Support configurable `LineHeight` in text widgets

3 files changed, 41 insertions, 8 deletions

diff --git a/tiny_skia/src/backend.rs b/tiny_skia/src/backend.rs
index 3ef7e717..99230a2f 100644
--- a/tiny_skia/src/backend.rs
+++ b/tiny_skia/src/backend.rs
@@ -216,6 +216,7 @@ impl Backend {
                 bounds,
                 color,
                 size,
+                line_height,
                 font,
                 horizontal_alignment,
                 vertical_alignment,
@@ -233,13 +234,15 @@ impl Backend {
 
                 self.text_pipeline.draw(
                     content,
-                    (*bounds + translation) * scale_factor,
+                    *bounds + translation,
                     *color,
-                    *size * scale_factor,
+                    *size,
+                    *line_height,
                     *font,
                     *horizontal_alignment,
                     *vertical_alignment,
                     *shaping,
+                    scale_factor,
                     pixels,
                     clip_mask,
                 );
@@ -626,18 +629,26 @@ impl backend::Text for Backend {
         &self,
         contents: &str,
         size: f32,
+        line_height: text::LineHeight,
         font: Font,
         bounds: Size,
         shaping: text::Shaping,
     ) -> (f32, f32) {
-        self.text_pipeline
-            .measure(contents, size, font, bounds, shaping)
+        self.text_pipeline.measure(
+            contents,
+            size,
+            line_height,
+            font,
+            bounds,
+            shaping,
+        )
     }
 
     fn hit_test(
         &self,
         contents: &str,
         size: f32,
+        line_height: text::LineHeight,
         font: Font,
         bounds: Size,
         shaping: text::Shaping,
@@ -647,6 +658,7 @@ impl backend::Text for Backend {
         self.text_pipeline.hit_test(
             contents,
             size,
+            line_height,
             font,
             bounds,
             shaping,
diff --git a/tiny_skia/src/geometry.rs b/tiny_skia/src/geometry.rs
index 7963fd89..a445b561 100644
--- a/tiny_skia/src/geometry.rs
+++ b/tiny_skia/src/geometry.rs
@@ -111,6 +111,7 @@ impl Frame {
             },
             color: text.color,
             size: text.size,
+            line_height: text.line_height,
             font: text.font,
             horizontal_alignment: text.horizontal_alignment,
             vertical_alignment: text.vertical_alignment,
diff --git a/tiny_skia/src/text.rs b/tiny_skia/src/text.rs
index 58079cc0..ba8a4e4b 100644
--- a/tiny_skia/src/text.rs
+++ b/tiny_skia/src/text.rs
@@ -1,7 +1,7 @@
 use crate::core::alignment;
 use crate::core::font::{self, Font};
-use crate::core::text::{Hit, Shaping};
-use crate::core::{Color, Point, Rectangle, Size};
+use crate::core::text::{Hit, LineHeight, Shaping};
+use crate::core::{Color, Pixels, Point, Rectangle, Size};
 
 use rustc_hash::{FxHashMap, FxHashSet};
 use std::borrow::Cow;
@@ -46,13 +46,21 @@ impl Pipeline {
         bounds: Rectangle,
         color: Color,
         size: f32,
+        line_height: LineHeight,
         font: Font,
         horizontal_alignment: alignment::Horizontal,
         vertical_alignment: alignment::Vertical,
         shaping: Shaping,
+        scale_factor: f32,
         pixels: &mut tiny_skia::PixmapMut<'_>,
         clip_mask: Option<&tiny_skia::Mask>,
     ) {
+        let line_height =
+            f32::from(line_height.to_absolute(Pixels(size))) * scale_factor;
+
+        let bounds = bounds * scale_factor;
+        let size = size * scale_factor;
+
         let font_system = self.font_system.get_mut();
         let key = Key {
             bounds: {
@@ -64,6 +72,7 @@ impl Pipeline {
             content,
             font,
             size,
+            line_height,
             shaping,
         };
 
@@ -76,7 +85,7 @@ impl Pipeline {
                 (i + 1, buffer.line_w.max(max))
             });
 
-        let total_height = total_lines as f32 * size * 1.2;
+        let total_height = total_lines as f32 * line_height;
 
         let x = match horizontal_alignment {
             alignment::Horizontal::Left => bounds.x,
@@ -130,17 +139,21 @@ impl Pipeline {
         &self,
         content: &str,
         size: f32,
+        line_height: LineHeight,
         font: Font,
         bounds: Size,
         shaping: Shaping,
     ) -> (f32, f32) {
         let mut measurement_cache = self.measurement_cache.borrow_mut();
 
+        let line_height = f32::from(line_height.to_absolute(Pixels(size)));
+
         let (_, paragraph) = measurement_cache.allocate(
             &mut self.font_system.borrow_mut(),
             Key {
                 content,
                 size,
+                line_height,
                 font,
                 bounds,
                 shaping,
@@ -154,13 +167,14 @@ impl Pipeline {
                 (i + 1, buffer.line_w.max(max))
             });
 
-        (max_width, size * 1.2 * total_lines as f32)
+        (max_width, line_height * total_lines as f32)
     }
 
     pub fn hit_test(
         &self,
         content: &str,
         size: f32,
+        line_height: LineHeight,
         font: Font,
         bounds: Size,
         shaping: Shaping,
@@ -169,11 +183,14 @@ impl Pipeline {
     ) -> Option<Hit> {
         let mut measurement_cache = self.measurement_cache.borrow_mut();
 
+        let line_height = f32::from(line_height.to_absolute(Pixels(size)));
+
         let (_, paragraph) = measurement_cache.allocate(
             &mut self.font_system.borrow_mut(),
             Key {
                 content,
                 size,
+                line_height,
                 font,
                 bounds,
                 shaping,
@@ -380,9 +397,11 @@ impl Cache {
 
             key.content.hash(&mut hasher);
             key.size.to_bits().hash(&mut hasher);
+            key.line_height.to_bits().hash(&mut hasher);
             key.font.hash(&mut hasher);
             key.bounds.width.to_bits().hash(&mut hasher);
             key.bounds.height.to_bits().hash(&mut hasher);
+            key.shaping.hash(&mut hasher);
 
             hasher.finish()
         };
@@ -432,6 +451,7 @@ impl Cache {
 struct Key<'a> {
     content: &'a str,
     size: f32,
+    line_height: f32,
     font: Font,
     bounds: Size,
     shaping: Shaping,