From 33f6a4b91472af2c75bcbda9e8d46e2f3a62e6d6 Mon Sep 17 00:00:00 2001
From: Keith Simmons <keith@the-simmons.net>
Date: Wed, 6 Jan 2021 16:42:26 -0800
Subject: [PATCH] Fix dpi scaling (#438)

* fixing dpi

* refactor rendered window for better dpi scaling

* prevent cursor from animating out of the window bounds

Co-authored-by: Gabby Grinslade <grinsladeg@gmail.com>
---
 src/editor/window.rs                |   2 +
 src/renderer/cursor_renderer/mod.rs |  19 ++-
 src/renderer/mod.rs                 |  14 +-
 src/renderer/rendered_window.rs     | 233 ++++++++++++++++------------
 src/renderer/utils.rs               |  99 ------------
 src/window/mod.rs                   |   1 +
 src/window/sdl2/mod.rs              |   3 +-
 7 files changed, 159 insertions(+), 212 deletions(-)
 delete mode 100644 src/renderer/utils.rs

diff --git a/src/editor/window.rs b/src/editor/window.rs
index a34f3fd..c9eb181 100644
--- a/src/editor/window.rs
+++ b/src/editor/window.rs
@@ -166,11 +166,13 @@ impl Window {
         self.grid_left = grid_left;
         self.grid_top = grid_top;
         self.send_updated_position();
+        self.redraw();
     }
 
     pub fn resize(&mut self, width: u64, height: u64) {
         self.grid.resize(width, height);
         self.send_updated_position();
+        self.redraw();
     }
 
     fn modify_grid(
diff --git a/src/renderer/cursor_renderer/mod.rs b/src/renderer/cursor_renderer/mod.rs
index 8814aa3..c78f8ce 100644
--- a/src/renderer/cursor_renderer/mod.rs
+++ b/src/renderer/cursor_renderer/mod.rs
@@ -247,13 +247,18 @@ impl CursorRenderer {
         let (cursor_grid_x, cursor_grid_y) = self.cursor.grid_position;
 
         if let Some(window) = windows.get(&self.cursor.parent_window_id) {
-            self.destination = (
-                (cursor_grid_x as f32 + window.grid_current_position.x) * font_width,
-                (cursor_grid_y as f32 + window.grid_current_position.y
-                    - (window.current_scroll - window.current_surfaces.top_line))
-                    * font_height,
-            )
-                .into();
+            let grid_x = cursor_grid_x as f32 + window.grid_current_position.x;
+            let mut grid_y = cursor_grid_y as f32 + window.grid_current_position.y
+                - (window.current_scroll - window.current_surfaces.top_line);
+
+            // Prevent the cursor from targeting a position outside its current window. Since only
+            // the vertical direction is effected by scrolling, we only have to clamp the vertical
+            // grid position.
+            grid_y = grid_y
+                .max(window.grid_current_position.y)
+                .min(window.grid_current_position.y + window.grid_height as f32 - 1.0);
+
+            self.destination = (grid_x * font_width, grid_y * font_height).into();
         } else {
             self.destination = (
                 cursor_grid_x as f32 * font_width,
diff --git a/src/renderer/mod.rs b/src/renderer/mod.rs
index 6b65b44..169db7a 100644
--- a/src/renderer/mod.rs
+++ b/src/renderer/mod.rs
@@ -217,7 +217,12 @@ impl Renderer {
         canvas.restore();
     }
 
