From 050dde6b4f613af7d5b9fa8fd78f12efb64500ff Mon Sep 17 00:00:00 2001
From: Wez Furlong <wez@wezfurlong.org>
Date: Sat, 21 Sep 2019 07:44:28 -0700
Subject: [PATCH] clean up draw_image api

---
 window/src/bitmaps/mod.rs       | 30 +++++++++++-------------------
 window/src/lib.rs               | 18 ++----------------
 window/src/os/macos/window.rs   |  6 +++---
 window/src/os/windows/window.rs |  6 +++---
 window/src/os/x11/window.rs     | 17 ++++-------------
 5 files changed, 23 insertions(+), 54 deletions(-)

diff --git a/window/src/bitmaps/mod.rs b/window/src/bitmaps/mod.rs
index 75f20d835..406456fe0 100644
--- a/window/src/bitmaps/mod.rs
+++ b/window/src/bitmaps/mod.rs
@@ -87,7 +87,7 @@ pub trait BitmapImage {
         }
     }
 
-    /// Draw a line starting at (start_x, start_y) and ending at (dest_x, dest_y).
+    /// Draw a line starting at `start` and ending at `end`.
     /// The line will be anti-aliased and applied to the surface using the
     /// specified Operator.
     fn draw_line(&mut self, start: Point, end: Point, color: Color, operator: Operator) {
@@ -157,30 +157,22 @@ pub trait BitmapImage {
         );
     }
 
-    fn draw_image(&mut self, top_left: Point, im: &dyn BitmapImage, operator: Operator) {
-        let (width, height) = im.image_dimensions();
-        self.draw_image_subset(
-            top_left,
-            Rect {
-                top_left: Point { x: 0, y: 0 },
-                width,
-                height,
-            },
-            im,
-            operator,
-        )
-    }
-
-    fn draw_image_subset(
+    fn draw_image(
         &mut self,
         dest_top_left: Point,
-        src_rect: Rect,
+        src_rect: Option<Rect>,
         im: &dyn BitmapImage,
         operator: Operator,
     ) {
-        let (dest_width, dest_height) = im.image_dimensions();
+        let (im_width, im_height) = im.image_dimensions();
+        let src_rect = src_rect.unwrap_or_else(|| Rect {
+            top_left: Point { x: 0, y: 0 },
+            width: im_width,
+            height: im_height,
+        });
+
         let (dim_width, dim_height) = self.image_dimensions();
-        debug_assert!(src_rect.width <= dest_width && src_rect.height <= dest_height);
+        debug_assert!(src_rect.width <= im_width && src_rect.height <= im_height);
         for y in src_rect.top_left.y as usize..src_rect.top_left.y as usize + src_rect.height {
             let dest_y = y as isize + dest_top_left.y - src_rect.top_left.y as isize;
             if dest_y < 0 {
diff --git a/window/src/lib.rs b/window/src/lib.rs
index eaebef471..9eaba282f 100644
--- a/window/src/lib.rs
+++ b/window/src/lib.rs
@@ -85,24 +85,10 @@ pub trait PaintContext {
     /// Clear a rectangle to the specified color
     fn clear_rect(&mut self, rect: Rect, color: Color);
 
-    fn draw_image(&mut self, top_left: Point, im: &dyn BitmapImage, operator: Operator) {
-        let (width, height) = im.image_dimensions();
-        self.draw_image_subset(
-            top_left,
-            Rect {
-                top_left: Point { x: 0, y: 0 },
-                width,
-                height,
-            },
-            im,
-            operator,
-        )
-    }
-
-    fn draw_image_subset(
+    fn draw_image(
         &mut self,
         dest_top_left: Point,
-        src_rect: Rect,
+        src_rect: Option<Rect>,
         im: &dyn BitmapImage,
         operator: Operator,
     );
diff --git a/window/src/os/macos/window.rs b/window/src/os/macos/window.rs
index 628a502dc..42dbd7ce1 100644
--- a/window/src/os/macos/window.rs
+++ b/window/src/os/macos/window.rs
@@ -216,15 +216,15 @@ impl<'a> PaintContext for MacGraphicsContext<'a> {
         }
     }
 
-    fn draw_image_subset(
+    fn draw_image(
         &mut self,
         dest_top_left: Point,
-        src_rect: Rect,
+        src_rect: Option<Rect>,
         im: &dyn BitmapImage,
         operator: Operator,
     ) {
         self.buffer
-            .draw_image_subset(dest_top_left, src_rect, im, operator)
+            .draw_image(dest_top_left, src_rect, im, operator)
     }
 
     fn draw_line(&mut self, start: Point, end: Point, color: Color, operator: Operator) {
diff --git a/window/src/os/windows/window.rs b/window/src/os/windows/window.rs
index 248aabb4a..058772425 100644
--- a/window/src/os/windows/window.rs
+++ b/window/src/os/windows/window.rs
@@ -345,15 +345,15 @@ impl PaintContext for GdiGraphicsContext {
         }
     }
 
-    fn draw_image_subset(
+    fn draw_image(
         &mut self,
         dest_top_left: Point,
-        src_rect: Rect,
+        src_rect: Option<Rect>,
         im: &dyn BitmapImage,
         operator: Operator,
     ) {
         self.buffer
-            .draw_image_subset(dest_top_left, src_rect, im, operator)
+            .draw_image(dest_top_left, src_rect, im, operator)
     }
 
     fn draw_line(&mut self, start: Point, end: Point, color: Color, operator: Operator) {
diff --git a/window/src/os/x11/window.rs b/window/src/os/x11/window.rs
index a69e3fb96..92df1f5c1 100644
--- a/window/src/os/x11/window.rs
+++ b/window/src/os/x11/window.rs
@@ -101,15 +101,15 @@ impl<'a> PaintContext for X11GraphicsContext<'a> {
         }
     }
 
-    fn draw_image_subset(
+    fn draw_image(
         &mut self,
         dest_top_left: Point,
-        src_rect: Rect,
+        src_rect: Option<Rect>,
         im: &dyn BitmapImage,
         operator: Operator,
     ) {
         self.buffer
-            .draw_image_subset(dest_top_left, src_rect, im, operator)
+            .draw_image(dest_top_left, src_rect, im, operator)
     }
 
     fn draw_line(&mut self, start: Point, end: Point, color: Color, operator: Operator) {
@@ -184,16 +184,7 @@ impl WindowInner {
                     } else {
                         let mut im = Image::new(rect.width as usize, rect.height as usize);
 
-                        im.draw_image_subset(
-                            0,
-                            0,
-                            rect.x as usize,
-                            rect.y as usize,
-                            rect.width as usize,
-                            rect.height as usize,
-                            buffer,
-                            Operator::Source,
-                        );
+                        im.draw_image(Point { x: 0, y: 0 }, Some(rect), buffer, Operator::Source);
 
                         self.window_context
                             .put_image(rect.x as i16, rect.y as i16, &im);