fix inconsistent triangle inside check

src/function.jl

@@ -340,18 +340,19 @@ function _sample(f::FeFunction)
 	A = SArray{Tuple{ndims_space(mesh), nvertices_cell(mesh)}}(
 	    view(mesh.vertices, :, view(mesh.cells, :, cell)))
 
-        # TODO: cleanup when minimum/maximum on StaticArrays becomes
+        # TODO: cleanup when minimum/maximum with dims on StaticArrays becomes
         # type-stable
-	I0 = round.(Int, SVector(minimum(A[1, :]), minimum(A[2, :])) .- m0)
-	I1 = round.(Int, SVector(maximum(A[1, :]), maximum(A[2, :])) .- m0)
+	I0 = round.(Int, SVector(minimum(A[1, :]), minimum(A[2, :])) .- m0) .+ 1
+	I1 = round.(Int, SVector(maximum(A[1, :]), maximum(A[2, :])) .- m0) .+ 1
 
 	for I in CartesianIndex(I0[1], I0[2]):CartesianIndex(I1[1], I1[2])
-            x = SVector(Tuple(I) .+ m0)
+            x = SVector(Tuple(I) .- m0)
             # TODO: move to global-to-local function or inside-triangle test
             xloc = (A[:, SUnitRange(2, 3)] .- A[:, 1])::SArray \
                 (x .- A[:, 1])
-	    if all(xloc .>= 0) && sum(xloc) <= 1
-                out[fcolon..., I + CartesianIndex(1, 1)] .= evaluate(f, xloc)
+            ε = eps()
+            if all(xloc .>= -ε) && sum(xloc) <= 1 + ε
+                out[fcolon..., I] .= evaluate(f, xloc)
             end
 	end
     end