From a066bec3bb28d00439f61912d002925dfb3d6171 Mon Sep 17 00:00:00 2001
From: Sam Hocevar <sam@hocevar.net>
Date: Wed, 30 Jun 2010 22:54:13 +0000
Subject: [PATCH] Sort layers before rendering.

---
 src/test-map.cpp |  2 +-
 src/tiler.cpp    | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/test-map.cpp b/src/test-map.cpp
index 305d9790..7220e45c 100644
--- a/src/test-map.cpp
+++ b/src/test-map.cpp
@@ -54,7 +54,7 @@ void DrawScene()
     /* Test stuff */
     int playerx, playery;
     SDL_GetMouseState(&playerx, &playery);
-    tiler->AddTile(50, playerx, playery, nlayers);
+    tiler->AddTile(50, playerx, playery, 1);
 
     tiler->Render();
     video->Refresh(33.33333f);
diff --git a/src/tiler.cpp b/src/tiler.cpp
index a1f40822..f30cc3b0 100644
--- a/src/tiler.cpp
+++ b/src/tiler.cpp
@@ -27,6 +27,14 @@ class TilerData
     friend class Tiler;
 
 private:
+    static int Compare(void const *p1, void const *p2)
+    {
+        int const *n1 = (int const *)p1;
+        int const *n2 = (int const *)p2;
+
+        return n1[2] + 32 * n1[3] - (n2[2] + 32 * n2[3]);
+    }
+
     int *tiles;
     int ntiles;
 
@@ -90,6 +98,9 @@ void Tiler::AddTile(int n, int x, int y, int z)
 
 void Tiler::Render()
 {
+    /* Sort tiles */
+    qsort(data->tiles, data->ntiles, 4 * sizeof(int), TilerData::Compare);
+
     /* Texture coord buffer */
     float uvs[8 * data->ntiles];
     for (int n = 0; n < data->ntiles; n++)