Simplify image rotation API and its internals

4 files changed, 20 insertions, 55 deletions

diff --git a/wgpu/src/image/mod.rs b/wgpu/src/image/mod.rs
index 69f8a8ca..3ec341fc 100644
--- a/wgpu/src/image/mod.rs
+++ b/wgpu/src/image/mod.rs
@@ -141,14 +141,12 @@ impl Pipeline {
                             2 => Float32x2,
                             // Rotation
                             3 => Float32,
-                            // Scale
-                            4 => Float32x2,
                             // Atlas position
-                            5 => Float32x2,
+                            4 => Float32x2,
                             // Atlas scale
-                            6 => Float32x2,
+                            5 => Float32x2,
                             // Layer
-                            7 => Sint32,
+                            6 => Sint32,
                         ),
                     }],
                 },
@@ -232,7 +230,6 @@ impl Pipeline {
                     filter_method,
                     bounds,
                     rotation,
-                    scale,
                 } => {
                     if let Some(atlas_entry) =
                         cache.upload_raster(device, encoder, handle)
@@ -240,8 +237,7 @@ impl Pipeline {
                         add_instances(
                             [bounds.x, bounds.y],
                             [bounds.width, bounds.height],
-                            *rotation,
-                            [scale.width, scale.height],
+                            f32::from(*rotation),
                             atlas_entry,
                             match filter_method {
                                 crate::core::image::FilterMethod::Nearest => {
@@ -263,7 +259,6 @@ impl Pipeline {
                     color,
                     bounds,
                     rotation,
-                    scale,
                 } => {
                     let size = [bounds.width, bounds.height];
 
@@ -278,8 +273,7 @@ impl Pipeline {
                         add_instances(
                             [bounds.x, bounds.y],
                             size,
-                            *rotation,
-                            [scale.width, scale.height],
+                            f32::from(*rotation),
                             atlas_entry,
                             nearest_instances,
                         );
@@ -510,7 +504,6 @@ struct Instance {
     _center: [f32; 2],
     _size: [f32; 2],
     _rotation: f32,
-    _scale: [f32; 2],
     _position_in_atlas: [f32; 2],
     _size_in_atlas: [f32; 2],
     _layer: u32,
@@ -530,7 +523,6 @@ fn add_instances(
     image_position: [f32; 2],
     image_size: [f32; 2],
     rotation: f32,
-    scale: [f32; 2],
     entry: &atlas::Entry,
     instances: &mut Vec<Instance>,
 ) {
@@ -546,7 +538,6 @@ fn add_instances(
                 center,
                 image_size,
                 rotation,
-                scale,
                 allocation,
                 instances,
             );
@@ -576,8 +567,7 @@ fn add_instances(
                 ];
 
                 add_instance(
-                    position, center, size, rotation, scale, allocation,
-                    instances,
+                    position, center, size, rotation, allocation, instances,
                 );
             }
         }
@@ -590,7 +580,6 @@ fn add_instance(
     center: [f32; 2],
     size: [f32; 2],
     rotation: f32,
-    scale: [f32; 2],
     allocation: &atlas::Allocation,
     instances: &mut Vec<Instance>,
 ) {
@@ -603,7 +592,6 @@ fn add_instance(
         _center: center,
         _size: size,
         _rotation: rotation,
-        _scale: scale,
         _position_in_atlas: [
             (x as f32 + 0.5) / atlas::SIZE as f32,
             (y as f32 + 0.5) / atlas::SIZE as f32,
diff --git a/wgpu/src/layer.rs b/wgpu/src/layer.rs
index 648ec476..e0242c59 100644
--- a/wgpu/src/layer.rs
+++ b/wgpu/src/layer.rs
@@ -1,5 +1,5 @@
 use crate::core::{
-    renderer, Background, Color, Point, Rectangle, Size, Transformation,
+    renderer, Background, Color, Point, Radians, Rectangle, Transformation,
 };
 use crate::graphics;
 use crate::graphics::color;
@@ -118,15 +118,13 @@ impl Layer {
         filter_method: crate::core::image::FilterMethod,
         bounds: Rectangle,
         transformation: Transformation,
-        rotation: f32,
-        scale: Size,
+        rotation: Radians,
     ) {
         let image = Image::Raster {
             handle,
             filter_method,
             bounds: bounds * transformation,
             rotation,
-            scale,
         };
 
         self.images.push(image);
@@ -138,15 +136,13 @@ impl Layer {
         color: Option<Color>,
         bounds: Rectangle,
         transformation: Transformation,
-        rotation: f32,
-        scale: Size,
+        rotation: Radians,
     ) {
         let svg = Image::Vector {
             handle,
             color,
             bounds: bounds * transformation,
             rotation,
-            scale,
         };
 