-    pub fn handle_draw_command(&mut self, root_canvas: &mut Canvas, draw_command: DrawCommand) {
+    pub fn handle_draw_command(
+        &mut self,
+        root_canvas: &mut Canvas,
+        draw_command: DrawCommand,
+        scaling: f32,
+    ) {
         warn!("{:?}", &draw_command);
         match draw_command {
             DrawCommand::Window {
@@ -228,7 +233,8 @@ impl Renderer {
             }
             DrawCommand::Window { grid_id, command } => {
                 if let Some(rendered_window) = self.rendered_windows.remove(&grid_id) {
-                    let rendered_window = rendered_window.handle_window_draw_command(self, command);
+                    let rendered_window =
+                        rendered_window.handle_window_draw_command(self, command, scaling);
                     self.rendered_windows.insert(grid_id, rendered_window);
                 } else if let WindowDrawCommand::Position {
                     grid_left,
@@ -246,6 +252,7 @@ impl Renderer {
                         (grid_left as f32, grid_top as f32).into(),
                         width,
                         height,
+                        scaling,
                     );
                     self.rendered_windows.insert(grid_id, new_window);
                 } else {
@@ -273,6 +280,7 @@ impl Renderer {
         root_canvas: &mut Canvas,
         coordinate_system_helper: &CoordinateSystemHelper,
         dt: f32,
+        scaling: f32,
     ) -> bool {
         trace!("Rendering");
         let mut font_changed = false;
@@ -287,7 +295,7 @@ impl Renderer {
             if let DrawCommand::FontChanged(_) = draw_command {
                 font_changed = true;
             }
-            self.handle_draw_command(root_canvas, draw_command);
+            self.handle_draw_command(root_canvas, draw_command, scaling);
         }
 
         root_canvas.clear(
diff --git a/src/renderer/rendered_window.rs b/src/renderer/rendered_window.rs
index 5fcec5f..e2b18ea 100644
--- a/src/renderer/rendered_window.rs
+++ b/src/renderer/rendered_window.rs
@@ -1,10 +1,10 @@
 use std::collections::VecDeque;
-use std::iter;
 
 use skulpin::skia_safe::canvas::{SaveLayerRec, SrcRectConstraint};
 use skulpin::skia_safe::gpu::SurfaceOrigin;
 use skulpin::skia_safe::{
-    image_filters::blur, BlendMode, Budgeted, Canvas, Color, ImageInfo, Paint, Point, Rect, Surface,
+    image_filters::blur, BlendMode, Budgeted, Canvas, Color, Image, ImageInfo, Paint, Point, Rect,
+    Surface,
 };
 
 use super::animation_utils::*;
@@ -45,9 +45,10 @@ fn build_window_surface_with_grid_size(
     renderer: &Renderer,
     grid_width: u64,
     grid_height: u64,
+    scaling: f32,
 ) -> Surface {
-    let pixel_width = (grid_width as f32 * renderer.font_width) as i32;
-    let pixel_height = (grid_height as f32 * renderer.font_height) as i32;
+    let pixel_width = (grid_width as f32 * renderer.font_width / scaling) as i32;
+    let pixel_height = (grid_height as f32 * renderer.font_height / scaling) as i32;
     build_window_surface(parent_canvas, pixel_width, pixel_height)
 }
 
@@ -56,28 +57,30 @@ fn build_background_window_surface(
     renderer: &Renderer,
     grid_width: u64,
     grid_height: u64,
+    scaling: f32,
 ) -> Surface {
-    let mut surface =
-        build_window_surface_with_grid_size(parent_canvas, renderer, grid_width, grid_height);
+    let mut surface = build_window_surface_with_grid_size(
+        parent_canvas,
+        renderer,
+        grid_width,
+        grid_height,
+        scaling,
+    );
     let canvas = surface.canvas();
     canvas.clear(renderer.get_default_background());
     surface
 }
 
-fn clone_window_surface(surface: &mut Surface) -> Surface {
-    let snapshot = surface.image_snapshot();
-    let mut canvas = surface.canvas();
-    let mut new_surface = build_window_surface(&mut canvas, snapshot.width(), snapshot.height());
-    let new_canvas = new_surface.canvas();
-    new_canvas.draw_image(snapshot, (0.0, 0.0), None);
-    new_surface
+pub struct SnapshotPair {
+    background: Image,
+    foreground: Image,
+    top_line: f32,
 }
 
 pub struct SurfacePair {
     background: Surface,
     foreground: Surface,
     pub top_line: f32,
-    bottom_line: f32,
 }
 
 impl SurfacePair {
@@ -87,43 +90,51 @@ impl SurfacePair {
         grid_width: u64,
         grid_height: u64,
         top_line: f32,
-        bottom_line: f32,
+        scaling: f32,
     ) -> SurfacePair {
-        let background =
-            build_background_window_surface(parent_canvas, renderer, grid_width, grid_height);
-        let foreground =
-            build_window_surface_with_grid_size(parent_canvas, renderer, grid_width, grid_height);
+        let background = build_background_window_surface(
+            parent_canvas,
+            renderer,
+            grid_width,
+            grid_height,
+            scaling,
+        );
+        let foreground = build_window_surface_with_grid_size(
+            parent_canvas,
+            renderer,
+            grid_width,
+            grid_height,
+            scaling,
+        );
 
