From: Holger Schemel <info@artsoft.org>
Date: Sun, 3 Dec 2017 11:35:49 +0000 (+0100)
Subject: added touch controls (follow finger) for MM game engine on Android
X-Git-Tag: 4.1.0.0~37
X-Git-Url: https://git.artsoft.org/?a=commitdiff_plain;h=471051c626d95bc35e2272c6f9c67bc32c8bf830;p=rocksndiamonds.git

added touch controls (follow finger) for MM game engine on Android
---

diff --git a/src/events.c b/src/events.c
index d1c4ff64..c8f7248f 100644
--- a/src/events.c
+++ b/src/events.c
@@ -1051,7 +1051,92 @@ static void HandleButtonOrFinger_WipeGestures_MM(int mx, int my, int button)
 
 static void HandleButtonOrFinger_FollowFinger_MM(int mx, int my, int button)
 {
-  // (not implemented yet)
+  static int old_mx = 0, old_my = 0;
+  static int last_button = MB_LEFTBUTTON;
+  static boolean touched = FALSE;
+  static boolean tapped = FALSE;
+
+  // screen tile was tapped (but finger not touching the screen anymore)
+  // (this point will also be reached without receiving a touch event)
+  if (tapped && !touched)
+  {
+    SetPlayerMouseAction(old_mx, old_my, MB_RELEASED);
+
+    tapped = FALSE;
+  }
+
+  // stop here if this function was not triggered by a touch event
+  if (button == -1)
+    return;
+
+  if (button == MB_PRESSED && IN_GFX_FIELD_PLAY(mx, my))
+  {
+    // finger started touching the screen
+
+    touched = TRUE;
+    tapped = TRUE;
+
+    if (!motion_status)
+    {
+      old_mx = mx;
+      old_my = my;
+
+      ClearPlayerMouseAction();
+
+      Error(ERR_DEBUG, "---------- TOUCH ACTION STARTED ----------");
+    }
+  }
+  else if (button == MB_RELEASED && touched)
+  {
+    // finger stopped touching the screen
+
+    touched = FALSE;
+
+    if (tapped)
+      SetPlayerMouseAction(old_mx, old_my, last_button);
+    else
+      SetPlayerMouseAction(old_mx, old_my, MB_RELEASED);
+
+    Error(ERR_DEBUG, "---------- TOUCH ACTION STOPPED ----------");
+  }
+
+  if (touched)
+  {
+    // finger moved while touching the screen
+
+    int old_x = getLevelFromScreenX(old_mx);
+    int old_y = getLevelFromScreenY(old_my);
+    int new_x = getLevelFromScreenX(mx);
+    int new_y = getLevelFromScreenY(my);
+
+    if (new_x != old_x || new_y != old_y)
+    {
+      // finger moved away from starting position
+
+      int button_nr = getButtonFromTouchPosition(old_x, old_y, mx, my);
+
+      // quickly alternate between clicking and releasing for maximum speed
+      if (FrameCounter % 2 == 0)
+	button_nr = MB_RELEASED;
+
+      SetPlayerMouseAction(old_mx, old_my, button_nr);
+
+      if (button_nr)
+	last_button = button_nr;
+
+      tapped = FALSE;
+
+      Error(ERR_DEBUG, "---------- TOUCH ACTION: ROTATING ----------");
+    }
+    else
+    {
+      // finger stays at or returned to starting position
+
+      SetPlayerMouseAction(old_mx, old_my, MB_RELEASED);
+
+      Error(ERR_DEBUG, "---------- TOUCH ACTION PAUSED ----------");
+    }
+  }
 }
 
 static void HandleButtonOrFinger_FollowFinger(int mx, int my, int button)
diff --git a/src/game_mm/export.h b/src/game_mm/export.h
index 65d2e3a5..5e6f6d40 100644
--- a/src/game_mm/export.h
+++ b/src/game_mm/export.h
@@ -250,4 +250,6 @@ extern void RedrawPlayfield_MM();
 extern void LoadEngineSnapshotValues_MM();
 extern void SaveEngineSnapshotValues_MM(ListNode **);
 
+extern int getButtonFromTouchPosition(int, int, int, int);
+
 #endif	/* GAME_MM_EXPORT_H */
diff --git a/src/game_mm/mm_game.c b/src/game_mm/mm_game.c
index 19439a84..3fcc8f8b 100644
--- a/src/game_mm/mm_game.c
+++ b/src/game_mm/mm_game.c
@@ -9,6 +9,8 @@
 // mm_game.c
 // ============================================================================
 
+#include <math.h>
+
 #include "main_mm.h"
 
 #include "mm_main.h"
@@ -4283,3 +4285,79 @@ void LoadEngineSnapshotValues_MM()
 
   RedrawPlayfield_MM(TRUE);
 }
+
+static int getAngleFromTouchDelta(int dx, int dy)
+{
+  double pi = 3.141592653;
+  double rad = atan2((double)-dy, (double)dx);
+  double rad2 = (rad < 0 ? rad + 2 * pi : rad);
+  double deg = rad2 * 180.0 / pi;
+
+  return (int)(deg * 16.0 / 360.0 + 0.5) % 16;
+}
+
+int getButtonFromTouchPosition(int x, int y, int dst_mx, int dst_my)
+{
+  // calculate start (source) position to be at the middle of the tile
+  int src_mx = SX + x * TILESIZE_VAR + TILESIZE_VAR / 2;
+  int src_my = SY + y * TILESIZE_VAR + TILESIZE_VAR / 2;
+  int dx = dst_mx - src_mx;
+  int dy = dst_my - src_my;
+  int element;
+  int angle_old = -1;
+  int angle_new = -1;
+  int button = 0;
+  int i;
+
+  if (!IN_LEV_FIELD(x, y))
+    return 0;
+
+  element = Feld[x][y];
+
+  if (!IS_MCDUFFIN(element) &&
+      !IS_LASER(element) &&
+      !IS_MIRROR(element) &&
+      !IS_BEAMER(element) &&
+      !IS_POLAR(element) &&
+      !IS_POLAR_CROSS(element) &&
+      !IS_DF_MIRROR(element) &&
+      !IS_DF_MIRROR_AUTO(element))
+    return 0;
+
+  if (IS_MCDUFFIN(element) ||
+      IS_LASER(element))
+  {
+    angle_old = laser.start_angle;
+    angle_new = (dx > 0 && ABS(dy) < ABS(dx) ? ANG_RAY_RIGHT :
+		 dy < 0 && ABS(dx) < ABS(dy) ? ANG_RAY_UP :
+		 dx < 0 && ABS(dy) < ABS(dx) ? ANG_RAY_LEFT :
+		 dy > 0 && ABS(dx) < ABS(dy) ? ANG_RAY_DOWN :
+		 -1);
+  }
+  else
+  {
+    for (i = 0; i < laser.num_damages; i++)
+    {
+      if (laser.damage[i].x == x &&
+	  laser.damage[i].y == y &&
+	  ObjHit(x, y, HIT_POS_CENTER))
+      {
+	angle_old = laser.damage[i].angle;
+
+	break;
+      }
+    }
+
+    if (angle_old == -1)
+      return 0;
+
+    angle_old = get_mirrored_angle(angle_old, get_element_angle(element));
+    angle_new = getAngleFromTouchDelta(dx, dy);
+  }
+
+  button = (angle_new == angle_old ? 0 :
+	    (angle_new - angle_old + 16) % 16 < 8 ? MB_LEFTBUTTON :
+	    MB_RIGHTBUTTON);
+
+  return button;
+}