From 4389670939112f52cbfcd0b16066bcb9c704e3e1 Mon Sep 17 00:00:00 2001
From: hdpoliveira <hdpoliveira@gmail.com>
Date: Sun, 26 Apr 2020 18:30:00 -0300
Subject: [PATCH] Improve names in UpdateDodgemsCollision

---
 src/openrct2/ride/Ride.cpp    |  2 +-
 src/openrct2/ride/Vehicle.cpp | 40 ++++++++++++++++++++---------------
 src/openrct2/ride/Vehicle.h   |  2 +-
 3 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/src/openrct2/ride/Ride.cpp b/src/openrct2/ride/Ride.cpp
index f69bb28d30..5d32811d6f 100644
--- a/src/openrct2/ride/Ride.cpp
+++ b/src/openrct2/ride/Ride.cpp
@@ -4402,7 +4402,7 @@ static Vehicle* vehicle_create_car(
             vehicle->sprite_direction = scenario_rand() & 0x1E;
             chosenLoc.y = y + (scenario_rand() & 0xFF);
             chosenLoc.x = x + (scenario_rand() & 0xFF);
-        } while (vehicle->UpdateDodgemsCollision(chosenLoc.x, chosenLoc.y, nullptr));
+        } while (vehicle->DodgemsCarWouldCollideAt(chosenLoc, nullptr));
 
         sprite_move(chosenLoc.x, chosenLoc.y, z, vehicle);
     }
diff --git a/src/openrct2/ride/Vehicle.cpp b/src/openrct2/ride/Vehicle.cpp
index ae07ea0a5b..a14173d973 100644
--- a/src/openrct2/ride/Vehicle.cpp
+++ b/src/openrct2/ride/Vehicle.cpp
@@ -6286,7 +6286,7 @@ int32_t Vehicle::UpdateMotionDodgems()
         location.x += Unk9A36C4[oldCollisionDirection + 1].x;
         location.y += Unk9A36C4[oldCollisionDirection + 1].y;
 
-        if (!UpdateDodgemsCollision(location.x, location.y, &collideSprite))
+        if (!DodgemsCarWouldCollideAt(location, &collideSprite))
         {
             Invalidate();
             sprite_move(location.x, location.y, location.z, this);
@@ -6315,7 +6315,7 @@ int32_t Vehicle::UpdateMotionDodgems()
             location.x += Unk9A36C4[direction].x;
             location.y += Unk9A36C4[direction].y;
 
-            if (UpdateDodgemsCollision(location.x, location.y, &collideSprite))
+            if (DodgemsCarWouldCollideAt(location, &collideSprite))
                 break;
 
             remaining_distance -= Unk9A36C4[direction].distance;
@@ -6396,24 +6396,30 @@ int32_t Vehicle::UpdateMotionDodgems()
  *
  *  rct2: 0x006DD365
  */
-bool Vehicle::UpdateDodgemsCollision(int16_t curX, int16_t curY, uint16_t* spriteId)
+static bool wouldCollideWithDodgemsTrackEdge(
+    CoordsXY coords, CoordsXY trackLocation, uint32_t trackType, uint16_t dodgemsCarRadius)
+{
+    int16_t rideLeft = trackLocation.x + DodgemsTrackSize[trackType].left;
+    int16_t rideRight = trackLocation.x + DodgemsTrackSize[trackType].right;
+    int16_t rideTop = trackLocation.y + DodgemsTrackSize[trackType].top;
+    int16_t rideBottom = trackLocation.y + DodgemsTrackSize[trackType].bottom;
+
+    return coords.x - dodgemsCarRadius < rideLeft || coords.y - dodgemsCarRadius < rideTop
+        || coords.x + dodgemsCarRadius > rideRight || coords.y + dodgemsCarRadius > rideBottom;
+}
+
+bool Vehicle::DodgemsCarWouldCollideAt(CoordsXY coords, uint16_t* collidedWith) const
 {
-    uint16_t bp = (var_44 * 30) >> 9;
     uint32_t trackType = track_type >> 2;
 
-    int16_t rideLeft = TrackLocation.x + DodgemsTrackSize[trackType].left;
-    int16_t rideRight = TrackLocation.x + DodgemsTrackSize[trackType].right;
-    int16_t rideTop = TrackLocation.y + DodgemsTrackSize[trackType].top;
-    int16_t rideBottom = TrackLocation.y + DodgemsTrackSize[trackType].bottom;
-
-    if (curX - bp < rideLeft || curY - bp < rideTop || curX + bp > rideRight || curY + bp > rideBottom)
+    if (wouldCollideWithDodgemsTrackEdge(coords, TrackLocation, trackType, (var_44 * 30) >> 9))
     {
-        if (spriteId != nullptr)
-            *spriteId = SPRITE_INDEX_NULL;
+        if (collidedWith != nullptr)
+            *collidedWith = SPRITE_INDEX_NULL;
         return true;
     }
 
-    auto location = CoordsXY{ curX, curY };
+    auto location = coords;
 
     ride_id_t rideIndex = ride;
     for (auto xy_offset : SurroundingTiles)
@@ -6435,11 +6441,11 @@ bool Vehicle::UpdateDodgemsCollision(int16_t curX, int16_t curY, uint16_t* sprit
             if (vehicle2->ride != rideIndex)
                 continue;
 
-            int32_t distX = abs(curX - vehicle2->x);
+            int32_t distX = abs(coords.x - vehicle2->x);
             if (distX > 32768)
                 continue;
 
-            int32_t distY = abs(curY - vehicle2->y);
+            int32_t distY = abs(coords.y - vehicle2->y);
             if (distY > 32768)
                 continue;
 
@@ -6448,8 +6454,8 @@ bool Vehicle::UpdateDodgemsCollision(int16_t curX, int16_t curY, uint16_t* sprit
             ecx >>= 8;
             if (std::max(distX, distY) < ecx)
             {
-                if (spriteId != nullptr)
-                    *spriteId = vehicle2->sprite_index;
+                if (collidedWith != nullptr)
+                    *collidedWith = vehicle2->sprite_index;
                 return true;
             }
         }
diff --git a/src/openrct2/ride/Vehicle.h b/src/openrct2/ride/Vehicle.h
index 3eed9f4733..ff48adaf5d 100644
--- a/src/openrct2/ride/Vehicle.h
+++ b/src/openrct2/ride/Vehicle.h
@@ -305,7 +305,7 @@ struct Vehicle : SpriteBase
     void SetState(VEHICLE_STATUS vehicleStatus, uint8_t subState = 0);
     bool IsGhost() const;
     void UpdateSoundParams(std::vector<rct_vehicle_sound_params>& vehicleSoundParamsList) const;
-    bool UpdateDodgemsCollision(int16_t x, int16_t y, uint16_t* spriteId);
+    bool DodgemsCarWouldCollideAt(CoordsXY coords, uint16_t* spriteId) const;
     int32_t UpdateTrackMotion(int32_t* outStation);
     rct_ride_entry_vehicle* Entry() const;
     Vehicle* TrainHead() const;