         SurfacePair {
             background,
             foreground,
             top_line,
-            bottom_line,
         }
     }
 
-    fn clone(&mut self) -> SurfacePair {
-        let new_background = clone_window_surface(&mut self.background);
-        let new_foreground = clone_window_surface(&mut self.foreground);
-        SurfacePair {
-            background: new_background,
-            foreground: new_foreground,
+    fn snapshot(&mut self) -> SnapshotPair {
+        let background = self.background.image_snapshot();
+        let foreground = self.foreground.image_snapshot();
+        SnapshotPair {
+            background,
+            foreground,
             top_line: self.top_line,
-            bottom_line: self.bottom_line,
         }
     }
 }
 
 pub struct RenderedWindow {
-    old_surfaces: VecDeque<SurfacePair>,
+    snapshots: VecDeque<SnapshotPair>,
     pub current_surfaces: SurfacePair,
 
     pub id: u64,
     pub hidden: bool,
     pub floating: bool,
 
-    grid_width: u64,
-    grid_height: u64,
+    pub grid_width: u64,
+    pub grid_height: u64,
 
     grid_start_position: Point,
     pub grid_current_position: Point,
@@ -150,12 +161,19 @@ impl RenderedWindow {
         grid_position: Point,
         grid_width: u64,
         grid_height: u64,
+        scaling: f32,
     ) -> RenderedWindow {
-        let current_surfaces =
-            SurfacePair::new(parent_canvas, renderer, grid_width, grid_height, 0.0, 0.0);
+        let current_surfaces = SurfacePair::new(
+            parent_canvas,
+            renderer,
+            grid_width,
+            grid_height,
+            0.0,
+            scaling,
+        );
 
         RenderedWindow {
-            old_surfaces: VecDeque::new(),
+            snapshots: VecDeque::new(),
             current_surfaces,
             id,
             hidden: false,
@@ -213,7 +231,7 @@ impl RenderedWindow {
             if (self.scroll_t - 1.0).abs() < std::f32::EPSILON {
                 // We are at destination, move t out of 0-1 range to stop the animation
                 self.scroll_t = 2.0;
-                self.old_surfaces.clear();
+                self.snapshots.clear();
             } else {
                 animating = true;
                 self.scroll_t = (self.scroll_t + dt / settings.scroll_animation_length).min(1.0);
@@ -275,36 +293,59 @@ impl RenderedWindow {
 
             paint.set_color(Color::from_argb(a, 255, 255, 255));
 
-            for surface_pair in iter::once(&mut self.current_surfaces)
-                .chain(self.old_surfaces.iter_mut())
-                .rev()
-            {
+            // Draw background scrolling snapshots
+            for snapshot_pair in self.snapshots.iter_mut().rev() {
                 let scroll_offset =
-                    surface_pair.top_line * font_height - self.current_scroll * font_height;
-                surface_pair.background.draw(
-                    root_canvas.as_mut(),
-                    (pixel_region.left(), pixel_region.top() + scroll_offset),
-                    Some(&paint),
+                    snapshot_pair.top_line * font_height - self.current_scroll * font_height;
+                let background_snapshot = &mut snapshot_pair.background;
+                root_canvas.draw_image_rect(
+                    background_snapshot,
+                    None,
+                    pixel_region.with_offset((0.0, scroll_offset)),
+                    &paint,
                 );
             }
+            // Draw background
+            let scroll_offset =
+                self.current_surfaces.top_line * font_height - self.current_scroll * font_height;
+            let background_snapshot = self.current_surfaces.background.image_snapshot();
+            root_canvas.draw_image_rect(
+                background_snapshot,
+                None,
+                pixel_region.with_offset((0.0, scroll_offset)),
+                &paint,
+            );
+
             root_canvas.restore();
         }
 
