From 9f5bf25b6b648e6ff42a67094c72a963b2a6a2c2 Mon Sep 17 00:00:00 2001
From: Christian Meissl <meissl.christian@gmail.com>
Date: Thu, 6 Jan 2022 19:24:50 +0100
Subject: [PATCH] clamp the damage rect to the destination rect

this fixes issues when the damage rect is greater
than the destination rect, like providing i32::Max as
the damage size
---
 src/backend/renderer/gles2/mod.rs | 15 +++++++++++----
 src/utils/geometry.rs             | 31 +++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/src/backend/renderer/gles2/mod.rs b/src/backend/renderer/gles2/mod.rs
index 4faa4c3..7b73dee 100644
--- a/src/backend/renderer/gles2/mod.rs
+++ b/src/backend/renderer/gles2/mod.rs
@@ -1286,11 +1286,18 @@ impl Frame for Gles2Frame {
         let damage = damage
             .iter()
             .map(|rect| {
+                let rect = rect.to_f64();
+
+                let rect_constrained_loc = rect
+                    .loc
+                    .constrain(Rectangle::from_extemities((0f64, 0f64), dest.size.to_point()));
+                let rect_clamped_size = rect.size.clamp((0f64, 0f64), dest.size);
+
                 [
-                    rect.loc.x as f32 / dest.size.w as f32,
-                    rect.loc.y as f32 / dest.size.h as f32,
-                    rect.size.w as f32 / dest.size.w as f32,
-                    rect.size.h as f32 / dest.size.h as f32,
+                    (rect_constrained_loc.x / dest.size.w) as f32,
+                    (rect_constrained_loc.y / dest.size.h) as f32,
+                    (rect_clamped_size.w / dest.size.w) as f32,
+                    (rect_clamped_size.h / dest.size.h) as f32,
                 ]
             })
             .flatten()
diff --git a/src/utils/geometry.rs b/src/utils/geometry.rs
index dc62786..b4a14a3 100644
--- a/src/utils/geometry.rs
+++ b/src/utils/geometry.rs
@@ -296,6 +296,23 @@ impl<N: Coordinate, Kind> Point<N, Kind> {
     }
 }
 
+impl<N: Coordinate, Kind> Point<N, Kind> {
+    /// Constrain this [`Point`] within a [`Rectangle`] with the same coordinates
+    ///
+    /// The [`Point`] returned is guaranteed to be not smaller than the [`Rectangle`]
+    /// location and not greater than the [`Rectangle`] size.
+    #[inline]
+    pub fn constrain(self, rect: impl Into<Rectangle<N, Kind>>) -> Point<N, Kind> {
+        let rect = rect.into();
+
+        Point {
+            x: self.x.max(rect.loc.x).min(rect.size.w),
+            y: self.y.max(rect.loc.y).min(rect.size.h),
+            _kind: std::marker::PhantomData,
+        }
+    }
+}
+
 impl<N: Coordinate, Kind> Point<N, Kind> {
     /// Convert the underlying numerical type to f64 for floating point manipulations
     #[inline]
@@ -543,6 +560,20 @@ impl<N: Coordinate, Kind> Size<N, Kind> {
     }
 }
 
+impl<N: Coordinate, Kind> Size<N, Kind> {
+    /// Restrict this [`Size`] to min and max [`Size`] with the same coordinates
+    pub fn clamp(self, min: impl Into<Size<N, Kind>>, max: impl Into<Size<N, Kind>>) -> Size<N, Kind> {
+        let min = min.into();
+        let max = max.into();
+
+        Size {
+            w: self.w.max(min.w).min(max.w),
+            h: self.h.max(min.h).min(max.h),
+            _kind: std::marker::PhantomData,
+        }
+    }
+}
+
 impl<N: Coordinate, Kind> Size<N, Kind> {
     /// Convert the underlying numerical type to f64 for floating point manipulations
     #[inline]