Add 3D eagle movement

as4/as4.cpp

@@ -53,6 +53,7 @@ struct Entity {
     raylib::Vector3 position = raylib::Vector3::Zero();
     float speed = 0;
     raylib::Degree heading = 0;
+    raylib::Degree pitch = 0;
     raylib::Model *model;
     enum EntityType {
         Penguin = 0,
@@ -89,6 +90,19 @@ raylib::Vector3 from_magnitude_and_heading_xy(
     };
 }
 
+raylib::Vector3 from_magnitude_heading_pitch(
+    float magnitude,
+    raylib::Degree heading,
+    raylib::Degree pitch
+) {
+    float cos_pitch = std::cos(pitch.RadianValue());
+    return raylib::Vector3 {
+        magnitude * cos_pitch * std::sin(heading.RadianValue()),
+        magnitude * std::sin(pitch.RadianValue()),
+        magnitude * cos_pitch * std::cos(heading.RadianValue())
+    };
+}
+
 const float ACCELERATION = 100.0f;
 const raylib::Degree ANGULAR_VELOCITY = raylib::Degree(180.0f);
 
@@ -178,8 +192,18 @@ int main() {
             selected.speed = 0.0f;
         }
 
+        if (selected.type == Entity::EntityType::Eagle) {
+            if (IsKeyDown(KEY_Q)) {
+                selected.pitch += dt * ANGULAR_VELOCITY;
+            }
+            if (IsKeyDown(KEY_Z)) {
+                selected.pitch -= dt * ANGULAR_VELOCITY;
+            }
+        }
+
         for (Entity &e : entities) {
             e.heading = angle_normalize(e.heading);
+            e.pitch = angle_normalize(e.pitch);
         }
 
         camera.BeginMode();
@@ -190,7 +214,7 @@ int main() {
         for (size_t i = 0; i < entities.size(); ++i) {
             Entity &e = entities[i];
             if (e.type == Entity::EntityType::Eagle) {
-                e.position += from_magnitude_and_heading_xy(e.speed, e.heading) * dt;
+                e.position += from_magnitude_heading_pitch(e.speed, e.heading, e.pitch) * dt;
             } else {
                 e.position += from_magnitude_and_heading(e.speed, e.heading) * dt;
             }
@@ -200,7 +224,8 @@ int main() {
             DrawBoundedModel(*e.model, drawBox, [&e](raylib::Matrix transform) {
                 if (e.type == Entity::EntityType::Eagle) {
                     return transform
-                        .RotateZ(raylib::Degree(0) - e.heading)
+                        .RotateX(raylib::Degree(0) - e.pitch)
+                        .RotateY(e.heading)
                         .Scale(40, 40, 40)
                         .Translate(e.position);
                 } else {