         {
             // Save layer so that text may safely overwrite images underneath
             root_canvas.save_layer(&SaveLayerRec::default());
-            for surface_pair in iter::once(&mut self.current_surfaces)
-                .chain(self.old_surfaces.iter_mut())
-                .rev()
-            {
+
+            // Draw foreground scrolling snapshots
+            for snapshot_pair in self.snapshots.iter_mut().rev() {
                 let scroll_offset =
-                    surface_pair.top_line * font_height - self.current_scroll * font_height;
-                surface_pair.foreground.draw(
-                    root_canvas.as_mut(),
-                    (pixel_region.left(), pixel_region.top() + scroll_offset),
-                    Some(&paint),
+                    snapshot_pair.top_line * font_height - self.current_scroll * font_height;
+                let foreground_snapshot = &mut snapshot_pair.foreground;
+                root_canvas.draw_image_rect(
+                    foreground_snapshot,
+                    None,
+                    pixel_region.with_offset((0.0, scroll_offset)),
+                    &paint,
                 );
             }
+
+            // Draw foreground
+            let scroll_offset =
+                self.current_surfaces.top_line * font_height - self.current_scroll * font_height;
+            let foreground_snapshot = self.current_surfaces.foreground.image_snapshot();
+            root_canvas.draw_image_rect(
+                foreground_snapshot,
+                None,
+                pixel_region.with_offset((0.0, scroll_offset)),
+                &paint,
+            );
             root_canvas.restore();
         }
 
@@ -325,6 +366,7 @@ impl RenderedWindow {
         mut self,
         renderer: &mut Renderer,
         draw_command: WindowDrawCommand,
+        scaling: f32,
     ) -> Self {
         match draw_command {
             WindowDrawCommand::Position {
@@ -360,6 +402,7 @@ impl RenderedWindow {
                             &renderer,
                             grid_width,
                             grid_height,
+                            scaling,
                         );
                         old_background.draw(
                             self.current_surfaces.background.canvas(),
@@ -375,6 +418,7 @@ impl RenderedWindow {
                             &renderer,
                             grid_width,
                             grid_height,
+                            scaling,
                         );
                         old_foreground.draw(
                             self.current_surfaces.foreground.canvas(),
@@ -406,24 +450,19 @@ impl RenderedWindow {
                 let grid_position = (window_left, window_top);
 
                 {
-                    let mut background_canvas = self.current_surfaces.background.canvas();
-                    renderer.draw_background(
-                        &mut background_canvas,
-                        grid_position,
-                        cell_width,
-                        &style,
-                    );
+                    let canvas = self.current_surfaces.background.canvas();
+                    canvas.save();
+                    canvas.scale((1.0 / scaling, 1.0 / scaling));
+                    renderer.draw_background(canvas, grid_position, cell_width, &style);
+                    canvas.restore();
                 }
 
                 {
-                    let mut foreground_canvas = self.current_surfaces.foreground.canvas();
-                    renderer.draw_foreground(
-                        &mut foreground_canvas,
-                        &text,
-                        grid_position,
-                        cell_width,
-                        &style,
-                    );
+                    let canvas = self.current_surfaces.foreground.canvas();
+                    canvas.save();
+                    canvas.scale((1.0 / scaling, 1.0 / scaling));
+                    renderer.draw_foreground(canvas, &text, grid_position, cell_width, &style);
+                    canvas.restore();
                 }
             }
             WindowDrawCommand::Scroll {
@@ -435,12 +474,18 @@ impl RenderedWindow {
                 cols,
             } => {
                 let scrolled_region = Rect::new(
-                    left as f32 * renderer.font_width,
-                    top as f32 * renderer.font_height,
-                    right as f32 * renderer.font_width,
-                    bot as f32 * renderer.font_height,
+                    left as f32 * renderer.font_width / scaling,
+                    top as f32 * renderer.font_height / scaling,
+                    right as f32 * renderer.font_width / scaling,
+                    bot as f32 * renderer.font_height / scaling,
                 );
 
+                let mut translated_region = scrolled_region;
+                translated_region.offset((
+                    -cols as f32 * renderer.font_width / scaling,
+                    -rows as f32 * renderer.font_height / scaling,
+                ));
+
                 {
                     let background_snapshot = self.current_surfaces.background.image_snapshot();
                     let background_canvas = self.current_surfaces.background.canvas();
@@ -448,12 +493,6 @@ impl RenderedWindow {
                     background_canvas.save();
                     background_canvas.clip_rect(scrolled_region, None, Some(false));
 
