refactor: split up and move texture-related code into src/texture submodule

src/texture/animated.rs

@@ -0,0 +1,72 @@
+//! This module provides a simple animation and atlas system for textures.
+use sdl2::{
+    render::{Canvas, Texture},
+    video::Window,
+};
+
+use crate::direction::Direction;
+use crate::texture::atlas::AtlasTexture;
+use crate::texture::FrameDrawn;
+
+/// An animated texture using a texture atlas.
+pub struct AnimatedAtlasTexture<'a> {
+    pub atlas: AtlasTexture<'a>,
+    pub ticks_per_frame: u32,
+    pub ticker: u32,
+    pub reversed: bool,
+    pub paused: bool,
+}
+
+impl<'a> AnimatedAtlasTexture<'a> {
+    pub fn new(
+        texture: Texture<'a>,
+        ticks_per_frame: u32,
+        frame_count: u32,
+        width: u32,
+        height: u32,
+        offset: Option<(i32, i32)>,
+    ) -> Self {
+        AnimatedAtlasTexture {
+            atlas: AtlasTexture::new(texture, frame_count, width, height, offset),
+            ticks_per_frame,
+            ticker: 0,
+            reversed: false,
+            paused: false,
+        }
+    }
+
+    fn current_frame(&self) -> u32 {
+        self.ticker / self.ticks_per_frame
+    }
+
+    /// Advances the animation by one tick, unless paused.
+    pub fn tick(&mut self) {
+        if self.paused {
+            return;
+        }
+        if self.reversed {
+            if self.ticker > 0 {
+                self.ticker -= 1;
+            }
+            if self.ticker == 0 {
+                self.reversed = !self.reversed;
+            }
+        } else {
+            self.ticker += 1;
+            if self.ticker + 1 == self.ticks_per_frame * self.atlas.frame_count {
+                self.reversed = !self.reversed;
+            }
+        }
+    }
+
+    pub fn set_color_modulation(&mut self, r: u8, g: u8, b: u8) {
+        self.atlas.set_color_modulation(r, g, b);
+    }
+}
+
+impl<'a> FrameDrawn for AnimatedAtlasTexture<'a> {
+    fn render(&self, canvas: &mut Canvas<Window>, position: (i32, i32), direction: Direction, frame: Option<u32>) {
+        let frame = frame.unwrap_or_else(|| self.current_frame());
+        self.atlas.render(canvas, position, direction, Some(frame));
+    }
+}