From 7bf8602796daf22cfc0c6f472b7cbad7cbe9ff4c Mon Sep 17 00:00:00 2001
From: Daniel Flanagan <daniel@lyte.dev>
Date: Wed, 31 Jul 2024 17:14:09 -0500
Subject: [PATCH] Crosshair aims :tada:

---
 Cargo.toml    |  2 +-
 src/input.rs  | 36 ++++++++++++++++++++++++++++++++++--
 src/player.rs | 12 +++++++++++-
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index e1a50d6..6f0bb25 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,13 +22,13 @@ bevy = { version = "0.14.0", default-features = false, features = [
   "wayland",
   "wav",                # sound files
   "sysinfo_plugin",     # probably will want this for troubleshooting or just surfacing useful information to the gamer (such as FPS?)
+  "bevy_gizmos",        # debug geometry?
 
   # TODO: would be nice to get this working while developing
   "dynamic_linking",
 
   # NOTE: Features we may want at some point.
   # "vorbis", # music -- maybe mp3?
-  # "bevy_gizmos", # debug geometry?
   # "track_change_detection", # for hot-reloading of assets? (scripts?)
   # "file_watcher", # for hot-reloading of assets? (scripts?)
   # "serialize" # for saving games or game-related information?
diff --git a/src/input.rs b/src/input.rs
index 1036432..bd2ea11 100644
--- a/src/input.rs
+++ b/src/input.rs
@@ -1,4 +1,8 @@
-use bevy::prelude::*;
+use bevy::{
+    color::palettes::css::{GREEN, RED},
+    prelude::*,
+    window::PrimaryWindow,
+};
 
 #[derive(Resource, Default, Debug, Clone, PartialEq)]
 pub struct Input {
@@ -9,9 +13,11 @@ pub struct Input {
 }
 
 pub fn process_input(
+    mut gizmos: Gizmos,
     mut input: ResMut<Input>,
     keys: Res<ButtonInput<KeyCode>>,
     // mouse: Res<ButtonInput<MouseButton>>,
+    window: Query<&Window, With<PrimaryWindow>>,
 ) {
     input.movement.x = 0.;
     input.movement.y = 0.;
@@ -33,10 +39,36 @@ pub fn process_input(
         }
     }
     input.movement = input.movement.normalize_or_zero();
-    // input.target // not set using keyboard, see mouse
     input.action = input.action || keys.any_pressed([KeyCode::Space, KeyCode::Enter]);
     input.cancel = input.cancel || keys.just_pressed(KeyCode::Escape);
 
+    // FOR CURSOR POSITION
+    // origin is top-left
+    // x increases as mouse goes right
+    // y increases as mouse goes down
+
+    // FOR 2D WORLD COORDINATE
+    // origin is bottom-left
+    // x increases as thing moves right
+    // y increases as thing moves up
+
+    // with this in mind, to convert mouse coordinates to world coordinates for comparing against our logical window center, we take the absolute of the difference in height
+
+    gizmos.line(Vec3::ZERO, Vec3::X * 100., GREEN);
+    if let Ok(window) = window.get_single() {
+        if let Some(target) = window.cursor_position() {
+            let size = window.size();
+            let center = size / 2.;
+            let modified_target = target.with_y(size.y - target.y) - center;
+            gizmos.line(Vec2::ZERO.extend(0.), modified_target.extend(0.), RED);
+            input.angle = modified_target.to_angle();
+            info!(
+                "pos@{target:?} -- {center:?} -> {modified_target:?} for angle of {:?}",
+                input.angle
+            );
+        }
+    }
+
     info!("Input: {:#?}", input);
 }
 
diff --git a/src/player.rs b/src/player.rs
index af7ac6c..9c6a310 100644
--- a/src/player.rs
+++ b/src/player.rs
@@ -1,3 +1,5 @@
+use std::f32::consts::TAU;
+
 use crate::camera::Watched;
 use crate::movement::{Heading, Mover, Speed, Velocity, YSortable};
 use crate::prelude::*;
@@ -89,10 +91,18 @@ pub fn startup(
         });
 }
 
-pub fn control(input: Res<Input>, mut player: Query<&mut Heading, With<Player>>) {
+pub fn control(
+    input: Res<Input>,
+    mut crosshair: Query<&mut Transform, With<Crosshair>>,
+    mut player: Query<&mut Heading, With<Player>>,
+    // time: Res<Time>,
+) {
     if let Ok(mut heading) = player.get_single_mut() {
         heading.0 = input.movement;
     }
+    if let Ok(mut transform) = crosshair.get_single_mut() {
+        transform.rotation = Quat::from_rotation_z(input.angle + (TAU / 4.));
+    }
 }
 
 pub fn player_debug_info(mut player: Query<(&Heading, &Transform), With<Player>>) {