairo.SurfacePattern(sub_surface)
     pattern.set_extend(cairo.EXTEND_REPEAT)
 
@@ -637,27 +626,15 @@ def draw_collapsed_borders(context, table, enable_hinting):
 
 def draw_replacedbox(context, box):
     """Draw the given :class:`boxes.ReplacedBox` to a ``cairo.context``."""
-    if box.style.visibility == 'hidden':
+    if box.style.visibility == 'hidden' or box.width == 0 or box.height == 0:
         return
 
-    x, y = box.content_box_x(), box.content_box_y()
-    width, height = box.width, box.height
-    scale_width = width / box.replacement.intrinsic_width
-    scale_height = height / box.replacement.intrinsic_height
-    # Draw nothing for width:0 or height:0
-    if scale_width != 0 and scale_height != 0:
-        with stacked(context):
-            context.translate(x, y)
-            context.rectangle(0, 0, width, height)
-            context.clip()
-            context.scale(scale_width, scale_height)
-            pattern = box.replacement.get_pattern()
-            # We might get a shared Pattern that was previously used
-            # in a repeating background.
-            pattern.set_filter(IMAGE_RENDERING_TO_FILTER[
-                box.style.image_rendering])
-            context.set_source(pattern)
-            context.paint()
+    with stacked(context):
+        context.translate(box.content_box_x(), box.content_box_y())
+        context.rectangle(0, 0, box.width, box.height)
+        context.clip()
+        box.replacement.draw(
+            context, box.width, box.height, box.style.image_rendering)
 
 
 def draw_inline_level(context, page, box, enable_hinting):

weasyprint/images.py

@@ -31,6 +31,15 @@ except OSError:
 from .logger import LOGGER
 
 
+# Map values of the image-rendering property to cairo FILTER values:
+# Values are normalized to lower case.
+IMAGE_RENDERING_TO_FILTER = dict(
+    optimizespeed=cairocffi.FILTER_FAST,
+    auto=cairocffi.FILTER_GOOD,
+    optimizequality=cairocffi.FILTER_BEST,
+)
+
+
 class RasterImage(object):
     def __init__(self, image_surface):
         self.image_surface = image_surface
@@ -38,8 +47,14 @@ class RasterImage(object):
         self.intrinsic_height = image_surface.get_height()
         self.intrinsic_ratio = self.intrinsic_width / self.intrinsic_height
 
-    def get_pattern(self):
-        return cairocffi.SurfacePattern(self.image_surface)
+    def draw(self, context, concrete_width, concrete_height, image_rendering):
+        if self.intrinsic_width > 0 and self.intrinsic_height > 0:
+            context.scale(concrete_width / self.intrinsic_width,
+                          concrete_height / self.intrinsic_height)
+            context.set_source_surface(self.image_surface)
+            context.get_source().set_filter(
+                IMAGE_RENDERING_TO_FILTER[image_rendering])
+            context.paint()
 
 
 class ScaledSVGSurface(cairosvg.surface.SVGSurface):
@@ -62,14 +77,14 @@ class SVGImage(object):
         self._svg_data = svg_data
 
         # TODO: find a way of not doing twice the whole rendering.
-        cairosvg_result = self._render()
+        svg = self._render()
         # TODO: support SVG images with none or only one of intrinsic
         #       width, height and ratio.
-        if not (cairosvg_result.width > 0 and cairosvg_result.height > 0):
+        if not (svg.width > 0 and svg.height > 0):
             raise ValueError(
                 'SVG Images without an intrinsic size are not supported.')
-        self.intrinsic_width = cairosvg_result.width
-        self.intrinsic_height = cairosvg_result.height
+        self.intrinsic_width = svg.width
+        self.intrinsic_height = svg.height
         self.intrinsic_ratio = self.intrinsic_width / self.intrinsic_height
 
     def _render(self):
@@ -79,11 +94,14 @@ class SVGImage(object):
             cairosvg.parser.Tree(bytestring=self._svg_data, url=self._base_url),
             output=None, dpi=96)
 
-    def get_pattern(self):
-        # Do not re-use the Surface object, but regenerate it as needed.
+    def draw(self, context, concrete_width, concrete_height, image_rendering):
+        # Do not re-use the rendered Surface object, but regenerate it as needed.
         # If a surface for a SVG image is still alive by the time we call
         # show_page(), cairo will rasterize the image instead writing vectors.
-        return cairocffi.SurfacePattern(self._render().cairo)
+        svg = self._render()
+        context.scale(concrete_width / svg.width, concrete_height / svg.height)
+        context.set_source_surface(svg.cairo)
+        context.paint()
 
 
 def get_image_from_uri(cache, url_fetcher, uri, forced_mime_type=None):