calculating line height from the font

docs/TODO_ux.md

@@ -66,9 +66,9 @@
 ## Switch to OpenGL (for speed)
 
 - no bugs
-	- text entry needs to draw the cursor differently anyway.
-	- top menu is very buggy
-	- need padding around text; and selecting stuff from menus is weird. LINE_HEIGHT.
+	- text entry needs to draw the cursor differently
+	- top menu is very buggy. MAX_CHAR_WIDTH is weird
+	- need padding around text; and selecting stuff from menus is weird
 	- forking is buggy (traffic signal diagram)
 	- arrows
 	- some colors are wrong
@@ -76,4 +76,7 @@
 - make polygon store points and indices efficiently
 - change ezgui API to allow uploading geometry once
 - undo the y inversion hacks at last!
-- probably use f32, not f64 everywhere
+- refactoring
+	- pass canvas to text module, make it do the glyph borrowing?
+	- pass dims to draw_text_bubble; all callers have it anyway, right?
+	- probably use f32, not f64 everywhere

editor/src/plugins/view/turn_cycler.rs

@@ -2,7 +2,7 @@ use crate::objects::{Ctx, ID};
 use crate::plugins::{Plugin, PluginCtx};
 use crate::render::{draw_signal_diagram, DrawTurn};
 use dimensioned::si;
-use ezgui::{Color, GfxCtx, Key, TOP_MENU_HEIGHT};
+use ezgui::{Color, GfxCtx, Key};
 use map_model::{IntersectionID, LaneID, TurnType};
 
 pub struct TurnCyclerState {
@@ -101,7 +101,7 @@ impl Plugin for TurnCyclerState {
                             i,
                             cycle.idx,
                             Some(time_left),
-                            TOP_MENU_HEIGHT + 10.0,
+                            ctx.canvas.top_menu_height() + 10.0,
                             g,
                             ctx,
                         );

ezgui/src/canvas.rs

@@ -25,6 +25,7 @@ pub struct Canvas {
 
     // TODO Super gross, but we can't create this immediately.
     pub(crate) glyphs: RefCell<Option<GlyphBrush<'static, 'static>>>,
+    pub(crate) line_height: f64,
 
     // TODO Bit weird and hacky to mutate inside of draw() calls.
     covered_areas: RefCell<Vec<ScreenRectangle>>,
@@ -46,6 +47,7 @@ impl Canvas {
             window_height: f64::from(initial_height),
 
             glyphs: RefCell::new(None),
+            line_height: 0.0,
             covered_areas: RefCell::new(Vec::new()),
         }
     }
@@ -95,7 +97,7 @@ impl Canvas {
 
     pub fn draw_mouse_tooltip(&self, g: &mut GfxCtx, txt: Text) {
         let mut glyphs = self.glyphs.borrow_mut();
-        let (width, height) = txt.dims(glyphs.as_mut().unwrap());
+        let (width, height) = txt.dims(glyphs.as_mut().unwrap(), self);
         let x1 = self.cursor_x - (width / 2.0);
         let y1 = self.cursor_y - (height / 2.0);
         // No need to cover the tooltip; this tooltip follows the mouse anyway.
@@ -111,7 +113,7 @@ impl Canvas {
     // TODO Rename these draw_nonblocking_text_*
     pub fn draw_text_at(&self, g: &mut GfxCtx, txt: Text, map_pt: Pt2D) {
         let mut glyphs = self.glyphs.borrow_mut();
-        let (width, height) = txt.dims(glyphs.as_mut().unwrap());
+        let (width, height) = txt.dims(glyphs.as_mut().unwrap(), self);
         let pt = self.map_to_screen(map_pt);
         text::draw_text_bubble(
             g,
@@ -147,7 +149,7 @@ impl Canvas {
             return;
         }
         let mut glyphs = self.glyphs.borrow_mut();
-        let (width, height) = txt.dims(glyphs.as_mut().unwrap());
+        let (width, height) = txt.dims(glyphs.as_mut().unwrap(), self);
         let x1 = match horiz {
             HorizontalAlignment::Left => 0.0,
             HorizontalAlignment::Center => (self.window_width - width) / 2.0,
@@ -155,7 +157,7 @@ impl Canvas {
         };
         let y1 = match vert {
             VerticalAlignment::Top => 0.0,
-            VerticalAlignment::BelowTopMenu => text::LINE_HEIGHT,
+            VerticalAlignment::BelowTopMenu => self.line_height,
             VerticalAlignment::Center => (self.window_height - height) / 2.0,
             VerticalAlignment::Bottom => self.window_height - height,
         };
@@ -169,7 +171,7 @@ impl Canvas {
     }
 
