text: /****************************************************************************
  Copyright (c) 2011      ForzeField Studios S.L.
  Copyright (c) 2010-2012 cocos2d-x.org
  Copyright (c) 2013-2014 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 false 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.
  ****************************************************************************/
  
  #include "2d/CCMotionStreak.h"
  #include "math/CCVertex.h"
  #include "base/CCDirector.h"
  #include "renderer/CCTextureCache.h"
  #include "renderer/ccGLStateCache.h"
  #include "renderer/CCTexture2D.h"
  #include "renderer/CCRenderer.h"
  #include "renderer/CCGLProgramState.h"
  
  NS_CC_BEGIN
  
  MotionStreak::MotionStreak()
  : _fastMode(false)
  , _startingPositionInitialized(false)
  , _texture(nullptr)
  , _blendFunc(BlendFunc::ALPHA_NON_PREMULTIPLIED)
  , _stroke(0.0f)
  , _fadeDelta(0.0f)
  , _minSeg(0.0f)
  , _maxPoints(0)
  , _nuPoints(0)
  , _previousNuPoints(0)
  , _pointVertexes(nullptr)
  , _pointState(nullptr)
  , _vertices(nullptr)
  , _colorPointer(nullptr)
  , _texCoords(nullptr)
  {
  }
  
  MotionStreak::~MotionStreak()
  {
      CC_SAFE_RELEASE(_texture);
      CC_SAFE_FREE(_pointState);
      CC_SAFE_FREE(_pointVertexes);
      CC_SAFE_FREE(_vertices);
      CC_SAFE_FREE(_colorPointer);
      CC_SAFE_FREE(_texCoords);
  }
  
  MotionStreak* MotionStreak::create(float fade, float minSeg, float stroke, const Color3B& color, const std::string& path)
  {
      MotionStreak *ret = new (std::nothrow) MotionStreak();
      if (ret && ret->initWithFade(fade, minSeg, stroke, color, path))
      {
          ret->autorelease();
          return ret;
      }
  
      CC_SAFE_DELETE(ret);
      return nullptr;
  }
  
  MotionStreak* MotionStreak::create(float fade, float minSeg, float stroke, const Color3B& color, Texture2D* texture)
  {
      MotionStreak *ret = new (std::nothrow) MotionStreak();
      if (ret && ret->initWithFade(fade, minSeg, stroke, color, texture))
      {
          ret->autorelease();
          return ret;
      }
  
      CC_SAFE_DELETE(ret);
      return nullptr;
  }
  
  bool MotionStreak::initWithFade(float fade, float minSeg, float stroke, const Color3B& color, const std::string& path)
  {
      CCASSERT(!path.empty(), "Invalid filename");
  
      Texture2D *texture = Director::getInstance()->getTextureCache()->addImage(path);
      return initWithFade(fade, minSeg, stroke, color, texture);
  }
  
  bool MotionStreak::initWithFade(float fade, float minSeg, float stroke, const Color3B& color, Texture2D* texture)
  {
      Node::setPosition(Vec2::ZERO);
      setAnchorPoint(Vec2::ZERO);
      setIgnoreAnchorPointForPosition(true);
      _startingPositionInitialized = false;
  
      _positionR.setZero();
      _fastMode = true;
      _minSeg = (minSeg == -1.0f) ? stroke/5.0f : minSeg;
      _minSeg *= _minSeg;
  
      _stroke = stroke;
      _fadeDelta = 1.0f/fade;
  
      _maxPoints = (int)(fade*60.0f)+2;
      _nuPoints = 0;
      _pointState = (float *)malloc(sizeof(float) * _maxPoints);
      _pointVertexes = (Vec2*)malloc(sizeof(Vec2) * _maxPoints);
  
      _vertices = (Vec2*)malloc(sizeof(Vec2) * _maxPoints * 2);
      _texCoords = (Tex2F*)malloc(sizeof(Tex2F) * _maxPoints * 2);
      _colorPointer =  (GLubyte*)malloc(sizeof(GLubyte) * _maxPoints * 2 * 4);
  
      // Set blend mode
      _blendFunc = BlendFunc::ALPHA_NON_PREMULTIPLIED;
  
