/****************************************************************************
 Copyright (c) 2014 Chukong Technologies Inc.
 
 http://www.cocos2d-x.org
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.

 Code based GamePlay3D's Camera: http://gameplay3d.org

 ****************************************************************************/
#include "2d/CCCamera.h"
#include "base/CCDirector.h"
#include "platform/CCGLView.h"
#include "2d/CCScene.h"
#include "renderer/CCRenderer.h"
#include "renderer/CCQuadCommand.h"
#include "renderer/CCGLProgramCache.h"
#include "renderer/ccGLStateCache.h"
#include "renderer/CCFrameBuffer.h"
#include "renderer/CCRenderState.h"

NS_CC_BEGIN

Camera* Camera::_visitingCamera = nullptr;
experimental::Viewport Camera::_defaultViewport;

Camera* Camera::getDefaultCamera()
{
    auto scene = Director::getInstance()->getRunningScene();
    if(scene)
    {
        return scene->getDefaultCamera();
    }

    return nullptr;
}

Camera* Camera::create()
{
    Camera* camera = new (std::nothrow) Camera();
    camera->initDefault();
    camera->autorelease();
    camera->setDepth(0.f);
    
    return camera;
}

Camera* Camera::createPerspective(float fieldOfView, float aspectRatio, float nearPlane, float farPlane)
{
    auto ret = new (std::nothrow) Camera();
    if (ret)
    {
        ret->initPerspective(fieldOfView, aspectRatio, nearPlane, farPlane);
        ret->autorelease();
        return ret;
    }
    CC_SAFE_DELETE(ret);
    return nullptr;
}

Camera* Camera::createOrthographic(float zoomX, float zoomY, float nearPlane, float farPlane)
{
    auto ret = new (std::nothrow) Camera();
    if (ret)
    {
        ret->initOrthographic(zoomX, zoomY, nearPlane, farPlane);
        ret->autorelease();
        return ret;
    }
    CC_SAFE_DELETE(ret);
    return nullptr;
}

Camera::Camera()
: _scene(nullptr)
, _viewProjectionDirty(true)
, _cameraFlag(1)
, _frustumDirty(true)
, _depth(-1)
, _fbo(nullptr)
{
    _frustum.setClipZ(true);
}

Camera::~Camera()
{
    CC_SAFE_RELEASE_NULL(_fbo);
}

const Mat4& Camera::getProjectionMatrix() const
{
    return _projection;
}
const Mat4& Camera::getViewMatrix() const
{
    Mat4 viewInv(getNodeToWorldTransform());
    static int count = sizeof(float) * 16;
    if (memcmp(viewInv.m, _viewInv.m, count) != 0)
    {
        _viewProjectionDirty = true;
        _frustumDirty = true;
        _viewInv = viewInv;
        _view = viewInv.getInversed();
    }
    return _view;
}
void Camera::lookAt(const Vec3& lookAtPos, const Vec3& up)
{
    Vec3 upv = up;
    upv.normalize();
    Vec3 zaxis;
    Vec3::subtract(this->getPosition3D(), lookAtPos, &zaxis);
    zaxis.normalize();
    
    Vec3 xaxis;
    Vec3::cross(upv, zaxis, &xaxis);
    xaxis.normalize();
    
    Vec3 yaxis;
    Vec3::cross(zaxis, xaxis, &yaxis);
    yaxis.normalize();
    Mat4  rotation;
    rotation.m[0] = xaxis.x;
    rotation.m[1] = xaxis.y;
    rotation.m[2] = xaxis.z;
    rotation.m[3] = 0;
    
    rotation.m[4] = yaxis.x;
    rotation.m[5] = yaxis.y;
    rotation.m[6] = yaxis.z;
    rotation.m[7] = 0;
    rotation.m[8] = zaxis.x;
    rotation.m[9] = zaxis.y;
    rotation.m[10] = zaxis.z;
    rotation.m[11] = 0;
    
