diff --git a/src/engine/blend.hh b/src/engine/blend.hh
new file mode 100644
index 0000000..c360fca
--- /dev/null
+++ b/src/engine/blend.hh
@@ -0,0 +1,45 @@
+#ifndef BLEND_HH
+#define BLEND_HH
+
+#include <shared/gl.hh>
+
+#include <shared/tools.hh>
+#include <shared/geom.hh>
+
+extern int worldsize; /* FIXME: remove */
+
+void optimizeblendmap();
+void resetblendmap();
+void enlargeblendmap();
+void shrinkblendmap(int octant);
+bool usesblendmap(int x1 = 0, int y1 = 0, int x2 = worldsize, int y2 = worldsize);
+void cleanupblendmap();
+
+int calcblendlayer(int x1, int y1, int x2, int y2);
+void bindblendtexture(const ivec &p);
+void updateblendtextures(int x1 = 0, int y1 = 0, int x2 = worldsize, int y2 = worldsize);
+void renderblendtexture(uchar *dst, int dsize, int dx, int dy, int dw, int dh);
+void clearblendtextures();
+
+extern int blendpaintmode;
+
+void stoppaintblendmap();
+void trypaintblendmap();
+
+void renderblendbrush(GLuint tex, float x, float y, float w, float h);
+void renderblendbrush();
+
+bool loadblendmap(stream *f, int info);
+void saveblendmap(stream *f);
+uchar shouldsaveblendmap();
+
+/* currently not used */
+
+struct BlendMapCache;
+BlendMapCache *newblendmapcache();
+void freeblendmapcache(BlendMapCache *&cache);
+bool setblendmaporigin(BlendMapCache *cache, const ivec &o, int size);
+bool hasblendmap(BlendMapCache *cache);
+uchar lookupblendmap(BlendMapCache *cache, const vec &pos);
+
+#endif