Adds touch pan

guillaumeblanc · Sep 23, 2023 · ace4710 · ace4710
1 parent e43c1aa
commit ace4710
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Showing 2 changed files with 8 additions and 5 deletions.
diff --git a/src/impl/orbit_camera.cpp b/src/impl/orbit_camera.cpp
@@ -129,13 +129,15 @@ bool OrbitCamera::Event(const sapp_event& _event) {
         const auto v0 = HMM_Vec2{touch0.pos_x, touch0.pos_y};
         const auto v1 = HMM_Vec2{touch1.pos_x, touch1.pos_y};
 
-        const auto& prev_v0 = last_touches_[touch0.identifier];
-        const auto& prev_v1 = last_touches_[touch1.identifier];
+        const auto& pv0 = last_touches_[touch0.identifier];
+        const auto& pv1 = last_touches_[touch1.identifier];
 
-        const float length0 = HMM_LenV2(v1 - v0);
-        const float length1 = HMM_LenV2(prev_v1 - prev_v0);
+        Zoom((HMM_LenV2(pv1 - pv0) - HMM_LenV2(v1 - v0)) * kZoomTouchFactor);
 
-        Zoom((length1 - length0) * kZoomTouchFactor);
+        const auto m = (v1 + v0) / 2;
+        const auto pm = (pv1 + pv0) / 2;
+        const auto dm = (m - pm) * kPanTouchFactor;
+        Pan(dm.X, dm.Y);
       }
 
       // Updates all touch coords

diff --git a/src/impl/orbit_camera.h b/src/impl/orbit_camera.h
@@ -34,6 +34,7 @@ class OrbitCamera : public Camera {
   const float kOrbitFactor = .01f;
   const float kOrbitTouchFactor = .3f;
   const float kPanFactor = .002f;
+  const float kPanTouchFactor = .002f;
   const float kMoveFactor = .002f;
   const float kZoomFactor = .5f;
   const float kZoomTouchFactor = .02f;