-                    let mut translated_region = scrolled_region;
-                    translated_region.offset((
-                        -cols as f32 * renderer.font_width,
-                        -rows as f32 * renderer.font_height,
-                    ));
-
                     background_canvas.draw_image_rect(
                         background_snapshot,
                         Some((&scrolled_region, SrcRectConstraint::Fast)),
@@ -471,12 +510,6 @@ impl RenderedWindow {
                     foreground_canvas.save();
                     foreground_canvas.clip_rect(scrolled_region, None, Some(false));
 
-                    let mut translated_region = scrolled_region;
-                    translated_region.offset((
-                        -cols as f32 * renderer.font_width,
-                        -rows as f32 * renderer.font_height,
-                    ));
-
                     foreground_canvas.draw_image_rect(
                         foreground_snapshot,
                         Some((&scrolled_region, SrcRectConstraint::Fast)),
@@ -488,21 +521,23 @@ impl RenderedWindow {
                 }
             }
             WindowDrawCommand::Clear => {
-                let background_canvas = self.current_surfaces.background.canvas();
                 self.current_surfaces.background = build_background_window_surface(
-                    background_canvas,
+                    self.current_surfaces.background.canvas(),
                     &renderer,
                     self.grid_width,
                     self.grid_height,
+                    scaling,
                 );
 
-                let foreground_canvas = self.current_surfaces.foreground.canvas();
                 self.current_surfaces.foreground = build_window_surface_with_grid_size(
-                    foreground_canvas,
+                    self.current_surfaces.foreground.canvas(),
                     &renderer,
                     self.grid_width,
                     self.grid_height,
+                    scaling,
                 );
+
+                self.snapshots.clear();
             }
             WindowDrawCommand::Show => {
                 if self.hidden {
@@ -512,27 +547,21 @@ impl RenderedWindow {
                 }
             }
             WindowDrawCommand::Hide => self.hidden = true,
-            WindowDrawCommand::Viewport {
-                top_line,
-                bottom_line,
-            } => {
+            WindowDrawCommand::Viewport { top_line, .. } => {
                 if (self.current_surfaces.top_line - top_line as f32).abs() > std::f32::EPSILON {
-                    let mut new_surfaces = self.current_surfaces.clone();
-                    new_surfaces.top_line = top_line as f32;
-                    new_surfaces.bottom_line = bottom_line as f32;
+                    let new_snapshot = self.current_surfaces.snapshot();
+                    self.snapshots.push_back(new_snapshot);
+
+                    if self.snapshots.len() > 5 {
+                        self.snapshots.pop_front();
+                    }
+
+                    self.current_surfaces.top_line = top_line as f32;
 
