Paint mouse cursor in kittest snapshot images (#7721)

Very simple triangle shape, but helps understand why a widget has a
hovered effect

crates/egui_kittest/src/lib.rs

@@ -657,7 +657,28 @@ impl<'a, State> Harness<'a, State> {
     /// Returns an error if the rendering fails.
     #[cfg(any(feature = "wgpu", feature = "snapshot"))]
     pub fn render(&mut self) -> Result<image::RgbaImage, String> {
-        self.renderer.render(&self.ctx, &self.output)
+        let mut output = self.output.clone();
+
+        if let Some(mouse_pos) = self.ctx.input(|i| i.pointer.hover_pos()) {
+            // Paint a mouse cursor:
+            let triangle = vec![
+                mouse_pos,
+                mouse_pos + egui::vec2(16.0, 8.0),
+                mouse_pos + egui::vec2(8.0, 16.0),
+            ];
+
+            output.shapes.push(ClippedShape {
+                clip_rect: self.ctx.content_rect(),
+                shape: egui::epaint::PathShape::convex_polygon(
+                    triangle,
+                    Color32::WHITE,
+                    egui::Stroke::new(1.0, Color32::BLACK),
+                )
+                .into(),
+            });
+        }
+
+        self.renderer.render(&self.ctx, &output)
     }
 
     /// Get the root viewport output

crates/egui_kittest/tests/snapshots/combobox_opened.png

@@ -1,3 +1,3 @@
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-oid sha256:8f70ef032c241cd63675a246de07886c5c822e6fe21525b3a6d3fee106a589c9
-size 7501
+oid sha256:42911cbb500fa49170aac0da8e4167641c5d7c9724a6accd4d400258fc74e2d7
+size 8061

crates/egui_kittest/tests/snapshots/menu/closed_hovered.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:dd6e159a462dde10240c4ca51da5ca5badfb7fc170bad97a59106babb72f8ae3
-size 10795
+oid sha256:94ba2e648c981bf4afbd9b9d01eef0708f7067be6e4cefbdfacc13aa219c6289
+size 11253

crates/egui_kittest/tests/snapshots/menu/opened.png

@@ -1,3 +1,3 @@
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-oid sha256:8f2a5873350f85457d599c1fd165ac756ed69758e7647e160c64f44d2f35c804
-size 21812
+oid sha256:436999f511dce318f29172f0b7e2007e1f0fedae58f5e0e85e19f1d8e0bee361
+size 22273

crates/egui_kittest/tests/snapshots/menu/submenu.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:facc05c499745594ac286f15645e40447633a176058337cad9edcb850ad578c7
-size 29379
+oid sha256:28435faf5c8c6d880cd50d52050c9f4cd6b992d0c621f01ca28fb5502eed16a1
+size 29863

crates/egui_kittest/tests/snapshots/menu/subsubmenu.png

@@ -1,3 +1,3 @@
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-oid sha256:9f23ff8c6782befdbe7bd5f076dcdda15c38555f8e505282369bf52e43938c1b
-size 34194
+oid sha256:f9a364b4b8c4ad3e78a80b0c6825d9de28c0e0d2e18dcfcd0ff18652ca86c859
+size 34750

crates/egui_kittest/tests/snapshots/readme_example.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:bb8d702361987803995c0f557ce94552a87b97dcd25bed5ee39af4c0e6090700
-size 1904
+oid sha256:87c76a9d07174e4e24ad3d08585c1df7bf3628bdc8f183d11beb6f9e14c4b2ec
+size 2325

crates/egui_kittest/tests/snapshots/test_tooltip_shown.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:c267530452adb4f1ed1440df476d576ef4c2d96e6c58068bb57fed4615f5e113
-size 4453
+oid sha256:e269ede9c0784d00c153d51a13566d9c8f0d61ce11565997691fa63be06ec889
+size 5075