// Created on: 2015-01-16
// Created by: Anastasia BORISOVA
// Copyright (c) 2015 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#include <OpenGl_BackgroundArray.hxx>

#include <Aspect_FillMethod.hxx>
#include <NCollection_AlignedAllocator.hxx>
#include <OpenGl_Texture.hxx>

// =======================================================================
// method  : Constructor
// purpose :
// =======================================================================
OpenGl_BackgroundArray::OpenGl_BackgroundArray (const Graphic3d_TypeOfBackground theType)
: OpenGl_PrimitiveArray (NULL, Graphic3d_TOPA_TRIANGLESTRIPS, NULL, NULL, NULL),
  myToUpdate (Standard_False),
  myType (theType),
  myViewWidth (0),
  myViewHeight (0),
  myFillMethod (Aspect_FM_NONE)
{
  Handle(NCollection_AlignedAllocator) anAlloc = new NCollection_AlignedAllocator (16);
  myAttribs = new Graphic3d_Buffer (anAlloc);

  myDrawMode = Graphic3d_TOPA_TRIANGLESTRIPS;

  myGradientParams.color1 = OpenGl_Vec4 (0.0f, 0.0f, 0.0f, 1.0f);
  myGradientParams.color2 = OpenGl_Vec4 (0.0f, 0.0f, 0.0f, 1.0f);
  myGradientParams.type   = Aspect_GFM_NONE;
}

// =======================================================================
// method  : SetTextureParameters
// purpose :
// =======================================================================
void OpenGl_BackgroundArray::SetTextureParameters (const Aspect_FillMethod theFillMethod)
{
  if (myType != Graphic3d_TOB_TEXTURE)
  {
    return;
  }

  myFillMethod = theFillMethod;
  invalidateData();
}

// =======================================================================
// method  : SetTextureFillMethod
// purpose :
// =======================================================================
void OpenGl_BackgroundArray::SetTextureFillMethod (const Aspect_FillMethod theFillMethod)
{
  myFillMethod = theFillMethod;
  invalidateData();
}

// =======================================================================
// method  : SetGradientParameters
// purpose :
// =======================================================================
void OpenGl_BackgroundArray::SetGradientParameters (const Quantity_Color&           theColor1,
                                                    const Quantity_Color&           theColor2,
                                                    const Aspect_GradientFillMethod theType)
{
  if (myType != Graphic3d_TOB_GRADIENT)
  {
    return;
  }

  Standard_Real anR, aG, aB;
  theColor1.Values (anR, aG, aB, Quantity_TOC_RGB);
  myGradientParams.color1 = OpenGl_Vec4 ((float)anR, (float)aG, (float)aB, 0.0f);

  theColor2.Values (anR, aG, aB, Quantity_TOC_RGB);
  myGradientParams.color2 = OpenGl_Vec4 ((float)anR, (float)aG, (float)aB, 0.0f);

  myGradientParams.type = theType;
  invalidateData();
}

// =======================================================================
// method  : SetGradientFillMethod
// purpose :
// =======================================================================
void OpenGl_BackgroundArray::SetGradientFillMethod (const Aspect_GradientFillMethod theType)
{
  if (myType != Graphic3d_TOB_GRADIENT)
  {
    return;
  }

  myGradientParams.type = theType;
  invalidateData();
}

// =======================================================================
// method  : IsDefined
// purpose :
// =======================================================================
bool OpenGl_BackgroundArray::IsDefined() const
{
  switch (myType)
  {
    case Graphic3d_TOB_GRADIENT: return myGradientParams.type != Aspect_GFM_NONE;
    case Graphic3d_TOB_TEXTURE:  return myFillMethod          != Aspect_FM_NONE;
    case Graphic3d_TOB_NONE:     return Standard_False;
  }
  return Standard_False;
}

// =======================================================================
// method  : invalidateData
// purpose :
// =======================================================================
void OpenGl_BackgroundArray::invalidateData()
{
  myToUpdate = Standard_True;
}

// =======================================================================
// method  : Init
// purpose :
// =======================================================================
Standard_Boolean OpenGl_BackgroundArray::Init (const Handle(OpenGl_Workspace)& theWorkspace)
{
  switch (myType)
  {
    case Graphic3d_TOB_GRADIENT:
    {
      if (!createGradientArray())
      {
        return Standard_False;
      }
      break;
    }
    case Graphic3d_TOB_TEXTURE:
    {
      myViewWidth  = theWorkspace->Width();
      myViewHeight = theWorkspace->Height();
      if (!createTextureArray (theWorkspace))
      {
        return Standard_False;
      }
      break;
    }
    case Graphic3d_TOB_NONE:
    default:
    {
      return Standard_False;
    }
  }

  // Init VBO
  const Handle(OpenGl_Context)& aCtx = theWorkspace->GetGlContext();
  if (myIsVboInit)
  {
    clearMemoryGL (aCtx);
  }
  buildVBO (aCtx, Standard_True);
  myIsVboInit = Standard_True;

