1 files changed, 69 insertions, 0 deletions
diff --git a/src/swapchain/present_region.rs b/src/swapchain/present_region.rs
new file mode 100644
index 0000000..7e5fdf4
--- /dev/null
+++ b/src/swapchain/present_region.rs
@@ -0,0 +1,69 @@
+// Copyright (c) 2017 The vulkano developers
+// Licensed under the Apache License, Version 2.0
+// <LICENSE-APACHE or
+// https://www.apache.org/licenses/LICENSE-2.0> or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>,
+// at your option. All files in the project carrying such
+// notice may not be copied, modified, or distributed except
+// according to those terms.
+
+use crate::swapchain::Swapchain;
+
+/// Represents a region on an image.
+///
+/// A region consists of an arbitrary amount of rectangles.
+#[derive(Debug, Clone)]
+pub struct PresentRegion {
+    pub rectangles: Vec<RectangleLayer>,
+}
+
+impl PresentRegion {
+    /// Returns true if this present region is compatible with swapchain.
+    pub fn is_compatible_with<W>(&self, swapchain: &Swapchain<W>) -> bool {
+        self.rectangles
+            .iter()
+            .all(|rect| rect.is_compatible_with(swapchain))
+    }
+}
+
+/// Represents a rectangular region on an image layer.
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub struct RectangleLayer {
+    /// Coordinates in pixels of the top-left hand corner of the rectangle.
+    pub offset: [i32; 2],
+
+    /// Dimensions in pixels of the rectangle.
+    pub extent: [u32; 2],
+
+    /// The layer of the image. For images with only one layer, the value of layer must be 0.
+    pub layer: u32,
+}
+
+impl RectangleLayer {
+    /// Returns true if this rectangle layer is compatible with swapchain.
+    pub fn is_compatible_with<W>(&self, swapchain: &Swapchain<W>) -> bool {
+        // FIXME negative offset is not disallowed by spec, but semantically should not be possible
+        debug_assert!(self.offset[0] >= 0);
+        debug_assert!(self.offset[1] >= 0);
+        self.offset[0] as u32 + self.extent[0] <= swapchain.dimensions()[0]
+            && self.offset[1] as u32 + self.extent[1] <= swapchain.dimensions()[1]
+            && self.layer < swapchain.layers()
+    }
+}
+
+impl From<&RectangleLayer> for ash::vk::RectLayerKHR {
+    #[inline]
+    fn from(val: &RectangleLayer) -> Self {
+        ash::vk::RectLayerKHR {
+            offset: ash::vk::Offset2D {
+                x: val.offset[0],
+                y: val.offset[1],
+            },
+            extent: ash::vk::Extent2D {
+                width: val.extent[0],
+                height: val.extent[1],
+            },
+            layer: val.layer,
+        }
+    }
+}