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| 1 | +use torin::prelude::{ |
| 2 | + Area, |
| 3 | + Point2D, |
| 4 | +}; |
| 5 | + |
| 6 | +/// Position of a [`TransformOrigin`] along a single axis. |
| 7 | +#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))] |
| 8 | +#[derive(Debug, Clone, Copy, PartialEq)] |
| 9 | +pub enum OriginValue { |
| 10 | + /// Fraction of the element's length along the axis, where `0.0` is the start |
| 11 | + /// and `1.0` is the end. |
| 12 | + Fraction(f32), |
| 13 | + /// Absolute pixels measured from the element's top-left corner. |
| 14 | + Pixels(f32), |
| 15 | +} |
| 16 | + |
| 17 | +impl OriginValue { |
| 18 | + /// Resolve this value into an absolute offset given the element's length on the axis. |
| 19 | + fn resolve(self, length: f32) -> f32 { |
| 20 | + match self { |
| 21 | + OriginValue::Fraction(fraction) => length * fraction, |
| 22 | + OriginValue::Pixels(pixels) => pixels, |
| 23 | + } |
| 24 | + } |
| 25 | +} |
| 26 | + |
| 27 | +/// Reference point that the scale and rotation effects of an element pivot around. |
| 28 | +/// |
| 29 | +/// Defaults to the element's center. |
| 30 | +#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))] |
| 31 | +#[derive(Debug, Clone, Copy, PartialEq)] |
| 32 | +pub struct TransformOrigin { |
| 33 | + pub x: OriginValue, |
| 34 | + pub y: OriginValue, |
| 35 | +} |
| 36 | + |
| 37 | +impl Default for TransformOrigin { |
| 38 | + fn default() -> Self { |
| 39 | + Self::center() |
| 40 | + } |
| 41 | +} |
| 42 | + |
| 43 | +impl TransformOrigin { |
| 44 | + /// Resolve the origin point in absolute coordinates for the given element area. |
| 45 | + pub fn origin(&self, area: &Area) -> Point2D { |
| 46 | + Point2D::new( |
| 47 | + area.min_x() + self.x.resolve(area.width()), |
| 48 | + area.min_y() + self.y.resolve(area.height()), |
| 49 | + ) |
| 50 | + } |
| 51 | + |
| 52 | + pub fn center() -> Self { |
| 53 | + Self { |
| 54 | + x: OriginValue::Fraction(0.5), |
| 55 | + y: OriginValue::Fraction(0.5), |
| 56 | + } |
| 57 | + } |
| 58 | + |
| 59 | + pub fn top_left() -> Self { |
| 60 | + Self { |
| 61 | + x: OriginValue::Fraction(0.0), |
| 62 | + y: OriginValue::Fraction(0.0), |
| 63 | + } |
| 64 | + } |
| 65 | + |
| 66 | + pub fn top() -> Self { |
| 67 | + Self { |
| 68 | + x: OriginValue::Fraction(0.5), |
| 69 | + y: OriginValue::Fraction(0.0), |
| 70 | + } |
| 71 | + } |
| 72 | + |
| 73 | + pub fn top_right() -> Self { |
| 74 | + Self { |
| 75 | + x: OriginValue::Fraction(1.0), |
| 76 | + y: OriginValue::Fraction(0.0), |
| 77 | + } |
| 78 | + } |
| 79 | + |
| 80 | + pub fn left() -> Self { |
| 81 | + Self { |
| 82 | + x: OriginValue::Fraction(0.0), |
| 83 | + y: OriginValue::Fraction(0.5), |
| 84 | + } |
| 85 | + } |
| 86 | + |
| 87 | + pub fn right() -> Self { |
| 88 | + Self { |
| 89 | + x: OriginValue::Fraction(1.0), |
| 90 | + y: OriginValue::Fraction(0.5), |
| 91 | + } |
| 92 | + } |
| 93 | + |
| 94 | + pub fn bottom_left() -> Self { |
| 95 | + Self { |
| 96 | + x: OriginValue::Fraction(0.0), |
| 97 | + y: OriginValue::Fraction(1.0), |
| 98 | + } |
| 99 | + } |
| 100 | + |
| 101 | + pub fn bottom() -> Self { |
| 102 | + Self { |
| 103 | + x: OriginValue::Fraction(0.5), |
| 104 | + y: OriginValue::Fraction(1.0), |
| 105 | + } |
| 106 | + } |
| 107 | + |
| 108 | + pub fn bottom_right() -> Self { |
| 109 | + Self { |
| 110 | + x: OriginValue::Fraction(1.0), |
| 111 | + y: OriginValue::Fraction(1.0), |
| 112 | + } |
| 113 | + } |
| 114 | +} |
| 115 | + |
| 116 | +/// Shorthand for a fractional [`TransformOrigin`], where `0.0` is the start and `1.0` the end of each axis. |
| 117 | +impl From<(f32, f32)> for TransformOrigin { |
| 118 | + fn from((x, y): (f32, f32)) -> Self { |
| 119 | + Self { |
| 120 | + x: OriginValue::Fraction(x), |
| 121 | + y: OriginValue::Fraction(y), |
| 122 | + } |
| 123 | + } |
| 124 | +} |
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