      // shader state
      setGLProgramState(GLProgramState::getOrCreateWithGLProgramName(GLProgram::SHADER_NAME_POSITION_TEXTURE_COLOR));
  
      setTexture(texture);
      setColor(color);
      scheduleUpdate();
  
      return true;
  }
  
  void MotionStreak::setPosition(const Vec2& position)
  {
      if (!_startingPositionInitialized) {
          _startingPositionInitialized = true;
      }
      _positionR = position;
  }
  
  void MotionStreak::setPosition(float x, float y)
  {
      if (!_startingPositionInitialized) {
          _startingPositionInitialized = true;
      }
      _positionR.x = x;
      _positionR.y = y;
  }
  
  const Vec2& MotionStreak::getPosition() const
  {
      return _positionR;
  }
  
  void MotionStreak::getPosition(float* x, float* y) const
  {
      *x = _positionR.x;
      *y = _positionR.y;
  }
  
  float MotionStreak::getPositionX() const
  {
      return _positionR.x;
  }
  
  Vec3 MotionStreak::getPosition3D() const
  {
      return Vec3(_positionR.x, _positionR.y, getPositionZ());
  }
  
  void MotionStreak::setPositionX(float x)
  {
      if (!_startingPositionInitialized) {
          _startingPositionInitialized = true;
      }
      _positionR.x = x;
  }
  
  float MotionStreak::getPositionY() const
  {
      return  _positionR.y;
  }
  
  void MotionStreak::setPositionY(float y)
  {
      if (!_startingPositionInitialized) {
          _startingPositionInitialized = true;
      }
      _positionR.y = y;
  }
  
  void MotionStreak::tintWithColor(const Color3B& colors)
  {
      setColor(colors);
  
      // Fast assignation
      for(unsigned int i = 0; i<_nuPoints*2; i++) 
      {
          *((Color3B*) (_colorPointer+i*4)) = colors;
      }
  }
  
  Texture2D* MotionStreak::getTexture(void) const
  {
      return _texture;
  }
  
  void MotionStreak::setTexture(Texture2D *texture)
  {
      if (_texture != texture)
      {
          CC_SAFE_RETAIN(texture);
          CC_SAFE_RELEASE(_texture);
          _texture = texture;
      }
  }
  
  void MotionStreak::setBlendFunc(const BlendFunc &blendFunc)
  {
      _blendFunc = blendFunc;
  }
  
  const BlendFunc& MotionStreak::getBlendFunc(void) const
  {
      return _blendFunc;
  }
  
  void MotionStreak::setOpacity(GLubyte opacity)
  {
      CCASSERT(false, "Set opacity no supported");
  }
  
  GLubyte MotionStreak::getOpacity(void) const
  {
      CCASSERT(false, "Opacity no supported");
      return 0;
  }
  
  void MotionStreak::setOpacityModifyRGB(bool bValue)
  {
      CC_UNUSED_PARAM(bValue);
  }
  
  bool MotionStreak::isOpacityModifyRGB(void) const
  {
      return false;
  }
  
  void MotionStreak::update(float delta)
  {
      if (!_startingPositionInitialized)
      {
          return;
      }
      
      delta *= _fadeDelta;
  
      unsigned int newIdx, newIdx2, i, i2;
      unsigned int mov = 0;
  
      // Update current points
      for(i = 0; i<_nuPoints; i++)
      {
          _pointState[i]-=delta;
  
          if(_pointState[i] <= 0)
              mov++;
          else
          {
              newIdx = i-mov;
  
              if(mov>0)
              {
                  // Move data
                  _pointState[newIdx] = _pointState[i];
  
                  // Move point
                  _pointVertexes[newIdx] = _pointVertexes[i];
  
                  // Move vertices
                  i2 = i*2;
                  newIdx2 = newIdx*2;
                  _vertices[newIdx2] = _vertices[i2];
                  _vertices[newIdx2+1] = _vertices[i2+1];
  
