Torque3D/Engine/source/gfx/bitmap/gBitmap.cpp

//-----------------------------------------------------------------------------
// 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 "platform/platform.h"
#include "gfx/bitmap/gBitmap.h"

#include "core/resourceManager.h"
#include "core/stream/fileStream.h"
#include "core/strings/stringFunctions.h"
#include "core/color.h"
#include "gfx/bitmap/bitmapUtils.h"
#include "math/mRect.h"
#include "console/console.h"
#include "platform/profiler.h"
#include "console/engineAPI.h"
#include "gfx/bitmap/ddsFile.h"

using namespace Torque;

const U32 GBitmap::csFileVersion   = 3;

Vector<GBitmap::Registration>   GBitmap::sRegistrations( __FILE__, __LINE__ );


GBitmap::GBitmap()
 : mInternalFormat(GFXFormatR8G8B8),
   mBits(NULL),
   mByteSize(0),
   mWidth(0),
   mHeight(0),
   mBytesPerPixel(0),
   mNumMipLevels(0),
   mHasTransparency(false),
   mNumFaces(1)
{
   std::fill_n(mMipLevelOffsets, c_maxMipLevels, 0xffffffff);
   std::fill_n(mFaceOffsets, 6, 0xffffffff);
}

GBitmap::GBitmap(const GBitmap& rCopy)
{
   mInternalFormat = rCopy.mInternalFormat;

   mByteSize = rCopy.mByteSize;
   mBits    = new U8[mByteSize];
   dMemcpy(mBits, rCopy.mBits, mByteSize);

   mWidth         = rCopy.mWidth;
   mHeight        = rCopy.mHeight;
   mBytesPerPixel = rCopy.mBytesPerPixel;
   mNumMipLevels  = rCopy.mNumMipLevels;
   dMemcpy(mMipLevelOffsets, rCopy.mMipLevelOffsets, sizeof(mMipLevelOffsets));
   dMemcpy(mFaceOffsets, rCopy.mFaceOffsets, sizeof(mFaceOffsets));

   mHasTransparency = rCopy.mHasTransparency;
   mNumFaces = rCopy.mNumFaces;
}


GBitmap::GBitmap(const U32  in_width,
                 const U32  in_height,
                 const bool in_extrudeMipLevels,
                 const GFXFormat in_format,
                 const U32 in_numFaces)
 : mBits(NULL),
   mByteSize(0),
   mNumFaces(in_numFaces)
{
   for (U32 i = 0; i < c_maxMipLevels; i++)
      mMipLevelOffsets[i] = 0xffffffff;

   for(U32 i = 0; i < 6; i++)
      mFaceOffsets[i] = 0xffffffff;

   allocateBitmap(in_width, in_height, in_extrudeMipLevels, in_format, in_numFaces);

   mHasTransparency = false;
}

GBitmap::GBitmap(const U32  in_width,
                 const U32  in_height,
                 const U8*  data,
                 const U32 in_numFaces)
 : mBits(NULL),
   mByteSize(0),
   mNumFaces(in_numFaces)
{
   allocateBitmap(in_width, in_height, false, GFXFormatR8G8B8A8, in_numFaces);

   mHasTransparency = false;

   for (U32 x = 0; x < in_width; x++)
   {
      for (U32 y = 0; y < in_height; y++)
      {
         U32 offset = (x + y * in_width) * 4;

         ColorI color(data[offset],
                      data[offset + 1],
                      data[offset + 2],
                      data[offset + 3]);

         if (color.alpha < 255)
            mHasTransparency = true;

         setColor(x, y, color);
      }
   }
}


//--------------------------------------------------------------------------

GBitmap::~GBitmap()
{
   deleteImage();
}

//--------------------------------------------------------------------------

U32 GBitmap::getFormatBytesPerPixel(GFXFormat fmt)
{
   switch (fmt)
   {
      // 8-bit formats
   case GFXFormatA8:
   case GFXFormatL8:
   case GFXFormatA4L4:
      return 1;

      // 16-bit formats
   case GFXFormatR5G6B5:
   case GFXFormatR5G5B5A1:
   case GFXFormatR5G5B5X1:
   case GFXFormatA8L8:
   case GFXFormatL16:
   case GFXFormatR16F:
   case GFXFormatD16:
      return 2;

      // 24-bit formats
   case GFXFormatR8G8B8:
   case GFXFormatR8G8B8_SRGB:
      return 3;

      // 32-bit formats
   case GFXFormatR8G8B8A8:
   case GFXFormatR8G8B8X8:
   case GFXFormatB8G8R8A8:
   case GFXFormatR8G8B8A8_SRGB:
   case GFXFormatR32F:
   case GFXFormatR10G10B10A2:
   case GFXFormatR11G11B10:
   case GFXFormatD24X8:
   case GFXFormatD24S8:
   case GFXFormatD24FS8:
   case GFXFormatR16G16:
   case GFXFormatR16G16F:
   case GFXFormatR8G8B8A8_LINEAR_FORCE:
      return 4;

