Font configuration

Author: WhatAmISupposedToPutHere

Cargo.lock

@@ -10,7 +10,7 @@ repository = "https://github.com/WhatAmISupposedToPutHere/tiny-dfr"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-cairo-rs = { version = "0.18", default-features = false }
+cairo-rs = { version = "0.18", default-features = false, features = ["freetype"] }
 librsvg = "2.56.0"
 drm = "0.10.0"
 anyhow = "1"
@@ -23,3 +23,7 @@ privdrop = "0.5.3"
 serde = { version = "1", features = ["derive"] }
 toml = "0.8"
 rand = "0.8"
+freetype-rs = "0.32"
+
+[build-dependencies]
+pkg-config = "0.3"

Cargo.toml

@@ -3,7 +3,7 @@ The most basic dynamic function row daemon possible
 
 
 ## Dependencies
-pango, libinput, uinput enabled in kernel config
+cairo, libinput, freetype, fontconfig, uinput enabled in kernel config
 
 ## License
 

README.md

@@ -0,0 +1,3 @@
+fn main() {
+    pkg_config::probe_library("fontconfig").unwrap();
+}

build.rs

@@ -14,3 +14,12 @@ ShowButtonOutlines = true
 # In theory this helps with screen longevity, but macos does not bother doint it
 # Disabling ShowButtonOutlines will make this effect less noticeable to the eye
 EnablePixelShift = false
+
+# Set this to the fontconfig pattern to be used to pick a font for text labels
+# Some examples are:
+# "" - default regular sans-serif font
+# ":bold" - default regular sans-serif font
+# For full reference on accepted values see the fontconfig user guide,
+# section "Font Names"
+# https://www.freedesktop.org/software/fontconfig/fontconfig-user.html
+FontTemplate = ":bold"

share/tiny-dfr/config.toml

@@ -0,0 +1,105 @@
+use std::ffi::{c_char, c_int, CStr, CString};
+use std::ptr;
+
+#[repr(C)]
+struct FcPattern {
+    _data: [u8; 0]
+}
+#[repr(C)]
+struct FcConfig {
+    _data: [u8; 0]
+}
+type FcResult = c_int;
+type FcMatchKind = c_int;
+#[allow(non_upper_case_globals)]
+const FcMatchPattern: FcMatchKind = 0;
+
+pub struct FontConfig {
+    config: *const FcConfig
+}
+
+impl FontConfig {
+    pub fn new() -> FontConfig {
+        let config = unsafe {
+            FcInitLoadConfigAndFonts()
+        };
+        FontConfig {
+            config
+        }
+    }
+    pub fn match_pattern(&self, pattern: &Pattern) -> Pattern {
+        let mut result: FcResult = 0;
+        let match_ = unsafe {
+            FcFontMatch(self.config, pattern.pattern, &mut result)
+        };
+        Pattern {
+            pattern: match_
+        }
+    }
+    pub fn perform_substitutions(&self, pattern: &mut Pattern) {
+        unsafe {
+            FcConfigSubstitute(self.config, pattern.pattern, FcMatchPattern);
+            FcDefaultSubstitute(pattern.pattern);
+        }
+    }
+}
+
+impl Drop for FontConfig {
+    fn drop(&mut self) {
+        unsafe {
+            FcConfigDestroy(self.config)
+        }
+    }
+}
+
+pub struct Pattern {
+    pattern: *const FcPattern
+}
+
+impl Pattern {
+    pub fn new(st: &str) -> Pattern {
+        let cstr = CString::new(st).unwrap();
+        let pattern = unsafe {
+            FcNameParse(cstr.as_ptr())
+        };
+        Pattern {
+            pattern
+        }
+    }
+    pub fn get_file_name(&self) -> &str {
+        let name = b"file\0";
+        unsafe {
+            let mut file_name = ptr::null();
+            FcPatternGetString(self.pattern, name.as_ptr(), 0, &mut file_name);
+            CStr::from_ptr(file_name).to_str().unwrap()
+        }
+    }
+    pub fn get_font_index(&self) -> isize {
+        let name = b"index\0";
+        unsafe {
+            let mut index = 0;
+            FcPatternGetInteger(self.pattern, name.as_ptr(), 0, &mut index);
+            index as isize
+        }
+    }
+}
+
+impl Drop for Pattern {
+    fn drop(&mut self) {
+        unsafe {
+            FcPatternDestroy(self.pattern)
+        }
+    }
+}
+
+extern "C" {
+    fn FcInitLoadConfigAndFonts() -> *const FcConfig;
+    fn FcConfigDestroy(_: *const FcConfig) -> ();
+    fn FcNameParse(_: *const c_char) -> *const FcPattern;
+    fn FcPatternDestroy(_: *const FcPattern) -> ();
+    fn FcFontMatch(_: *const FcConfig, _: *const FcPattern, _: *mut FcResult) -> *mut FcPattern;
+    fn FcPatternGetString(_: *const FcPattern, _: *const c_char, _: c_int, _: *mut *const c_char) -> FcResult;
+    fn FcPatternGetInteger(_: *const FcPattern, _: *const c_char, _: c_int, _: *mut c_int) -> FcResult;
+    fn FcConfigSubstitute(_: *const FcConfig, _: *const FcPattern, _: FcMatchKind) -> c_int;
+    fn FcDefaultSubstitute(_: *const FcPattern);
+}

