render: simplify buffer coordinates

src/utils/transform_ext.rs

@@ -0,0 +1,71 @@
+use {
+    crate::ifs::wl_output::{
+        TF_180, TF_270, TF_90, TF_FLIPPED, TF_FLIPPED_180, TF_FLIPPED_270, TF_FLIPPED_90, TF_NORMAL,
+    },
+    jay_config::video::{
+        Transform,
+        Transform::{
+            Flip, FlipRotate180, FlipRotate270, FlipRotate90, None, Rotate180, Rotate270, Rotate90,
+        },
+    },
+};
+
+pub trait TransformExt: Sized {
+    fn maybe_swap<T>(self, args: (T, T)) -> (T, T);
+
+    fn to_wl(self) -> i32;
+
+    fn from_wl(wl: i32) -> Option<Self>;
+
+    fn apply_point(self, width: i32, height: i32, point: (i32, i32)) -> (i32, i32);
+}
+
+impl TransformExt for Transform {
+    fn maybe_swap<T>(self, (left, right): (T, T)) -> (T, T) {
+        match self {
+            None | Rotate180 | Flip | FlipRotate180 => (left, right),
+            Rotate90 | Rotate270 | FlipRotate90 | FlipRotate270 => (right, left),
+        }
+    }
+
+    fn to_wl(self) -> i32 {
+        match self {
+            None => TF_NORMAL,
+            Rotate90 => TF_90,
+            Rotate180 => TF_180,
+            Rotate270 => TF_270,
+            Flip => TF_FLIPPED,
+            FlipRotate90 => TF_FLIPPED_90,
+            FlipRotate180 => TF_FLIPPED_180,
+            FlipRotate270 => TF_FLIPPED_270,
+        }
+    }
+
+    fn from_wl(wl: i32) -> Option<Self> {
+        let tf = match wl {
+            TF_NORMAL => None,
+            TF_90 => Rotate90,
+            TF_180 => Rotate180,
+            TF_270 => Rotate270,
+            TF_FLIPPED => Flip,
+            TF_FLIPPED_90 => FlipRotate90,
+            TF_FLIPPED_180 => FlipRotate180,
+            TF_FLIPPED_270 => FlipRotate270,
+            _ => return Option::None,
+        };
+        Some(tf)
+    }
+
+    fn apply_point(self, width: i32, height: i32, (x, y): (i32, i32)) -> (i32, i32) {
+        match self {
+            None => (x, y),
+            Rotate90 => (y, height - x),
+            Rotate180 => (width - x, height - y),
+            Rotate270 => (width - y, x),
+            Flip => (width - x, y),
+            FlipRotate90 => (y, x),
+            FlipRotate180 => (x, height - y),
+            FlipRotate270 => (width - y, height - x),
+        }
+    }
+}