      // 64-bit formats
   case GFXFormatR16G16B16A16:
   case GFXFormatR16G16B16A16F:
   case GFXFormatD32FS8X24:
      return 8;

      // 128-bit formats
   case GFXFormatR32G32B32A32F:
      return 16;

   default:
      AssertWarn(false, "getFormatBytesPerPixel() - Unknown or compressed format");
      return 4;
   }
}

//--------------------------------------------------------------------------

void GBitmap::sRegisterFormat( const GBitmap::Registration &reg )
{
   U32 insert = sRegistrations.size();
   for ( U32 i = 0; i < sRegistrations.size(); i++ )
   {
      if ( sRegistrations[i].priority <= reg.priority )
      {
         insert = i;
         break;
      }
   }

   sRegistrations.insert( insert, reg );
}

const GBitmap::Registration   *GBitmap::sFindRegInfo( const String &extension )
{
   for ( U32 i = 0; i < GBitmap::sRegistrations.size(); i++ )
   {
      const GBitmap::Registration   &reg = GBitmap::sRegistrations[i];
      const Vector<String>          &extensions = reg.extensions;

      for ( U32 j = 0; j < extensions.size(); ++j )
      {    
         if ( extensions[j].equal( extension, String::NoCase ) )
            return &reg;
      }
   }

   return NULL;
}

bool GBitmap::sFindFile( const Path &path, Path *outPath )
{
   PROFILE_SCOPE( GBitmap_sFindFile );

   const String origExt( String::ToLower( path.getExtension() ) );

   Path tryPath( path );

   for ( U32 i = 0; i < sRegistrations.size(); i++ )
   {
      const Registration &reg = sRegistrations[i];
      const Vector<String> &extensions = reg.extensions;

      for ( U32 j = 0; j < extensions.size(); ++j )
      {
         // We've already tried this one.
         if ( extensions[j] == origExt )
            continue;

         tryPath.setExtension( extensions[j] );
         if ( !Torque::FS::IsFile( tryPath ) )
            continue;

         if ( outPath )
            *outPath = tryPath;
         return true;
      }
   }

   return false;
}

bool GBitmap::sFindFiles( const Path &path, Vector<Path> *outFoundPaths )
{
   PROFILE_SCOPE( GBitmap_sFindFiles );
   
   Path  tryPath( path );

   for ( U32 i = 0; i < GBitmap::sRegistrations.size(); i++ )
   {
      const GBitmap::Registration   &reg = GBitmap::sRegistrations[i];
      const Vector<String>          &extensions = reg.extensions;

      for ( U32 j = 0; j < extensions.size(); ++j )
      {
         tryPath.setExtension( extensions[j] );

         if ( Torque::FS::IsFile( tryPath ) )
         {
            if ( outFoundPaths )
               outFoundPaths->push_back( tryPath );
            else
               return true;
         }
      }
   }

   return outFoundPaths ? outFoundPaths->size() > 0 : false;
}

String GBitmap::sGetExtensionList()
{
   String list;

   for ( U32 i = 0; i < sRegistrations.size(); i++ )
   {
      const Registration &reg = sRegistrations[i];
      for ( U32 j = 0; j < reg.extensions.size(); j++ )
      {
         list += reg.extensions[j];
         list += " ";         
      }
   }

   return list;
}

//--------------------------------------------------------------------------
void GBitmap::deleteImage()
{
   delete [] mBits;
   mBits    = NULL;
   mByteSize = 0;

   mWidth        = 0;
   mHeight       = 0;
   mNumMipLevels = 0;
}


//--------------------------------------------------------------------------

void GBitmap::copyRect(const GBitmap *src, const RectI &srcRect, const Point2I &dstPt, const U32 srcMipLevel, const U32 dstMipLevel)
{
   if(src->getFormat() != getFormat())
      return;
   if(srcRect.extent.x + srcRect.point.x > src->getWidth(srcMipLevel) || srcRect.extent.y + srcRect.point.y > src->getHeight(srcMipLevel))
      return;
   if(srcRect.extent.x + dstPt.x > getWidth(dstMipLevel) || srcRect.extent.y + dstPt.y > getHeight(dstMipLevel))
      return;

   for(U32 i = 0; i < srcRect.extent.y; i++)
   {
      dMemcpy(getAddress(dstPt.x, dstPt.y + i, dstMipLevel),
              src->getAddress(srcRect.point.x, srcRect.point.y + i, srcMipLevel),
              mBytesPerPixel * srcRect.extent.x);
   }
}

//--------------------------------------------------------------------------
void GBitmap::allocateBitmap(const U32 in_width, const U32 in_height, const bool in_extrudeMipLevels, const GFXFormat in_format, const U32 in_numFaces)
{
   //-------------------------------------- Some debug checks...
   U32 svByteSize = mByteSize;
   U8 *svBits = mBits;

