From 6dd74a8049976f1eec3faa328b9549f088cccce9 Mon Sep 17 00:00:00 2001
From: Matthias Braun <matze@braunis.de>
Date: Sun, 12 Feb 2006 13:02:11 +0000
Subject: [PATCH] applied patch from christoph sommer (thanks alot)

SVN-Revision: 3057
---
 src/object/player.cpp | 24 ++++++++++++++++++++++++
 src/object/player.hpp |  1 +
 2 files changed, 25 insertions(+)

diff --git a/src/object/player.cpp b/src/object/player.cpp
index 6ac97dd2c..1e354bdd8 100644
--- a/src/object/player.cpp
+++ b/src/object/player.cpp
@@ -141,6 +141,8 @@ Player::init()
   on_ground_flag = false;
   grabbed_object = 0;
 
+  floor_normal = Vector(0,-1);
+
   physic.reset();
 }
 
@@ -329,6 +331,16 @@ Player::handle_horizontal_input()
     bbox.set_width(31.8);
   }
 
+  // on downward slopes, adjust vertical velocity to match slope angle
+  if (on_ground()) {
+    if (floor_normal.y != 0) {
+      if ((floor_normal.x * vx) > 0) {
+        // we overdo it a little, just to be on the safe side
+        vy = vx * (floor_normal.x / floor_normal.y) * 2;
+      }
+    }
+  }
+
   physic.set_velocity(vx, vy);
   physic.set_acceleration(ax, ay);
 }
@@ -720,6 +732,18 @@ Player::collision(GameObject& other, const CollisionHit& hit)
       if(physic.get_velocity_y() < 0)
         physic.set_velocity_y(0);
       on_ground_flag = true;
+
+      // remember normal of this tile
+      if (hit.normal.y > -0.9) {
+        floor_normal.x = hit.normal.x;
+        floor_normal.y = hit.normal.y;
+      } else {
+        // slowly adjust to unisolid tiles. 
+        // Necessary because our bounding box sometimes reaches through slopes and thus hits unisolid tiles
+        floor_normal.x = (floor_normal.x * 0.9) + (hit.normal.x * 0.1);
+        floor_normal.y = (floor_normal.y * 0.9) + (hit.normal.y * 0.1);
+      }
+
     } else if(hit.normal.y > 0) { // bumped against the roof
       physic.set_velocity_y(.1);
     }
diff --git a/src/object/player.hpp b/src/object/player.hpp
index fa4b80fd4..880337275 100644
--- a/src/object/player.hpp
+++ b/src/object/player.hpp
@@ -178,6 +178,7 @@ private:
   Sprite* smalltux_gameover;
   Sprite* smalltux_star;
   Sprite* bigtux_star;
+  Vector floor_normal;
 };
 
 #endif /*SUPERTUX_PLAYER_H*/
-- 
2.11.0