diff options
Diffstat (limited to 'components/style/piecewise_linear.rs')
| -rw-r--r-- | components/style/piecewise_linear.rs | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/components/style/piecewise_linear.rs b/components/style/piecewise_linear.rs index 61bb6e31837..f833d6350ea 100644 --- a/components/style/piecewise_linear.rs +++ b/components/style/piecewise_linear.rs @@ -137,6 +137,7 @@ impl PiecewiseLinearFunctionBuilder { fn create_entry(&mut self, y: ValueType, x: Option<ValueType>) { let x = match x { Some(x) if x.is_finite() => x, + _ if self.entries.is_empty() => 0.0, // First x is 0 if not specified (Or not finite) _ => { self.entries.push(BuildEntry { x: None, y }); return; @@ -184,22 +185,15 @@ impl PiecewiseLinearFunctionBuilder { }; } // Guaranteed at least two elements. - // Start and end elements guaranteed to have defined x value. - // Note(dshin): Spec asserts that start/end elements are supposed to have 0/1 assigned - // respectively if their x values are undefined at this time; however, the spec does - // not disallow negative/100%+ inputs, and inputs like `linear(0, 0.1 -10%, 0.9 110%, 1.0)` - // would break the assumption that the x values in the list increase monotonically. - // Otherwise, we still want 0/1 assigned to the start/end values regardless of - // adjacent x values (i.e. `linear(0, 0.1 10%, 0.9 90%, 1.0)` == - // `linear(0 0%, 0.1 10%, 0.9 90%, 1.0)` != `linear(0 10%, 0.1 10%, 0.9 90%, 1.0 90%)`) - self.entries[0] - .x - .get_or_insert(self.smallest_x.filter(|x| x < &0.0).unwrap_or(0.0)); + // Start element's x value should've been assigned when the first value was pushed. + debug_assert!(self.entries[0].x.is_some(), "Expected an entry with x defined!"); + // Spec asserts that if the last entry does not have an x value, it is assigned the largest seen x value. self.entries .last_mut() .unwrap() .x .get_or_insert(self.largest_x.filter(|x| x > &1.0).unwrap_or(1.0)); + // Now we have at least two elements with x values, with start & end x values guaranteed. let mut result = Vec::with_capacity(self.entries.len()); result.push(PiecewiseLinearFunctionEntry { |