Implement basic presentation with `softbuffer` for `iced_tiny_skia`

2 files changed, 70 insertions, 15 deletions

diff --git a/tiny_skia/src/backend.rs b/tiny_skia/src/backend.rs
index 4282a745..62373ec7 100644
--- a/tiny_skia/src/backend.rs
+++ b/tiny_skia/src/backend.rs
@@ -1,7 +1,8 @@
-use crate::{Font, Settings, Size};
+use crate::{Color, Font, Settings, Size, Viewport};
 
 use iced_graphics::backend;
 use iced_graphics::text;
+use iced_graphics::Primitive;
 
 use std::borrow::Cow;
 
@@ -17,6 +18,22 @@ impl Backend {
             default_text_size: settings.default_text_size,
         }
     }
+
+    pub fn draw<T: AsRef<str>>(
+        &mut self,
+        pixels: &mut tiny_skia::Pixmap,
+        _primitives: &[Primitive],
+        _viewport: &Viewport,
+        background_color: Color,
+        _overlay: &[T],
+    ) {
+        pixels.fill(into_color(background_color));
+    }
+}
+
+fn into_color(color: Color) -> tiny_skia::Color {
+    tiny_skia::Color::from_rgba(color.r, color.g, color.b, color.a)
+        .expect("Convert color from iced to tiny_skia")
 }
 
 impl iced_graphics::Backend for Backend {
diff --git a/tiny_skia/src/window/compositor.rs b/tiny_skia/src/window/compositor.rs
index 053bb29b..164d99c6 100644
--- a/tiny_skia/src/window/compositor.rs
+++ b/tiny_skia/src/window/compositor.rs
@@ -10,7 +10,11 @@ pub struct Compositor<Theme> {
     _theme: PhantomData<Theme>,
 }
 
-pub struct Surface;
+pub struct Surface {
+    window: softbuffer::GraphicsContext,
+    pixels: tiny_skia::Pixmap,
+    buffer: Vec<u32>,
+}
 
 impl<Theme> iced_graphics::window::Compositor for Compositor<Theme> {
     type Settings = Settings;
@@ -28,19 +32,33 @@ impl<Theme> iced_graphics::window::Compositor for Compositor<Theme> {
 
     fn create_surface<W: HasRawWindowHandle + HasRawDisplayHandle>(
         &mut self,
-        _window: &W,
+        window: &W,
+        width: u32,
+        height: u32,
     ) -> Surface {
-        // TODO
-        Surface
+        let window =
+            unsafe { softbuffer::GraphicsContext::new(window, window) }
+                .expect("Create softbuffer for window");
+
+        let pixels = tiny_skia::Pixmap::new(width, height)
+            .expect("Create pixmap for window");
+
+        Surface {
+            window,
+            pixels,
+            buffer: vec![0; (width * height) as usize],
+        }
     }
 
     fn configure_surface(
         &mut self,
-        _surface: &mut Surface,
-        _width: u32,
-        _height: u32,
+        surface: &mut Surface,
+        width: u32,
+        height: u32,
     ) {
-        // TODO
+        surface.pixels = tiny_skia::Pixmap::new(width, height)
+            .expect("Create pixmap for window");
+        surface.buffer = vec![0; (width * height) as usize];
     }
 
     fn fetch_information(&self) -> Information {
@@ -84,13 +102,33 @@ pub fn new<Theme>(settings: Settings) -> (Compositor<Theme>, Backend) {
 
 pub fn present<Theme, T: AsRef<str>>(
     _compositor: &mut Compositor<Theme>,
-    _backend: &mut Backend,
-    _surface: &mut Surface,
-    _primitives: &[Primitive],
-    _viewport: &Viewport,
-    _background_color: Color,
-    _overlay: &[T],
+    backend: &mut Backend,
+    surface: &mut Surface,
+    primitives: &[Primitive],
+    viewport: &Viewport,
+    background_color: Color,
+    overlay: &[T],
 ) -> Result<(), compositor::SurfaceError> {
+    backend.draw(
+        &mut surface.pixels,
+        primitives,
+        viewport,
+        background_color,
+        overlay,
+    );
+
+    for (i, pixel) in surface.pixels.pixels_mut().iter().enumerate() {
+        surface.buffer[i] = u32::from(pixel.red()) << 16
+            | u32::from(pixel.green()) << 8
+            | u32::from(pixel.blue());
+    }
+
+    surface.window.set_buffer(
+        &surface.buffer,
+        surface.pixels.width() as u16,
+        surface.pixels.height() as u16,
+    );
+
     // TODO
     Ok(())
 }