                  // Move color
                  i2 *= 4;
                  newIdx2 *= 4;
                  _colorPointer[newIdx2+0] = _colorPointer[i2+0];
                  _colorPointer[newIdx2+1] = _colorPointer[i2+1];
                  _colorPointer[newIdx2+2] = _colorPointer[i2+2];
                  _colorPointer[newIdx2+4] = _colorPointer[i2+4];
                  _colorPointer[newIdx2+5] = _colorPointer[i2+5];
                  _colorPointer[newIdx2+6] = _colorPointer[i2+6];
              }else
                  newIdx2 = newIdx*8;
  
              const GLubyte op = (GLubyte)(_pointState[newIdx] * 255.0f);
              _colorPointer[newIdx2+3] = op;
              _colorPointer[newIdx2+7] = op;
          }
      }
      _nuPoints-=mov;
  
      // Append new point
      bool appendNewPoint = true;
      if(_nuPoints >= _maxPoints)
      {
          appendNewPoint = false;
      }
  
      else if(_nuPoints>0)
      {
          bool a1 = _pointVertexes[_nuPoints-1].getDistanceSq(_positionR) < _minSeg;
          bool a2 = (_nuPoints == 1) ? false : (_pointVertexes[_nuPoints-2].getDistanceSq(_positionR)< (_minSeg * 2.0f));
          if(a1 || a2)
          {
              appendNewPoint = false;
          }
      }
  
      if(appendNewPoint)
      {
          _pointVertexes[_nuPoints] = _positionR;
          _pointState[_nuPoints] = 1.0f;
  
          // Color assignment
          const unsigned int offset = _nuPoints*8;
          *((Color3B*)(_colorPointer + offset)) = _displayedColor;
          *((Color3B*)(_colorPointer + offset+4)) = _displayedColor;
  
          // Opacity
          _colorPointer[offset+3] = 255;
          _colorPointer[offset+7] = 255;
  
          // Generate polygon
          if(_nuPoints > 0 && _fastMode )
          {
              if(_nuPoints > 1)
              {
                  ccVertexLineToPolygon(_pointVertexes, _stroke, _vertices, _nuPoints, 1);
              }
              else
              {
                  ccVertexLineToPolygon(_pointVertexes, _stroke, _vertices, 0, 2);
              }
          }
  
          _nuPoints ++;
      }
  
      if( ! _fastMode )
      {
          ccVertexLineToPolygon(_pointVertexes, _stroke, _vertices, 0, _nuPoints);
      }
  
      // Updated Tex Coords only if they are different than previous step
      if( _nuPoints  && _previousNuPoints != _nuPoints ) {
          float texDelta = 1.0f / _nuPoints;
          for( i=0; i < _nuPoints; i++ ) {
              _texCoords[i*2] = Tex2F(0, texDelta*i);
              _texCoords[i*2+1] = Tex2F(1, texDelta*i);
          }
  
          _previousNuPoints = _nuPoints;
      }
  }
  
  void MotionStreak::reset()
  {
      _nuPoints = 0;
  }
  
  void MotionStreak::onDraw(const Mat4 &transform, uint32_t flags)
  {  
      getGLProgram()->use();
      getGLProgram()->setUniformsForBuiltins(transform);
  
      GL::enableVertexAttribs(GL::VERTEX_ATTRIB_FLAG_POS_COLOR_TEX );
      GL::blendFunc( _blendFunc.src, _blendFunc.dst );
  
      GL::bindTexture2D( _texture->getName() );
  
      glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, _vertices);
      glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_TEX_COORD, 2, GL_FLOAT, GL_FALSE, 0, _texCoords);
      glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_COLOR, 4, GL_UNSIGNED_BYTE, GL_TRUE, 0, _colorPointer);
  
      glDrawArrays(GL_TRIANGLE_STRIP, 0, (GLsizei)_nuPoints*2);
      CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1, _nuPoints*2);
  }
  
  void MotionStreak::draw(Renderer *renderer, const Mat4 &transform, uint32_t flags)
  {
      if(_nuPoints <= 1)
          return;
      _customCommand.init(_globalZOrder, transform, flags);
      _customCommand.func = CC_CALLBACK_0(MotionStreak::onDraw, this, transform, flags);
      renderer->addCommand(&_customCommand);
  }
  
  NS_CC_END
  