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

//
//  game_dispatch_test.cxx
//  engine-test
//
//  Created by Sam Jaffe on 7/10/19.
//  Copyright © 2019 Sam Jaffe. All rights reserved.
//

#include <memory>

#include <gmock/gmock.h>

#include "game/engine/events.hpp"
#include "game/engine/game_dispatch.hpp"
#include "game/engine/scene.hpp"
#include "game/graphics/renderer.hpp"
#include "game/util/env.hpp"

#include "mock_renderer.h"

struct mock_scene : engine::scene {
  mock_scene(std::shared_ptr<engine::game_dispatch> game)
      : engine::scene("mock", make_vector(0.f, 0.f), game) {}
  mock_scene(std::shared_ptr<engine::game_dispatch> game,
             math::vec2 dim)
  : engine::scene("mock2", dim, game) {}
  MOCK_METHOD1(update, void(float));
  MOCK_METHOD0(render, void());
  MOCK_METHOD1(handle_key_event, void(engine::event::key_event));
  MOCK_METHOD1(handle_mouse_event, void(engine::event::mouse_event));
};

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

  mock_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<mock_scene> scene_;
};

void GameDispatchTest::SetUp() {
  env::resize_screen({{100, 100}});
  renderer_.reset(new stub_renderer);
  dispatch_.reset(new engine::game_dispatch(renderer_));
  dispatch_->set_target_fps(env::fps::v60);
  scene_.reset(new mock_scene(dispatch_));
  game().register_scene(scene_);
  game().activate_scene("mock");
}

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

using testing::AnyNumber;
using testing::Eq;
using testing::Field;
using testing::FloatNear;
using testing::Ge;
using testing::Lt;
using testing::_;

TEST_F(GameDispatchTest, ManagerIsFetchedFromRenderer) {
  EXPECT_THAT(&game().graphics_manager(), Eq(renderer_->manager().get()));
}

// TODO: Set FPS to a much smaller value for testing purposes (e.g. 512fps)
TEST_F(GameDispatchTest, UpdateDispatchesToCurrentScene) {
  EXPECT_CALL(scene(), update(_)).Times(1);
  game().update();
}

TEST_F(GameDispatchTest, UpdateIsCappedInFrequencyByFPSParam) {
  auto fps60 = 1.0 / 60.0;
  EXPECT_CALL(scene(), update(Ge(fps60))).Times(AnyNumber());
  EXPECT_CALL(scene(), update(Lt(fps60))).Times(0);
  for (int i = 0; i < 10; i++) {
    game().update();
  }
}

TEST_F(GameDispatchTest, FPSCanBeChanged) {
  game().set_target_fps(env::fps::v120);
  auto fps120 = 1.0 / 120.0;
  EXPECT_CALL(scene(), update(Ge(fps120))).Times(AnyNumber());
  EXPECT_CALL(scene(), update(Lt(fps120))).Times(0);
  for (int i = 0; i < 10; i++) {
    game().update();
  }
}

TEST_F(GameDispatchTest, UpdateHasNoUpperBoundOnTime) {
  EXPECT_CALL(scene(), update(Ge(0.03))).Times(1);
  usleep(300000);
  game().update();
}

TEST_F(GameDispatchTest, SetCurrentTimestampOverridesWaiting) {
  auto fps60 = 1.0 / 60.0;
  EXPECT_CALL(scene(), update(Ge(0.03))).Times(0);
  EXPECT_CALL(scene(), update(FloatNear(fps60, 1E-2))).Times(1);
  usleep(300000);
  game().set_current_timestamp();
  game().update();
}

TEST_F(GameDispatchTest, RenderDispatchesToCurrentScene) {
  EXPECT_CALL(scene(), render()).Times(1);
  game().render();
}

using MouseEventTest = GameDispatchTest;

TEST_F(MouseEventTest, DispatchesToCurrentScene) {
  EXPECT_CALL(scene(), handle_mouse_event(_)).Times(1);
  game().process_mouse_event({{0.f, 0.f}}, true);
}

TEST_F(MouseEventTest, TranslatesFrameOfRef) {
  // Resize the scene (not a supported operation)
  scene_.reset(new mock_scene(dispatch_, make_vector(10.f, 10.f)));
  game().register_scene(scene_);
  game().activate_scene("mock2");
  auto mouse_pos = &engine::event::mouse_event::current_mouse_position;
  auto const where = make_vector(5.f, 5.f);
  EXPECT_CALL(scene(), handle_mouse_event(Field(mouse_pos, where))).Times(1);
  game().process_mouse_event({{50.f, 50.f}}, true);
}

using KeyEventTest = GameDispatchTest;

TEST_F(KeyEventTest, DoesNotDispatchUnmappedKeys) {
  EXPECT_CALL(scene(), handle_key_event(_)).Times(0);
  game().process_key_event('A', true);
}

TEST_F(KeyEventTest, RemapsKeyWhenForwarding) {
  // TODO: Properly set this instead of using this garbage
  const_cast<engine::key_binding &>(scene().keys()).emplace('A', 'B');
  auto key_value = &engine::event::key_event::key;
  EXPECT_CALL(scene(), handle_key_event(Field(key_value, 'A'))).Times(0);
  EXPECT_CALL(scene(), handle_key_event(Field(key_value, 'B'))).Times(1);
  game().process_key_event('A', true);
}