added tile_width option

3 files changed, 22 insertions, 6 deletions

diff --git a/example/src/main.rs b/example/src/main.rs
index c06f1ce..78b4a29 100644
--- a/example/src/main.rs
+++ b/example/src/main.rs
@@ -119,6 +119,7 @@ impl App<AssetId> for TowerGame {
 fn main() {
     let info = AppInfo::with_max_dims(86., 48.)
                        .min_dims(64., 44.)
+                       .tile_width(16)
                        .title("Tower");
     gate::run(info, TowerGame { pillars: vec![vec![4, 3, 2, 1, 0], vec![], vec![]], held: None });
 }
diff --git a/gate/src/app_info.rs b/gate/src/app_info.rs
index e1c48bc..e9ecaa6 100644
--- a/gate/src/app_info.rs
+++ b/gate/src/app_info.rs
@@ -27,6 +27,7 @@
 ///
 /// let info = AppInfo::with_max_dims(160., 90.)
 ///                    .min_dims(120., 86.)
+///                    .tile_width(16)
 ///                    .title("My Game")
 ///                    .target_fps(30.)
 ///                    .print_workload_info()
@@ -36,6 +37,7 @@ pub struct AppInfo {
     pub(crate) window_pixels: (u32, u32),
     pub(crate) min_dims: (f64, f64),
     pub(crate) max_dims: (f64, f64),
+    pub(crate) tile_width: Option<u32>,
     pub(crate) title: &'static str,
     pub(crate) target_fps: f64,
     pub(crate) print_workload_info: bool,
@@ -52,6 +54,7 @@ impl AppInfo {
             window_pixels: (800, 600),
             min_dims: (0., 0.),
             max_dims: (max_width, max_height),
+            tile_width: None,
             title: "untitled app",
             target_fps: 60.,
             print_workload_info: false,
@@ -65,6 +68,12 @@ impl AppInfo {
         self
     }
 
+    pub fn tile_width(mut self, tile_width: u32) -> Self {
+        assert!(tile_width > 0 && tile_width <= 10000, "unrealistic tile_width {}", tile_width);
+        self.tile_width = Some(tile_width);
+        self
+    }
+
     /// Specifies a window title (default is "untitled app").
     pub fn title(mut self, title: &'static str) -> Self { self.title = title; self }
 
diff --git a/gate/src/renderer/render_buffer.rs b/gate/src/renderer/render_buffer.rs
index 916863a..61b3daa 100644
--- a/gate/src/renderer/render_buffer.rs
+++ b/gate/src/renderer/render_buffer.rs
@@ -25,6 +25,7 @@ pub(super) enum Mode { Sprite }
 pub(super) struct RenderDims {
     pub min_dims: (f64, f64),
     pub max_dims: (f64, f64),
+    pub tile_width: Option<u32>,
     pub native_dims: (u32, u32),
     pub pixel_scalar: f64,
     pub native_pre_pad: (u32, u32),
@@ -33,9 +34,14 @@ pub(super) struct RenderDims {
 }
 
 impl RenderDims {
-    fn new(min_dims: (f64, f64), max_dims: (f64, f64), native_dims: (u32, u32)) -> RenderDims {
-        let scalar_from_min = (native_dims.0 as f64 / min_dims.0).min(native_dims.1 as f64 / min_dims.1);
-        let scalar_from_max = (native_dims.0 as f64 / max_dims.0).max(native_dims.1 as f64 / max_dims.1);
+    fn new(min_dims: (f64, f64), max_dims: (f64, f64), tile_width: Option<u32>, native_dims: (u32, u32)) -> RenderDims {
+        let mut scalar_from_min = (native_dims.0 as f64 / min_dims.0).min(native_dims.1 as f64 / min_dims.1);
+        let mut scalar_from_max = (native_dims.0 as f64 / max_dims.0).max(native_dims.1 as f64 / max_dims.1);
+        if let Some(tile_width) = tile_width {
+            let tile_width = tile_width as f64;
+            scalar_from_min = (scalar_from_min * tile_width).floor() / tile_width;
+            scalar_from_max = (scalar_from_max * tile_width).ceil() / tile_width;
+        }
         let pixel_scalar = scalar_from_min.min(scalar_from_max).max(1.0);
         let used_native_dims = (
             native_dims.0.min((max_dims.0 * pixel_scalar).floor() as u32),
@@ -44,11 +50,11 @@ impl RenderDims {
         let native_pad = (native_dims.0 - used_native_dims.0, native_dims.1 - used_native_dims.1);
         let native_pre_pad = (native_pad.0 / 2, native_pad.1 / 2);
         let dims = (used_native_dims.0 as f64 / pixel_scalar, used_native_dims.1 as f64 / pixel_scalar);
-        RenderDims { min_dims, max_dims, native_dims, pixel_scalar, native_pre_pad, used_native_dims, dims }
+        RenderDims { min_dims, max_dims, tile_width, native_dims, pixel_scalar, native_pre_pad, used_native_dims, dims }
     }
 
     pub fn set_native_dims(&mut self, native_dims: (u32, u32)) {
-        *self = RenderDims::new(self.min_dims, self.max_dims, native_dims);
+        *self = RenderDims::new(self.min_dims, self.max_dims, self.tile_width, native_dims);
     }
 
     pub fn to_app_pos(&self, raw_x: i32, raw_y: i32) -> (f64, f64) {
@@ -73,7 +79,7 @@ impl RenderBuffer {
             sprite_atlas,
             mode: Mode::Sprite,
             vbo_data: Vec::new(),
-            dims: RenderDims::new(info.min_dims, info.max_dims, native_dims),
+            dims: RenderDims::new(info.min_dims, info.max_dims, info.tile_width, native_dims),
         }
     }