cpp-game-engine/engine/test/scene_test.cxx

//
//  scene_test.cxx
//  engine-test
//
//  Created by Sam Jaffe on 7/12/19.
//  Copyright © 2019 Sam Jaffe. All rights reserved.
//

#include <gmock/gmock.h>

#include "game/engine/entity.hpp"
#include "game/engine/game_dispatch.hpp"
#include "game/engine/scene.hpp"

#include "mock_renderer.h"

struct test_scene : engine::scene {
  using engine::scene::scene;

  void update(float) override { check_collisions(); }
  void render(graphics::renderer &) override {}
  void handle_key_event(engine::event::key_event) override {}
  void handle_mouse_event(engine::event::mouse_event) override {}

  void add_with(engine::collision_t t, engine::collidable & c) {
    colliders[t].push_back(&c);
  }
  void add_as(engine::collision_t t, engine::collidable & c) {
    collidables[t].push_back(&c);
  }
};

struct mock_collidable : engine::collidable {
  mock_collidable(math::dim2::rectangle bounds)
      : engine::collidable({bounds, bounds, cast<graphics::material>(1), {}}) {}
  MOCK_METHOD1(collide, void(engine::collidable const &));
};

class SceneTest : public testing::Test {
protected:
  void SetUp() override;
  void TearDown() override;

  test_scene & scene() const { return *scene_; }
  engine::game_dispatch & game() const { return *dispatch_; }

  std::shared_ptr<stub_renderer> renderer_;
  std::shared_ptr<engine::game_dispatch> dispatch_;
  std::shared_ptr<test_scene> scene_;
};

void SceneTest::SetUp() {
  renderer_.reset(new stub_renderer);
  dispatch_.reset(new engine::game_dispatch(renderer_));
  scene_.reset(new test_scene("test", dispatch_));
}

void SceneTest::TearDown() {
  scene_.reset();
  dispatch_.reset();
  renderer_.reset();
}

using testing::Ref;

TEST_F(SceneTest, WillCollideOverlappingObjects) {
  math::dim2::rectangle bnds{{{0.f, 0.f}}, {{1.f, 1.f}}};
  mock_collidable one{bnds}, two{bnds};
  scene().add_with(1, one);
  scene().add_as(1, two);
  EXPECT_CALL(one, collide(Ref(two))).Times(1);
  scene().update(0.f);
}

TEST_F(SceneTest, NonOverlappingDontCollide) {
  mock_collidable one{{{{0.f, 0.f}}, {{1.f, 1.f}}}};
  mock_collidable two{{{{2.f, 2.f}}, {{1.f, 1.f}}}};
  scene().add_with(1, one);
  scene().add_as(1, two);
  EXPECT_CALL(one, collide(Ref(two))).Times(0);
  scene().update(0.f);
}

TEST_F(SceneTest, CollisionIsOneWay) {
  math::dim2::rectangle bnds{{{0.f, 0.f}}, {{1.f, 1.f}}};
  mock_collidable one{bnds}, two{bnds};
  scene().add_with(1, one);
  scene().add_as(1, two);
  EXPECT_CALL(one, collide(Ref(two))).Times(1);
  EXPECT_CALL(two, collide(Ref(one))).Times(0);
  scene().update(0.f);
}

TEST_F(SceneTest, ObjectCannotCollideSelf) {
  math::dim2::rectangle bnds{{{0.f, 0.f}}, {{1.f, 1.f}}};
  mock_collidable one{bnds};
  scene().add_with(1, one);
  scene().add_as(1, one);
  EXPECT_CALL(one, collide(Ref(one))).Times(0);
  scene().update(0.f);
}

TEST_F(SceneTest, CollisionMatchesAsWithKeys) {
  math::dim2::rectangle bnds{{{0.f, 0.f}}, {{1.f, 1.f}}};
  mock_collidable one{bnds}, two{bnds}, three{bnds};
  scene().add_with(2, one);
  scene().add_as(1, two);
  scene().add_as(2, three);
  EXPECT_CALL(one, collide(Ref(two))).Times(0);
  EXPECT_CALL(one, collide(Ref(three))).Times(1);
  scene().update(0.f);
}

TEST_F(SceneTest, ObjectCanBeInMultipleCollidesWithGroups) {
  math::dim2::rectangle bnds{{{0.f, 0.f}}, {{1.f, 1.f}}};
  mock_collidable one{bnds}, two{bnds}, three{bnds};
  scene().add_with(1, one);
  scene().add_with(2, one);
  scene().add_as(1, two);
  scene().add_as(2, three);
  EXPECT_CALL(one, collide(Ref(two))).Times(1);
  EXPECT_CALL(one, collide(Ref(three))).Times(1);
  scene().update(0.f);
}

TEST_F(SceneTest, ObjectCanBeInMultipleCollidableAsGroups) {
  math::dim2::rectangle bnds{{{0.f, 0.f}}, {{1.f, 1.f}}};
  mock_collidable one{bnds}, two{bnds}, three{bnds};
  scene().add_with(1, one);
  scene().add_with(2, three);
  scene().add_as(1, two);
  scene().add_as(2, two);
  EXPECT_CALL(one, collide(Ref(two))).Times(1);
  EXPECT_CALL(three, collide(Ref(two))).Times(1);
  scene().update(0.f);
}

TEST_F(SceneTest, DoubleCollisionCanOccur) {
  math::dim2::rectangle bnds{{{0.f, 0.f}}, {{1.f, 1.f}}};
  mock_collidable one{bnds}, two{bnds};
  scene().add_with(1, one);
  scene().add_with(2, one);
  scene().add_as(1, two);
  scene().add_as(2, two);
  EXPECT_CALL(one, collide(Ref(two))).Times(1);
  scene().update(0.f);
}