Add window padding option

Padding can be configured by using the `padding` field in the config
file, like so:

    padding:
      x: 2
      y: 2

which would result in a 2px padding within each side of the window.

alacritty.yml

@@ -20,6 +20,13 @@ dimensions:
   columns: 80
   lines: 24
 
+# Adds this many blank pixels of padding around the window
+# Units are physical pixels; this is not DPI aware.
+# (change requires restart)
+padding:
+  x: 2
+  y: 2
+
 # The FreeType rasterizer needs to know the device DPI for best results
 # (changes require restart)
 dpi:

alacritty_macos.yml

@@ -19,6 +19,13 @@ dimensions:
   columns: 80
   lines: 24
 
+# Adds this many blank pixels of padding around the window
+# Units are physical pixels; this is not DPI aware.
+# (change requires restart)
+padding:
+  x: 2
+  y: 2
+
 # The FreeType rasterizer needs to know the device DPI for best results
 # (changes require restart)
 dpi:

src/config.rs

@@ -182,6 +182,10 @@ pub struct Config {
     #[serde(default)]
     dimensions: Dimensions,
 
+    /// Pixel padding
+    #[serde(default="default_padding")]
+    padding: Delta,
+
     /// Pixels per inch
     #[serde(default)]
     dpi: Dpi,
@@ -235,6 +239,10 @@ pub struct Config {
     hide_cursor_when_typing: bool,
 }
 
+fn default_padding() -> Delta {
+    Delta { x: 2., y: 2. }
+}
+
 #[cfg(not(target_os="macos"))]
 static DEFAULT_ALACRITTY_CONFIG: &'static str = include_str!("../alacritty.yml");
 #[cfg(target_os="macos")]
@@ -280,6 +288,7 @@ impl Default for Config {
             visual_bell: Default::default(),
             env: Default::default(),
             hide_cursor_when_typing: Default::default(),
+            padding: default_padding(),
         }
     }
 }
@@ -1008,6 +1017,10 @@ impl Config {
         &self.selection
     }
 
+    pub fn padding(&self) -> &Delta {
+        &self.padding
+    }
+
     #[inline]
     pub fn draw_bold_text_with_bright_colors(&self) -> bool {
         self.draw_bold_text_with_bright_colors

src/display.rs

@@ -149,7 +149,7 @@ impl Display {
         let rasterizer = font::Rasterizer::new(dpi.x(), dpi.y(), dpr, config.use_thin_strokes())?;
 
         // Create renderer
-        let mut renderer = QuadRenderer::new(size)?;
+        let mut renderer = QuadRenderer::new(&config, size)?;
 
         // Initialize glyph cache
         let glyph_cache = {
@@ -182,15 +182,21 @@ impl Display {
         let size = Size { width: Pixels(width), height: Pixels(height) };
         info!("set_inner_size: {}", size);
 
-        window.set_inner_size(size);
-        renderer.resize(*size.width as _, *size.height as _);
+        let viewport_size = Size {
+            width: Pixels(width + 2 * config.padding().x as u32),
+            height: Pixels(width + 2 * config.padding().y as u32),
+        };
+        window.set_inner_size(&viewport_size);
+        renderer.resize(viewport_size.width.0 as _, viewport_size.height.0 as _);
         info!("Cell Size: ({} x {})", cell_width, cell_height);
 
         let size_info = SizeInfo {
-            width: *size.width as f32,
-            height: *size.height as f32,
+            width: viewport_size.width.0 as f32,
+            height: viewport_size.height.0 as f32,
             cell_width: cell_width as f32,
-            cell_height: cell_height as f32
+            cell_height: cell_height as f32,
+            padding_x: config.padding().x.floor(),
+            padding_y: config.padding().y.floor(),
         };
 
         // Channel for resize events

src/input.rs

@@ -546,6 +546,8 @@ mod tests {
                     height: 51.0,
                     cell_width: 3.0,
                     cell_height: 3.0,
+                    padding_x: 0.0,
+                    padding_y: 0.0,
                 };
 
                 let mut terminal = Term::new(&config, size);

src/renderer/mod.rs

@@ -116,6 +116,9 @@ pub struct ShaderProgram {
     ///
     /// Rendering is split into two passes; 1 for backgrounds, and one for text
     u_background: GLint,
+
+    padding_x: f32,
+    padding_y: f32,
 }
 
