[demo] Show detailed memory usage statistics of paint lists

egui/src/context.rs

@@ -8,17 +8,12 @@ use ahash::AHashMap;
 use crate::{
     animation_manager::AnimationManager,
     mutex::{Mutex, MutexGuard},
-    paint::*,
+    paint::{stats::*, *},
     *,
 };
 
 #[derive(Clone, Copy, Default)]
-struct PaintStats {
+struct SliceStats<T>(usize, std::marker::PhantomData<T>);
-    num_jobs: usize,
-    num_primitives: usize,
-    num_vertices: usize,
-    num_triangles: usize,
-}
 
 #[derive(Clone, Debug, Default)]
 struct Options {
@@ -225,20 +220,10 @@ impl Context {
         let mut paint_options = self.options.lock().paint_options;
         paint_options.aa_size = 1.0 / self.pixels_per_point();
         let paint_commands = self.drain_paint_lists();
-        let num_primitives = paint_commands.len();
+        let paint_stats = PaintStats::from_paint_commands(&paint_commands); // TODO: internal allocations
         let paint_jobs =
             tessellator::tessellate_paint_commands(paint_commands, paint_options, self.fonts());
-
+        *self.paint_stats.lock() = paint_stats.with_paint_jobs(&paint_jobs);
-        {
-            let mut stats = PaintStats::default();
-            stats.num_jobs = paint_jobs.len();
-            stats.num_primitives = num_primitives;
-            for (_, triangles) in &paint_jobs {
-                stats.num_vertices += triangles.vertices.len();
-                stats.num_triangles += triangles.indices.len() / 3;
-            }
-            *self.paint_stats.lock() = stats;
-        }
 
         paint_jobs
     }
@@ -542,21 +527,12 @@ impl Context {
 
     pub fn inspection_ui(&self, ui: &mut Ui) {
         use crate::containers::*;
-        ui.style_mut().body_text_style = TextStyle::Monospace;
 
         CollapsingHeader::new("Input")
             .default_open(true)
             .show(ui, |ui| ui.input().clone().ui(ui));
 
-        ui.collapsing("Stats", |ui| {
+        ui.collapsing("Paint stats", |ui| {
-            ui.label(format!(
-                "Screen size: {} x {} points, pixels_per_point: {:?}",
-                ui.input().screen_size.x,
-                ui.input().screen_size.y,
-                ui.input().pixels_per_point,
-            ));
-
-            ui.heading("Painting:");
             self.paint_stats.lock().ui(ui);
         });
     }
@@ -642,14 +618,3 @@ impl paint::PaintOptions {
         ui.checkbox(debug_ignore_clip_rects, "Ignore clip rectangles (debug)");
     }
 }
-
-impl PaintStats {
-    pub fn ui(&self, ui: &mut Ui) {
-        ui.label(format!("Jobs: {}", self.num_jobs))
-            .on_hover_text("Number of separate clip rectangles");
-        ui.label(format!("Primitives: {}", self.num_primitives))
-            .on_hover_text("Boxes, circles, text areas etc");
-        ui.label(format!("Vertices: {}", self.num_vertices));
-        ui.label(format!("Triangles: {}", self.num_triangles));
-    }
-}

egui/src/demos/demo_window.rs

@@ -84,7 +84,7 @@ impl DemoWindow {
                 });
             });
 
-        CollapsingHeader::new("Painting")
+        CollapsingHeader::new("Paint with your mouse")
             .default_open(false)
             .show(ui, |ui| self.painting.ui(ui));
 

egui/src/input.rs

@@ -208,6 +208,10 @@ impl InputState {
         }
     }
 
+    pub fn screen_rect(&self) -> Rect {
+        Rect::from_min_size(pos2(0.0, 0.0), self.screen_size)
+    }
+
     pub fn wants_repaint(&self) -> bool {
         self.mouse.pressed
             || self.mouse.released
@@ -372,6 +376,7 @@ impl InputState {
             events,
         } = self;
 
+        ui.style_mut().body_text_style = crate::paint::TextStyle::Monospace;
         ui.collapsing("Raw Input", |ui| raw.ui(ui));
 
         crate::containers::CollapsingHeader::new("mouse")

egui/src/paint/mod.rs

@@ -6,6 +6,7 @@ pub mod color;
 pub mod command;
 pub mod font;
 pub mod fonts;
+pub mod stats;
 pub mod tessellator;
 mod texture_atlas;
 
