crown-engine/engine/device.h

/*
 * Copyright (c) 2012-2014 Daniele Bartolini and individual contributors.
 * License: https://github.com/taylor001/crown/blob/master/LICENSE
 */

#pragma once

#include "types.h"
#include "config.h"
#include "linear_allocator.h"
#include "world_types.h"

namespace crown
{

class Filesystem;
struct LuaEnvironment;
class ResourceManager;
struct ResourcePackage;
class World;
class WorldManager;
struct Camera;

/// @defgroup Device Device

/// Holds data for a display mode.
///
/// @ingroup Device
struct DisplayMode
{
	uint32_t id;
	uint16_t width;
	uint16_t height;
};

/// This is the place where to look for accessing all of
/// the engine subsystems and related stuff.
///
/// @ingroup Device
struct Device
{
	Device(Filesystem& fs, StringId64 boot_package, StringId64 boot_script);

	void init();

	/// Shutdowns the engine freeing all the allocated resources
	void shutdown();

	/// Returns a string identifying what platform the engine is running on.
	const char* platform() const { return CROWN_PLATFORM_NAME; }

	/// Returns a string identifying what architecture the engine is running on.
	const char* architecture() const { return CROWN_ARCH_NAME; }

	/// Returns a string identifying the engine version.
	const char* version() const { return CROWN_VERSION_MAJOR "." CROWN_VERSION_MINOR "." CROWN_VERSION_MICRO; }

	/// Returns wheter the engine is running (i.e. it is advancing
	/// the simulation).
	bool is_running() const;

	/// Return the number of frames rendered from the first
	/// call to Device::start()
	uint64_t frame_count() const;

	/// Returns the time in seconds needed to render the last frame
	float last_delta_time() const;

	/// Returns the time in seconds since the first call to start().
	double time_since_start() const;

	/// Quits the application.
	void quit();

	/// Pauses the engine
	void pause();

	/// Unpauses the engine
	void unpause();

	void update_resolution(uint16_t width, uint16_t height)
	{
		_width = width;
		_height = height;
	}

	/// Returns the main window resolution.
	void resolution(uint16_t& width, uint16_t& height)
	{
		width = _width;
		height = _height;
	}

	/// Updates all the subsystems
	void update();

	/// Renders the given @a world from the point of view of the given @a camera.
	void render_world(World* world, Camera* camera);

	/// Creates a new world.
	WorldId create_world();

	/// Destroys the given @a world.
	void destroy_world(WorldId world);

	/// Returns the resource package with the given @a package_name name.
	ResourcePackage* create_resource_package(const char* name);
	ResourcePackage* create_resource_package(StringId64 id);

	/// Destroy a previously created resource @a package.
	/// @note
	/// To unload the resources loaded by the package, you have to call
	/// ResourcePackage::unload() first.
	void destroy_resource_package(ResourcePackage* package);

	void reload(const char* type, const char* name);

	ResourceManager* resource_manager();
	LuaEnvironment* lua_environment();
	WorldManager* world_manager() { return _world_manager; }

private:

	// Used to allocate all subsystems
	LinearAllocator _allocator;

	uint16_t _width;
	uint16_t _height;

	bool _is_init		: 1;
	bool _is_running	: 1;
	bool _is_paused		: 1;

	uint64_t _frame_count;
	int64_t _last_time;
	int64_t _current_time;
	float _last_delta_time;
	double _time_since_start;

	Filesystem& _fs;
	StringId64 _boot_package_id;
	StringId64 _boot_script_id;
	ResourcePackage* _boot_package;

	LuaEnvironment* _lua_environment;
	ResourceManager* _resource_manager;
	WorldManager* _world_manager;

private:

	// Disable copying
	Device(const Device&);
	Device& operator=(const Device&);
};

namespace device_globals
{
	void init(Filesystem& fs, StringId64 boot_package, StringId64 boot_script);
	void shutdown();
} // namespace device_globals

Device* device();

} // namespace crown