3 files changed, 42 insertions, 22 deletions

diff --git a/font/src/darwin/mod.rs b/font/src/darwin/mod.rs
index 877564fa..a6deba3b 100644
--- a/font/src/darwin/mod.rs
+++ b/font/src/darwin/mod.rs
@@ -462,17 +462,31 @@ impl Font {
 
     pub fn get_glyph(&self, character: char, _size: f64, use_thin_strokes: bool) -> Result<RasterizedGlyph, Error> {
         // Render custom symbols for underline and beam cursor
-        if character == super::UNDERLINE_CURSOR_CHAR {
-            let descent = -(self.ct_font.descent() as i32);
-            let width = self.glyph_advance('0') as i32;
-            return super::get_underline_cursor_glyph(descent, width);
-        } else if character == super::BEAM_CURSOR_CHAR {
-            let metrics = self.metrics();
-            let height = metrics.line_height;
-            let ascent = height - self.ct_font.descent() + 1.;
-            let width = self.glyph_advance('0') as i32;
-            return super::get_beam_cursor_glyph(ascent as i32, height as i32, width);
-        };
+        match character {
+            super::UNDERLINE_CURSOR_CHAR => {
+                // Get the bottom of the bounding box
+                let descent = -(self.ct_font.descent() as i32);
+                // Get the width of the cell
+                let width = self.glyph_advance('0') as i32;
+                // Return the new custom glyph
+                return super::get_underline_cursor_glyph(descent, width);
+            },
+            super::BEAM_CURSOR_CHAR => {
+                // Get the top of the bounding box
+                let metrics = self.metrics();
+                let height = metrics.line_height;
+                let mut ascent = height - self.ct_font.descent() + 1.;
+                if ascent.floor() == ascent {
+                    // Fix off-by-one with an exact X.0 ascent
+                    ascent -= 1.;
+                }
+                // Get the width of the cell
+                let width = self.glyph_advance('0') as i32;
+                // Return the new custom glyph
+                return super::get_beam_cursor_glyph(ascent as i32, height as i32, width);
+            },
+            _ => (),
+        }
 
         let glyph_index = self.glyph_index(character)
             .ok_or(Error::MissingGlyph(character))?;
diff --git a/font/src/ft/mod.rs b/font/src/ft/mod.rs
index 7b22fb03..765e8efb 100644
--- a/font/src/ft/mod.rs
+++ b/font/src/ft/mod.rs
@@ -298,7 +298,8 @@ impl FreeTypeRasterizer {
         match glyph_key.c {
             super::UNDERLINE_CURSOR_CHAR => {
                 // Get the bottom of the bounding box
-                let size_metrics = face.ft_face.size_metrics()
+                let size_metrics = face.ft_face
+                    .size_metrics()
                     .ok_or(Error::MissingSizeMetrics)?;
                 let descent = (size_metrics.descender / 64) as i32;
 
@@ -308,10 +309,11 @@ impl FreeTypeRasterizer {
 
                 // Return the new custom glyph
                 super::get_underline_cursor_glyph(descent, width)
-            },
+            }
             super::BEAM_CURSOR_CHAR => {
                 // Get the top of the bounding box
-                let size_metrics = face.ft_face.size_metrics()
+                let size_metrics = face.ft_face
+                    .size_metrics()
                     .ok_or(Error::MissingSizeMetrics)?;
                 let ascent = (size_metrics.ascender / 64) as i32 - 1;
 
@@ -325,7 +327,7 @@ impl FreeTypeRasterizer {
 
                 // Return the new custom glyph
                 super::get_beam_cursor_glyph(ascent, height, width)
-            },
+            }
             _ => {
                 // If it's not a special char, return the normal glyph
                 Ok(RasterizedGlyph {
diff --git a/font/src/lib.rs b/font/src/lib.rs
index a2580fc8..f9eaaac6 100644
--- a/font/src/lib.rs
+++ b/font/src/lib.rs
@@ -43,7 +43,7 @@ extern crate foreign_types;
 extern crate log;
 
 use std::hash::{Hash, Hasher};
-use std::fmt;
+use std::{fmt, cmp};
 use std::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};
 
 // If target isn't macos, reexport everything from ft
@@ -65,6 +65,8 @@ pub const UNDERLINE_CURSOR_CHAR: char = '\u{10a3e2}';
 /// Character used for the beam cursor
 // This is part of the private use area and should not conflict with any font
 pub const BEAM_CURSOR_CHAR: char = '\u{10a3e3}';
+/// Width of the beam cursor relative to the font width
+pub const BEAM_CURSOR_WIDTH_PERCENTAGE: i32 = 15;
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct FontDesc {
@@ -211,11 +213,10 @@ impl Default for RasterizedGlyph {
 }
 
 // Returns a custom underline cursor character
-// TODO: Make sure this works with positive/0 descent -> small fonts
 pub fn get_underline_cursor_glyph(descent: i32, width: i32) -> Result<RasterizedGlyph, Error> {
     // Create a new rectangle, the height is half the distance between
     // bounding box bottom and the baseline
-    let height = i32::abs(descent / 2);
+    let height = cmp::max(i32::abs(descent / 2), 1);
     let buf = vec![255u8; (width * height * 3) as usize];
 
     // Create a custom glyph with the rectangle data attached to it
@@ -230,10 +231,13 @@ pub fn get_underline_cursor_glyph(descent: i32, width: i32) -> Result<Rasterized
 }
 
 // Returns a custom beam cursor character
-// TODO: Make sure this works with positive/0 descent -> small fonts
-pub fn get_beam_cursor_glyph(ascent: i32, height: i32, width: i32) -> Result<RasterizedGlyph, Error> {
-    // Create a new rectangle
-    let beam_width = (f64::from(width) / 5.) as i32;
+pub fn get_beam_cursor_glyph(
+    ascent: i32,
+    height: i32,
+    width: i32,
+) -> Result<RasterizedGlyph, Error> {
+    // Create a new rectangle that is at least one pixel wide
+    let beam_width = cmp::max(width * BEAM_CURSOR_WIDTH_PERCENTAGE / 100, 1);
     let buf = vec![255u8; (beam_width * height * 3) as usize];
 
     // Create a custom glyph with the rectangle data attached to it