   AssertFatal(in_width != 0 && in_height != 0, "GBitmap::allocateBitmap: width or height is 0");

   if (in_extrudeMipLevels == true) 
   {
      AssertFatal(isPow2(in_width) == true && isPow2(in_height) == true, "GBitmap::GBitmap: in order to extrude mip levels, bitmap w/h must be pow2");
   }

   mInternalFormat = in_format;
   mWidth          = in_width;
   mHeight         = in_height;
   mNumFaces       = in_numFaces;

   mBytesPerPixel = getFormatBytesPerPixel(mInternalFormat);

   // Set up the mip levels, if necessary...
   mNumMipLevels       = 1;
   mMipLevelOffsets[0] = 0;

   if (in_extrudeMipLevels == true) 
   {
      U32 currWidth  = in_width;
      U32 currHeight = in_height;

      while (currWidth != 1 || currHeight != 1)
      {
         mMipLevelOffsets[mNumMipLevels] = mMipLevelOffsets[mNumMipLevels - 1] +
                                         (currWidth * currHeight * mBytesPerPixel);
         currWidth  >>= 1;
         currHeight >>= 1;
         if (currWidth  == 0) currWidth  = 1;
         if (currHeight == 0) currHeight = 1;

         mNumMipLevels++;
      }

      U32 expectedMips = mFloor(mLog2(mMax(in_width, in_height))) + 1;
      AssertFatal(mNumMipLevels == expectedMips, "GBitmap::allocateBitmap: mipmap count wrong");
   }
   AssertFatal(mNumMipLevels <= c_maxMipLevels, "GBitmap::allocateBitmap: too many miplevels");

   U32 faceStride = 0;
   for (U32 mip = 0; mip < mNumMipLevels; mip++)
      faceStride += getWidth(mip) * getHeight(mip) * mBytesPerPixel;

   for (U32 face = 0; face < mNumFaces; face++)
      mFaceOffsets[face] = face * faceStride;

   U32 allocBytes = faceStride * mNumFaces;

   // Set up the memory...
   mByteSize = allocBytes;
   mBits    = new U8[mByteSize];

   dMemset(mBits, 0xFF, mByteSize);

   if(svBits != NULL)
   {
      dMemcpy(mBits, svBits, getMin(mByteSize, svByteSize));
      delete[] svBits;
   }
}

//--------------------------------------------------------------------------
void GBitmap::allocateBitmapWithMips(const U32 in_width, const U32 in_height, const U32 in_numMips, const GFXFormat in_format, const U32 in_numFaces)
{
   //-------------------------------------- Some debug checks...
   U32 svByteSize = mByteSize;
   U8 *svBits = mBits;

   AssertFatal(in_width != 0 && in_height != 0, "GBitmap::allocateBitmap: width or height is 0");

   mInternalFormat = in_format;
   mWidth = in_width;
   mHeight = in_height;
   mNumFaces = in_numFaces;

   mBytesPerPixel = getFormatBytesPerPixel(mInternalFormat);

   // Set up the mip levels, if necessary...
   mNumMipLevels = 1;
   mMipLevelOffsets[0] = 0;

   if (in_numMips != 0)
   {
      U32 currWidth = in_width;
      U32 currHeight = in_height;

      do
      {
         mMipLevelOffsets[mNumMipLevels] = mMipLevelOffsets[mNumMipLevels - 1] +
            (currWidth * currHeight * mBytesPerPixel);
         currWidth >>= 1;
         currHeight >>= 1;
         if (currWidth == 0) currWidth = 1;
         if (currHeight == 0) currHeight = 1;

         mNumMipLevels++;
      } while ((currWidth != 1 || currHeight != 1) && (mNumMipLevels != in_numMips));
   }
   AssertFatal(mNumMipLevels <= c_maxMipLevels, "GBitmap::allocateBitmap: too many miplevels");

   U32 faceStride = 0;
   for (U32 mip = 0; mip < mNumMipLevels; mip++)
      faceStride += getWidth(mip) * getHeight(mip) * mBytesPerPixel;

   for (U32 face = 0; face < mNumFaces; face++)
      mFaceOffsets[face] = face * faceStride;

   U32 allocBytes = faceStride * mNumFaces;

   // Set up the memory...
   mByteSize = allocBytes;
   mBits = new U8[mByteSize];

   dMemset(mBits, 0xFF, mByteSize);

   if (svBits != NULL)
   {
      dMemcpy(mBits, svBits, getMin(mByteSize, svByteSize));
      delete[] svBits;
   }
}

//--------------------------------------------------------------------------
void GBitmap::extrudeMipLevels(bool clearBorders)
{
   if(mNumMipLevels == 1)
      allocateBitmap(getWidth(), getHeight(), true, getFormat());


   if (getFormat() == GFXFormatR5G5B5A1)
   {
      for (U32 i = 1; i < mNumMipLevels; i++)
         bitmapExtrude5551(getBits(i - 1), getWritableBits(i), getHeight(i), getWidth(i));
   }
   else
   {
      for (U32 i = 1; i < mNumMipLevels; i++)
      {
         bitmapResizeToOutput(
            getBits(i - 1),
            getHeight(i - 1),
            getWidth(i - 1),
            getWritableBits(i),
            getHeight(i),
            getWidth(i),
            mBytesPerPixel,
            getFormat()
         );
      }
   }

