From 2bb8cbc852338c4d7c9180d0f605edf2364ed3a5 Mon Sep 17 00:00:00 2001
From: Avii <git@avii.nl>
Date: Thu, 11 Jul 2024 20:23:34 +0200
Subject: [PATCH] mouse camera controls

---
 src/helpers/camera.rs | 77 +++++++++++++++++++++++++------------------
 src/helpers/grid.rs   | 14 ++++----
 2 files changed, 52 insertions(+), 39 deletions(-)

diff --git a/src/helpers/camera.rs b/src/helpers/camera.rs
index 5a06eca..5c737fe 100644
--- a/src/helpers/camera.rs
+++ b/src/helpers/camera.rs
@@ -1,46 +1,59 @@
-use bevy::{input::ButtonInput, math::Vec3, prelude::*, render::camera::Camera};
+use bevy::{
+    input::{mouse::MouseWheel, ButtonInput},
+    prelude::*,
+    render::camera::Camera,
+    window::PrimaryWindow,
+};
 
 use crate::TileOffset;
 
-// Todo: Middle mouse button should drag the playfield around
-// Zoom with + and -
-#[allow(dead_code)]
-pub fn movement(
-    time: Res<Time>,
-    keyboard_input: Res<ButtonInput<KeyCode>>,
-    mut query: Query<(&mut Transform, &mut TileOffset, &mut OrthographicProjection), With<Camera>>,
+pub fn mouse_zoom(
+    mut evr_scroll: EventReader<MouseWheel>,
+    mut query: Query<&mut OrthographicProjection, With<Camera>>,
 ) {
-    for (mut transform, mut offset, mut ortho) in query.iter_mut() {
-        let mut direction = Vec3::ZERO;
+    use bevy::input::mouse::MouseScrollUnit;
+    for ev in evr_scroll.read() {
+        match ev.unit {
+            MouseScrollUnit::Line => {
+                let scroll = ev.y / 10.0;
 
-        if keyboard_input.pressed(KeyCode::KeyA) {
-            direction -= Vec3::new(1.0, 0.0, 0.0);
+                for mut ortho in query.iter_mut() {
+                    ortho.scale -= scroll;
+                    ortho.scale = ortho.scale.clamp(0.5, 1.0);
+                    dbg!(ortho.scale);
+                }
+            }
+            MouseScrollUnit::Pixel => {}
         }
+    }
+}
 
-        if keyboard_input.pressed(KeyCode::KeyD) {
-            direction += Vec3::new(1.0, 0.0, 0.0);
-        }
+pub fn mouse_movement(
+    primary_window: Query<&Window, With<PrimaryWindow>>,
+    mouse_buttons: Res<ButtonInput<MouseButton>>,
+    mut query: Query<(&mut Transform, &mut TileOffset, &OrthographicProjection), With<Camera>>,
+    mut last_pos: Local<Option<Vec2>>,
+) {
+    if !mouse_buttons.pressed(MouseButton::Middle) {
+        *last_pos = None;
+        return;
+    }
 
-        if keyboard_input.pressed(KeyCode::KeyW) {
-            direction += Vec3::new(0.0, 1.0, 0.0);
-        }
+    let Ok(window) = primary_window.get_single() else {
+        return;
+    };
 
-        if keyboard_input.pressed(KeyCode::KeyS) {
-            direction -= Vec3::new(0.0, 1.0, 0.0);
-        }
-
-        if keyboard_input.pressed(KeyCode::KeyZ) {
-            ortho.scale += time.delta_seconds();
-        }
-
-        if keyboard_input.pressed(KeyCode::KeyX) {
-            ortho.scale -= time.delta_seconds();
-        }
-
-        ortho.scale = ortho.scale.clamp(0.5, 1.0);
+    for (mut transform, mut offset, ortho) in query.iter_mut() {
+        let current_pos = match window.cursor_position() {
+            Some(c) => Vec2::new(c.x, -c.y),
+            None => return,
+        };
+        let delta_device_pixels = current_pos - last_pos.unwrap_or(current_pos);
+        *last_pos = Some(current_pos);
 
         let z = transform.translation.z;
-        offset.translation += time.delta_seconds() * direction * (16.0 * 8.0);
+        offset.translation.x -= delta_device_pixels.x * ortho.scale;
+        offset.translation.y -= delta_device_pixels.y * ortho.scale;
 
         offset.x = (offset.translation.x / 16.0) as isize;
         offset.y = (offset.translation.y / 16.0) as isize;
diff --git a/src/helpers/grid.rs b/src/helpers/grid.rs
index cdaa5f4..7527adb 100644
--- a/src/helpers/grid.rs
+++ b/src/helpers/grid.rs
@@ -86,7 +86,13 @@ impl Plugin for GridPlugin {
         app.add_systems(Startup, generate_grid);
         app.add_systems(
             First,
-            (camera::movement, update_cursor_pos, click_tile).chain(),
+            (
+                camera::mouse_movement,
+                camera::mouse_zoom,
+                update_cursor_pos,
+                click_tile,
+            )
+                .chain(),
         );
         app.add_systems(Update, update_tiles);
     }
@@ -131,7 +137,6 @@ fn generate_grid(mut commands: Commands, asset_server: Res<AssetServer>) {
     });
 }
 
-// This is where we check which tile the cursor is hovered over.
 fn click_tile(
     buttons: Res<ButtonInput<MouseButton>>,
     cursor_pos: Res<CursorPos>,
@@ -146,18 +151,13 @@ fn click_tile(
     let offset = offset.single();
 
     for (map_size, grid_size, tile_storage, map_transform) in tilemap_q.iter() {
-        // Grab the cursor position from the `Res<CursorPos>`
         let cursor_pos: Vec2 = cursor_pos.0;
-        // We need to make sure that the cursor's world position is correct relative to the map
-        // due to any map transformation.
         let cursor_in_map_pos: Vec2 = {
-            // Extend the cursor_pos vec3 by 0.0 and 1.0
             let cursor_pos = Vec4::from((cursor_pos, 0.0, 1.0));
             let cursor_in_map_pos = map_transform.compute_matrix().inverse() * cursor_pos;
             cursor_in_map_pos.xy()
         };
 
-        // Once we have a world position we can transform it into a possible tile position.
         let Some(tile_pos) = TilePos::from_world_pos(
             &cursor_in_map_pos,
             map_size,