From 516d6420790e3cf3f168bfcbce88bcf9fbd18e17 Mon Sep 17 00:00:00 2001
From: Max Ammann <max@maxammann.org>
Date: Tue, 13 Dec 2022 17:52:02 +0100
Subject: [PATCH] Define a minimum and maximum pitch (#149)

---
 maplibre-winit/src/input/tilt_handler.rs |  7 +---
 maplibre/src/render/camera.rs            | 51 ++++++++++++++----------
 2 files changed, 32 insertions(+), 26 deletions(-)

diff --git a/maplibre-winit/src/input/tilt_handler.rs b/maplibre-winit/src/input/tilt_handler.rs
index 8d01bc5e..0cf8e222 100644
--- a/maplibre-winit/src/input/tilt_handler.rs
+++ b/maplibre-winit/src/input/tilt_handler.rs
@@ -16,10 +16,7 @@ impl UpdateState for TiltHandler {
     fn update_state(
         &mut self,
         MapContext {
-            world: World {
-                view_state: _view_state,
-                ..
-            },
+            world: World { view_state, .. },
             ..
         }: &mut MapContext,
         dt: Duration,
@@ -27,7 +24,7 @@ impl UpdateState for TiltHandler {
         let dt = dt.as_secs_f64() * (1.0 / self.speed);
 
         let delta = self.delta_pitch * dt;
-        _view_state.camera_mut().pitch_self(delta);
+        view_state.camera_mut().tilt(delta);
         self.delta_pitch -= delta;
     }
 }
diff --git a/maplibre/src/render/camera.rs b/maplibre/src/render/camera.rs
index 1be13249..e180c163 100644
--- a/maplibre/src/render/camera.rs
+++ b/maplibre/src/render/camera.rs
@@ -66,6 +66,9 @@ impl ModelViewProjection {
     }
 }
 
+const MIN_PITCH: Rad<f64> = Rad(-0.5);
+const MAX_PITCH: Rad<f64> = Rad(0.5);
+
 #[derive(Debug, Clone)]
 pub struct Camera {
     position: Point3<f64>, // The z axis never changes, the zoom is used instead
@@ -87,7 +90,7 @@ impl SignificantlyDifferent for Camera {
 }
 
 impl Camera {
-    pub fn new<V: Into<Point3<f64>>, Y: Into<cgmath::Rad<f64>>, P: Into<cgmath::Rad<f64>>>(
+    pub fn new<V: Into<Point3<f64>>, Y: Into<Rad<f64>>, P: Into<Rad<f64>>>(
         position: V,
         yaw: Y,
         pitch: P,
@@ -103,14 +106,6 @@ impl Camera {
         }
     }
 
-    pub fn move_to(&mut self, point: Point3<f64>) {
-        self.position = point;
-    }
-
-    pub fn move_relative(&mut self, delta: Vector3<f64>) {
-        self.position += delta;
-    }
-
     pub fn resize(&mut self, width: u32, height: u32) {
         self.width = width as f64;
         self.height = height as f64;
@@ -364,7 +359,7 @@ impl Camera {
         self.yaw
     }
 
-    pub fn yaw_self<P: Into<Rad<f64>>>(&mut self, delta: P) {
+    pub fn rotate<P: Into<Rad<f64>>>(&mut self, delta: P) {
         self.yaw += delta.into();
     }
 
@@ -372,13 +367,33 @@ impl Camera {
         self.pitch
     }
 
-    pub fn pitch_self<P: Into<Rad<f64>>>(&mut self, delta: P) {
-        self.pitch += delta.into();
+    pub fn tilt<P: Into<Rad<f64>>>(&mut self, delta: P) {
+        let new_pitch = self.pitch + delta.into();
+
+        if new_pitch <= MAX_PITCH && new_pitch >= MIN_PITCH {
+            self.pitch = new_pitch;
+        }
+    }
+
+    pub fn move_relative(&mut self, delta: Vector3<f64>) {
+        self.position += delta;
+    }
+
+    pub fn move_to(&mut self, new_position: Point3<f64>) {
+        self.position = new_position;
+    }
+
+    pub fn position_vector(&self) -> Vector3<f64> {
+        self.position.to_vec()
+    }
+
+    pub fn homogenous_position(&self) -> Vector4<f64> {
+        self.position.to_homogeneous()
     }
 }
 
 pub struct Perspective {
-    fovy: cgmath::Rad<f64>,
+    fovy: Rad<f64>,
     znear: f64,
     zfar: f64,
 
@@ -386,13 +401,7 @@ pub struct Perspective {
 }
 
 impl Perspective {
-    pub fn new<F: Into<cgmath::Rad<f64>>>(
-        width: u32,
-        height: u32,
-        fovy: F,
-        znear: f64,
-        zfar: f64,
-    ) -> Self {
+    pub fn new<F: Into<Rad<f64>>>(width: u32, height: u32, fovy: F, znear: f64, zfar: f64) -> Self {
         let rad = fovy.into();
         Self {
             current_projection: Self::calc_matrix(width as f64 / height as f64, rad, znear, zfar),
@@ -411,7 +420,7 @@ impl Perspective {
         );
     }
 
-    fn calc_matrix(aspect: f64, fovy: cgmath::Rad<f64>, znear: f64, zfar: f64) -> Matrix4<f64> {
+    fn calc_matrix(aspect: f64, fovy: Rad<f64>, znear: f64, zfar: f64) -> Matrix4<f64> {
         OPENGL_TO_WGPU_MATRIX * cgmath::perspective(fovy, aspect, znear, zfar)
     }
 }