     pub fn text_dims(&self, txt: &Text) -> (f64, f64) {
-        txt.dims(self.glyphs.borrow_mut().as_mut().unwrap())
+        txt.dims(self.glyphs.borrow_mut().as_mut().unwrap(), self)
     }
 
     fn zoom_towards_mouse(&mut self, delta_zoom: f64) {
@@ -237,6 +239,12 @@ impl Canvas {
         b.update(self.screen_to_map(ScreenPt::new(self.window_width, self.window_height)));
         b
     }
+
+    // TODO Not super happy about exposing this; fork_screenspace for external callers should be
+    // smarter.
+    pub fn top_menu_height(&self) -> f64 {
+        self.line_height
+    }
 }
 
 pub enum HorizontalAlignment {

ezgui/src/lib.rs

@@ -27,10 +27,6 @@ pub use crate::wizard::{Wizard, WrappedWizard};
 use geom::{Angle, Circle, Line, Polygon, Pt2D, Triangle};
 use glium::{implement_vertex, uniform, Surface};
 
-// TODO Not super happy about exposing this; fork_screenspace for external callers should be
-// smarter.
-pub const TOP_MENU_HEIGHT: f64 = text::LINE_HEIGHT;
-
 pub struct ToggleableLayer {
     layer_name: String,
     // If None, never automatically enable at a certain zoom level.

ezgui/src/log_scroller.rs

@@ -66,7 +66,7 @@ impl LogScroller {
         let can_fit = {
             // Subtract 1 for the title, and an additional TODO hacky
             // few to avoid the bottom OSD and stuff.
-            let n = (canvas.window_height / text::LINE_HEIGHT).floor() as isize - 1 - 6;
+            let n = (canvas.window_height / canvas.line_height).floor() as isize - 1 - 6;
             if n <= 0 {
                 0
             } else {

ezgui/src/menu.rs

@@ -1,5 +1,4 @@
 use crate::screen_geom::ScreenRectangle;
-use crate::text::LINE_HEIGHT;
 use crate::{text, Canvas, Event, GfxCtx, InputResult, Key, ScreenPt, Text};
 
 // Stores some associated data with each choice
@@ -66,7 +65,7 @@ impl<T: Clone> Menu<T> {
                 } else {
                     total_width
                 };
-                ScreenPt::new(canvas.window_width - w, LINE_HEIGHT)
+                ScreenPt::new(canvas.window_width - w, canvas.line_height)
             }
         };
 

ezgui/src/runner.rs

@@ -1,8 +1,9 @@
 use crate::input::{ContextMenu, ModalMenuState};
-use crate::{Canvas, Event, GfxCtx, ModalMenu, TopMenu, UserInput};
+use crate::{text, Canvas, Event, GfxCtx, ModalMenu, TopMenu, UserInput};
 use abstutil::Timer;
 use glium::glutin;
 use glium_glyph::glyph_brush::rusttype::Font;
+use glium_glyph::glyph_brush::rusttype::Scale;
 use glium_glyph::GlyphBrush;
 use std::cell::RefCell;
 use std::io::Write;
@@ -275,6 +276,10 @@ pub fn run<T, G: GUI<T>>(mut gui: G, window_title: &str) {
 
     let dejavu: &[u8] = include_bytes!("DejaVuSans.ttf");
     let fonts = vec![Font::from_bytes(dejavu).unwrap()];
+    let vmetrics = fonts[0].v_metrics(Scale::uniform(text::FONT_SIZE));
+    // TODO This works for this font, but could be more paranoid with abs()
+    gui.get_mut_canvas().line_height =
+        (vmetrics.ascent - vmetrics.descent + vmetrics.line_gap) as f64;
     gui.get_mut_canvas().glyphs = RefCell::new(Some(GlyphBrush::new(&display, fonts)));
 
     let mut state = State {

ezgui/src/scrolling_menu.rs

@@ -59,7 +59,7 @@ impl<T: Clone> ScrollingMenu<T> {
         let can_fit = {
             // Subtract 1 for the prompt, and an additional TODO hacky
             // few to avoid the bottom OSD and stuff.
-            let n = (canvas.window_height / text::LINE_HEIGHT).floor() as isize - 1 - 6;
+            let n = (canvas.window_height / canvas.line_height).floor() as isize - 1 - 6;
             if n <= 0 {
                 // Weird small window, just display the prompt and bail out.
                 canvas.draw_blocking_text(g, txt, CENTERED);

ezgui/src/text.rs

@@ -14,10 +14,8 @@ pub const SELECTED_COLOR: Color = Color::RED;
 pub const HOTKEY_COLOR: Color = Color::GREEN;
 pub const INACTIVE_CHOICE_COLOR: Color = Color::grey(0.4);
 