                     // Set new target viewport position and initialize animation timer
                     self.start_scroll = self.current_scroll;
                     self.scroll_destination = top_line as f32;
                     self.scroll_t = 0.0;
-
-                    let current_surfaces = self.current_surfaces;
-                    self.current_surfaces = new_surfaces;
-                    self.old_surfaces.push_back(current_surfaces);
-
-                    if self.old_surfaces.len() > 5 {
-                        self.old_surfaces.pop_front();
-                    }
                 }
             }
             _ => {}
diff --git a/src/renderer/utils.rs b/src/renderer/utils.rs
deleted file mode 100644
index bfc4941..0000000
--- a/src/renderer/utils.rs
+++ /dev/null
@@ -1,99 +0,0 @@
-fn compute_text_region(grid_pos: (u64, u64), cell_width: u64, font_width: f32, font_height: f32) -> Rect {
-    let (grid_x, grid_y) = grid_pos;
-    let x = grid_x as f32 * font_width;
-    let y = grid_y as f32 * font_height;
-    let width = cell_width as f32 * font_width as f32;
-    let height = font_height as f32;
-    Rect::new(x, y, x + width, y + height)
-}
-
-fn draw_background(
-    canvas: &mut Canvas,
-    grid_pos: (u64, u64),
-    cell_width: u64,
-    style: &Option<Arc<Style>>,
-    default_style: &Arc<Style>,
-    floating: bool,
-    settings: &RendererSettings
-) {
-    self.paint.set_blend_mode(BlendMode::Src);
-
-    let region = self.compute_text_region(grid_pos, cell_width);
-    let style = style.as_ref().unwrap_or(default_style);
-
-    let mut color = style.background(&default_style.colors);
-
-    if floating {
-        color.a = color.a * settings.floating_opacity.min(1.0).max(0.0);
-    }
-
-    self.paint.set_color(color.to_color());
-    canvas.draw_rect(region, &self.paint);
-}
-
-fn draw_foreground(
-    canvas: &mut Canvas,
-    text: &str,
-    grid_pos: (u64, u64),
-    cell_width: u64,
-    style: &Option<Arc<Style>>,
-    default_style: &Arc<Style>,
-) {
-    let (grid_x, grid_y) = grid_pos;
-    let x = grid_x as f32 * self.font_width;
-    let y = grid_y as f32 * self.font_height;
-    let width = cell_width as f32 * self.font_width;
-
-    let style = style.as_ref().unwrap_or(default_style);
-
-    canvas.save();
-
-    let region = self.compute_text_region(grid_pos, cell_width);
-
-    canvas.clip_rect(region, None, Some(false));
-
-    if style.underline || style.undercurl {
-        let line_position = self.shaper.underline_position();
-        let stroke_width = self.shaper.options.size / 10.0;
-        self.paint
-            .set_color(style.special(&default_style.colors).to_color());
-        self.paint.set_stroke_width(stroke_width);
-
-        if style.undercurl {
-            self.paint.set_path_effect(dash_path_effect::new(
-                &[stroke_width * 2.0, stroke_width * 2.0],
-                0.0,
-            ));
-        } else {
-            self.paint.set_path_effect(None);
-        }
-
-        canvas.draw_line(
-            (x, y - line_position + self.font_height),
-            (x + width, y - line_position + self.font_height),
-            &self.paint,
-        );
-    }
-
-    self.paint
-        .set_color(style.foreground(&default_style.colors).to_color());
-    let text = text.trim_end();
-    if !text.is_empty() {
-        for blob in self
-            .shaper
-            .shape_cached(text, style.bold, style.italic)
-            .iter()
-        {
-            canvas.draw_text_blob(blob, (x, y), &self.paint);
-        }
-    }
-
-    if style.strikethrough {
-        let line_position = region.center_y();
-        self.paint
-            .set_color(style.special(&default_style.colors).to_color());
-        canvas.draw_line((x, line_position), (x + width, line_position), &self.paint);
-    }
-
-    canvas.restore();
-}
diff --git a/src/window/mod.rs b/src/window/mod.rs
index dfbdc37..d9fb295 100644
--- a/src/window/mod.rs
+++ b/src/window/mod.rs
@@ -66,6 +66,7 @@ pub fn window_geometry_or_default() -> (u64, u64) {
 
 #[cfg(target_os = "windows")]
 fn windows_fix_dpi() {
+    println!("dpi fix applied");
     use winapi::shared::windef::DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2;
     use winapi::um::winuser::SetProcessDpiAwarenessContext;
     unsafe {
diff --git a/src/window/sdl2/mod.rs b/src/window/sdl2/mod.rs
index 276d3f4..0856cec 100644
--- a/src/window/sdl2/mod.rs
+++ b/src/window/sdl2/mod.rs
@@ -362,11 +362,12 @@ impl Sdl2WindowWrapper {
         if REDRAW_SCHEDULER.should_draw() || SETTINGS.get::<WindowSettings>().no_idle {
             log::debug!("Render Triggered");
 
+            let scaling = sdl_window_wrapper.scale_factor();
             let renderer = &mut self.renderer;
             self.skulpin_renderer.draw(
                 &sdl_window_wrapper,
                 |canvas, coordinate_system_helper| {
-                    if renderer.draw_frame(canvas, &coordinate_system_helper, dt) {
+                    if renderer.draw_frame(canvas, &coordinate_system_helper, dt, scaling as f32) {
                         handle_new_grid_size(current_size, &renderer, &ui_command_sender);
                     }
                 },