//-----------------------------------------------------------------------------
// Copyright (c) 2012 GarageGames, LLC
//
// 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.
//-----------------------------------------------------------------------------

#include "gfx/gl/gfxGLDevice.h"
#include "gfx/gl/gfxGLPrimitiveBuffer.h"
#include "gfx/gl/gfxGLEnumTranslate.h"

#include "gfx/gl/tGL/tGL.h"
#include "gfx/gl/gfxGLUtils.h"

#include "gfx/gl/gfxGLCircularVolatileBuffer.h"

GLCircularVolatileBuffer* getCircularVolatileIndexBuffer()
{
   static GLCircularVolatileBuffer sCircularVolatileIndexBuffer(GL_ELEMENT_ARRAY_BUFFER);
   return &sCircularVolatileIndexBuffer;
}

GFXGLPrimitiveBuffer::GFXGLPrimitiveBuffer(GFXDevice *device, U32 indexCount, U32 primitiveCount, GFXBufferType bufferType) :
   GFXPrimitiveBuffer(device, indexCount, primitiveCount, bufferType),
   mBufferOffset(0),
   mZombieCache(NULL),
   lockedIndexEnd(0),
   lockedIndexStart(0)
{
   if( mBufferType == GFXBufferTypeVolatile )
   {
      mBuffer = getCircularVolatileIndexBuffer()->getHandle();
      return;
   }

   // Generate a buffer and allocate the needed memory
   glGenBuffers(1, &mBuffer);
   
   PRESERVE_INDEX_BUFFER();
   glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mBuffer);
   glBufferData(GL_ELEMENT_ARRAY_BUFFER, indexCount * sizeof(U16), NULL, GFXGLBufferType[bufferType]);   
}

GFXGLPrimitiveBuffer::~GFXGLPrimitiveBuffer()
{
	// This is heavy handed, but it frees the buffer memory
   if( mBufferType != GFXBufferTypeVolatile )
	   glDeleteBuffers(1, &mBuffer);
   
   if( mZombieCache )
      delete [] mZombieCache;
}

void GFXGLPrimitiveBuffer::lock(U32 indexStart, U32 indexEnd, void **indexPtr)
{
   if( mBufferType == GFXBufferTypeVolatile )
   {
      AssertFatal(indexStart == 0, "");
      getCircularVolatileIndexBuffer()->lock( mIndexCount * sizeof(U16), 0, mBufferOffset, *indexPtr );
   }
   else
   {
      mFrameAllocator.lock( mIndexCount * sizeof(U16) );

      *indexPtr = (void*)(mFrameAllocator.getlockedPtr() + (indexStart * sizeof(U16)) );
   }

   lockedIndexStart = indexStart;
   lockedIndexEnd = indexEnd;
}

void GFXGLPrimitiveBuffer::unlock()
{
   PROFILE_SCOPE(GFXGLPrimitiveBuffer_unlock);

   if( mBufferType == GFXBufferTypeVolatile )
   {
      getCircularVolatileIndexBuffer()->unlock();
   }
   else
   {   
      U32 offset = lockedIndexStart * sizeof(U16);
      U32 length = (lockedIndexEnd - lockedIndexStart) * sizeof(U16);
   
      // Preserve previous binding
      PRESERVE_INDEX_BUFFER();
   
      // Bind ourselves
      glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mBuffer);

      if( !lockedIndexStart && lockedIndexEnd == mIndexCount)
         glBufferData(GL_ELEMENT_ARRAY_BUFFER, mIndexCount * sizeof(U16), NULL, GFXGLBufferType[mBufferType]); // orphan the buffer

      glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, offset, length, mFrameAllocator.getlockedPtr() + offset );
   
      mFrameAllocator.unlock();
   }

   lockedIndexStart = 0;
   lockedIndexEnd = 0;
}

void GFXGLPrimitiveBuffer::prepare()
{
	// Bind
   GFXGLDevice* glDevice = static_cast<GFXGLDevice*>(mDevice);
   glDevice->setPB(this);
   glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mBuffer);
   glDevice->getOpenglCache()->setCacheBinded(GL_ELEMENT_ARRAY_BUFFER, mBuffer);
}

void GFXGLPrimitiveBuffer::finish()
{
   glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
   static_cast<GFXGLDevice*>(mDevice)->getOpenglCache()->setCacheBinded(GL_ELEMENT_ARRAY_BUFFER, 0);
}

GLvoid* GFXGLPrimitiveBuffer::getBuffer()
{
	// NULL specifies no offset into the hardware buffer
   return (GLvoid*)(uintptr_t)mBufferOffset;
}

void GFXGLPrimitiveBuffer::zombify()
{
   if(mZombieCache)
      return;
      
   mZombieCache = new U8[mIndexCount * sizeof(U16)];
   glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mBuffer);
   glGetBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, mIndexCount * sizeof(U16), mZombieCache);
   glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
   glDeleteBuffers(1, &mBuffer);
   mBuffer = 0;
}

void GFXGLPrimitiveBuffer::resurrect()
{
   if(!mZombieCache)
      return;
   
   glGenBuffers(1, &mBuffer);
   glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mBuffer);
   glBufferData(GL_ELEMENT_ARRAY_BUFFER, mIndexCount * sizeof(U16), mZombieCache, GFXGLBufferType[mBufferType]);
   glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
   
   delete[] mZombieCache;
   mZombieCache = NULL;
}

namespace
{
   bool onGFXDeviceSignal( GFXDevice::GFXDeviceEventType type )
   {
      if( GFX->getAdapterType() == OpenGL && GFXDevice::deEndOfFrame == type )
         getCircularVolatileIndexBuffer()->protectUsedRange();

      return true;
   }
}

MODULE_BEGIN( GFX_GL_PrimitiveBuffer )
   MODULE_INIT_AFTER( gfx )
   MODULE_SHUTDOWN_BEFORE( gfx )

   MODULE_INIT
   {
      GFXDevice::getDeviceEventSignal( ).notify( &onGFXDeviceSignal );
   }

   MODULE_SHUTDOWN
   {
      GFXDevice::getDeviceEventSignal( ).remove( &onGFXDeviceSignal );
   }
MODULE_END