From: Ondřej Hošek <ondra.hosek@gmail.com>
Date: Mon, 16 Jan 2006 20:04:28 +0000 (+0000)
Subject: Improved stay-on-platform code to handle non-32x32 badguys. Implemented s-o-p for... 
X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=a40453e7f04c072a8054063f1826ff9d7446fe22;p=supertux.git

Improved stay-on-platform code to handle non-32x32 badguys. Implemented s-o-p for Mr Tree as proof.

SVN-Revision: 3002
---

diff --git a/src/badguy/badguy.cpp b/src/badguy/badguy.cpp
index 7da606bea..bafa67bf4 100644
--- a/src/badguy/badguy.cpp
+++ b/src/badguy/badguy.cpp
@@ -24,6 +24,7 @@
 #include "object/tilemap.hpp"
 #include "tile.hpp"
 #include "statistics.hpp"
+#include "game_session.hpp"
 
 static const float SQUISH_TIME = 2;
 static const float X_OFFSCREEN_DISTANCE = 1600;
@@ -310,10 +311,14 @@ bool
 BadGuy::may_fall_off_platform()
 {
   int tile_x, tile_y;
-  // First, let's say the badguy moves once its width in the
-  // direction it's heading.
-  Vector pos = get_pos();
-  pos.x += (dir == LEFT ? -bbox.get_width() : bbox.get_width());
+  // First, let's say the badguy moves 32 units in the
+  // direction it's heading, so do some voodoo maths magic
+  // to determine its future position.
+  Vector pos;
+  if (dir == LEFT)
+    pos = Vector(bbox.p1.x - 32.f, bbox.p2.y);
+  else
+    pos = Vector(bbox.p2.x, bbox.p2.y);
 
   // Now, snap the badguy's X coordinate to the 32x32/cell grid.
   if (dir == LEFT) // use the ceiling
@@ -325,8 +330,14 @@ BadGuy::may_fall_off_platform()
   // get the lower position. (Positive Y goes downward.)
   tile_y = (int)ceilf(pos.y/32.0f);
 
+#if defined(DEBUG_STAY_ON_PLATFORM)
+  // Draw!
+  GameSession::current()->context->draw_filled_rect(Vector(tile_x*32.0f, tile_y*32.0f), Vector(32.f, 32.f), Color(1.f, 0.f, 0.f), 999);
+#endif
+
   // Now, if the badguy intersects with a tile, he won't fall off.
   // If he doesn't intersect, he probably will.
+  // Note that the tile's Y coordinate is offset by +1 from the object's Y.
   if (Sector::current()->solids->get_tile(tile_x, tile_y)->getAttributes() & FLAG_SOLID)
   {
     // It's a solid tile. Good.
diff --git a/src/badguy/mrtree.cpp b/src/badguy/mrtree.cpp
index 3f73bd44e..b06e5bd28 100644
--- a/src/badguy/mrtree.cpp
+++ b/src/badguy/mrtree.cpp
@@ -30,6 +30,8 @@ MrTree::MrTree(const lisp::Lisp& reader)
 {
   reader.get("x", start_position.x);
   reader.get("y", start_position.y);
+  stay_on_platform = false;
+  reader.get("stay-on-platform", stay_on_platform);
   bbox.set_size(84.8, 95.8);
   sprite = sprite_manager->create("images/creatures/mr_tree/mr_tree.sprite");
 }
@@ -57,6 +59,19 @@ MrTree::activate()
   }
 }
 
+void
+MrTree::active_update(float elapsed_time)
+{
+  if (stay_on_platform && may_fall_off_platform())
+  {
+    dir = (dir == LEFT ? RIGHT : LEFT);
+    sprite->set_action(dir == LEFT ? "left" : "right");
+    physic.set_velocity_x(-physic.get_velocity_x());
+  }
+
+  BadGuy::active_update(elapsed_time);
+}
+
 bool
 MrTree::collision_squished(Player& player)
 {
diff --git a/src/badguy/mrtree.hpp b/src/badguy/mrtree.hpp
index 058e26141..93463f74f 100644
--- a/src/badguy/mrtree.hpp
+++ b/src/badguy/mrtree.hpp
@@ -29,6 +29,7 @@ public:
   MrTree(const lisp::Lisp& reader);
 
   void activate();
+  void active_update(float elapsed_time);
   void write(lisp::Writer& writer);
   HitResponse collision_solid(GameObject& other, const CollisionHit& hit);
   HitResponse collision_badguy(BadGuy& badguy, const CollisionHit& hit);
@@ -38,7 +39,8 @@ protected:
     STATE_BIG, STATE_NORMAL
   };
   MyState mystate;
-  
+  bool stay_on_platform;
+
   bool collision_squished(Player& player);
 };