@@ -13,6 +14,7 @@ pub use {
     color::{Rgba, Srgba},
     command::{PaintCmd, Stroke},
     fonts::{FontDefinitions, Fonts, TextStyle},
-    tessellator::{PaintJobs, PaintOptions, TextureId, Triangles, Vertex, WHITE_UV},
+    stats::PaintStats,
+    tessellator::{PaintJob, PaintJobs, PaintOptions, TextureId, Triangles, Vertex, WHITE_UV},
     texture_atlas::Texture,
 };

egui/src/paint/stats.rs

@@ -0,0 +1,224 @@
+use crate::{paint::*, Rect};
+
+#[derive(Clone, Copy, PartialEq)]
+enum ElementSize {
+    Unknown,
+    Homogeneous(usize),
+    Heterogenous,
+}
+
+impl Default for ElementSize {
+    fn default() -> Self {
+        Self::Unknown
+    }
+}
+
+#[derive(Clone, Copy, Default, PartialEq)]
+pub struct AllocInfo {
+    element_size: ElementSize,
+    num_allocs: usize,
+    num_elements: usize,
+    num_bytes: usize,
+}
+
+impl<T> From<&[T]> for AllocInfo {
+    fn from(slice: &[T]) -> Self {
+        Self::from_slice(slice)
+    }
+}
+
+impl std::ops::Add for AllocInfo {
+    type Output = AllocInfo;
+    fn add(self, rhs: AllocInfo) -> AllocInfo {
+        use ElementSize::{Heterogenous, Homogeneous, Unknown};
+        let element_size = match (self.element_size, rhs.element_size) {
+            (Heterogenous, _) | (_, Heterogenous) => Heterogenous,
+            (Unknown, other) | (other, Unknown) => other,
+            (Homogeneous(lhs), Homogeneous(rhs)) if lhs == rhs => Homogeneous(lhs),
+            _ => Heterogenous,
+        };
+
+        AllocInfo {
+            element_size,
+            num_allocs: self.num_allocs + rhs.num_allocs,
+            num_elements: self.num_elements + rhs.num_elements,
+            num_bytes: self.num_bytes + rhs.num_bytes,
+        }
+    }
+}
+
+impl std::ops::AddAssign for AllocInfo {
+    fn add_assign(&mut self, rhs: AllocInfo) {
+        *self = *self + rhs;
+    }
+}
+
+impl AllocInfo {
+    pub fn from_paint_cmd(cmd: &PaintCmd) -> Self {
+        match cmd {
+            PaintCmd::Noop
+            | PaintCmd::Circle { .. }
+            | PaintCmd::LineSegment { .. }
+            | PaintCmd::Rect { .. } => Self::default(),
+            PaintCmd::Path { points, .. } => Self::from_slice(points),
+            PaintCmd::Text { galley, .. } => Self::from_galley(galley),
+            PaintCmd::Triangles(triangles) => Self::from_triangles(triangles),
+        }
+    }
+
+    pub fn from_galley(galley: &font::Galley) -> Self {
+        Self::from_slice(galley.text.as_bytes()) + Self::from_slice(&galley.lines)
+    }
+
+    pub fn from_triangles(triangles: &Triangles) -> Self {
+        Self::from_slice(&triangles.indices) + Self::from_slice(&triangles.vertices)
+    }
+
+    pub fn from_slice<T>(slice: &[T]) -> Self {
+        use std::mem::size_of;
+        let element_size = size_of::<T>();
+        Self {
+            element_size: ElementSize::Homogeneous(element_size),
+            num_allocs: 1,
+            num_elements: slice.len(),
+            num_bytes: slice.len() * element_size,
+        }
+    }
+
+    pub fn num_elements(&self) -> usize {
+        assert!(self.element_size != ElementSize::Heterogenous);
+        self.num_elements
+    }
+    pub fn num_allocs(&self) -> usize {
+        self.num_allocs
+    }
+    pub fn num_bytes(&self) -> usize {
+        self.num_bytes
+    }
+
+    pub fn megabytes(&self) -> String {
+        megabytes(self.num_bytes())
+    }
+
+    pub fn format(&self, what: &str) -> String {
+        if self.num_allocs() == 0 {
+            format!("{:6} {:12}", 0, what)
+        } else if self.num_allocs() == 1 {
+            format!(
+                "{:6} {:12}  {}       1 allocation",
+                self.num_elements,
+                what,
+                self.megabytes()
+            )
+        } else if self.element_size != ElementSize::Heterogenous {
+            format!(
+                "{:6} {:12}  {}     {:3} allocations",
+                self.num_elements(),
+                what,