    Quaternion  quaternion;
    Quaternion::createFromRotationMatrix(rotation,&quaternion);
    quaternion.normalize();
    setRotationQuat(quaternion);
}

const Mat4& Camera::getViewProjectionMatrix() const
{
    getViewMatrix();
    if (_viewProjectionDirty)
    {
        _viewProjectionDirty = false;
        Mat4::multiply(_projection, _view, &_viewProjection);
    }
    
    return _viewProjection;
}

void Camera::setAdditionalProjection(const Mat4& mat)
{
    _projection = mat * _projection;
    getViewProjectionMatrix();
}

bool Camera::initDefault()
{
    auto size = Director::getInstance()->getWinSize();
    //create default camera
    auto projection = Director::getInstance()->getProjection();
    switch (projection)
    {
        case Director::Projection::_2D:
        {
            initOrthographic(size.width, size.height, -1024, 1024);
            setPosition3D(Vec3(0.0f, 0.0f, 0.0f));
            setRotation3D(Vec3(0.f, 0.f, 0.f));
            break;
        }
        case Director::Projection::_3D:
        {
            float zeye = Director::getInstance()->getZEye();
            initPerspective(60, (GLfloat)size.width / size.height, 10, zeye + size.height / 2.0f);
            Vec3 eye(size.width/2, size.height/2.0f, zeye), center(size.width/2, size.height/2, 0.0f), up(0.0f, 1.0f, 0.0f);
            setPosition3D(eye);
            lookAt(center, up);
            break;
        }
        default:
            CCLOG("unrecognized projection");
            break;
    }
    return true;
}

bool Camera::initPerspective(float fieldOfView, float aspectRatio, float nearPlane, float farPlane)
{
    _fieldOfView = fieldOfView;
    _aspectRatio = aspectRatio;
    _nearPlane = nearPlane;
    _farPlane = farPlane;
    Mat4::createPerspective(_fieldOfView, _aspectRatio, _nearPlane, _farPlane, &_projection);
    _viewProjectionDirty = true;
    _frustumDirty = true;
    
    return true;
}

bool Camera::initOrthographic(float zoomX, float zoomY, float nearPlane, float farPlane)
{
    _zoom[0] = zoomX;
    _zoom[1] = zoomY;
    _nearPlane = nearPlane;
    _farPlane = farPlane;
    Mat4::createOrthographicOffCenter(0, _zoom[0], 0, _zoom[1], _nearPlane, _farPlane, &_projection);
    _viewProjectionDirty = true;
    _frustumDirty = true;
    
    return true;
}

Vec2 Camera::project(const Vec3& src) const
{
    Vec2 screenPos;
    
    auto viewport = Director::getInstance()->getWinSize();
    Vec4 clipPos;
    getViewProjectionMatrix().transformVector(Vec4(src.x, src.y, src.z, 1.0f), &clipPos);
    
    CCASSERT(clipPos.w != 0.0f, "");
    float ndcX = clipPos.x / clipPos.w;
    float ndcY = clipPos.y / clipPos.w;
    
    screenPos.x = (ndcX + 1.0f) * 0.5f * viewport.width;
    screenPos.y = (1.0f - (ndcY + 1.0f) * 0.5f) * viewport.height;
    return screenPos;
}

Vec2 Camera::projectGL(const Vec3& src) const
{
    Vec2 screenPos;
    
    auto viewport = Director::getInstance()->getWinSize();
    Vec4 clipPos;
    getViewProjectionMatrix().transformVector(Vec4(src.x, src.y, src.z, 1.0f), &clipPos);
    
    CCASSERT(clipPos.w != 0.0f, "");
    float ndcX = clipPos.x / clipPos.w;
    float ndcY = clipPos.y / clipPos.w;
    
    screenPos.x = (ndcX + 1.0f) * 0.5f * viewport.width;
    screenPos.y = (ndcY + 1.0f) * 0.5f * viewport.height;
    return screenPos;
}

Vec3 Camera::unproject(const Vec3& src) const
{
    Vec3 dst;
    unproject(Director::getInstance()->getWinSize(), &src, &dst);
    return dst;
}