   if (clearBorders)
   {
      for (U32 i = 1; i<mNumMipLevels; i++)
      {
         U32 width = getWidth(i);
         U32 height = getHeight(i);
         if (height<3 || width<3)
            // bmp is all borders at this mip level
            dMemset(getWritableBits(i),0,width*height*mBytesPerPixel);
         else
         {
            width *= mBytesPerPixel;
            U8 * bytes = getWritableBits(i);
            U8 * end = bytes + (height-1)*width - mBytesPerPixel; // end = last row, 2nd column
            // clear first row sans the last pixel
            dMemset(bytes,0,width-mBytesPerPixel);
            bytes -= mBytesPerPixel;
            while (bytes<end)
            {
               // clear last pixel of row N-1 and first pixel of row N
               bytes += width;
               dMemset(bytes,0,mBytesPerPixel*2);
            }
            // clear last row sans the first pixel
            dMemset(bytes+2*mBytesPerPixel,0,width-mBytesPerPixel);
         }
      }
   }
}

//--------------------------------------------------------------------------
void GBitmap::chopTopMips(U32 mipsToChop)
{
   U32 scalePower = getMin(mipsToChop, getNumMipLevels() - 1);
   U32 newMipCount = getNumMipLevels() - scalePower;

   U32 realWidth = getMax((U32)1, getWidth() >> scalePower);
   U32 realHeight = getMax((U32)1, getHeight() >> scalePower);

   U8 *destBits = mBits;

   U32 destOffsets[c_maxMipLevels];

   for (U32 i = scalePower; i<mNumMipLevels; i++)
   {
      // Copy to the new bitmap...
      dMemcpy(destBits,
         getWritableBits(i),
         getSurfaceSize(i));

      destOffsets[i - scalePower] = destBits - mBits;
      destBits += getSurfaceSize(i);
   }

   dMemcpy(mMipLevelOffsets, destOffsets, sizeof(destOffsets));

   mWidth = realWidth;
   mHeight = realHeight;
   mByteSize = destBits - mBits;
   mNumMipLevels = newMipCount;
}

//--------------------------------------------------------------------------
void GBitmap::extrudeMipLevelsDetail()
{
   AssertFatal(getFormat() == GFXFormatR8G8B8, "Error, only handles RGB for now...");
   U32 i,j;

   if(mNumMipLevels == 1)
      allocateBitmap(getWidth(), getHeight(), true, getFormat());

   for (i = 1; i < mNumMipLevels; i++) {
      bitmapExtrudeRGB(getBits(i - 1), getWritableBits(i), getHeight(i-1), getWidth(i-1), mBytesPerPixel);
   }

   // Ok, now that we have the levels extruded, we need to move the lower miplevels
   //  closer to 0.5.
   for (i = 1; i < mNumMipLevels - 1; i++) {
      U8* pMipBits = (U8*)getWritableBits(i);
      U32 numBytes = getWidth(i) * getHeight(i) * 3;

      U32 shift    = i;
      U32 start    = ((1 << i) - 1) * 0x80;

      for (j = 0; j < numBytes; j++) {
         U32 newVal = (start + pMipBits[j]) >> shift;
         AssertFatal(newVal <= 255, "Error, oob");
         pMipBits[j] = U8(newVal);
      }
   }
   AssertFatal(getWidth(mNumMipLevels - 1) == 1 && getHeight(mNumMipLevels - 1) == 1,
               "Error, last miplevel should be 1x1!");
   ((U8*)getWritableBits(mNumMipLevels - 1))[0] = 0x80;
   ((U8*)getWritableBits(mNumMipLevels - 1))[1] = 0x80;
   ((U8*)getWritableBits(mNumMipLevels - 1))[2] = 0x80;
}

//--------------------------------------------------------------------------
bool GBitmap::setFormat(GFXFormat fmt)
{
   if (getFormat() == fmt)
      return true;

   PROFILE_SCOPE(GBitmap_setFormat);

   // this is a nasty pointer math hack
   // is there a quick way to calc pixels of a fully mipped bitmap?
   U32 pixels = 0;
   for (U32 i=0; i < mNumMipLevels; i++)
      pixels += getHeight(i) * getWidth(i);

   if (getFormat() == GFXFormatR8G8B8 && fmt == GFXFormatR5G5B5A1)
   {
#ifdef _XBOX
      bitmapConvertRGB_to_1555(mBits, pixels);
#else
      bitmapConvertRGB_to_5551(mBits, pixels);
#endif
      mInternalFormat = GFXFormatR5G5B5A1;
      mBytesPerPixel = 2;
   }
   else
   {
      bitmapConvertToOutput(&mBits, pixels, getFormat(), fmt);
      mInternalFormat = fmt;
      mBytesPerPixel = getFormatBytesPerPixel(fmt);
   }

