vulkan: implement async shm textures

src/cpu_worker/jobs/img_copy.rs

@@ -0,0 +1,62 @@
+use {
+    crate::{
+        cpu_worker::{AsyncCpuWork, CpuWork},
+        rect::Rect,
+    },
+    std::ptr,
+};
+
+#[expect(clippy::manual_non_exhaustive)]
+pub struct ImgCopyWork {
+    pub src: *mut u8,
+    pub dst: *mut u8,
+    pub width: i32,
+    pub stride: i32,
+    pub bpp: i32,
+    pub rects: Vec<Rect>,
+    _priv: (),
+}
+
+unsafe impl Send for ImgCopyWork {}
+
+impl ImgCopyWork {
+    pub unsafe fn new() -> Self {
+        Self {
+            src: ptr::null_mut(),
+            dst: ptr::null_mut(),
+            width: 0,
+            stride: 0,
+            bpp: 0,
+            rects: vec![],
+            _priv: (),
+        }
+    }
+}
+
+impl CpuWork for ImgCopyWork {
+    fn run(&mut self) -> Option<Box<dyn AsyncCpuWork>> {
+        for rect in &self.rects {
+            let mut offset = rect.y1() * self.stride + rect.x1() * self.bpp;
+            if rect.width() == self.width {
+                let offset = offset as usize;
+                let len = rect.height() * self.stride;
+                unsafe {
+                    ptr::copy_nonoverlapping(self.src.add(offset), self.dst.add(offset), len as _);
+                }
+            } else {
+                let len = rect.width() * self.bpp;
+                for _ in 0..rect.height() {
+                    unsafe {
+                        ptr::copy_nonoverlapping(
+                            self.src.add(offset as _),
+                            self.dst.add(offset as _),
+                            len as _,
+                        );
+                    }
+                    offset += self.stride;
+                }
+            }
+        }
+        None
+    }
+}