dump_atlas

diff --git a/src/tileatlasvx.cpp b/src/tileatlasvx.cpp
index d8ac718..e0bae38 100644
--- a/src/tileatlasvx.cpp
+++ b/src/tileatlasvx.cpp
@@ -31,6 +31,7 @@
 #include "glstate.h"
 #include "texpool.h"
 #include "util.h"
+#include <SDL_image.h>

 #include <assert.h>
 #include <vector>
@@ -314,6 +315,14 @@ void build(TEXFBO &tf, Bitmap *bitmaps[BM_COUNT])
 #undef EXEC_BLITS

    GLMeta::blitEnd();
+
+   int bpp; Uint32 rs, gs, bs, as;
+   SDL_PixelFormatEnumToMasks(SDL_PIXELFORMAT_ABGR8888, &bpp, &rs, &gs, &bs, &as);
+   SDL_Surface *surf = SDL_CreateRGBSurface(0, tf.width, tf.height, bpp, rs, gs, bs, as);
+   FBO::bind(tf.fbo);
+   gl.ReadPixels(0, 0, tf.width, tf.height, GL_RGBA, GL_UNSIGNED_BYTE, surf->pixels);
+   IMG_SavePNG(surf, "__atlas.png");
+   SDL_FreeSurface(surf);
 }

 #define OVER_PLAYER_FLAG (1 << 4)