   
   U32 offset = 0;
   for (U32 j=0; j < mNumMipLevels; j++)
   {
      mMipLevelOffsets[j] = offset;
      offset += getHeight(j) * getWidth(j) * mBytesPerPixel;
   }

   return true;
}

//------------------------------------------------------------------------------

bool GBitmap::checkForTransparency()
{
   mHasTransparency = false;

   if (!mBits || mByteSize == 0)
      return false;

   ColorI pixel(255, 255, 255, 255);

   // Only check formats that can *possibly* have alpha.
   switch (mInternalFormat)
   {
   case GFXFormatA8:
   case GFXFormatA4L4:
   case GFXFormatA8L8:
   case GFXFormatR5G5B5A1:
   case GFXFormatR8G8B8A8:
   case GFXFormatB8G8R8A8:
   case GFXFormatR8G8B8A8_SRGB:
   case GFXFormatR10G10B10A2:
   case GFXFormatR16G16B16A16:
   case GFXFormatR16G16B16A16F:
   case GFXFormatR32G32B32A32F:
      break; // alpha-capable
   default:
      return false; // skip formats with no alpha
   }

   for (U32 x = 0; x < mWidth; x++)
   {
      for (U32 y = 0; y < mHeight; y++)
      {
         if (getColor(x, y, pixel))
         {
            if (pixel.alpha < 255)
            {
               mHasTransparency = true;
               break;
            }
         }
      }
   }

   return mHasTransparency;
}

//------------------------------------------------------------------------------
LinearColorF GBitmap::sampleTexel(F32 u, F32 v, bool retAlpha) const
{
   LinearColorF col(0.5f, 0.5f, 0.5f);
   // normally sampling wraps all the way around at 1.0,
   // but locking doesn't support this, and we seem to calc
   // the uv based on a clamped 0 - 1...
   Point2F max((F32)(getWidth()-1), (F32)(getHeight()-1));
   Point2F posf;
   posf.x = mClampF(((u) * max.x), 0.0f, max.x);
   posf.y = mClampF(((v) * max.y), 0.0f, max.y);
   Point2I posi((S32)posf.x, (S32)posf.y);

   const U8 *buffer = getBits();
   U32 lexelindex = ((posi.y * getWidth()) + posi.x) * mBytesPerPixel;

   if(mBytesPerPixel == 2)
   {
      //U16 *buffer = (U16 *)lockrect->pBits;
   }
   else if(mBytesPerPixel > 2)
   {     
      col.red = F32(buffer[lexelindex + 0]) / 255.0f;
      col.green = F32(buffer[lexelindex + 1]) / 255.0f;
      col.blue = F32(buffer[lexelindex + 2]) / 255.0f;
      if (retAlpha)
      {
         if (getHasTransparency())
            col.alpha = F32(buffer[lexelindex + 3]) / 255.0f;
         else
            col.alpha = 1.0f;
      }
   }

   return col;
}

//--------------------------------------------------------------------------
bool GBitmap::getColor(const U32 x, const U32 y, ColorI& rColor, const U32 mipLevel, const U32 face) const
{
   if (x >= mWidth || y >= mHeight)
      return false;
   U32 targMip = getNumMipLevels() < mipLevel ? getNumMipLevels()-1 : mipLevel;
   U32 targFace = getNumFaces() < face ? getNumFaces()-1 : face;
   const U8* p = getAddress(x, y, targMip, targFace);

   switch (mInternalFormat)
   {
      // --- 8-bit ---
   case GFXFormatA8:
      rColor.set(255, 255, 255, p[0]);
      break;

   case GFXFormatL8:
      rColor.set(p[0], p[0], p[0], 255);
      break;

   case GFXFormatA4L4:
   {
      U8 v = p[0];
      U8 lum = (v & 0x0F) * 17;
      U8 alp = ((v >> 4) & 0x0F) * 17;
      rColor.set(lum, lum, lum, alp);
      break;
   }

   // --- 16-bit ---
   case GFXFormatR5G6B5:
   {
      U16 c = ((U16*)p)[0];
#ifdef TORQUE_BIG_ENDIAN
      c = convertLEndianToHost(c);
#endif
      U8 r = (c >> 11) & 0x1F;
      U8 g = (c >> 5) & 0x3F;
      U8 b = c & 0x1F;
      rColor.set((r << 3) | (r >> 2),
         (g << 2) | (g >> 4),
         (b << 3) | (b >> 2),
         255);
      break;
   }

   case GFXFormatR5G5B5A1:
   {
      U16 c = ((U16*)p)[0];
#ifdef TORQUE_BIG_ENDIAN
      c = convertLEndianToHost(c);
#endif
      U8 r = (c >> 11) & 0x1F;
      U8 g = (c >> 6) & 0x1F;
      U8 b = (c >> 1) & 0x1F;
      U8 a = (c & 0x01) ? 255 : 0;
      rColor.set((r << 3) | (r >> 2),
         (g << 3) | (g >> 2),
         (b << 3) | (b >> 2),
         a);
      break;
   }

   case GFXFormatA8L8:
   {
      U16 c = ((U16*)p)[0];
#ifdef TORQUE_BIG_ENDIAN
      c = convertLEndianToHost(c);
#endif
      U8 l = c & 0xFF;
      U8 a = (c >> 8) & 0xFF;
      rColor.set(l, l, l, a);
      break;
   }

   case GFXFormatL16:
   {
      U16 l = ((U16*)p)[0];
#ifdef TORQUE_BIG_ENDIAN
      l = convertLEndianToHost(l);
#endif
      rColor.set(convert16To8(l), convert16To8(l), convert16To8(l), 255);
      break;
   }
   case GFXFormatR16F:
   {
      const U16* v = (U16*)p;
      rColor.set(
         floatTo8(convertHalfToFloat(v[0])),
         0,
         0,
         255
      );
      break;
   }

