From d82c4f02b69a8e16057a42de470c5bea114ffda6 Mon Sep 17 00:00:00 2001 From: Christian Duerr Date: Thu, 7 Dec 2017 21:52:50 +0100 Subject: [PATCH] Add custom beam cursor In issue jwilm/asacritty#31 a few people complained about Beam cursor being weird with their fonts, so to make all cursors uniform in alacritty, a custom cursor has been added for the Beam too. The beam cursor's height is always the full height of the monospace font glyph bounding box. The width depends on the font size. It is calculated using the width of the cell and dividing it by two. The block is always aligned at the far-left of the cell. The implementation is identical to the one of the underline cursor, but it has been refactored so the glyphs are created in `lib.rs`, which can be used by darwin/macos to implement these features too. A small bug in the underline cursor has also been fixed, until now the width was just using the width of the unicode character. Now it should be using the full width of the monospace glyph bounding box with every font. Here are some screenshots for the Beam cursor: ![Small](https://u.teknik.io/v1QH3.png) ![Normal](https://u.teknik.io/RTlp2.png) ![Big](https://u.teknik.io/DLu2M.png) ![Huge](https://u.teknik.io/pSAFX.png) --- font/src/ft/mod.rs | 71 +++++++++++++++++++++++++++------------------- font/src/lib.rs | 42 +++++++++++++++++++++++++++ src/term/mod.rs | 2 +- 3 files changed, 85 insertions(+), 30 deletions(-) diff --git a/font/src/ft/mod.rs b/font/src/ft/mod.rs index b855923..7b22fb0 100644 --- a/font/src/ft/mod.rs +++ b/font/src/ft/mod.rs @@ -24,7 +24,7 @@ use libc::c_uint; pub mod fc; -use super::{FontDesc, RasterizedGlyph, Metrics, Size, FontKey, GlyphKey, Weight, Slant, Style, UNDERLINE_CURSOR_CHAR}; +use super::{FontDesc, RasterizedGlyph, Metrics, Size, FontKey, GlyphKey, Weight, Slant, Style}; struct FixedSize { pixelsize: f64, @@ -294,37 +294,50 @@ impl FreeTypeRasterizer { let (pixel_width, buf) = Self::normalize_buffer(&glyph.bitmap())?; - // Render a custom symbol for the underline cursor - if glyph_key.c == UNDERLINE_CURSOR_CHAR { - // Get the bottom of the bounding box - let size_metrics = face.ft_face.size_metrics() - .ok_or(Error::MissingSizeMetrics)?; - let descent = (size_metrics.descender / 64) as f32; + // Render a custom symbol for the underline and beam cursor + match glyph_key.c { + super::UNDERLINE_CURSOR_CHAR => { + // Get the bottom of the bounding box + let size_metrics = face.ft_face.size_metrics() + .ok_or(Error::MissingSizeMetrics)?; + let descent = (size_metrics.descender / 64) as i32; - // Create a new rectangle, the height is half the distance between - // bounding box bottom and the baseline - let height = f32::abs(descent / 2.) as i32; - let buf = vec![255u8; (pixel_width * height * 3) as usize]; + // Get the width of the cell + let metrics = glyph.metrics(); + let width = (metrics.vertAdvance as f32 / 128.).round() as i32; - // Create a custom glyph with the rectangle data attached to it - return Ok(RasterizedGlyph { - c: glyph_key.c, - top: descent as i32 + height, - left: glyph.bitmap_left(), - height, - width: pixel_width, - buf: buf, - }); + // 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() + .ok_or(Error::MissingSizeMetrics)?; + let ascent = (size_metrics.ascender / 64) as i32 - 1; + + // Get the height of the cell + let descent = (size_metrics.descender / 64) as i32; + let height = ascent - descent; + + // Get the width of the cell + let metrics = glyph.metrics(); + let width = (metrics.vertAdvance as f32 / 128.).round() as i32; + + // 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 { + c: glyph_key.c, + top: glyph.bitmap_top(), + left: glyph.bitmap_left(), + width: pixel_width, + height: glyph.bitmap().rows(), + buf: buf, + }) + } } - - Ok(RasterizedGlyph { - c: glyph_key.c, - top: glyph.bitmap_top(), - left: glyph.bitmap_left(), - width: pixel_width, - height: glyph.bitmap().rows(), - buf: buf, - }) } fn ft_load_flags(pat: &fc::Pattern) -> freetype::face::LoadFlag { diff --git a/font/src/lib.rs b/font/src/lib.rs index 5d35e47..776127e 100644 --- a/font/src/lib.rs +++ b/font/src/lib.rs @@ -65,6 +65,13 @@ pub const UNDERLINE_CURSOR_CHAR: char = '\u{10a3e2}'; #[cfg(target_os = "macos")] pub const UNDERLINE_CURSOR_CHAR: char = '▁'; +/// Character used for the beam cursor +#[cfg(not(target_os = "macos"))] +// This is part of the private use area and should not conflict with any font +pub const BEAM_CURSOR_CHAR: char = '\u{10a3e3}'; +#[cfg(target_os = "macos")] +pub const BEAM_CURSOR_CHAR: char = '▎'; + #[derive(Debug, Clone, PartialEq, Eq, Hash)] pub struct FontDesc { name: String, @@ -209,6 +216,41 @@ impl Default for RasterizedGlyph { } } +// Returns a custom underline cursor character +pub fn get_underline_cursor_glyph(descent: i32, width: i32) -> Result { + // Create a new rectangle, the height is half the distance between + // bounding box bottom and the baseline + let height = i32::abs(descent / 2); + let buf = vec![255u8; (width * height * 3) as usize]; + + // Create a custom glyph with the rectangle data attached to it + return Ok(RasterizedGlyph { + c: UNDERLINE_CURSOR_CHAR, + top: descent + height, + left: 0, + height, + width, + buf: buf, + }); +} + +// Returns a custom beam cursor character +pub fn get_beam_cursor_glyph(ascent: i32, height: i32, width: i32) -> Result { + // Create a new rectangle + let beam_width = (f64::from(width) / 5.) as i32; + let buf = vec![255u8; (beam_width * height * 3) as usize]; + + // Create a custom glyph with the rectangle data attached to it + return Ok(RasterizedGlyph { + c: BEAM_CURSOR_CHAR, + top: ascent, + left: 0, + height, + width: beam_width, + buf: buf, + }); +} + struct BufDebugger<'a>(&'a [u8]); impl<'a> fmt::Debug for BufDebugger<'a> { diff --git a/src/term/mod.rs b/src/term/mod.rs index 2e1365f..8611517 100644 --- a/src/term/mod.rs +++ b/src/term/mod.rs @@ -181,7 +181,7 @@ impl<'a> RenderableCellsIter<'a> { }); let cursor_color = self.text_cursor_color(&cursor_cell); - cursor_cell.c = '▎'; + cursor_cell.c = font::BEAM_CURSOR_CHAR; cursor_cell.fg = cursor_color; self.cursor_cells.push_back(Indexed { line: self.cursor.line,