From 54769dff40025a2e798d2544df6d745196968f94 Mon Sep 17 00:00:00 2001
From: Matthias Braun <matze@braunis.de>
Date: Thu, 29 Apr 2004 13:44:58 +0000
Subject: [PATCH] -optimized and cleaned up collision_object_map -fixed
 collision detection moving tux far away from his last position -fixed fuck
 code not resetting old_base.

All in all ducking and sliding in small areas should work like expected now.

SVN-Revision: 841
---
 src/collision.cpp | 67 +++++++++++++++++++++++++++----------------------------
 src/level.cpp     | 11 ++++++++-
 src/level.h       |  6 ++++-
 src/player.cpp    |  9 ++------
 4 files changed, 50 insertions(+), 43 deletions(-)

diff --git a/src/collision.cpp b/src/collision.cpp
index a9fccd4c5..fc7a902a2 100644
--- a/src/collision.cpp
+++ b/src/collision.cpp
@@ -42,48 +42,41 @@ bool rectcollision_offset(const base_type& one, const base_type& two, float off_
           one.y <= two.y + two.height + off_y - 1);
 }
 
-bool collision_object_map(const base_type& pbase)
+bool collision_object_map(const base_type& base)
 {
-  int v = (int)pbase.height / 16;
-  int h = (int)pbase.width / 16;
-
-  if(issolid(pbase.x + 1, pbase.y + 1) ||
-     issolid(pbase.x + pbase.width -1, pbase.y + 1) ||
-     issolid(pbase.x +1, pbase.y + pbase.height -1) ||
-     issolid(pbase.x + pbase.width -1, pbase.y + pbase.height - 1))
-    return true;
-
-  for(int i = 1; i < h; ++i)
-    {
-      if(issolid(pbase.x + i*16,pbase.y + 1))
-        return true;
-    }
-
-  for(int i = 1; i < h; ++i)
-    {
-      if(  issolid(pbase.x + i*16,pbase.y + pbase.height - 1))
-        return true;
-    }
-
-  for(int i = 1; i < v; ++i)
-    {
-      if(  issolid(pbase.x + 1, pbase.y + i*16))
-        return true;
-    }
-  for(int i = 1; i < v; ++i)
-    {
-      if(  issolid(pbase.x + pbase.width - 1, pbase.y + i*16))
+  const Level& level = *World::current()->get_level();
+  TileManager& tilemanager = *TileManager::instance();
+
+  // we make the collision rectangle 1 pixel smaller
+  int starttilex = int(base.x+1) / 32;
+  int starttiley = int(base.y+1) / 32;
+  int max_x = int(base.x + base.width);
+  int max_y = int(base.y + base.height);
+
+  for(int x = starttilex; x*32 < max_x; ++x) {
+    for(int y = starttiley; y*32 < max_y; ++y) {
+      Tile* tile = tilemanager.get(level.get_tile_at(x, y));
+      if(tile->solid)
         return true;
     }
+  }
 
   return false;
 }
 
 void* collision_func(const base_type& base, tiletestfunction function)
 {
-  for(float x = base.x; x < base.x + base.width; x += 32) {
-    for(float y = base.y; y < base.y + base.height; y += 32) {
-      Tile* tile = gettile(x, y);
+  const Level& level = *World::current()->get_level();
+  TileManager& tilemanager = *TileManager::instance();
+  
+  int starttilex = int(base.x) / 32;
+  int starttiley = int(base.y) / 32;
+  int max_x = int(base.x + base.width);
+  int max_y = int(base.y + base.height);
+
+  for(int x = starttilex; x*32 < max_x; ++x) {
+    for(int y = starttiley; y*32 < max_y; ++y) {
+      Tile* tile = tilemanager.get(level.get_tile_at(x, y));
       void* result = function(tile);
       if(result != 0)
         return result;
@@ -168,6 +161,8 @@ void collision_swept_object_map(base_type* old, base_type* current)
 
   steps = (int)(lpath / (float)16);
 
+  float orig_x = old->x;
+  float orig_y = old->y;
   old->x += xd;
   old->y += yd;
 
@@ -234,10 +229,14 @@ void collision_swept_object_map(base_type* old, base_type* current)
         }
     }
 
+  if((xd > 0 && current->x < orig_x) || (xd < 0 && current->x > orig_x))
+    current->x = orig_x;
+  if((yd > 0 && current->y < orig_y) || (yd < 0 && current->y > orig_y))
+    current->y = orig_y;
+
   *old = *current;
 }
 
-
 Tile* gettile(float x, float y)
 {
   return TileManager::instance()->get(World::current()->get_level()->gettileid(x, y));
diff --git a/src/level.cpp b/src/level.cpp
index 34a914a3e..cbda1f591 100644
--- a/src/level.cpp
+++ b/src/level.cpp
@@ -733,7 +733,7 @@ Level::get_level_music_fast()
 }
 
 unsigned int 
-Level::gettileid(float x, float y)
+Level::gettileid(float x, float y) const
 {
   int xx, yy;
   unsigned int c;
@@ -749,4 +749,13 @@ Level::gettileid(float x, float y)
   return c;
 }
 
+unsigned int
+Level::get_tile_at(int x, int y) const
+{
+  if(x < 0 || x > width || y < 0 || y > 14)
+    return 0;
+  
+  return ia_tiles[y][x];
+}
+
 /* EOF */
diff --git a/src/level.h b/src/level.h
index 2da2c362a..1aa106a4a 100644
--- a/src/level.h
+++ b/src/level.h
@@ -131,7 +131,11 @@ class Level
   void change_size (int new_width);
 
   /** Return the id of the tile at position x/y */
-  unsigned int gettileid(float x, float y);
+  unsigned int gettileid(float x, float y) const;
+  /** returns the id of the tile at position x,y
+   * (these are logical and not pixel coordinates)
+   */
+  unsigned int get_tile_at(int x, int y) const;
 
   void load_image(Surface** ptexture, std::string theme, const char * file, int use_alpha);
 };
diff --git a/src/player.cpp b/src/player.cpp
index afc0c6517..afc4eb5e0 100644
--- a/src/player.cpp
+++ b/src/player.cpp
@@ -456,6 +456,8 @@ Player::handle_input()
       duck = false;
       base.y -= 32;
       base.height = 64;
+      // changing base size confuses collision otherwise
+      old_base = previous_base = base;                        
     }
 }
 
@@ -468,13 +470,6 @@ Player::grow()
   size = BIG;
   base.height = 64;
   base.y -= 32;
-  // eventually go in duck mode if there's no space
-  if(collision_object_map(base))
-    {
-      base.height = 32;
-      base.y += 32;
-      duck = true;
-    }
 
   old_base = previous_base = base;
 }
-- 
2.11.0