[core] Updated Size::isEmpty and TransformState::valid checks

4 files changed, 16 insertions, 7 deletions

diff --git a/src/mbgl/map/transform.cpp b/src/mbgl/map/transform.cpp
index c30b8d9687..5104aa0562 100644
--- a/src/mbgl/map/transform.cpp
+++ b/src/mbgl/map/transform.cpp
@@ -45,9 +45,13 @@ Transform::Transform(MapObserver& observer_,
 
 #pragma mark - Map View
 
-bool Transform::resize(const Size size) {
+void Transform::resize(const Size size) {
+    if (size.isEmpty()) {
+        throw std::runtime_error("failed to resize: size is empty");
+    }
+
     if (state.size == size) {
-        return false;
+        return;
     }
 
     observer.onCameraWillChange(MapObserver::CameraChangeMode::Immediate);
@@ -56,8 +60,6 @@ bool Transform::resize(const Size size) {
     state.constrain(state.scale, state.x, state.y);
 
     observer.onCameraDidChange(MapObserver::CameraChangeMode::Immediate);
-
-    return true;
 }
 
 #pragma mark - Camera
diff --git a/src/mbgl/map/transform.hpp b/src/mbgl/map/transform.hpp
index f11ac81287..15b97cb198 100644
--- a/src/mbgl/map/transform.hpp
+++ b/src/mbgl/map/transform.hpp
@@ -25,7 +25,7 @@ public:
     Transform(const TransformState &state_) : observer(MapObserver::nullObserver()), state(state_) {}
 
     // Map view
-    bool resize(Size size);
+    void resize(Size size);
 
     // Camera
     /** Returns the current camera options. */
diff --git a/src/mbgl/map/transform_state.cpp b/src/mbgl/map/transform_state.cpp
index 3fae7b205c..2e97cc9bc8 100644
--- a/src/mbgl/map/transform_state.cpp
+++ b/src/mbgl/map/transform_state.cpp
@@ -27,6 +27,9 @@ void TransformState::matrixFor(mat4& matrix, const UnwrappedTileID& tileID) cons
 }
 
 void TransformState::getProjMatrix(mat4& projMatrix) const {
+    if (size.isEmpty()) {
+        return;
+    }
 
      // Find the distance from the center point [width/2, height/2] to the
     // center top point [width/2, 0] in Z units, using the law of sines.
@@ -216,7 +219,7 @@ double TransformState::scaleZoom(double s) const {
 }
 
 ScreenCoordinate TransformState::latLngToScreenCoordinate(const LatLng& latLng) const {
-    if (!size) {
+    if (size.isEmpty()) {
         return {};
     }
 
@@ -229,7 +232,7 @@ ScreenCoordinate TransformState::latLngToScreenCoordinate(const LatLng& latLng)
 }
 
 LatLng TransformState::screenCoordinateToLatLng(const ScreenCoordinate& point, LatLng::WrapMode wrapMode) const {
-    if (!size) {
+    if (size.isEmpty()) {
         return {};
     }
 
diff --git a/src/mbgl/map/transform_state.hpp b/src/mbgl/map/transform_state.hpp
index a35aa5a255..d281c31995 100644
--- a/src/mbgl/map/transform_state.hpp
+++ b/src/mbgl/map/transform_state.hpp
@@ -74,6 +74,10 @@ public:
     double zoomScale(double zoom) const;
     double scaleZoom(double scale) const;
 
+    bool valid() const {
+        return !size.isEmpty() && (scale >= min_scale && scale <= max_scale);
+    }
+
 private:
     bool rotatedNorth() const;
     void constrain(double& scale, double& x, double& y) const;