Improve a bit calculations in viewport.

3 files changed, 34 insertions, 8 deletions

diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index db03887fb..cb91f09c4 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -526,6 +526,8 @@ void Gui::videoResized() const
         top->adjustAfterResize(oldWidth, oldHeight);
     }
 
+    if (viewport)
+        viewport->videoResized();
     Widget::distributeWindowResizeEvent();
 }
 
diff --git a/src/gui/viewport.cpp b/src/gui/viewport.cpp
index 341477c0f..8855c651f 100644
--- a/src/gui/viewport.cpp
+++ b/src/gui/viewport.cpp
@@ -77,6 +77,8 @@ Viewport::Viewport() :
     mMousePressY(0),
     mPixelViewX(0),
     mPixelViewY(0),
+    mMidTileX(0),
+    mMidTileY(0),
     mLocalWalkTime(-1),
     mCameraRelativeX(0),
     mCameraRelativeY(0),
@@ -100,6 +102,7 @@ Viewport::Viewport() :
     config.addListener("longmouseclick", this);
 
     setFocusable(true);
+    updateMidVars();
 }
 
 Viewport::~Viewport()
@@ -134,14 +137,10 @@ void Viewport::draw(Graphics *const graphics)
         lastTick = tick_time;
 
     // Calculate viewpoint
-    const int midTileX = (graphics->mWidth + mScrollCenterOffsetX) / 2;
-    const int midTileY = (graphics->mHeight + mScrollCenterOffsetY) / 2;
 
     const Vector &playerPos = localPlayer->getPosition();
-    const int player_x = CAST_S32(playerPos.x)
-                         - midTileX + mCameraRelativeX;
-    const int player_y = CAST_S32(playerPos.y)
-                         - midTileY + mCameraRelativeY;
+    const int player_x = CAST_S32(playerPos.x) - mMidTileX;
+    const int player_y = CAST_S32(playerPos.y) - mMidTileY;
 
     if (mScrollLaziness < 1)
         mScrollLaziness = 1;  // Avoids division by zero
@@ -950,6 +949,7 @@ void Viewport::toggleCameraMode()
     {
         mCameraRelativeX = 0;
         mCameraRelativeY = 0;
+        updateMidVars();
     }
     UpdateStatusListener::distributeEvent();
 }
@@ -974,6 +974,7 @@ void Viewport::moveCamera(const int dx, const int dy)
 {
     mCameraRelativeX += dx;
     mCameraRelativeY += dy;
+    updateMidVars();
 }
 
 void Viewport::moveCameraToActor(const BeingId actorId,
@@ -990,6 +991,7 @@ void Viewport::moveCameraToActor(const BeingId actorId,
     settings.cameraMode = 1;
     mCameraRelativeX = CAST_S32(actorPos.x - playerPos.x) + x;
     mCameraRelativeY = CAST_S32(actorPos.y - playerPos.y) + y;
+    updateMidVars();
 }
 
 void Viewport::moveCameraToPosition(const int x, const int y)
@@ -1002,6 +1004,7 @@ void Viewport::moveCameraToPosition(const int x, const int y)
 
     mCameraRelativeX = x - CAST_S32(playerPos.x);
     mCameraRelativeY = y - CAST_S32(playerPos.y);
+    updateMidVars();
 }
 
 void Viewport::moveCameraRelative(const int x, const int y)
@@ -1009,6 +1012,7 @@ void Viewport::moveCameraRelative(const int x, const int y)
     settings.cameraMode = 1;
     mCameraRelativeX += x;
     mCameraRelativeY += y;
+    updateMidVars();
 }
 
 void Viewport::returnCamera()
@@ -1016,6 +1020,7 @@ void Viewport::returnCamera()
     settings.cameraMode = 0;
     mCameraRelativeX = 0;
     mCameraRelativeY = 0;
+    updateMidVars();
 }
 
 void Viewport::validateSpeed()
@@ -1027,3 +1032,16 @@ void Viewport::validateSpeed()
             Game::instance()->setValidSpeed();
     }
 }
+
+void Viewport::updateMidVars()
+{
+    mMidTileX = (mainGraphics->mWidth + mScrollCenterOffsetX) / 2
+        - mCameraRelativeX;
+    mMidTileY = (mainGraphics->mHeight + mScrollCenterOffsetY) / 2
+        - mCameraRelativeY;
+}
+
+void Viewport::videoResized()
+{
+    updateMidVars();
+}
diff --git a/src/gui/viewport.h b/src/gui/viewport.h
index a03137761..fa02f244b 100644
--- a/src/gui/viewport.h
+++ b/src/gui/viewport.h
@@ -154,10 +154,10 @@ class Viewport final : public WindowContainer,
         { return mCameraRelativeY; }
 
         void setCameraRelativeX(const int n)
-        { mCameraRelativeX = n; }
+        { mCameraRelativeX = n; updateMidVars(); }
 
         void setCameraRelativeY(const int n)
-        { mCameraRelativeY = n; }
+        { mCameraRelativeY = n; updateMidVars(); }
 
         void moveCameraToActor(const BeingId actorId,
                                const int x = 0,
@@ -171,6 +171,8 @@ class Viewport final : public WindowContainer,
 
         void getMouseTile(int &destX, int &destY) const;
 
+        void videoResized();
+
         int mMouseX;                /**< Current mouse position in pixels. */
         int mMouseY;                /**< Current mouse position in pixels. */
 
@@ -180,6 +182,8 @@ class Viewport final : public WindowContainer,
         /// Clears any matching hovers
         void clearHover(const ActorSprite *const actor);
 
+        void updateMidVars();
+
         static void validateSpeed();
 
     private:
@@ -227,6 +231,8 @@ class Viewport final : public WindowContainer,
         int mMousePressY;
         int mPixelViewX;            /**< Current viewpoint in pixels. */
         int mPixelViewY;            /**< Current viewpoint in pixels. */
+        int mMidTileX;
+        int mMidTileY;
 
         int mLocalWalkTime; /**< Timestamp before the next walk can be sent. */