src/fonts.rs

@@ -9,10 +9,7 @@ use std::{
     cmp::min
 };
 use std::os::fd::AsFd;
-use cairo::{
-    ImageSurface, Format, Context, Surface,
-    FontSlant, FontWeight, Rectangle
-};
+use cairo::{ImageSurface, Format, Context, Surface, Rectangle, FontFace};
 use rsvg::{Loader, CairoRenderer, SvgHandle};
 use drm::control::ClipRect;
 use anyhow::{Error, Result};
@@ -30,15 +27,18 @@ use input_linux_sys::{uinput_setup, input_id, timeval, input_event};
 use nix::poll::{poll, PollFd, PollFlags};
 use privdrop::PrivDrop;
 use serde::Deserialize;
+use freetype::Library as FtLibrary;
 
 mod backlight;
 mod display;
 mod pixel_shift;
+mod fonts;
 
 use backlight::BacklightManager;
 use display::DrmBackend;
 use pixel_shift::PixelShiftManager;
 use pixel_shift::PIXEL_SHIFT_WIDTH_PX;
+use fonts::{FontConfig, Pattern};
 
 const DFR_WIDTH: i32 = 2008;
 const DFR_HEIGHT: i32 = 64;
@@ -53,13 +53,15 @@ const TIMEOUT_MS: i32 = 10 * 1000;
 struct ConfigProxy {
     media_layer_default: Option<bool>,
     show_button_outlines: Option<bool>,
-    enable_pixel_shift: Option<bool>
+    enable_pixel_shift: Option<bool>,
+    font_template: Option<String>
 }
 
 struct Config {
     media_layer_default: bool,
     show_button_outlines: bool,
-    enable_pixel_shift: bool
+    enable_pixel_shift: bool,
+    font_face: FontFace
 }
 
 enum ButtonImage {
@@ -124,7 +126,7 @@ impl FunctionLayer {
 
         c.set_source_rgb(0.0, 0.0, 0.0);
         c.paint().unwrap();
-        c.select_font_face("sans-serif", FontSlant::Normal, FontWeight::Bold);
+        c.set_font_face(&config.font_face);
         c.set_font_size(32.0);
         for (i, button) in self.buttons.iter().enumerate() {
             let left_edge = (i as f64 * (button_width + BUTTON_SPACING_PX as f64)).floor() + pixel_shift_x + (PIXEL_SHIFT_WIDTH_PX / 2) as f64;
@@ -223,6 +225,18 @@ fn toggle_key<F>(uinput: &mut UInputHandle<F>, code: Key, value: i32) where F: A
     emit(uinput, EventKind::Synchronize, SynchronizeKind::Report as u16, 0);
 }
 
+fn load_font(name: &str) -> FontFace {
+    let fontconfig = FontConfig::new();
+    let mut pattern = Pattern::new(name);
+    fontconfig.perform_substitutions(&mut pattern);
+    let pat_match = fontconfig.match_pattern(&pattern);
+    let file_name = pat_match.get_file_name();
+    let file_idx = pat_match.get_font_index();
+    let ft_library = FtLibrary::init().unwrap();
+    let face = ft_library.new_face(file_name, file_idx).unwrap();
+    FontFace::create_from_ft(&face).unwrap()
+}
+
 fn load_config() -> Config {
     let mut base = toml::from_str::<ConfigProxy>(&read_to_string("/usr/share/tiny-dfr/config.toml").unwrap()).unwrap();
     let user = read_to_string("/etc/tiny-dfr/config.toml").map_err::<Error, _>(|e| e.into())
@@ -231,11 +245,13 @@ fn load_config() -> Config {
         base.media_layer_default = user.media_layer_default.or(base.media_layer_default);
         base.show_button_outlines = user.show_button_outlines.or(base.show_button_outlines);
         base.enable_pixel_shift = user.enable_pixel_shift.or(base.enable_pixel_shift);
+        base.font_template = user.font_template.or(base.font_template);
     };
     Config {
         media_layer_default: base.media_layer_default.unwrap(),
         show_button_outlines: base.show_button_outlines.unwrap(),
         enable_pixel_shift: base.enable_pixel_shift.unwrap(),
+        font_face: load_font(&base.font_template.unwrap())
     }
 }