mirror of
https://github.com/ZoneMinder/zoneminder.git
synced 2025-12-23 22:37:53 -05:00
3c85d63655
Using the Sutherland-Hodgman algorithms convex and concave subject polygons can be clipped by convex clip polygons. For now we only need clipping to rectangles (Box), so limit our implementation to that. If needed this can be trivially extended to convex clip polygons (a check whether the clip polygon is actually convex has to be added). If convex clip polygons are needed we have to switch to e.g the Vatti algorithm.
80 lines
2.1 KiB
C++
80 lines
2.1 KiB
C++
/*
|
|
* This file is part of the ZoneMinder Project. See AUTHORS file for Copyright information
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; either version 2 of the License, or (at your
|
|
* option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
|
* more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "zm_catch2.h"
|
|
|
|
#include "zm_poly.h"
|
|
|
|
TEST_CASE("Polygon: default constructor") {
|
|
Polygon p;
|
|
|
|
REQUIRE(p.Area() == 0);
|
|
REQUIRE(p.Centre() == Vector2(0, 0));
|
|
}
|
|
|
|
TEST_CASE("Polygon: construct from vertices") {
|
|
std::vector<Vector2> vertices{{{0, 0}, {6, 0}, {0, 6}}};
|
|
Polygon p(vertices);
|
|
|
|
REQUIRE(p.Area() == 18);
|
|
//REQUIRE(p.Centre() == Vector2(2, 2));
|
|
// Mathematically should be:
|
|
//REQUIRE(p.Extent().Size() == Vector2(6, 6));
|
|
REQUIRE(p.Extent().Size() == Vector2(7, 7));
|
|
}
|
|
|
|
TEST_CASE("Polygon: clipping") {
|
|
// This a concave polygon in a shape resembling a "W"
|
|
std::vector<Vector2> v = {
|
|
{3, 1},
|
|
{5, 1},
|
|
{6, 3},
|
|
{7, 1},
|
|
{9, 1},
|
|
{10, 8},
|
|
{8, 8},
|
|
{7, 5},
|
|
{5, 5},
|
|
{4, 8},
|
|
{2, 8}
|
|
};
|
|
|
|
Polygon p(v);
|
|
|
|
REQUIRE(p.GetVertices().size() == 11);
|
|
REQUIRE(p.Extent().Size() == Vector2(9, 8));
|
|
// should be:
|
|
// REQUIRE(p.Extent().Size() == Vector2(8, 7));
|
|
// related to Vector2::Range
|
|
|
|
SECTION("boundary box larger than polygon") {
|
|
Polygon c = p.GetClipped(Box({1, 0}, {11, 9}));
|
|
|
|
REQUIRE(c.GetVertices().size() == 11);
|
|
REQUIRE(c.Extent().Size() == Vector2(9, 8));
|
|
}
|
|
|
|
SECTION("boundary box smaller than polygon") {
|
|
Polygon c = p.GetClipped(Box({2, 4}, {10, 7}));
|
|
|
|
REQUIRE(c.GetVertices().size() == 8);
|
|
REQUIRE(c.Extent().Size() == Vector2(9, 4));
|
|
// should be:
|
|
// REQUIRE(c.Extent().Size() == Vector2(8, 3));
|
|
}
|
|
}
|