/*
OneLoneCoder - Camera2D v1.00
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A 2D world camera with various modes
License (OLC-3)
~~~~~~~~~~~~~~~
Copyright 2018 - 2022 OneLoneCoder.com
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions or derivations of source code must retain the above
copyright notice, this list of conditions and the following disclaimer.
2. Redistributions or derivative works in binary form must reproduce
the above copyright notice. This list of conditions and the following
disclaimer must be reproduced in the documentation and/or other
materials provided with the distribution.
3. Neither the name of the copyright holder nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Links
~~~~~
YouTube: https://www.youtube.com/javidx9
Discord: https://discord.gg/WhwHUMV
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Twitch: https://www.twitch.tv/javidx9
GitHub: https://www.github.com/onelonecoder
Homepage: https://www.onelonecoder.com
Author
~~~~~~
David Barr, aka javidx9, �OneLoneCoder 2019, 2020, 2021, 2022
*/
#pragma once
#include "olcPixelGameEngine.h"
namespace olc::utils
{
class Camera2D
{
public:
enum class Mode : uint8_t
{
Simple, // No motion, just directly settable
EdgeMove, // Moves as target crosses boundary
LazyFollow, // Lazily follows the target
FixedScreens, // Moves statically between "screens"
};
public:
inline Camera2D() : m_pTarget(&m_vLocalTarget) {}
// Construct a camera with a viewable area size, and an optional starting position
inline Camera2D(const olc::vf2d& vViewSize, const olc::vf2d& vViewPos = { 0.0f, 0.0f }) : m_pTarget(&m_vLocalTarget)
{
m_vViewSize = vViewSize;
m_vViewPos = vViewPos;
}
// Set the operational mode of this camera
inline void SetMode(const Mode t)
{
m_nMode = t;
}
// Get the operational mode of this camera
inline Mode GetMode() const
{
return m_nMode;
}
// Get the position of the target being tracked by this camera
inline const olc::vf2d& GetTarget() const
{
return *m_pTarget;
}
// Get the position of the cameras focus point
inline const olc::vf2d& GetPosition() const
{
return m_vPosition;
}
// Get the top left of teh cameras visible area in world space
inline const olc::vf2d& GetViewPosition() const
{
return m_vViewPos;
}
// Get the camera's visible area
inline const olc::vf2d& GetViewSize() const
{
return m_vViewSize;
}
// Set tracked point via pointer
inline void SetTarget(olc::vf2d& vTarget)
{
m_pTarget = &vTarget;
}
// Set tracked point via const ref - {10, 35} for example
inline void SetTarget(const olc::vf2d&& vTarget)
{
m_vLocalTarget = vTarget;
m_pTarget = &m_vLocalTarget;
}
// Set world boundary rectangle
inline void SetWorldBoundary(const olc::vf2d& vPos, const olc::vf2d& vSize)
{
m_vWorldBoundaryPos = vPos;
m_vWorldBoundarySize = vSize;
}
// Instruct camera to respect world boundaries
inline void EnableWorldBoundary(const bool bEnable)
{
m_bWorldBoundary = bEnable;
}
// Are we using a world boundary?
inline bool IsWorldBoundaryEnabled() const
{
return m_bWorldBoundary;
}
// Get the world boundary rectangle position
inline const olc::vf2d& GetWorldBoundaryPosition() const
{
return m_vWorldBoundaryPos;
}
// Get the world boundary rectangle size
inline const olc::vf2d& GetWorldBoundarySize() const
{
return m_vWorldBoundarySize;
}
// Set the velocity at which the lazy follower reaches tracked point
inline void SetLazyFollowRate(const float fRate)
{
m_fLazyFollowRate = fRate;
}
// Get the velocity at which the lazy follower reaches tracked point
inline float GetLazyFollowRate() const
{
return m_fLazyFollowRate;
}
// Set distance from tracked point to start nudging screen
inline void SetEdgeTriggerDistance(const olc::vf2d& vEdge)
{
m_vEdgeTriggerDistance = vEdge;
}
// Return disance from tracked point that screen will nudge
inline const olc::vf2d& GetEdgeTriggerDistance() const
{
return m_vEdgeTriggerDistance;
}
// Update camera, animating if necessary, obeying world boundary rules
// returns true if target is visible
inline virtual bool Update(const float fElapsedTime)
{
switch (m_nMode)
{
case Mode::Simple:
{
m_vPosition = GetTarget();
}
break;
case Mode::EdgeMove:
{
olc::vf2d vOverlap = GetTarget() - m_vPosition;
if (vOverlap.x > m_vEdgeTriggerDistance.x) m_vPosition.x += vOverlap.x - m_vEdgeTriggerDistance.x;
if (vOverlap.x < -m_vEdgeTriggerDistance.x) m_vPosition.x += vOverlap.x + m_vEdgeTriggerDistance.x;
if (vOverlap.y > m_vEdgeTriggerDistance.y) m_vPosition.y += vOverlap.y - m_vEdgeTriggerDistance.y;
if (vOverlap.y < -m_vEdgeTriggerDistance.y) m_vPosition.y += vOverlap.y + m_vEdgeTriggerDistance.y;
}
break;
case Mode::LazyFollow:
{
m_vPosition += (GetTarget() - m_vPosition) * m_fLazyFollowRate * fElapsedTime;
}
break;
case Mode::FixedScreens:
{
m_vPosition = olc::vf2d(olc::vi2d(GetTarget() / m_vScreenSize) * olc::vi2d(m_vScreenSize)) + (m_vViewSize * 0.5f);
}
break;
}
// Make camera target the middle of the view
m_vViewPos = m_vPosition - (m_vViewSize * 0.5f);
// Clamp to World Boundary (if in place)
if (m_bWorldBoundary)
{
m_vViewPos = m_vViewPos.max(m_vWorldBoundaryPos).min(m_vWorldBoundaryPos + m_vWorldBoundarySize - m_vViewSize);
}
return GetTarget().x >= m_vViewPos.x && GetTarget().x < (m_vViewPos.x + m_vViewSize.x) &&
GetTarget().y >= m_vViewPos.y && GetTarget().y < (m_vViewPos.y + m_vViewSize.y);
}
protected:
// Position of camera focus point in the world
olc::vf2d m_vPosition;
// Rectangular size of camera viewing area
olc::vf2d m_vViewSize;
// Top left coordinate of camera viewing area
olc::vf2d m_vViewPos;
// Camera movement mode
Mode m_nMode = Mode::Simple;
// Target Vector2D object camera should follow (either ref or ptr)
olc::vf2d* m_pTarget = nullptr;
olc::vf2d m_vLocalTarget;
// World Boundary
bool m_bWorldBoundary = false;
olc::vf2d m_vWorldBoundaryPos = { 0.0f, 0.0f };
olc::vf2d m_vWorldBoundarySize = { 256.0f, 240.0f };
// Mode specific
olc::vf2d m_vEdgeTriggerDistance = { 1.0f, 1.0f };
float m_fLazyFollowRate = 4.0f;
olc::vi2d m_vScreenSize = { 16,15 };
};
}
using namespace olc::utils;