-const FONT_SIZE: f32 = 24.0;
-// TODO These are dependent on FONT_SIZE, but hand-tuned. Glyphs all have 0 as their height, and
-// they need adjustments to their positioning.
-pub const LINE_HEIGHT: f64 = 32.0;
+pub const FONT_SIZE: f32 = 24.0;
+// TODO Don't do this!
 const MAX_CHAR_WIDTH: f64 = 25.0;
 
 #[derive(Debug, Clone)]
@@ -117,11 +115,15 @@ impl Text {
         self.lines.is_empty()
     }
 
-    pub(crate) fn dims(&self, glyphs: &mut GlyphBrush<'static, 'static>) -> (f64, f64) {
-        let mut widths: Vec<i32> = Vec::new();
-        let mut total_height: i32 = 0;
-
-        for (_, l) in &self.lines {
+    pub(crate) fn dims(
+        &self,
+        glyphs: &mut GlyphBrush<'static, 'static>,
+        canvas: &Canvas,
+    ) -> (f64, f64) {
+        let width = self
+            .lines
+            .iter()
+            .map(|(_, l)| {
                 let full_line = l.iter().fold(String::new(), |mut so_far, span| {
                     so_far.push_str(&span.text);
                     so_far
@@ -131,20 +133,18 @@ impl Text {
                     scale: Scale::uniform(FONT_SIZE),
                     ..Section::default()
                 }) {
-                widths.push(rect.width());
-                total_height += rect.height();
+                    rect.width()
                 } else {
                     // TODO Sometimes we want to space something like "    ", but no drawn glyphs
                     // means pixel_bounds fails. Hack?
-                widths.push((MAX_CHAR_WIDTH * (full_line.len() as f64)) as i32);
-                total_height += LINE_HEIGHT as i32;
-            }
+                    (MAX_CHAR_WIDTH * (full_line.len() as f64)) as i32
                 }
+            })
+            .max()
+            .unwrap() as f64;
 
-        (
-            widths.into_iter().max().unwrap() as f64,
-            total_height as f64,
-        )
+        // Always use the max height, since other stuff like menus assume a fixed height.
+        (width, (self.lines.len() as f64) * canvas.line_height)
     }
 }
 
@@ -158,7 +158,7 @@ pub fn draw_text_bubble(
     // TODO Is it expensive to constantly change uniforms and the shader program?
     g.fork_screenspace(canvas);
 
-    let (total_width, total_height) = txt.dims(glyphs);
+    let (total_width, total_height) = txt.dims(glyphs, canvas);
     if let Some(c) = txt.bg_color {
         g.draw_polygon(
             c,
@@ -185,16 +185,19 @@ pub fn draw_text_bubble(
                 .collect(),
             ..VariedSection::default()
         };
-        let height = glyphs.pixel_bounds(section.clone()).unwrap().height() as f64;
 
         if let Some(c) = line_color {
             g.draw_polygon(
                 *c,
-                &Polygon::rectangle_topleft(Pt2D::new(top_left.x, y), total_width, height),
+                &Polygon::rectangle_topleft(
+                    Pt2D::new(top_left.x, y),
+                    total_width,
+                    canvas.line_height,
+                ),
             );
         }
 
-        y += height;
+        y += canvas.line_height;
         glyphs.queue(section);
     }
 

ezgui/src/top_menu.rs

@@ -1,7 +1,6 @@
 use crate::menu::{Menu, Position};
 use crate::screen_geom::ScreenRectangle;
 use crate::text;
-use crate::TOP_MENU_HEIGHT;
 use crate::{Canvas, GfxCtx, InputResult, Key, ScreenPt, Text, UserInput};
 use geom::{Polygon, Pt2D};
 use std::collections::{HashMap, HashSet};
@@ -132,13 +131,17 @@ impl TopMenu {
             x1: 0.0,
             y1: 0.0,
             x2: canvas.window_width,
-            y2: TOP_MENU_HEIGHT,
+            y2: canvas.line_height,
         });
 
         g.fork_screenspace(canvas);
         g.draw_polygon(
             text::BG_COLOR,
-            &Polygon::rectangle_topleft(Pt2D::new(0.0, 0.0), canvas.window_width, TOP_MENU_HEIGHT),
+            &Polygon::rectangle_topleft(
+                Pt2D::new(0.0, 0.0),
+                canvas.window_width,
+                canvas.line_height,
+            ),
         );
 
         if let Some(idx) = self.highlighted {