// ----------------------------------------------------------------

// From Game Programming in C++ by Sanjay Madhav

// Copyright (C) 2017 Sanjay Madhav. All rights reserved.

//

// Released under the BSD License

// See LICENSE in root directory for full details.

// ----------------------------------------------------------------

#include "Game.h"

#include <algorithm>

#include "Renderer.h"

#include "Actor.h"

#include "SpriteComponent.h"

#include "MeshComponent.h"

#include "CameraActor.h"

#include "PlaneActor.h"

Game::Game()

:mRenderer(nullptr)

,mIsRunning(true)

,mUpdatingActors(false)

{

}

bool Game::Initialize()

{

if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_AUDIO) != 0)

{

SDL_Log("Unable to initialize SDL: %s", SDL_GetError());

return false;

}

// Create the renderer

mRenderer = new Renderer(this);

if (!mRenderer->Initialize(1024.0f, 768.0f))

{

SDL_Log("Failed to initialize renderer");

delete mRenderer;

mRenderer = nullptr;

return false;

}

LoadData();

mTicksCount = SDL_GetTicks();

return true;

}

void Game::RunLoop()

{

while (mIsRunning)

{

ProcessInput();

UpdateGame();

GenerateOutput();

}

}

void Game::ProcessInput()

{

SDL_Event event;

while (SDL_PollEvent(&event))

{

switch (event.type)

{

case SDL_QUIT:

mIsRunning = false;

break;

}

}

const Uint8* state = SDL_GetKeyboardState(NULL);

if (state[SDL_SCANCODE_ESCAPE])

{

mIsRunning = false;

}

for (auto actor : mActors)

{

actor->ProcessInput(state);

}

}

void Game::UpdateGame()

{

// Compute delta time

// Wait until 16ms has elapsed since last frame

while (!SDL_TICKS_PASSED(SDL_GetTicks(), mTicksCount + 16))

;

float deltaTime = (SDL_GetTicks() - mTicksCount) / 1000.0f;

if (deltaTime > 0.05f)

{

deltaTime = 0.05f;

}

mTicksCount = SDL_GetTicks();

// Update all actors

mUpdatingActors = true;

for (auto actor : mActors)

{

actor->Update(deltaTime);

}

mUpdatingActors = false;

// Move any pending actors to mActors

for (auto pending : mPendingActors)

{

pending->ComputeWorldTransform();

mActors.emplace_back(pending);

}

mPendingActors.clear();

// Add any dead actors to a temp vector

std::vector<Actor*> deadActors;

for (auto actor : mActors)

{

if (actor->GetState() == Actor::EDead)

{

deadActors.emplace_back(actor);

}

}

// Delete dead actors (which removes them from mActors)

for (auto actor : deadActors)

{

delete actor;

}

}

void Game::GenerateOutput()

{

mRenderer->Draw();

}

void Game::LoadData()

{

// Create actors

Actor* a = new Actor(this);

a->SetPosition(Vector3(200.0f, 75.0f, 0.0f));

a->SetScale(100.0f);

Quaternion q(Vector3::UnitY, -Math::PiOver2);

q = Quaternion::Concatenate(q, Quaternion(Vector3::UnitZ, Math::Pi + Math::Pi / 4.0f));

a->SetRotation(q);

MeshComponent* mc = new MeshComponent(a);

mc->SetMesh(mRenderer->GetMesh("Assets/Cube.gpmesh"));

a = new Actor(this);

a->SetPosition(Vector3(200.0f, -75.0f, 0.0f));

a->SetScale(3.0f);

mc = new MeshComponent(a);

mc->SetMesh(mRenderer->GetMesh("Assets/Sphere.gpmesh"));

// Setup floor

const float start = -1250.0f;

const float size = 250.0f;

for (int i = 0; i < 10; i++)

{

for (int j = 0; j < 10; j++)

{

a = new PlaneActor(this);

a->SetPosition(Vector3(start + i * size, start + j * size, -100.0f));

}

}

// Left/right walls

q = Quaternion(Vector3::UnitX, Math::PiOver2);

for (int i = 0; i < 10; i++)

{

a = new PlaneActor(this);

a->SetPosition(Vector3(start + i * size, start - size, 0.0f));

a->SetRotation(q);

a = new PlaneActor(this);

a->SetPosition(Vector3(start + i * size, -start + size, 0.0f));

a->SetRotation(q);

}

q = Quaternion::Concatenate(q, Quaternion(Vector3::UnitZ, Math::PiOver2));

// Forward/back walls

for (int i = 0; i < 10; i++)

{

a = new PlaneActor(this);

a->SetPosition(Vector3(start - size, start + i * size, 0.0f));

a->SetRotation(q);

a = new PlaneActor(this);

a->SetPosition(Vector3(-start + size, start + i * size, 0.0f));

a->SetRotation(q);

}

// Setup lights

mRenderer->SetAmbientLight(Vector3(0.2f, 0.2f, 0.2f));

DirectionalLight& dir = mRenderer->GetDirectionalLight();

dir.mDirection = Vector3(0.0f, -0.707f, -0.707f);

dir.mDiffuseColor = Vector3(0.78f, 0.88f, 1.0f);

dir.mSpecColor = Vector3(0.8f, 0.8f, 0.8f);

// Camera actor

mCameraActor = new CameraActor(this);

// UI elements

a = new Actor(this);

a->SetPosition(Vector3(-350.0f, -350.0f, 0.0f));

SpriteComponent* sc = new SpriteComponent(a);

sc->SetTexture(mRenderer->GetTexture("Assets/HealthBar.png"));

a = new Actor(this);

a->SetPosition(Vector3(375.0f, -275.0f, 0.0f));

a->SetScale(0.75f);

sc = new SpriteComponent(a);

sc->SetTexture(mRenderer->GetTexture("Assets/Radar.png"));

}

void Game::UnloadData()

{

// Delete actors

// Because ~Actor calls RemoveActor, have to use a different style loop

while (!mActors.empty())

{

delete mActors.back();

}

if (mRenderer)

{

mRenderer->UnloadData();

}

}

void Game::Shutdown()

{

UnloadData();

if (mRenderer)

{

mRenderer->Shutdown();

}

SDL_Quit();

}

void Game::AddActor(Actor* actor)

{

// If we're updating actors, need to add to pending

if (mUpdatingActors)

{

mPendingActors.emplace_back(actor);

}

else

{

mActors.emplace_back(actor);

}

}

void Game::RemoveActor(Actor* actor)

{

// Is it in pending actors?

auto iter = std::find(mPendingActors.begin(), mPendingActors.end(), actor);

if (iter != mPendingActors.end())

{

// Swap to end of vector and pop off (avoid erase copies)

std::iter_swap(iter, mPendingActors.end() - 1);

mPendingActors.pop_back();

}

// Is it in actors?

iter = std::find(mActors.begin(), mActors.end(), actor);

if (iter != mActors.end())

{

// Swap to end of vector and pop off (avoid erase copies)

std::iter_swap(iter, mActors.end() - 1);

mActors.pop_back();

}

}