From 0f017f6b519c6e9f8a30e281970880790becce98 Mon Sep 17 00:00:00 2001
From: Alejandro Aguilera <fenixin@lavabit.com>
Date: Sun, 7 Apr 2013 01:33:10 +0200
Subject: [PATCH] Lilypads are now properly oriented.

---
 overviewer_core/src/iterate.c | 17 ++++++++++++++++-
 overviewer_core/textures.py   | 16 ++++++++++++----
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/overviewer_core/src/iterate.c b/overviewer_core/src/iterate.c
index 2bc0a23..ee88f69 100644
--- a/overviewer_core/src/iterate.c
+++ b/overviewer_core/src/iterate.c
@@ -402,6 +402,20 @@ generate_pseudo_data(RenderState *state, unsigned char ancilData) {
         } else {
             return check_adjacent_blocks(state, x, y, z, state->block);
         }
+    } else if (state->block == 111) { /* lilypads */
+        int wx,wz,wy,rotation;
+        long pr;
+        /* calculate the global block coordinates of this position */
+        wx = (state->chunkx * 16) + x;
+        wz = (state->chunkz * 16) + z;
+        wy = (state->chunky * 16) + y;
+        /* lilypads orientation is obtained with these magic numbers */
+        /* magic numbers obtained from: */
+        /* http://llbit.se/?p=1537 */
+        pr = (wx * 3129871) ^ (wz * 116129781) ^ (wy);
+        pr = pr * pr * 42317861 + pr * 11;
+        rotation = 3 & (pr >> 16);
+        return rotation;
     }
 
 
@@ -549,7 +563,8 @@ chunk_render(PyObject *self, PyObject *args) {
                         (state.block == 71) || (state.block == 79) ||
                         (state.block == 85) || (state.block == 90) ||
                         (state.block == 101) || (state.block == 102) ||
-                        (state.block == 113) || (state.block == 139)) {
+                        (state.block == 111) || (state.block == 113) ||
+                        (state.block == 139)) {
                         ancilData = generate_pseudo_data(&state, ancilData);
                         state.block_pdata = ancilData;
                     } else {
diff --git a/overviewer_core/textures.py b/overviewer_core/textures.py
index 72db9c4..115a892 100644
--- a/overviewer_core/textures.py
+++ b/overviewer_core/textures.py
@@ -3433,12 +3433,20 @@ block(blockid=110, top_image="textures/blocks/mycel_top.png", side_image="textur
 
 # lilypad
 # At the moment of writing this lilypads has no ancil data and their
-# orientation depends on their position on the map. Because lilypads had
-# ancildata, leave some data values just in case an old map have some
-# with ancil data.
+# orientation depends on their position on the map. So it uses pseudo
+# ancildata.
 @material(blockid=111, data=range(4), transparent=True)
 def lilypad(self, blockid, data):
-    t = self.load_image_texture("textures/blocks/waterlily.png")
+    t = self.load_image_texture("textures/blocks/waterlily.png").copy()
+    if data == 0:
+        t = t.rotate(180)
+    elif data == 1:
+        t = t.rotate(270)
+    elif data == 2:
+        t = t
+    elif data == 3:
+        t = t.rotate(90)
+
     return self.build_full_block(None, None, None, None, None, t)
 
 # nether brick