Auto merge of #7161 - mbrubeck:underline, r=pcwalton

Snap rectangles to nearest pixels consistently.

Snapping the top-left and bottom-right corners separately can cause a rectangle to change size or even become empty when offset by a subpixel amount.  Instead, this patch snaps the top-left corner, then snaps the size to a whole pixel amount, so any rectangle of a given original size will always have the same snapped size.

Fixes #7152. r? @pcwalton or @glennw

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This commit is contained in:
bors-servo 2015-08-11 11:31:32 -06:00
commit 9c528c6382
5 changed files with 41 additions and 13 deletions

View file

@ -1171,16 +1171,10 @@ pub trait ToAzureRect {
impl ToAzureRect for Rect<Au> {
fn to_nearest_azure_rect(&self) -> Rect<AzFloat> {
let top_left = self.origin.to_nearest_azure_point();
let bottom_right = self.bottom_right().to_nearest_azure_point();
Rect::new(top_left,
Size2D::new((bottom_right.x - top_left.x) as AzFloat,
(bottom_right.y - top_left.y) as AzFloat))
Rect::new(self.origin.to_nearest_azure_point(), self.size.to_nearest_azure_size())
}
fn to_azure_rect(&self) -> Rect<AzFloat> {
Rect::new(self.origin.to_azure_point(), Size2D::new(self.size.width.to_f32_px(),
self.size.height.to_f32_px()))
Rect::new(self.origin.to_azure_point(), self.size.to_azure_size())
}
}
@ -1382,11 +1376,12 @@ impl DrawTargetExtensions for DrawTarget {
}
fn create_rectangular_path(&self, rect: &Rect<Au>) -> Path {
let rect = rect.to_nearest_azure_rect();
let path_builder = self.create_path_builder();
path_builder.move_to(rect.origin.to_nearest_azure_point());
path_builder.line_to(Point2D::new(rect.max_x(), rect.origin.y).to_nearest_azure_point());
path_builder.line_to(Point2D::new(rect.max_x(), rect.max_y()).to_nearest_azure_point());
path_builder.line_to(Point2D::new(rect.origin.x, rect.max_y()).to_nearest_azure_point());
path_builder.move_to(rect.origin);
path_builder.line_to(Point2D::new(rect.max_x(), rect.origin.y));
path_builder.line_to(Point2D::new(rect.max_x(), rect.max_y()));
path_builder.line_to(Point2D::new(rect.origin.x, rect.max_y()));
path_builder.finish()
}
}