Int, Float, Relative and Linear values 🍉

1 files changed, 51 insertions, 27 deletions

diff --git a/src/style.rs b/src/style.rs
index b6c1a278..74deeeb9 100644
--- a/src/style.rs
+++ b/src/style.rs
@@ -2,8 +2,8 @@
 
 use fontdock::{fallback, FallbackTree, FontStretch, FontStyle, FontVariant, FontWeight};
 
-use crate::geom::{Insets, Sides, Size};
-use crate::length::{Length, ScaleLength};
+use crate::geom::{Insets, Linear, Sides, Size};
+use crate::length::Length;
 use crate::paper::{Paper, PaperClass, PAPER_A4};
 
 /// Defines properties of pages and text.
@@ -28,37 +28,35 @@ pub struct TextStyle {
     /// Whether the emphasis toggle is active or inactive. This determines
     /// whether the next `_` makes italic or non-italic.
     pub emph: bool,
-    /// The base font size.
-    pub base_font_size: f64,
-    /// The font scale to apply on the base font size.
-    pub font_scale: f64,
-    /// The word spacing (as a multiple of the font size).
-    pub word_spacing_scale: f64,
-    /// The line spacing (as a multiple of the font size).
-    pub line_spacing_scale: f64,
-    /// The paragraphs spacing (as a multiple of the font size).
-    pub paragraph_spacing_scale: f64,
+    /// The font size.
+    pub font_size: FontSize,
+    /// The word spacing (relative to the the font size).
+    pub word_spacing: Linear,
+    /// The line spacing (relative to the the font size).
+    pub line_spacing: Linear,
+    /// The paragraphs spacing (relative to the the font size).
+    pub par_spacing: Linear,
 }
 
 impl TextStyle {
-    /// The scaled font size.
+    /// The absolute font size.
     pub fn font_size(&self) -> f64 {
-        self.base_font_size * self.font_scale
+        self.font_size.eval()
     }
 
     /// The absolute word spacing.
     pub fn word_spacing(&self) -> f64 {
-        self.word_spacing_scale * self.font_size()
+        self.word_spacing.eval(self.font_size())
     }
 
     /// The absolute line spacing.
     pub fn line_spacing(&self) -> f64 {
-        (self.line_spacing_scale - 1.0) * self.font_size()
+        self.line_spacing.eval(self.font_size())
     }
 
     /// The absolute paragraph spacing.
     pub fn paragraph_spacing(&self) -> f64 {
-        (self.paragraph_spacing_scale - 1.0) * self.font_size()
+        self.par_spacing.eval(self.font_size())
     }
 }
 
@@ -85,15 +83,41 @@ impl Default for TextStyle {
             },
             strong: false,
             emph: false,
-            base_font_size: Length::pt(11.0).as_raw(),
-            font_scale: 1.0,
-            word_spacing_scale: 0.25,
-            line_spacing_scale: 1.2,
-            paragraph_spacing_scale: 1.5,
+            font_size: FontSize::abs(Length::pt(11.0).as_raw()),
+            word_spacing: Linear::rel(0.25),
+            line_spacing: Linear::rel(0.2),
+            par_spacing: Linear::rel(0.5),
         }
     }
 }
 
+/// The font size, defined by base and scale.
+#[derive(Debug, Clone, PartialEq)]
+pub struct FontSize {
+    /// The base font size, updated whenever the font size is set absolutely.
+    pub base: f64,
+    /// The scale to apply on the base font size, updated when the font size
+    /// is set relatively.
+    pub scale: Linear,
+}
+
+impl FontSize {
+    /// Create a new font size.
+    pub fn new(base: f64, scale: Linear) -> Self {
+        Self { base, scale }
+    }
+
+    /// Create a new font size with the given `base` and a scale of `1.0`.
+    pub fn abs(base: f64) -> Self {
+        Self::new(base, Linear::rel(1.0))
+    }
+
+    /// Compute the absolute font size.
+    pub fn eval(&self) -> f64 {
+        self.scale.eval(self.base)
+    }
+}
+
 /// Defines the size and margins of a page.
 #[derive(Debug, Copy, Clone, PartialEq)]
 pub struct PageStyle {
@@ -103,7 +127,7 @@ pub struct PageStyle {
     pub size: Size,
     /// The amount of white space in the order [left, top, right, bottom]. If a
     /// side is set to `None`, the default for the paper class is used.
-    pub margins: Sides<Option<ScaleLength>>,
+    pub margins: Sides<Option<Linear>>,
 }
 
 impl PageStyle {
@@ -121,10 +145,10 @@ impl PageStyle {
         let Size { width, height } = self.size;
         let default = self.class.default_margins();
         Insets {
-            x0: -self.margins.left.unwrap_or(default.left).raw_scaled(width),
-            y0: -self.margins.top.unwrap_or(default.top).raw_scaled(height),
-            x1: -self.margins.right.unwrap_or(default.right).raw_scaled(width),
-            y1: -self.margins.bottom.unwrap_or(default.bottom).raw_scaled(height),
+            x0: -self.margins.left.unwrap_or(default.left).eval(width),
+            y0: -self.margins.top.unwrap_or(default.top).eval(height),
+            x1: -self.margins.right.unwrap_or(default.right).eval(width),
+            y1: -self.margins.bottom.unwrap_or(default.bottom).eval(height),
         }
     }
 }