   // --- 24-bit ---
   case GFXFormatR8G8B8:
   case GFXFormatR8G8B8_SRGB:
      rColor.set(p[0], p[1], p[2], 255);
      break;

   // --- 32-bit ---
   case GFXFormatR32F:
   {
      const F32* v = (F32*)p;
      rColor.set(
         floatTo8(v[0]), // red
         0,                                      // green
         0,                                      // blue
         255                                     // alpha
      );
      break;
   }
   case GFXFormatR16G16:
   {
      const U16* v = (U16*)p;
#ifdef TORQUE_BIG_ENDIAN
      U16 r = convertLEndianToHost(v[0]);
      U16 g = convertLEndianToHost(v[1]);
#else
      U16 r = v[0];
      U16 g = v[1];
#endif
      rColor.set(
         convert16To8(r),    // red
         convert16To8(g),    // green
         0,             // blue
         255            // alpha
      );
      break;
   }
   case GFXFormatR16G16F:
   {
      const U16* v = (U16*)p;
      rColor.set(
         floatTo8(convertHalfToFloat(v[0])),
         floatTo8(convertHalfToFloat(v[1])),
         0,
         255
      );
      break;
   }

   case GFXFormatR8G8B8A8:
   case GFXFormatR8G8B8A8_SRGB:
   case GFXFormatR8G8B8X8:
      rColor.set(p[0], p[1], p[2], (mInternalFormat == GFXFormatR8G8B8X8) ? 255 : p[3]);
      break;

   case GFXFormatB8G8R8A8:
      rColor.set(p[2], p[1], p[0], p[3]);
      break;

   // --- 64-bit ---
   case GFXFormatR16G16B16A16:
   {
      const U16* v = (U16*)p;
#ifdef TORQUE_BIG_ENDIAN
      rColor.set(
         convert16To8(v[2]),
         convert16To8(v[1]),
         convert16To8(v[0]),
         convert16To8(v[3]));
#else
      rColor.set(
         convert16To8(v[0]),
         convert16To8(v[1]),
         convert16To8(v[2]),
         convert16To8(v[3]));
#endif
      break;
   }

   case GFXFormatR16G16B16A16F:
   {
      const U16* v = (const U16*)p;
      rColor.set(floatTo8(
         convertHalfToFloat(v[0])),
         floatTo8(convertHalfToFloat(v[1])),
         floatTo8(convertHalfToFloat(v[2])),
         floatTo8(convertHalfToFloat(v[3])));
      break;
   }

   // --- 128-bit ---
   case GFXFormatR32G32B32A32F:
   {
      const F32* v = (const F32*)p;
      rColor.set(
         floatTo8(v[0]),
         floatTo8(v[1]),
         floatTo8(v[2]),
         floatTo8(v[3]));
      break;
   }

   default:
      AssertFatal(false, "Bad internal format");
      return false;
   }

   return true;
}


//--------------------------------------------------------------------------


bool GBitmap::setColor(const U32 x, const U32 y, const ColorI& rColor)
{
   if (x >= mWidth || y >= mHeight)
      return false;

   U8* p = getAddress(x, y);

   switch (mInternalFormat)
   {

   // --- 8-bit ---
   case GFXFormatA8:
      *p = rColor.alpha;
      break;

   case GFXFormatL8:
      *p = rColor.red; // L = R channel
      break;

   case GFXFormatA4L4:
   {
      U8 lum = rColor.red / 17;
      U8 alp = rColor.alpha / 17;
      *p = (alp << 4) | (lum & 0x0F);
      break;
   }

   // --- 16-bit ---
   case GFXFormatR5G6B5:
   {
      U16 r = rColor.red * 31 / 255;
      U16 g = rColor.green * 63 / 255;
      U16 b = rColor.blue * 31 / 255;
#ifdef TORQUE_BIG_ENDIAN
      * (U16*)p = (r << 11) | (g << 5) | b;
#else
      * (U16*)p = (b) | (g << 5) | (r << 11);
#endif
      break;
   }

   case GFXFormatR5G5B5A1:
   {
      U16 r = rColor.red * 31 / 255;
      U16 g = rColor.green * 31 / 255;
      U16 b = rColor.blue * 31 / 255;
      U16 a = (rColor.alpha > 0) ? 1 : 0;
#ifdef TORQUE_BIG_ENDIAN
      * (U16*)p = (a << 15) | (b << 10) | (g << 5) | r;
#else
      * (U16*)p = (r << 11) | (g << 6) | (b << 1) | a;
#endif
      break;
   }

   case GFXFormatA8L8:
   {
      U16 l = rColor.red;
      U16 a = rColor.alpha;
#ifdef TORQUE_BIG_ENDIAN
      * (U16*)p = (a << 8) | l;
#else
      * (U16*)p = (l) | (a << 8);
#endif
      break;
   }

   case GFXFormatL16:
      *(U16*)p = convert8To16(rColor.red);
      break;

   case GFXFormatR16F:
   {
      U16* v = (U16*)p;
      v[0] = convertFloatToHalf(rColor.red / 255.f);
      break;
   }

