Pac-Man/src/texture/atlas.rs

use sdl2::{
    rect::Rect,
    render::{Canvas, Texture},
    video::Window,
};

use crate::{direction::Direction, texture::FrameDrawn};

/// A texture atlas abstraction for static (non-animated) rendering.
pub struct AtlasTexture<'a> {
    pub raw_texture: Texture<'a>,
    pub offset: (i32, i32),
    pub frame_count: u32,
    pub frame_width: u32,
    pub frame_height: u32,
}

impl<'a> AtlasTexture<'a> {
    pub fn new(texture: Texture<'a>, frame_count: u32, frame_width: u32, frame_height: u32, offset: Option<(i32, i32)>) -> Self {
        AtlasTexture {
            raw_texture: texture,
            frame_count,
            frame_width,
            frame_height,
            offset: offset.unwrap_or((0, 0)),
        }
    }

    pub fn get_frame_rect(&self, frame: u32) -> Option<Rect> {
        if frame >= self.frame_count {
            return None;
        }
        Some(Rect::new(
            frame as i32 * self.frame_width as i32,
            0,
            self.frame_width,
            self.frame_height,
        ))
    }

    pub fn set_color_modulation(&mut self, r: u8, g: u8, b: u8) {
        self.raw_texture.set_color_mod(r, g, b);
    }
}

impl<'a> FrameDrawn for AtlasTexture<'a> {
    fn render(&self, canvas: &mut Canvas<Window>, position: (i32, i32), direction: Direction, frame: Option<u32>) {
        let texture_source_frame_rect = self.get_frame_rect(frame.unwrap_or(0));
        let canvas_destination_rect = Rect::new(
            position.0 + self.offset.0,
            position.1 + self.offset.1,
            self.frame_width,
            self.frame_height,
        );
        canvas
            .copy_ex(
                &self.raw_texture,
                texture_source_frame_rect,
                Some(canvas_destination_rect),
                direction.angle(),
                None,
                false,
                false,
            )
            .expect("Could not render texture on canvas");
    }
}