 
@@ -276,7 +279,6 @@ impl GlyphCache {
                 let mut rasterized = rasterizer.get_glyph(&glyph_key)
                     .unwrap_or_else(|_| Default::default());
 
-                // Apply offsets so they aren't computed every draw
                 rasterized.left += glyph_offset.x as i32;
                 rasterized.top += glyph_offset.y as i32;
                 rasterized.top -= metrics.descent as i32;
@@ -434,8 +436,8 @@ const ATLAS_SIZE: i32 = 1024;
 
 impl QuadRenderer {
     // TODO should probably hand this a transform instead of width/height
-    pub fn new(size: Size<Pixels<u32>>) -> Result<QuadRenderer, Error> {
-        let program = ShaderProgram::new(size)?;
+    pub fn new(config: &Config, size: Size<Pixels<u32>>) -> Result<QuadRenderer, Error> {
+        let program = ShaderProgram::new(config, size)?;
 
         let mut vao: GLuint = 0;
         let mut vbo: GLuint = 0;
@@ -600,7 +602,7 @@ impl QuadRenderer {
         while let Ok(msg) = self.rx.try_recv() {
             match msg {
                 Msg::ShaderReload => {
-                    self.reload_shaders(Size {
+                    self.reload_shaders(&config, Size {
                         width: Pixels(props.width as u32),
                         height: Pixels(props.height as u32)
                     });
@@ -652,8 +654,9 @@ impl QuadRenderer {
         })
     }
 
-    pub fn reload_shaders(&mut self, size: Size<Pixels<u32>>) {
-        let program = match ShaderProgram::new(size) {
+    pub fn reload_shaders(&mut self, config: &Config, size: Size<Pixels<u32>>) {
+        info!("Reloading shaders");
+        let program = match ShaderProgram::new(config, size) {
             Ok(program) => program,
             Err(err) => {
                 match err {
@@ -675,9 +678,12 @@ impl QuadRenderer {
     }
 
     pub fn resize(&mut self, width: i32, height: i32) {
+        let padding_x = self.program.padding_x as i32;
+        let padding_y = self.program.padding_y as i32;
+
         // viewport
         unsafe {
-            gl::Viewport(0, 0, width, height);
+            gl::Viewport(padding_x, padding_y, width - 2 * padding_x, height - 2 * padding_y);
         }
 
         // update projection
@@ -874,7 +880,10 @@ impl ShaderProgram {
         }
     }
 
-    pub fn new(size: Size<Pixels<u32>>) -> Result<ShaderProgram, ShaderCreationError> {
+    pub fn new(
+        config: &Config,
+        size: Size<Pixels<u32>>
+    ) -> Result<ShaderProgram, ShaderCreationError> {
         let vertex_source = if cfg!(feature = "live-shader-reload") {
             None
         } else {
@@ -937,6 +946,8 @@ impl ShaderProgram {
             u_cell_dim: cell_dim,
             u_visual_bell: visual_bell,
             u_background: background,
+            padding_x: config.padding().x.floor(),
+            padding_y: config.padding().y.floor(),
         };
 
         shader.update_projection(*size.width as f32, *size.height as f32);
@@ -947,8 +958,20 @@ impl ShaderProgram {
     }
 
     fn update_projection(&self, width: f32, height: f32) {
+        // Bounds check
+        if (width as u32) < (2 * self.padding_x as u32) ||
+            (height as u32) < (2 * self.padding_y as u32)
+        {
+            return;
+        }
+
         // set projection uniform
-        let ortho = cgmath::ortho(0., width, 0., height, -1., 1.);
+        //
+        // NB Not sure why padding change only requires changing the vertical
+        //    translation in the projection, but this makes everything work
+        //    correctly.
+        let ortho = cgmath::ortho(0., width - 2. * self.padding_x, 2. * self.padding_y, height,
+            -1., 1.);
         let projection: [[f32; 4]; 4] = ortho.into();
 