         self.images.push(svg);
diff --git a/wgpu/src/lib.rs b/wgpu/src/lib.rs
index a42d71c3..6920067b 100644
--- a/wgpu/src/lib.rs
+++ b/wgpu/src/lib.rs
@@ -61,7 +61,8 @@ pub use settings::Settings;
 pub use geometry::Geometry;
 
 use crate::core::{
-    Background, Color, Font, Pixels, Point, Rectangle, Size, Transformation,
+    Background, Color, Font, Pixels, Point, Radians, Rectangle, Size,
+    Transformation, Vector,
 };
 use crate::graphics::text::{Editor, Paragraph};
 use crate::graphics::Viewport;
@@ -378,7 +379,6 @@ impl Renderer {
         use crate::core::alignment;
         use crate::core::text::Renderer as _;
         use crate::core::Renderer as _;
-        use crate::core::Vector;
 
         self.with_layer(
             Rectangle::with_size(viewport.logical_size()),
@@ -517,8 +517,7 @@ impl core::image::Renderer for Renderer {
         handle: Self::Handle,
         filter_method: core::image::FilterMethod,
         bounds: Rectangle,
-        rotation: f32,
-        scale: Size,
+        rotation: Radians,
     ) {
         let (layer, transformation) = self.layers.current_mut();
         layer.draw_image(
@@ -527,7 +526,6 @@ impl core::image::Renderer for Renderer {
             bounds,
             transformation,
             rotation,
-            scale,
         );
     }
 }
@@ -543,18 +541,10 @@ impl core::svg::Renderer for Renderer {
         handle: core::svg::Handle,
         color_filter: Option<Color>,
         bounds: Rectangle,
-        rotation: f32,
-        scale: Size,
+        rotation: Radians,
     ) {
         let (layer, transformation) = self.layers.current_mut();
-        layer.draw_svg(
-            handle,
-            color_filter,
-            bounds,
-            transformation,
-            rotation,
-            scale,
-        );
+        layer.draw_svg(handle, color_filter, bounds, transformation, rotation);
     }
 }
 
diff --git a/wgpu/src/shader/image.wgsl b/wgpu/src/shader/image.wgsl
index de962098..71bf939c 100644
--- a/wgpu/src/shader/image.wgsl
+++ b/wgpu/src/shader/image.wgsl
@@ -10,12 +10,11 @@ struct VertexInput {
     @builtin(vertex_index) vertex_index: u32,
     @location(0) pos: vec2<f32>,
     @location(1) center: vec2<f32>,
-    @location(2) image_size: vec2<f32>,
+    @location(2) scale: vec2<f32>,
     @location(3) rotation: f32,
-    @location(4) scale: vec2<f32>,
-    @location(5) atlas_pos: vec2<f32>,
-    @location(6) atlas_scale: vec2<f32>,
-    @location(7) layer: i32,
+    @location(4) atlas_pos: vec2<f32>,
+    @location(5) atlas_scale: vec2<f32>,
+    @location(6) layer: i32,
 }
 
 struct VertexOutput {
@@ -36,7 +35,7 @@ fn vs_main(input: VertexInput) -> VertexOutput {
     out.layer = f32(input.layer);
 
     // Calculate the vertex position and move the center to the origin
-    v_pos = input.pos + v_pos * input.image_size - input.center;
+    v_pos = input.pos + v_pos * input.scale - input.center;
 
     // Apply the rotation around the center of the image
     let cos_rot = cos(input.rotation);
@@ -48,16 +47,8 @@ fn vs_main(input: VertexInput) -> VertexOutput {
         vec4<f32>(0.0, 0.0, 0.0, 1.0)
     );
 
-    // Scale the image and then translate to the final position by moving the center to the position
-    let scale_translate = mat4x4<f32>(
-        vec4<f32>(input.scale.x, 0.0, 0.0, 0.0),
-        vec4<f32>(0.0, input.scale.y, 0.0, 0.0),
-        vec4<f32>(0.0, 0.0, 1.0, 0.0),
-        vec4<f32>(input.center, 0.0, 1.0)
-    );
-
     // Calculate the final position of the vertex
-    out.position = globals.transform * scale_translate * rotate * vec4<f32>(v_pos, 0.0, 1.0);
+    out.position = globals.transform * (vec4<f32>(input.center, 0.0, 0.0) + rotate * vec4<f32>(v_pos, 0.0, 1.0));
 
     return out;
 }