MyCurry/test/unit/grid_raytrace.cpp

/*
	Copyright 2016, 2017 Michele "King_DuckZ" Santullo

	This file is part of MyCurry.

	MyCurry 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 3 of the License, or
	(at your option) any later version.

	MyCurry 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 MyCurry.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "catch.hpp"
#include "grid_raytrace.hpp"
#include "worldgrid.hpp"
#include "tileindextype.hpp"
#include "tileproperty.hpp"
#include <vector>

TEST_CASE ("Check that 2D raytracing works", "[raytracing][geometry]") {
	using curry::for_each_voxel_under_segment;
	using curry::vec2us;
	using curry::vec2f;
	using curry::WorldTileProperty;

	curry::WorldGrid world(vec2us(64));
	world.set_layers(vec2us(10, 10), std::vector<std::vector<curry::TileIndex>>( {{
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0
	}}));
	world.set_tile_properties(std::vector<curry::TileProperty>({ curry::TileProperty() }));

	REQUIRE(world.world_size() == vec2us(10));
	REQUIRE(world.layer_count() == 1);

	{
		std::vector<WorldTileProperty> diagonal;
		for_each_voxel_under_segment (
			vec2f(0.0f, 0.0f), //from
			vec2f(640.0f, 640.0f), //to
			vec2us(1, 1), //objsize
			world, //world
			[diagonal](const WorldTileProperty& wtp) mutable {diagonal.push_back(wtp); return true;}
		);

		const auto* tile_prop = &world.tile_property(world.tile(vec2us(0)));
		std::vector<WorldTileProperty> expected {
			WorldTileProperty{vec2us(0, 0), tile_prop},
			WorldTileProperty{vec2us(1, 1), tile_prop},
			WorldTileProperty{vec2us(2, 2), tile_prop},
			WorldTileProperty{vec2us(3, 3), tile_prop},
			WorldTileProperty{vec2us(4, 4), tile_prop},
			WorldTileProperty{vec2us(5, 5), tile_prop},
			WorldTileProperty{vec2us(6, 6), tile_prop},
			WorldTileProperty{vec2us(7, 7), tile_prop},
			WorldTileProperty{vec2us(8, 8), tile_prop},
			WorldTileProperty{vec2us(9, 9), tile_prop}
		};
		CHECK(expected == diagonal);
	}
}

TEST_CASE ("Check that segment intersection code used by the raytracing code works", "[geometry][intersection]") {
	using curry::vec2f;
	using curry::segment_intersection;

	{
		//Two segments crossing at <0, 0>
		const vec2f a0(-1.0f, 0.0f);
		const vec2f a1(2.0f, 0.0f);
		const vec2f b0(0.0f, 1.0f);
		const vec2f b1(0.0f, -2.0f);

		const float t1 = segment_intersection(a0, a1, b0, b1);
		CHECK(0.5f == t1);
		CHECK(vec2f(0.0f) == a0 + t1 * a1);
		const float t2 = segment_intersection(b0, b1, a0, a1);
		CHECK(0.5f == t2);
	}

	{
		//a diagonal segment starting off from a vertical segment
		const vec2f a0(-1.0f, 0.0f);
		const vec2f a1(3.0f, 2.0f);
		const vec2f b0(-1.0f, 1.0f);
		const vec2f b1(0.0f, -2.0f);

		const float t1 = segment_intersection(a0, a1, b0, b1);
		CHECK(0.0f == t1);
		const float t2 = segment_intersection(b0, b1, a0, a1);
		CHECK(0.5f == t2);
	}
}