   // --- 24-bit ---
   case GFXFormatR8G8B8:
   case GFXFormatR8G8B8_SRGB:
      p[0] = rColor.red;
      p[1] = rColor.green;
      p[2] = rColor.blue;
      break;

   // --- 32-bit ---
   case GFXFormatR32F:
   {
      F32* v = (F32*)p;
      v[0] = rColor.red / 255.f;
      break;
   }
   case GFXFormatR16G16:
   {
      U16* v = (U16*)p;
      v[0] = convert8To16(rColor.red);
      v[1] = convert8To16(rColor.green);
      break;
   }
   case GFXFormatR16G16F:
   {
      U16* v = (U16*)p;
      v[0] = convertFloatToHalf(rColor.red / 255.f);
      v[1] = convertFloatToHalf(rColor.green / 255.f);
      break;
   }
   case GFXFormatR8G8B8A8:
   case GFXFormatR8G8B8A8_SRGB:
   case GFXFormatR8G8B8X8:
      p[0] = rColor.red;
      p[1] = rColor.green;
      p[2] = rColor.blue;
      p[3] = (mInternalFormat == GFXFormatR8G8B8X8) ? 255 : rColor.alpha;
      break;

   case GFXFormatB8G8R8A8:
      p[0] = rColor.blue;
      p[1] = rColor.green;
      p[2] = rColor.red;
      p[3] = rColor.alpha;
      break;

   // --- 64-bit ---
   case GFXFormatR16G16B16A16:
   {
      U16* v = (U16*)p;
      v[0] = convert8To16(rColor.red);
      v[1] = convert8To16(rColor.green);
      v[2] = convert8To16(rColor.blue);
      v[3] = convert8To16(rColor.alpha);
      break;
   }

   case GFXFormatR16G16B16A16F:
   {
      U16* v = (U16*)p;
      v[0] = convertFloatToHalf(rColor.red / 255.f);
      v[1] = convertFloatToHalf(rColor.green / 255.f);
      v[2] = convertFloatToHalf(rColor.blue / 255.f);
      v[3] = convertFloatToHalf(rColor.alpha / 255.f);
      break;
   }

   // --- 128-bit ---
   case GFXFormatR32G32B32A32F:
   {
      F32* v = (F32*)p;
      v[0] = rColor.red / 255.f;
      v[1] = rColor.green / 255.f;
      v[2] = rColor.blue / 255.f;
      v[3] = rColor.alpha / 255.f;
      break;
   }

   default:
      AssertFatal(false, "Bad internal format in setColor");
      return false;
   }

   return true;
}

//--------------------------------------------------------------------------
U8 GBitmap::getChanelValueAt(U32 x, U32 y, U32 chan)
{
   ColorI pixelColor = ColorI(255,255,255,255);
   getColor(x, y, pixelColor);
   if (mInternalFormat == GFXFormatL16 || mInternalFormat == GFXFormatL8)
   {
      chan = 0;
   }
   switch (chan) {
   case 0: return pixelColor.red;
   case 1: return pixelColor.green;
   case 2: return pixelColor.blue;
   default: return pixelColor.alpha;
   }
}

//-----------------------------------------------------------------------------

bool GBitmap::combine( const GBitmap *bitmapA, const GBitmap *bitmapB, const TextureOp combineOp )
{
   // Check bitmapA format
   switch( bitmapA->getFormat() )
   {
   case GFXFormatR8G8B8:
   case GFXFormatR8G8B8X8:
   case GFXFormatR8G8B8A8:
      break;

   default:
      Con::errorf( "GBitmap::combine - invalid format for bitmapA" );
      return false;
   }

   // Check bitmapB format
   switch( bitmapB->getFormat() )
   {
   case GFXFormatR8G8B8:
   case GFXFormatR8G8B8X8:
   case GFXFormatR8G8B8A8:
      break;

   default:
      Con::errorf( "GBitmap::combine - invalid format for bitmapB" );
      return false;
   }

   // Determine format of result texture
   // CodeReview: This is dependent on the order of the GFXFormat enum. [5/11/2007 Pat]
   GFXFormat resFmt = static_cast<GFXFormat>( getMax( bitmapA->getFormat(), bitmapB->getFormat() ) );
   U32 resWidth = getMax( bitmapA->getWidth(), bitmapB->getWidth() );
   U32 resHeight = getMax( bitmapA->getHeight(), bitmapB->getHeight() );

