From fe5f91966fdf7054545b182659cb8a4e393d90d3 Mon Sep 17 00:00:00 2001
From: Derek Christ <christ.derek@gmail.com>
Date: Sun, 7 Aug 2022 00:23:14 +0200
Subject: [PATCH] Add game over system

---
 src/grid.rs  |  2 +-
 src/main.rs  | 15 +++++++++------
 src/snake.rs | 26 ++++++++++++++++++++++----
 3 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/src/grid.rs b/src/grid.rs
index d6773d9..789943a 100644
--- a/src/grid.rs
+++ b/src/grid.rs
@@ -1,7 +1,7 @@
 use bevy::prelude::*;
 use std::ops::{Add, AddAssign};
 
-type GridType = i16;
+pub type GridType = i16;
 
 pub const GRID_SIZE: GridType = 21;
 pub const GRID_SEGMENT_SIZE: f32 = 20.;
diff --git a/src/main.rs b/src/main.rs
index cdcefc6..d0d036a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -41,12 +41,15 @@ fn main() {
 }
 
 fn setup_system(mut commands: Commands) {
-    let vertical_height = GRID_SIZE as f32 * GRID_SEGMENT_SIZE * 1.2;
+    let grid_dimensions = GRID_SIZE as f32 * GRID_SEGMENT_SIZE * 1.2;
 
     commands
         .spawn_bundle(Camera2dBundle {
             projection: OrthographicProjection {
-                scaling_mode: ScalingMode::FixedVertical(vertical_height),
+                scaling_mode: ScalingMode::Auto {
+                    min_width: grid_dimensions,
+                    min_height: grid_dimensions,
+                },
                 ..Default::default()
             },
             ..Default::default()
@@ -66,16 +69,16 @@ fn camera_move_system(
         let mut delta = Vec3::ZERO;
 
         if keypress.pressed(KeyCode::Up) {
-            delta += Vec3::new(0., 1., 0.);
+            delta += Vec3::new(0., 10., 0.);
         }
         if keypress.pressed(KeyCode::Down) {
-            delta += Vec3::new(0., -1., 0.);
+            delta += Vec3::new(0., -10., 0.);
         }
         if keypress.pressed(KeyCode::Left) {
-            delta += Vec3::new(-1., 0., 0.);
+            delta += Vec3::new(-10., 0., 0.);
         }
         if keypress.pressed(KeyCode::Right) {
-            delta += Vec3::new(1., 0., 0.);
+            delta += Vec3::new(10., 0., 0.);
         }
 
         delta
diff --git a/src/snake.rs b/src/snake.rs
index c381695..407cf88 100644
--- a/src/snake.rs
+++ b/src/snake.rs
@@ -1,5 +1,5 @@
 use crate::{
-    grid::{GridCoordinate, GRID_SEGMENT_SIZE, GRID_SIZE},
+    grid::{GridCoordinate, GridType, GRID_SEGMENT_SIZE, GRID_SIZE},
     AppState,
 };
 use bevy::prelude::*;
@@ -28,9 +28,10 @@ impl Plugin for SnakePlugin {
                     .with_stage(fixed_time_systems0)
                     .with_stage(fixed_time_systems1),
             )
+            .add_system(game_over_system.run_in_state(AppState::InGame))
             .add_system(add_direction_system.run_in_state(AppState::Begin))
             .add_system(direction_system.run_in_state(AppState::InGame))
-            .add_system(grid_transform_system)
+            .add_system(grid_transform_system.run_in_state(AppState::InGame))
             .add_system(add_tail_system);
     }
 }
@@ -82,7 +83,7 @@ fn create_snake_segment(commands: &mut Commands, grid_position: GridCoordinate)
         .spawn_bundle(SpriteBundle {
             sprite: Sprite {
                 color: Color::RED,
-                custom_size: Some(Vec2::splat(GRID_SEGMENT_SIZE)*0.9),
+                custom_size: Some(Vec2::splat(GRID_SEGMENT_SIZE) * 0.9),
                 ..Default::default()
             },
             transform: grid_position.into(),
@@ -129,7 +130,7 @@ fn add_tail_system(
     mut snake_query: Query<(Entity, &mut SnakeSegments)>,
 ) {
     if keypress.just_pressed(KeyCode::Space) {
-        let segment = create_snake_segment(&mut commands, GridCoordinate::splat(-1));
+        let segment = create_snake_segment(&mut commands, GridCoordinate::splat(GridType::MIN / 2));
         let (snake, mut snake_segments) = snake_query.single_mut();
         snake_segments.0.push(segment);
         commands.entity(snake).add_child(segment);
@@ -186,3 +187,20 @@ fn segments_movement_system(
         }
     }
 }
+
+fn game_over_system(
+    mut commands: Commands,
+    query: Query<(&GridCoordinate, &Direction), With<SnakeHead>>,
+) {
+    const HIGH_BARRIER: GridType = GRID_SIZE - 1;
+
+    match query.single() {
+        (GridCoordinate(_, 0), Direction::Down)
+        | (GridCoordinate(_, HIGH_BARRIER), Direction::Up)
+        | (GridCoordinate(0, _), Direction::Left)
+        | (GridCoordinate(HIGH_BARRIER, _), Direction::Right) => {
+            commands.insert_resource(NextState(AppState::End))
+        }
+        _ => (),
+    };
+}