         info!("width: {}, height: {}", width, height);

src/term/mod.rs

@@ -551,26 +551,39 @@ pub struct SizeInfo {
 
     /// Height of individual cell
     pub cell_height: f32,
+
+    /// Horizontal window padding
+    pub padding_x: f32,
+
+    /// Horizontal window padding
+    pub padding_y: f32,
 }
 
 impl SizeInfo {
     #[inline]
     pub fn lines(&self) -> Line {
-        Line(((self.height - 4.0) / self.cell_height) as usize)
+        Line(((self.height - 2. * self.padding_y) / self.cell_height) as usize)
     }
 
     #[inline]
     pub fn cols(&self) -> Column {
-        Column(((self.width - 4.0) / self.cell_width) as usize)
+        Column(((self.width - 2. * self.padding_x) / self.cell_width) as usize)
+    }
+
+    fn contains_point(&self, x: usize, y:usize) -> bool {
+        x <= (self.width - self.padding_x) as usize ||
+            x >= self.padding_x as usize ||
+            y <= (self.height - self.padding_y) as usize ||
+            y >= self.padding_y as usize
     }
 
     pub fn pixels_to_coords(&self, x: usize, y: usize) -> Option<Point> {
-        if x > self.width as usize || y > self.height as usize {
+        if !self.contains_point(x, y) {
             return None;
         }
 
-        let col = Column(x / (self.cell_width as usize));
-        let line = Line(y / (self.cell_height as usize));
+        let col = Column((x - self.padding_x as usize) / (self.cell_width as usize));
+        let line = Line((y - self.padding_y as usize) / (self.cell_height as usize));
 
         Some(Point {
             line: min(line, self.lines() - 1),
@@ -857,21 +870,32 @@ impl Term {
 
     /// Resize terminal to new dimensions
     pub fn resize(&mut self, width: f32, height: f32) {
+        debug!("Term::resize");
+        // Bounds check; lots of math assumes width and height are > 0
+        if width as usize <= 2 * self.size_info.padding_x as usize ||
+            height as usize <= 2 * self.size_info.padding_y as usize
+        {
+            return;
+        }
+
         let size = SizeInfo {
             width: width,
             height: height,
             cell_width: self.size_info.cell_width,
             cell_height: self.size_info.cell_height,
+            padding_x: self.size_info.padding_x,
+            padding_y: self.size_info.padding_y,
         };
 
-        let old_cols = self.size_info.cols();
-        let old_lines = self.size_info.lines();
+        let old_cols = self.grid.num_cols();
+        let old_lines = self.grid.num_lines();
         let mut num_cols = size.cols();
         let mut num_lines = size.lines();
 
         self.size_info = size;
 
         if old_cols == num_cols && old_lines == num_lines {
+            debug!("Term::resize dimensions unchanged");
             return;
         }
 
@@ -1600,7 +1624,7 @@ impl ansi::Handler for Term {
             ansi::Mode::DECCOLM => self.deccolm(),
             ansi::Mode::Insert => self.mode.insert(mode::INSERT), // heh
             _ => {
-                debug!(".. ignoring set_mode");
+                trace!(".. ignoring set_mode");
             }
         }
     }
@@ -1626,7 +1650,7 @@ impl ansi::Handler for Term {
             ansi::Mode::DECCOLM => self.deccolm(),
             ansi::Mode::Insert => self.mode.remove(mode::INSERT),
             _ => {
-                debug!(".. ignoring unset_mode");
+                trace!(".. ignoring unset_mode");
             }
         }
     }
@@ -1684,6 +1708,8 @@ mod tests {
             height: 51.0,
             cell_width: 3.0,
             cell_height: 3.0,
+            padding_x: 0.0,
+            padding_y: 0.0,
         };
         let mut term = Term::new(&Default::default(), size);
         let mut grid: Grid<Cell> = Grid::new(Line(3), Column(5), &Cell::default());
@@ -1728,6 +1754,8 @@ mod tests {
             height: 51.0,
             cell_width: 3.0,
             cell_height: 3.0,
+            padding_x: 0.0,
+            padding_y: 0.0,
         };
         let mut term = Term::new(&Default::default(), size);
         let mut grid: Grid<Cell> = Grid::new(Line(1), Column(5), &Cell::default());
@@ -1771,6 +1799,8 @@ mod tests {
             height: 51.0,
             cell_width: 3.0,
             cell_height: 3.0,
+            padding_x: 0.0,
+            padding_y: 0.0,
         };
         let mut term = Term::new(&Default::default(), size);
         let cursor = Point::new(Line(0), Column(0));

