diff --git a/src/etc-internal.h b/src/etc-internal.h
index da40cb7..2d3e547 100644
--- a/src/etc-internal.h
+++ b/src/etc-internal.h
@@ -93,17 +93,20 @@ struct Vec2i
 	}
 };
 
-struct IntRect
+struct IntRect : SDL_Rect
 {
-	int x, y, w, h;
-
 	IntRect()
-	    : x(0), y(0), w(0), h(0)
-	{}
+	{
+		x = y = w = h = 0;
+	}
 
 	IntRect(int x, int y, int w, int h)
-	    : x(x), y(y), w(w), h(h)
-	{}
+	{
+		this->x = x;
+		this->y = y;
+		this->w = w;
+		this->h = h;
+	}
 
 	bool operator==(const IntRect &other) const
 	{
diff --git a/src/tileatlasvx.cpp b/src/tileatlasvx.cpp
index 45fab3a..7a5f48c 100644
--- a/src/tileatlasvx.cpp
+++ b/src/tileatlasvx.cpp
@@ -270,6 +270,19 @@ createShadowSet()
 	return surf;
 }
 
+static void doBlit(Bitmap *bm, const IntRect &src, const Vec2i &dst)
+{
+	/* Translate tile to pixel units */
+	IntRect _src(src.x*32, src.y*32, src.w*32, src.h*32);
+	Vec2i _dst(dst.x*32, dst.y*32);
+	IntRect bmr(0, 0, bm->width(), bm->height());
+
+	if (!SDL_IntersectRect(&_src, &bmr, &_src))
+		return;
+
+	GLMeta::blitRectangle(_src, _dst);
+}
+
 void build(TEXFBO &tf, Bitmap *bitmaps[BM_COUNT])
 {
 	assert(tf.width == ATLASVX_W && tf.height == ATLASVX_H);
@@ -296,13 +309,9 @@ void build(TEXFBO &tf, Bitmap *bitmaps[BM_COUNT])
 		GLMeta::blitSource(bm->getGLTypes()); \
 		for (size_t i = 0; i < blits##part##N; ++i) \
 		{\
-			IntRect src = blits##part[i].src; \
-			int w = std::min(bm->width(), src.w*32); \
-			int h = std::min(bm->height(), src.h*32); \
-			src = IntRect(src.x*32, src.y*32, w, h); \
-			Vec2i dst = blits##part[i].dst; \
-			dst = Vec2i(dst.x*32, dst.y*32); \
-			GLMeta::blitRectangle(src, dst); \
+			const IntRect &src = blits##part[i].src; \
+			const Vec2i &dst = blits##part[i].dst; \
+			doBlit(bm, src, dst); \
 		} \
 	}