Fix issue with orthographic cameras, add ortho example

examples/orthographic.rs

@@ -0,0 +1,56 @@
+//! Demonstrates usage with an orthographic camera
+
+use bevy::prelude::*;
+use bevy::render::camera::ScalingMode;
+use bevy_panorbit_camera::{PanOrbitCamera, PanOrbitCameraPlugin};
+
+fn main() {
+    App::new()
+        .add_plugins(DefaultPlugins)
+        .add_plugin(PanOrbitCameraPlugin)
+        .add_startup_system(setup)
+        .run();
+}
+
+fn setup(
+    mut commands: Commands,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<StandardMaterial>>,
+) {
+    // Ground
+    commands.spawn(PbrBundle {
+        mesh: meshes.add(shape::Plane::from_size(5.0).into()),
+        material: materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
+        ..default()
+    });
+    // Cube
+    commands.spawn(PbrBundle {
+        mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
+        material: materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
+        transform: Transform::from_xyz(0.0, 0.5, 0.0),
+        ..default()
+    });
+    // Light
+    commands.spawn(PointLightBundle {
+        point_light: PointLight {
+            intensity: 1500.0,
+            shadows_enabled: true,
+            ..default()
+        },
+        transform: Transform::from_xyz(4.0, 8.0, 4.0),
+        ..default()
+    });
+    // Camera
+    commands.spawn((
+        Camera3dBundle {
+            // Put the camera further away so clipping is less likely
+            transform: Transform::from_translation(Vec3::new(0.0, 5.5, 15.0)),
+            projection: Projection::Orthographic(OrthographicProjection {
+                scaling_mode: ScalingMode::FixedVertical(2.0),
+                ..default()
+            }),
+            ..default()
+        },
+        PanOrbitCamera::default(),
+    ));
+}

src/lib.rs

@@ -95,7 +95,7 @@ pub struct PanOrbitCamera {
     /// Defaults to `Vec3::ZERO`.
     pub focus: Vec3,
     /// The radius of the orbit, or the distance from the `focus` point.
-    /// For orthographic projection, this is converted the the scale factor of the projection.
+    /// For orthographic projection, this is ignored, and the projection's `scale` is used instead.
     /// If set to `None`, it will be calculated from the camera's current position during
     /// initialization.
     /// Automatically updated.
@@ -425,14 +425,13 @@ fn pan_orbit_camera(
                 has_moved = true;
             }
         } else if scroll.abs() > 0.0 {
-            pan_orbit.radius = pan_orbit
-                .radius
-                // Prevent zoom to zero otherwise we can get stuck there
-                .map(|radius| f32::max(radius - scroll * radius * 0.2, 0.05));
             if let Projection::Orthographic(ref mut p) = *projection {
-                if let Some(radius) = pan_orbit.radius {
-                    p.scale = radius;
-                }
+                p.scale = f32::max(p.scale - scroll * p.scale * 0.2, 0.05);
+            } else {
+                pan_orbit.radius = pan_orbit
+                    .radius
+                    // Prevent zoom to zero otherwise we can get stuck there
+                    .map(|radius| f32::max(radius - scroll * radius * 0.2, 0.05));
             }
             has_moved = true;
         }