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Determine if two triangles overlap: Difference between revisions
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* (0,0),(1,0),(0,1) and (1,0),(2,0),(1,1)
=={{header|Ada}}==
<lang ada>
WITH Ada.Text_IO; USE Ada.Text_IO;
PROCEDURE Main IS
TYPE Vertex IS MOD 3;
TYPE Point IS ARRAY (0 .. 1) OF Float;
TYPE Triangle IS ARRAY (Vertex) OF Point;
TYPE Triangle_Vertices IS ARRAY (0 .. 5) OF Float;
FUNCTION Same_Side (A, B, M, N : Point) RETURN Boolean IS
FUNCTION Aff (A, B , U : Point) RETURN Float IS
((B (1) - A (1)) * (U (0) - A (0)) + (A (0) - B (0)) * (U (1) - A (1)));
BEGIN
RETURN Aff (A, B, M) * Aff (A, B, N) >= 0.0;
END Same_Side;
FUNCTION In_Side (T1 , T2 : Triangle) RETURN Boolean IS
(FOR ALL V IN Vertex =>
(FOR Some P OF T2 => Same_Side (T1 (V + 1), T1 (V + 2), T1 (V), P)));
FUNCTION Overlap (T1, T2 : Triangle) RETURN Boolean IS
(In_Side (T1, T2) AND THEN In_Side (T2, T1));
FUNCTION "+" (T : Triangle_Vertices) RETURN Triangle IS
((T (0), T (1)), (T (2), T (3)), (T (4), T (5)));
PROCEDURE Put (T1, T2 : Triangle_Vertices) IS
BEGIN
Put_Line (Overlap (+T1, +T2)'Img);
END Put;
BEGIN
Put ((0.0, 0.0, 5.0, 0.0, 0.0, 5.0), (0.0, 0.0, 5.0, 0.0, 0.0, 6.0));
Put ((0.0, 0.0, 0.0, 5.0, 5.0, 0.0), (0.0, 0.0, 0.0, 5.0, 5.0, 0.0));
Put ((0.0, 0.0, 5.0, 0.0, 0.0, 5.0), (-10.0, 0.0, -5.0, 0.0, -1.0, 6.0));
Put ((0.0, 0.0, 5.0, 0.0, 2.5, 5.0), (0.0, 4.0, 2.5, -1.0, 5.0, 4.0));
Put ((0.0, 0.0, 1.0, 1.0, 0.0, 2.0), (2.0, 1.0, 3.0, 0.0, 3.0, 2.0));
Put ((0.0, 0.0, 1.0, 1.0, 0.0, 2.0), (2.0, 1.0, 3.0, -2.0, 3.0, 4.0));
Put ((0.0, 0.0, 1.0, 0.0, 0.0, 1.0), (1.0, 0.0, 2.0, 0.0, 1.0, 1.0));
END Main;
</lang>
{{out}}
<pre>true
true
false
true
false
false
true
</pre>
=={{header|C}}==
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