Add option to debug paint clip rects

emigui/src/emigui.rs

@@ -15,7 +15,7 @@ pub struct Emigui {
     pub last_input: RawInput,
     pub ctx: Arc<Context>,
     stats: Stats,
-    anti_alias: bool,
+    mesher_options: MesherOptions,
 }
 
 impl Emigui {
@@ -24,7 +24,7 @@ impl Emigui {
             last_input: Default::default(),
             ctx: Arc::new(Context::new(pixels_per_point)),
             stats: Default::default(),
-            anti_alias: true,
+            mesher_options: MesherOptions::default(),
         }
     }
 
@@ -60,12 +60,9 @@ impl Emigui {
     }
 
     pub fn paint(&mut self) -> PaintBatches {
-        let mesher_options = MesherOptions {
+        self.mesher_options.aa_size = 1.0 / self.last_input.pixels_per_point;
-            anti_alias: self.anti_alias,
-            aa_size: 1.0 / self.last_input.pixels_per_point,
-        };
         let paint_commands = self.ctx.drain_paint_lists();
-        let batches = mesh_paint_commands(&mesher_options, &self.ctx.fonts, paint_commands);
+        let batches = mesh_paint_commands(&self.mesher_options, &self.ctx.fonts, paint_commands);
         self.stats = Default::default();
         self.stats.num_batches = batches.len();
         for (_, mesh) in &batches {
@@ -77,7 +74,14 @@ impl Emigui {
 
     pub fn ui(&mut self, region: &mut Region) {
         region.foldable("Style", |region| {
-            region.add(Checkbox::new(&mut self.anti_alias, "Antialias"));
+            region.add(Checkbox::new(
+                &mut self.mesher_options.anti_alias,
+                "Antialias",
+            ));
+            region.add(Checkbox::new(
+                &mut self.mesher_options.debug_paint_clip_rects,
+                "Paint Clip Rects (debug)",
+            ));
             self.ctx.style_ui(region);
         });
 

emigui/src/mesher.rs

@@ -1,7 +1,13 @@
 #![allow(clippy::identity_op)]
 
 /// Outputs render info in a format suitable for e.g. OpenGL.
-use crate::{color::Color, fonts::Fonts, math::*, types::PaintCmd};
+use crate::{
+    color::{srgba, Color},
+    fonts::Fonts,
+    math::*,
+    types::PaintCmd,
+    Outline,
+};
 
 const WHITE_UV: (u16, u16) = (1, 1);
 
@@ -239,6 +245,17 @@ use self::PathType::*;
 pub struct MesherOptions {
     pub anti_alias: bool,
     pub aa_size: f32,
+    pub debug_paint_clip_rects: bool,
+}
+
+impl Default for MesherOptions {
+    fn default() -> Self {
+        Self {
+            anti_alias: true,
+            aa_size: 1.0,
+            debug_paint_clip_rects: false,
+        }
+    }
 }
 
 pub fn fill_closed_path(
@@ -506,6 +523,21 @@ pub fn mesh_paint_commands(
 
         if batches.is_empty() || batches.last().unwrap().0 != clip_rect {
             batches.push((clip_rect, Mesh::default()));
+
+            if options.debug_paint_clip_rects && !clip_rect.is_empty() {
+                let out_mesh = &mut batches.last_mut().unwrap().1;
+                mesh_command(
+                    options,
+                    fonts,
+                    PaintCmd::Rect {
+                        rect: clip_rect,
+                        corner_radius: 0.0,
+                        fill_color: Some(srgba(50, 100, 200, 64)),
+                        outline: Some(Outline::new(1.0, srgba(200, 200, 200, 255))),
+                    },
+                    out_mesh,
+                )
+            }
         }
 
         let out_mesh = &mut batches.last_mut().unwrap().1;