+                self.megabytes(),
+                self.num_allocs()
+            )
+        } else {
+            format!(
+                "{:6} {:12}  {}     {:3} allocations",
+                "",
+                what,
+                self.megabytes(),
+                self.num_allocs()
+            )
+        }
+    }
+}
+
+#[derive(Clone, Copy, Default)]
+pub struct PaintStats {
+    primitives: AllocInfo,
+    cmd_text: AllocInfo,
+    cmd_path: AllocInfo,
+    cmd_mesh: AllocInfo,
+
+    /// Number of separate clip rectangles
+    jobs: AllocInfo,
+    vertices: AllocInfo,
+    indices: AllocInfo,
+}
+
+impl PaintStats {
+    pub fn from_paint_commands(paint_commands: &[(Rect, PaintCmd)]) -> Self {
+        let mut stats = Self::default();
+        stats.cmd_path.element_size = ElementSize::Heterogenous; // nicer display later
+
+        stats.primitives = AllocInfo::from_slice(paint_commands);
+        for (_, cmd) in paint_commands {
+            match cmd {
+                PaintCmd::Noop
+                | PaintCmd::Circle { .. }
+                | PaintCmd::LineSegment { .. }
+                | PaintCmd::Rect { .. } => Default::default(),
+                PaintCmd::Path { points, .. } => {
+                    stats.cmd_path += AllocInfo::from_slice(points);
+                }
+                PaintCmd::Text { galley, .. } => {
+                    stats.cmd_text += AllocInfo::from_galley(galley);
+                }
+                PaintCmd::Triangles(triangles) => {
+                    stats.cmd_mesh += AllocInfo::from_triangles(triangles);
+                }
+            }
+        }
+        stats
+    }
+
+    pub fn with_paint_jobs(mut self, paint_jobs: &[crate::paint::PaintJob]) -> Self {
+        self.jobs += AllocInfo::from_slice(paint_jobs);
+        for (_, indices) in paint_jobs {
+            self.vertices += AllocInfo::from_slice(&indices.vertices);
+            self.indices += AllocInfo::from_slice(&indices.indices);
+        }
+        self
+    }
+
+    // pub fn total(&self) -> AllocInfo {
+    //     self.primitives
+    //         + self.cmd_text
+    //         + self.cmd_path
+    //         + self.cmd_mesh
+    //         + self.jobs
+    //         + self.vertices
+    //         + self.indices
+    // }
+}
+
+impl PaintStats {
+    pub fn ui(&self, ui: &mut crate::Ui) {
+        ui.label(
+            "Egui generates intermediate level primitives like circles and text. \
+            These are later tessellated into triangles.",
+        );
+        ui.advance_cursor(10.0);
+
+        ui.style_mut().body_text_style = TextStyle::Monospace;
+        ui.label("Intermediate:");
+        ui.label(self.primitives.format("primitives"))
+            .on_hover_text("Boxes, circles, etc");
+        ui.label(self.cmd_text.format("text"));
+        ui.label(self.cmd_path.format("paths"));
+        ui.label(self.cmd_mesh.format("meshes"));
+        ui.advance_cursor(10.0);
+
+        ui.label("Tessellated:");
+        ui.label(self.jobs.format("jobs"))
+            .on_hover_text("Number of separate clip rectangles");
+        ui.label(self.vertices.format("vertices"));
+        ui.label(self.indices.format("indices"))
+            .on_hover_text("Three 32-bit indices per triangles");
+        ui.advance_cursor(10.0);
+
+        // ui.label("Total:");
+        // ui.label(self.total().format(""));
+    }
+}
+
+fn megabytes(size: usize) -> String {
+    format!("{:.2} MB", size as f64 / 1e6)
+}

egui/src/paint/tessellator.rs

@@ -87,6 +87,12 @@ impl Triangles {
         }
     }
 
+    pub fn bytes_used(&self) -> usize {
+        std::mem::size_of::<Self>()
+            + self.vertices.len() * std::mem::size_of::<Vertex>()
+            + self.indices.len() * std::mem::size_of::<u32>()
+    }
+
     /// Are all indices within the bounds of the contained vertices?
     pub fn is_valid(&self) -> bool {
         let n = self.vertices.len() as u32;