src/window.rs

@@ -360,11 +360,11 @@ impl Proxy {
 }
 
 pub trait SetInnerSize<T> {
-    fn set_inner_size<S: ToPoints>(&mut self, size: S);
+    fn set_inner_size<S: ToPoints>(&mut self, size: &S);
 }
 
 impl SetInnerSize<Pixels<u32>> for Window {
-    fn set_inner_size<T: ToPoints>(&mut self, size: T) {
+    fn set_inner_size<T: ToPoints>(&mut self, size: &T) {
         let size = size.to_points(self.hidpi_factor());
         self.glutin_window.set_inner_size(*size.width as _, *size.height as _);
     }

tests/ref/fish_cc/size.json

@@ -1 +1 @@
-{"width":804.0,"height":604.0,"cell_width":10.0,"cell_height":25.0}
+{"width":804.0,"height":604.0,"cell_width":10.0,"cell_height":25.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/indexed_256_colors/size.json

@@ -1 +1 @@
-{"width":1124.0,"height":628.0,"cell_width":14.0,"cell_height":26.0}
+{"width":1124.0,"height":628.0,"cell_width":14.0,"cell_height":26.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/ll/size.json

@@ -1 +1 @@
-{"width":1124.0,"height":628.0,"cell_width":14.0,"cell_height":26.0}
+{"width":1124.0,"height":628.0,"cell_width":14.0,"cell_height":26.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/tab_rendering/size.json

@@ -1 +1 @@
-{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0}
+{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/tmux_git_log/size.json

@@ -1 +1 @@
-{"width":1124.0,"height":628.0,"cell_width":14.0,"cell_height":26.0}
+{"width":1124.0,"height":628.0,"cell_width":14.0,"cell_height":26.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/tmux_htop/size.json

@@ -1 +1 @@
-{"width":1124.0,"height":628.0,"cell_width":14.0,"cell_height":26.0}
+{"width":1124.0,"height":628.0,"cell_width":14.0,"cell_height":26.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/vim_large_window_scroll/size.json

@@ -1 +1 @@
-{"width":1028.0,"height":769.0,"cell_width":8.0,"cell_height":17.0}
+{"width":1028.0,"height":769.0,"cell_width":8.0,"cell_height":17.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/vim_simple_edit/size.json

@@ -1 +1 @@
-{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0}
+{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/vttest_cursor_movement_1/size.json

@@ -1 +1 @@
-{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0}
+{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/vttest_insert/size.json

@@ -1 +1 @@
-{"width":1124.0,"height":676.0,"cell_width":14.0,"cell_height":28.0}
+{"width":1124.0,"height":676.0,"cell_width":14.0,"cell_height":28.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/vttest_origin_mode_1/size.json

@@ -1 +1 @@
-{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0}
+{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/vttest_origin_mode_2/size.json

@@ -1 +1 @@
-{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0}
+{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/vttest_scroll/size.json

@@ -1 +1 @@
-{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0}
+{"width":644.0,"height":412.0,"cell_width":8.0,"cell_height":17.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/vttest_tab_clear_set/size.json

@@ -1 +1 @@
-{"width":1124.0,"height":676.0,"cell_width":14.0,"cell_height":28.0}
+{"width":1124.0,"height":676.0,"cell_width":14.0,"cell_height":28.0,"padding_x":0.0,"padding_y":0.0}

tests/ref/zsh_tab_completion/size.json

@@ -1 +1 @@
-{"width":1204.0,"height":676.0,"cell_width":15.0,"cell_height":28.0}
+{"width":1204.0,"height":676.0,"cell_width":15.0,"cell_height":28.0,"padding_x":0.0,"padding_y":0.0}