Render some tiles

src/game.rs

@@ -1,6 +1,11 @@
-use sfml::graphics::{RenderTarget, RenderWindow, Sprite};
+use sfml::graphics::{Rect, RenderTarget, RenderWindow, Sprite, Transformable};
 
-use crate::{math::WorldPos, res::Res, world::World};
+use crate::{
+    graphics::{ScreenPos, NATIVE_RESOLUTION},
+    math::{WorldPos, WorldPosScalar, TILE_SIZE},
+    res::Res,
+    world::{TilePos, World},
+};
 
 pub struct GameState {
     camera_offset: WorldPos,
@@ -8,7 +13,33 @@ pub struct GameState {
 }
 impl GameState {
     pub(crate) fn draw_world(&mut self, rw: &mut RenderWindow, res: &Res) {
-        rw.draw(&Sprite::with_texture(&res.tile_atlas));
+        let mut s = Sprite::with_texture(&res.tile_atlas);
+        for_each_tile(self.camera_offset, |tp, sp| {
+            let tile = self.world.tile_at_mut(tp);
+            s.set_texture_rect(Rect::new(tile.id as i32 * 32, 0, 32, 32));
+            s.set_position(sp.to_sf_vec());
+            rw.draw(&s);
+        });
+    }
+}
+
+fn for_each_tile(camera_offset: WorldPos, mut f: impl FnMut(TilePos, ScreenPos)) {
+    for y in (camera_offset.y..camera_offset.y + NATIVE_RESOLUTION.h as WorldPosScalar).step_by(32)
+    {
+        for x in
+            (camera_offset.x..camera_offset.x + NATIVE_RESOLUTION.w as WorldPosScalar).step_by(32)
+        {
+            f(
+                TilePos {
+                    x: x / 32,
+                    y: y / 32,
+                },
+                ScreenPos {
+                    x: (x - camera_offset.x) as i16,
+                    y: (y - camera_offset.y) as i16,
+                },
+            )
+        }
     }
 }