Vec3 Camera::unprojectGL(const Vec3& src) const
{
    Vec3 dst;
    unprojectGL(Director::getInstance()->getWinSize(), &src, &dst);
    return dst;
}

void Camera::unproject(const Size& viewport, const Vec3* src, Vec3* dst) const
{
    CCASSERT(src && dst, "vec3 can not be null");
    
    Vec4 screen(src->x / viewport.width, ((viewport.height - src->y)) / viewport.height, src->z, 1.0f);
    screen.x = screen.x * 2.0f - 1.0f;
    screen.y = screen.y * 2.0f - 1.0f;
    screen.z = screen.z * 2.0f - 1.0f;
    
    getViewProjectionMatrix().getInversed().transformVector(screen, &screen);
    if (screen.w != 0.0f)
    {
        screen.x /= screen.w;
        screen.y /= screen.w;
        screen.z /= screen.w;
    }
    
    dst->set(screen.x, screen.y, screen.z);
}

void Camera::unprojectGL(const Size& viewport, const Vec3* src, Vec3* dst) const
{
    CCASSERT(src && dst, "vec3 can not be null");
    
    Vec4 screen(src->x / viewport.width, src->y / viewport.height, src->z, 1.0f);
    screen.x = screen.x * 2.0f - 1.0f;
    screen.y = screen.y * 2.0f - 1.0f;
    screen.z = screen.z * 2.0f - 1.0f;
    
    getViewProjectionMatrix().getInversed().transformVector(screen, &screen);
    if (screen.w != 0.0f)
    {
        screen.x /= screen.w;
        screen.y /= screen.w;
        screen.z /= screen.w;
    }
    
    dst->set(screen.x, screen.y, screen.z);
}

bool Camera::isVisibleInFrustum(const AABB* aabb) const
{
    if (_frustumDirty)
    {
        _frustum.initFrustum(this);
        _frustumDirty = false;
    }
    return !_frustum.isOutOfFrustum(*aabb);
}

float Camera::getDepthInView(const Mat4& transform) const
{
    Mat4 camWorldMat = getNodeToWorldTransform();
    const Mat4 &viewMat = camWorldMat.getInversed();
    float depth = -(viewMat.m[2] * transform.m[12] + viewMat.m[6] * transform.m[13] + viewMat.m[10] * transform.m[14] + viewMat.m[14]);
    return depth;
}

void Camera::setDepth(int8_t depth)
{
    if (_depth != depth)
    {
        _depth = depth;
        if (_scene)
        {
            //notify scene that the camera order is dirty
            _scene->setCameraOrderDirty();
        }
    }
}

void Camera::onEnter()
{
    if (_scene == nullptr)
    {
        auto scene = getScene();
        if (scene)
        {
            setScene(scene);
        }
    }
    Node::onEnter();
}

void Camera::onExit()
{
    // remove this camera from scene
    setScene(nullptr);
    Node::onExit();
}

void Camera::setScene(Scene* scene)
{
    if (_scene != scene)
    {
        //remove old scene
        if (_scene)
        {
            auto& cameras = _scene->_cameras;
            auto it = std::find(cameras.begin(), cameras.end(), this);
            if (it != cameras.end())
                cameras.erase(it);
            _scene = nullptr;
        }
        //set new scene
        if (scene)
        {
            _scene = scene;
            auto& cameras = _scene->_cameras;
            auto it = std::find(cameras.begin(), cameras.end(), this);
            if (it == cameras.end())
            {
                _scene->_cameras.push_back(this);
                //notify scene that the camera order is dirty
                _scene->setCameraOrderDirty();
            }
        }
    }
}

void Camera::clearBackground(float depth)
{
    GLboolean oldDepthTest;
    GLint oldDepthFunc;
    GLboolean oldDepthMask;
    {
        glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
        glStencilMask(0);

        oldDepthTest = glIsEnabled(GL_DEPTH_TEST);
        glGetIntegerv(GL_DEPTH_FUNC, &oldDepthFunc);
        glGetBooleanv(GL_DEPTH_WRITEMASK, &oldDepthMask);

        glDepthMask(GL_TRUE);
        glEnable(GL_DEPTH_TEST);
        glDepthFunc(GL_ALWAYS);
    }