  // Data is up-to-date
  myToUpdate = Standard_False;
  return Standard_True;
}

// =======================================================================
// method  : createGradientArray
// purpose :
// =======================================================================
Standard_Boolean OpenGl_BackgroundArray::createGradientArray()
{
  // Initialize data for primitive array
  Graphic3d_Attribute aGragientAttribInfo[] =
  {
    { Graphic3d_TOA_POS,   Graphic3d_TOD_VEC2 },
    { Graphic3d_TOA_COLOR, Graphic3d_TOD_VEC3 }
  };

  if (!myAttribs->Init (4, aGragientAttribInfo, 2))
  {
    return Standard_False;
  }

  OpenGl_Vec2 aVertices[4] =
  {
    OpenGl_Vec2(-1.0f, -1.0f),
    OpenGl_Vec2( 1.0f, -1.0f),
    OpenGl_Vec2( 1.0f,  1.0f),
    OpenGl_Vec2(-1.0f,  1.0f)
  };

  Tfloat* aCorners[4]     = {};
  Tfloat  aDiagCorner1[3] = {};
  Tfloat  aDiagCorner2[3] = {};

  switch (myGradientParams.type)
  {
    case Aspect_GFM_HOR:
    {
      aCorners[0] = myGradientParams.color1.xyz().ChangeData();
      aCorners[1] = myGradientParams.color2.xyz().ChangeData();
      aCorners[2] = myGradientParams.color2.xyz().ChangeData();
      aCorners[3] = myGradientParams.color1.xyz().ChangeData();
      break;
    }
    case Aspect_GFM_VER:
    {
      aCorners[0] = myGradientParams.color2.xyz().ChangeData();
      aCorners[1] = myGradientParams.color2.xyz().ChangeData();
      aCorners[2] = myGradientParams.color1.xyz().ChangeData();
      aCorners[3] = myGradientParams.color1.xyz().ChangeData();
      break;
    }
    case Aspect_GFM_DIAG1:
    {
      aCorners[1] = myGradientParams.color2.xyz().ChangeData();
      aCorners[3] = myGradientParams.color1.xyz().ChangeData();
      aDiagCorner1[0] = aDiagCorner2[0] = 0.5f * (aCorners[1][0] + aCorners[3][0]);
      aDiagCorner1[1] = aDiagCorner2[1] = 0.5f * (aCorners[1][1] + aCorners[3][1]);
      aDiagCorner1[2] = aDiagCorner2[2] = 0.5f * (aCorners[1][2] + aCorners[3][2]);
      aCorners[0] = aDiagCorner1;
      aCorners[2] = aDiagCorner2;
      break;
    }
    case Aspect_GFM_DIAG2:
    {
      aCorners[0] = myGradientParams.color2.xyz().ChangeData();
      aCorners[2] = myGradientParams.color1.xyz().ChangeData();
      aDiagCorner1[0] = aDiagCorner2[0] = 0.5f * (aCorners[0][0] + aCorners[2][0]);
      aDiagCorner1[1] = aDiagCorner2[1] = 0.5f * (aCorners[0][1] + aCorners[2][1]);
      aDiagCorner1[2] = aDiagCorner2[2] = 0.5f * (aCorners[0][2] + aCorners[2][2]);
      aCorners[1] = aDiagCorner1;
      aCorners[3] = aDiagCorner2;
      break;
    }
    case Aspect_GFM_CORNER1:
    {
      aCorners[0] = myGradientParams.color2.xyz().ChangeData();
      aCorners[1] = myGradientParams.color2.xyz().ChangeData();
      aCorners[2] = myGradientParams.color2.xyz().ChangeData();
      aCorners[3] = myGradientParams.color1.xyz().ChangeData();
      break;
    }
    case Aspect_GFM_CORNER2:
    {
      aCorners[0] = myGradientParams.color2.xyz().ChangeData();
      aCorners[1] = myGradientParams.color2.xyz().ChangeData();
      aCorners[2] = myGradientParams.color1.xyz().ChangeData();
      aCorners[3] = myGradientParams.color2.xyz().ChangeData();
      break;
    }
    case Aspect_GFM_CORNER3:
    {
      aCorners[0] = myGradientParams.color2.xyz().ChangeData();
      aCorners[1] = myGradientParams.color1.xyz().ChangeData();
      aCorners[2] = myGradientParams.color2.xyz().ChangeData();
      aCorners[3] = myGradientParams.color2.xyz().ChangeData();
      break;
    }
    case Aspect_GFM_CORNER4:
    {
      aCorners[0] = myGradientParams.color1.xyz().ChangeData();
      aCorners[1] = myGradientParams.color2.xyz().ChangeData();
      aCorners[2] = myGradientParams.color2.xyz().ChangeData();
      aCorners[3] = myGradientParams.color2.xyz().ChangeData();
      break;
    }
    case Aspect_GFM_NONE:
    {
      break;
    }
  }

  if (myGradientParams.type != Aspect_GFM_CORNER1
   && myGradientParams.type != Aspect_GFM_CORNER3)
  {
    for (Standard_Integer anIt = 0; anIt < 4; ++anIt)
    {
      OpenGl_Vec2* aVertData  = reinterpret_cast<OpenGl_Vec2* >(myAttribs->changeValue (anIt));
      *aVertData = aVertices[anIt];

