fixed getting level position after laser hits something in MM engine

[rocksndiamonds.git] / src / game_mm / mm_game.c

diff --git a/src/game_mm/mm_game.c b/src/game_mm/mm_game.c
index be1bfad64051591d5fc725f781c1064269ef04b6..a5b34f290936e49ac503786a01760362e785a201 100644 (file)
--- a/src/game_mm/mm_game.c
+++ b/src/game_mm/mm_game.c
@@ -893,6 +893,16 @@ static int getMaskFromElement(int element)
     return MM_MASK_CIRCLE;
 }
 
+static int getLevelFromLaserX(int x)
+{
+  return x / TILEX - (x < 0 ? 1 : 0);          // correct negative values
+}
+
+static int getLevelFromLaserY(int y)
+{
+  return y / TILEY - (y < 0 ? 1 : 0);          // correct negative values
+}
+
 static int ScanPixel(void)
 {
   int hit_mask = 0;
@@ -944,8 +954,8 @@ static int ScanPixel(void)
       int py = LY + (i / 2) * 2;
       int dx = px % TILEX;
       int dy = py % TILEY;
-      int lx = (px + TILEX) / TILEX - 1;  // ...+TILEX...-1 to get correct
-      int ly = (py + TILEY) / TILEY - 1;  // negative values!
+      int lx = getLevelFromLaserX(px);
+      int ly = getLevelFromLaserY(py);
       Pixel pixel;
 
       if (IN_LEV_FIELD(lx, ly))
@@ -1062,9 +1072,26 @@ static void ScanLaser(void)
          LX, LY, XS, YS);
 #endif
 
-    // hit something -- check out what it was
-    ELX = (LX + XS + TILEX) / TILEX - 1;  // ...+TILEX...-1 to get correct
-    ELY = (LY + YS + TILEY) / TILEY - 1;  // negative values!
+    // check if laser scan has hit two diagonally adjacent element corners
+    boolean diag_1 = ((hit_mask & HIT_MASK_DIAGONAL_1) == HIT_MASK_DIAGONAL_1);
+    boolean diag_2 = ((hit_mask & HIT_MASK_DIAGONAL_2) == HIT_MASK_DIAGONAL_2);
+
+    // check if laser scan has crossed element boundaries (not just mini tiles)
+    boolean cross_x = (getLevelFromLaserX(LX) != getLevelFromLaserX(LX + 2));
+    boolean cross_y = (getLevelFromLaserY(LY) != getLevelFromLaserY(LY + 2));
+
+    if (cross_x || cross_y)
+    {
+      // hit something at next tile -- check out what it was
+      ELX = getLevelFromLaserX(LX + XS);
+      ELY = getLevelFromLaserY(LY + YS);
+    }
+    else
+    {
+      // hit something at same tile -- check out what it was
+      ELX = getLevelFromLaserX(LX);
+      ELY = getLevelFromLaserY(LY);
+    }
 
 #if 0
     Debug("game:mm:ScanLaser", "hit_mask (1) == '%x' (%d, %d) (%d, %d)",
@@ -1094,14 +1121,6 @@ static void ScanLaser(void)
       break;
     }
 
-    // check if laser scan has hit two diagonally adjacent element corners
-    boolean diag_1 = ((hit_mask & HIT_MASK_DIAGONAL_1) == HIT_MASK_DIAGONAL_1);
-    boolean diag_2 = ((hit_mask & HIT_MASK_DIAGONAL_2) == HIT_MASK_DIAGONAL_2);
-
-    // check if laser scan has crossed element boundaries (not just mini tiles)
-    boolean cross_x = (LX / TILEX != (LX + 2) / TILEX);
-    boolean cross_y = (LY / TILEY != (LY + 2) / TILEY);
-
     // handle special case of laser hitting two diagonally adjacent elements
     // (with or without a third corner element behind these two elements)
     if ((diag_1 || diag_2) && cross_x && cross_y)