added methods for dealing with native pixel alignment

4 files changed, 24 insertions, 8 deletions

diff --git a/gate/src/app_context.rs b/gate/src/app_context.rs
index 1dfe3e1..45a59d5 100644
--- a/gate/src/app_context.rs
+++ b/gate/src/app_context.rs
@@ -24,15 +24,17 @@ pub struct AppContext<A: AppAssetId> {
     dims: (f64, f64),
     cursor: (f64, f64),
     close_requested: bool,
+    native_px: f64,
 }
 
 impl<A: AppAssetId> AppContext<A> {
-    pub(crate) fn new(audio: CoreAudio, dims: (f64, f64)) -> AppContext<A> {
+    pub(crate) fn new(audio: CoreAudio, dims: (f64, f64), native_px: f64) -> AppContext<A> {
         AppContext {
             audio: Audio { core: audio, phantom: PhantomData },
             dims,
             cursor: (0., 0.),
             close_requested: false,
+            native_px,
         }
     }
 
@@ -41,8 +43,9 @@ impl<A: AppAssetId> AppContext<A> {
         self.bound_cursor();
     }
 
-    pub(crate) fn set_dims(&mut self, dims: (f64, f64)) {
+    pub(crate) fn set_dims(&mut self, dims: (f64, f64), native_px: f64) {
         self.dims = dims;
+        self.native_px = native_px;
         self.bound_cursor();
     }
 
@@ -63,6 +66,15 @@ impl<A: AppAssetId> AppContext<A> {
     /// The y coordinate lies in the range `-0.5 * self.dims().1` to `0.5 * self.dims().1`.
     pub fn cursor(&self) -> (f64, f64) { self.cursor }
 
+    pub fn native_px(&self) -> f64 { self.native_px }
+
+    pub fn native_px_align(&self, x: f64, y: f64) -> (f64, f64) {
+        (
+            (x / self.native_px).round() * self.native_px,
+            (y / self.native_px).round() * self.native_px,
+        )
+    }
+
     /// Closes the app entirely.
     pub fn close(&mut self) { self.close_requested = true; }
 
diff --git a/gate/src/core/sdl/mod.rs b/gate/src/core/sdl/mod.rs
index 51cb2d2..e4006c1 100644
--- a/gate/src/core/sdl/mod.rs
+++ b/gate/src/core/sdl/mod.rs
@@ -72,7 +72,7 @@ pub fn run<AS: AppAssetId, AP: App<AS>>(info: AppInfo, mut app: AP) {
 
     gl_error_check();
 
-    let mut ctx = AppContext::new(CoreAudio::new(AS::Sound::count()), renderer.app_dims());
+    let mut ctx = AppContext::new(CoreAudio::new(AS::Sound::count()), renderer.app_dims(), renderer.native_px());
 
     if info.print_gl_info { print_gl_info(); }
 
@@ -89,7 +89,7 @@ pub fn run<AS: AppAssetId, AP: App<AS>>(info: AppInfo, mut app: AP) {
         let screen_dims = sdl_renderer.window().unwrap().size();
         if screen_dims.0 > 0 && screen_dims.1 > 0 {
             renderer.set_screen_dims(screen_dims);
-            ctx.set_dims(renderer.app_dims());
+            ctx.set_dims(renderer.app_dims(), renderer.native_px());
             app.render(&mut renderer, &ctx);
             renderer.flush();
         }
diff --git a/gate/src/core/wasm/mod.rs b/gate/src/core/wasm/mod.rs
index f7f0881..ccdce54 100644
--- a/gate/src/core/wasm/mod.rs
+++ b/gate/src/core/wasm/mod.rs
@@ -107,13 +107,15 @@ impl<AS: AppAssetId, AP: App<AS>> TraitAppRunner for AppRunner<AS, AP> {
         let core_renderer = CoreRenderer::new();
         self.renderer = Some(Renderer::<AS>::new(render_buffer, core_renderer));
 
-        self.ctx.set_dims(self.renderer.as_ref().unwrap().app_dims());
+        let renderer = self.renderer.as_ref().unwrap();
+        self.ctx.set_dims(renderer.app_dims(), renderer.native_px());
         self.app.start(&mut self.ctx);
     }
 
     fn resize(&mut self, dims: (u32, u32)) {
-        self.renderer.as_mut().unwrap().set_screen_dims(dims);
-        self.ctx.set_dims(self.renderer.as_ref().unwrap().app_dims());
+        let renderer = self.renderer.as_mut().unwrap();
+        renderer.set_screen_dims(dims);
+        self.ctx.set_dims(renderer.app_dims(), renderer.native_px());
     }
 
     fn update_and_draw(&mut self, time_sec: f64) {
@@ -151,7 +153,7 @@ pub fn run<AS: 'static + AppAssetId, AP: 'static + App<AS>>(info: AppInfo, app:
     mark_app_created_flag();
     *APP_RUNNER.r.borrow_mut() = Some(Box::new(AppRunner {
         app, info,
-        ctx: AppContext::new(CoreAudio { }, (0., 0.)),
+        ctx: AppContext::new(CoreAudio { }, (0., 0.), 1.),
         renderer: None,
         last_time_sec: None,
         held_keys: HashSet::new(),
diff --git a/gate/src/renderer/renderer.rs b/gate/src/renderer/renderer.rs
index e2ff84f..f9c7760 100644
--- a/gate/src/renderer/renderer.rs
+++ b/gate/src/renderer/renderer.rs
@@ -57,6 +57,8 @@ impl<A: AppAssetId> Renderer<A> {
 
     pub(crate) fn app_dims(&self) -> (f64, f64) { self.b.dims.dims }
 
+    pub(crate) fn native_px(&self) -> f64 { 1. / self.b.dims.pixel_scalar }
+
     pub(crate) fn to_app_pos(&self, raw_x: i32, raw_y: i32) -> (f64, f64) {
         self.b.dims.to_app_pos(raw_x, raw_y)
     }