      OpenGl_Vec3* aColorData = reinterpret_cast<OpenGl_Vec3* >(myAttribs->changeValue (anIt) + myAttribs->AttributeOffset (1));
      *aColorData = OpenGl_Vec3(aCorners[anIt][0], aCorners[anIt][1], aCorners[anIt][2]);
    }
  }
  else //if (myGradientParams.type == Aspect_GFM_CORNER1 || myGradientParams.type == Aspect_GFM_CORNER3)
  {
    for (Standard_Integer anIt = 0; anIt < 4; ++anIt)
    {
      // Indices should be in sequence 1, 2, 3, 0
      Standard_Integer anIndex = (anIt + 1) % 4;
      OpenGl_Vec2* aVertData  = reinterpret_cast<OpenGl_Vec2* >(myAttribs->changeValue (anIt));
      *aVertData = aVertices[anIndex];

      OpenGl_Vec3* aColorData = reinterpret_cast<OpenGl_Vec3* >(myAttribs->changeValue (anIt) + myAttribs->AttributeOffset (1));
      *aColorData = OpenGl_Vec3(aCorners[anIndex][0], aCorners[anIndex][1], aCorners[anIndex][2]);
    }
  }

  return Standard_True;
}

// =======================================================================
// method  : createTextureArray
// purpose :
// =======================================================================
Standard_Boolean OpenGl_BackgroundArray::createTextureArray (const Handle(OpenGl_Workspace)& theWorkspace)
{
  Graphic3d_Attribute aTextureAttribInfo[] =
  {
    { Graphic3d_TOA_POS, Graphic3d_TOD_VEC2 },
    { Graphic3d_TOA_UV,  Graphic3d_TOD_VEC2 }
  };

  if (!myAttribs->Init (4, aTextureAttribInfo, 2))
  {
    return Standard_False;
  }

  GLfloat aTexRangeX = 1.0f; // texture <s> coordinate
  GLfloat aTexRangeY = 1.0f; // texture <t> coordinate

  // Set up for stretching or tiling
  GLfloat anOffsetX = 1.0f;
  GLfloat anOffsetY = 1.0f;

  // Setting this coefficient to -1.0f allows to tile textures relatively to the top-left corner of the view
  // (value 1.0f corresponds to the initial behavior - tiling from the bottom-left corner)
  GLfloat aCoef = -1.0f;

  // Get texture parameters
  const Handle(OpenGl_Context)& aCtx = theWorkspace->GetGlContext();
  const OpenGl_AspectFace* anAspectFace = theWorkspace->AspectFace (Standard_False);
  GLfloat aTextureWidth  = (GLfloat )anAspectFace->TextureRes (aCtx)->SizeX();
  GLfloat aTextureHeight = (GLfloat )anAspectFace->TextureRes (aCtx)->SizeY();

  if (myFillMethod == Aspect_FM_CENTERED)
  {
    anOffsetX = aTextureWidth  / (GLfloat )myViewWidth;
    anOffsetY = aTextureHeight / (GLfloat )myViewHeight;
  }
  else if (myFillMethod == Aspect_FM_TILED)
  {
    aTexRangeX = (GLfloat )myViewWidth  / aTextureWidth;
    aTexRangeY = (GLfloat )myViewHeight / aTextureHeight;
  }

  // NOTE: texture is mapped using GL_REPEAT wrapping mode so integer part
  // is simply ignored, and negative multiplier is here for convenience only
  // and does not result e.g. in texture mirroring

  OpenGl_Vec2* aData = reinterpret_cast<OpenGl_Vec2* >(myAttribs->changeValue (0));
  aData[0] = OpenGl_Vec2 (-anOffsetX, -aCoef * anOffsetY);
  aData[1] = OpenGl_Vec2 (0.0f, 0.0f);

  aData = reinterpret_cast<OpenGl_Vec2* >(myAttribs->changeValue (1));
  aData[0] = OpenGl_Vec2 (anOffsetX, -aCoef * anOffsetY);
  aData[1] = OpenGl_Vec2 (aTexRangeX, 0.0f);

  aData = reinterpret_cast<OpenGl_Vec2* >(myAttribs->changeValue (2));
  aData[0] = OpenGl_Vec2 (anOffsetX,  aCoef * anOffsetY);
  aData[1] = OpenGl_Vec2 (aTexRangeX, aCoef * aTexRangeY);

  aData = reinterpret_cast<OpenGl_Vec2* >(myAttribs->changeValue (3));
  aData[0] = OpenGl_Vec2 (-anOffsetX, aCoef * anOffsetY);
  aData[1] = OpenGl_Vec2 (0.0f, aCoef * aTexRangeY);

  return Standard_True;
}