    //draw
    static V3F_C4B_T2F_Quad quad;
    quad.bl.vertices = Vec3(-1,-1,0);
    quad.br.vertices = Vec3(1,-1,0);
    quad.tl.vertices = Vec3(-1,1,0);
    quad.tr.vertices = Vec3(1,1,0);
    
    quad.bl.colors = quad.br.colors = quad.tl.colors = quad.tr.colors = Color4B(0,0,0,1);
    
    quad.bl.texCoords = Tex2F(0,0);
    quad.br.texCoords = Tex2F(1,0);
    quad.tl.texCoords = Tex2F(0,1);
    quad.tr.texCoords = Tex2F(1,1);
    
    auto shader = GLProgramCache::getInstance()->getGLProgram(GLProgram::SHADER_CAMERA_CLEAR);
    auto programState = GLProgramState::getOrCreateWithGLProgram(shader);
    programState->setUniformFloat("depth", 1.0);
    programState->apply(Mat4());
    GLshort indices[6] = {0, 1, 2, 3, 2, 1};
    
    {
        GL::bindVAO(0);
        glBindBuffer(GL_ARRAY_BUFFER, 0);
        
        GL::enableVertexAttribs(GL::VERTEX_ATTRIB_FLAG_POS_COLOR_TEX);
        
        // vertices
        glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 3, GL_FLOAT, GL_FALSE, sizeof(V3F_C4B_T2F), &quad.tl.vertices);
        
        // colors
        glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_COLOR, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(V3F_C4B_T2F), &quad.tl.colors);
        
        // tex coords
        glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_TEX_COORD, 2, GL_FLOAT, GL_FALSE, sizeof(V3F_C4B_T2F), &quad.tl.texCoords);
        
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
        glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);
    }

    
    {
        if(GL_FALSE == oldDepthTest)
        {
            glDisable(GL_DEPTH_TEST);
        }
        glDepthFunc(oldDepthFunc);

        if(GL_FALSE == oldDepthMask)
        {
            glDepthMask(GL_FALSE);
        }

        /* IMPORTANT: We only need to update the states that are not restored.
         Since we don't know what was the previous value of the mask, we update the RenderState
         after setting it.
         The other values don't need to be updated since they were restored to their original values
         */
        glStencilMask(0xFFFFF);
        RenderState::StateBlock::_defaultState->setStencilWrite(0xFFFFF);

        /* BUG: RenderState does not support glColorMask yet. */
        glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    }
}

void Camera::setFrameBufferObject(experimental::FrameBuffer *fbo)
{
    CC_SAFE_RETAIN(fbo);
    CC_SAFE_RELEASE_NULL(_fbo);
    _fbo = fbo;
    if(_scene)
    {
        _scene->setCameraOrderDirty();
    }
}

void Camera::applyFrameBufferObject()
{
    if(nullptr == _fbo)
    {
        experimental::FrameBuffer::applyDefaultFBO();
    }
    else
    {
        _fbo->applyFBO();
    }
}

void Camera::apply()
{
    applyFrameBufferObject();
    applyViewport();
}

void Camera::applyViewport()
{
    if(nullptr == _fbo)
    {
        glViewport(getDefaultViewport()._left, getDefaultViewport()._bottom, getDefaultViewport()._width, getDefaultViewport()._height);
    }
    else
    {
        glViewport(_viewport._left * _fbo->getWidth(), _viewport._bottom * _fbo->getHeight(),
                   _viewport._width * _fbo->getWidth(), _viewport._height * _fbo->getHeight());
    }
    
}

int Camera::getRenderOrder() const
{
    int result(0);
    if(_fbo)
    {
        result = _fbo->getFID()<<8;
    }
    else
    {
        result = 127 <<8;
    }
    result += _depth;
    return result;
}

NS_CC_END