   // Adjust size OF bitmap based on the biggest one
   if( bitmapA->getWidth() != bitmapB->getWidth() ||
       bitmapA->getHeight() != bitmapB->getHeight() )
   {
      // Delete old bitmap
      deleteImage();

      // Allocate new one
      allocateBitmap( resWidth, resHeight, false, resFmt );
   }
   
   // Adjust format of result bitmap (if resFmt == getFormat() it will not perform the format convert)
   setFormat( resFmt );

   // Perform combine
   U8 *destBits = getWritableBits();
   const U8 *aBits = bitmapA->getBits();
   const U8 *bBits = bitmapB->getBits();

   for( S32 y = 0; y < getHeight(); y++ )
   {
      for( S32 x = 0; x < getWidth(); x++ )
      {
         for( S32 _byte = 0; _byte < mBytesPerPixel; _byte++ )
         {
            U8 pxA = 0;
            U8 pxB = 0;

            // Get contributions from A and B
            if( y < bitmapA->getHeight() && 
                x < bitmapA->getWidth() &&
                _byte < bitmapA->mBytesPerPixel )
               pxA = *aBits++;

            if( y < bitmapB->getHeight() && 
               x < bitmapB->getWidth() &&
               _byte < bitmapB->mBytesPerPixel )
               pxB = *bBits++;

            // Combine them (clamp values 0-U8_MAX)
            switch( combineOp )
            {
               case Add:
                  *destBits++ = getMin( U8( pxA + pxB ), U8_MAX );
                  break;

               case Subtract:
                  *destBits++ = getMax( U8( pxA - pxB ), U8( 0 ) );
                  break;
               default:
                  AssertFatal(false, "GBitmap::combine - Invalid combineOp");
                  break;
            }
         }
      }
   }

   return true;
}

void GBitmap::fill( const ColorI &rColor )
{
   // Set the first pixel using the slow 
   // but proper method.
   setColor( 0, 0, rColor );
   mHasTransparency = rColor.alpha < 255;
      
   // Now fill the first row of the bitmap by 
   // copying the first pixel across the row.
   const U32 stride = getWidth() * mBytesPerPixel;
   const U8 *src = getBits();
   U8 *dest = getWritableBits() + mBytesPerPixel;
   const U8 *end = src + stride;
   for ( ; dest != end; dest += mBytesPerPixel )
      dMemcpy( dest, src, mBytesPerPixel );

   // Now copy the first row to all the others.
   // 
   // TODO: This could adaptively size the copy 
   // amount to copy more rows from the source
   // and reduce the total number of memcpy calls.
   //
   dest = getWritableBits() + stride;
   end = src + ( stride * getHeight() );
   for ( ; dest != end; dest += stride )
      dMemcpy( dest, src, stride );
}

void GBitmap::fillWhite()
{
   dMemset( getWritableBits(), 255, mByteSize );
   mHasTransparency = false;
}

GBitmap* GBitmap::createPaddedBitmap() const
{
   if (isPow2(getWidth()) && isPow2(getHeight()))
      return NULL;

   AssertFatal(getNumMipLevels() == 1,
      "Cannot have non-pow2 bitmap with miplevels");

   U32 width = getWidth();
   U32 height = getHeight();

   U32 newWidth  = getNextPow2(getWidth());
   U32 newHeight = getNextPow2(getHeight());

   GBitmap* pReturn = new GBitmap(newWidth, newHeight, false, getFormat());

   for (U32 i = 0; i < height; i++) 
   {
      U8*       pDest = (U8*)pReturn->getAddress(0, i);
      const U8* pSrc  = (const U8*)getAddress(0, i);

      dMemcpy(pDest, pSrc, width * mBytesPerPixel);

      pDest += width * mBytesPerPixel;
      // set the src pixel to the last pixel in the row
      const U8 *pSrcPixel = pDest - mBytesPerPixel; 

      for(U32 j = width; j < newWidth; j++)
         for(U32 k = 0; k < mBytesPerPixel; k++)
            *pDest++ = pSrcPixel[k];
   }

   for(U32 i = height; i < newHeight; i++)
   {
      U8* pDest = (U8*)pReturn->getAddress(0, i);
      U8* pSrc = (U8*)pReturn->getAddress(0, height-1);
      dMemcpy(pDest, pSrc, newWidth * mBytesPerPixel);
   }

   return pReturn;
}

GBitmap* GBitmap::createPow2Bitmap() const
{
   if (isPow2(getWidth()) && isPow2(getHeight()))
      return NULL;

   AssertFatal(getNumMipLevels() == 1,
               "Cannot have non-pow2 bitmap with miplevels");

   U32 width = getWidth();
   U32 height = getHeight();

   U32 newWidth  = getNextPow2(getWidth());
   U32 newHeight = getNextPow2(getHeight());

   GBitmap* pReturn = new GBitmap(newWidth, newHeight, false, getFormat());

   U8*       pDest = (U8*)pReturn->getAddress(0, 0);
   const U8* pSrc  = (const U8*)getAddress(0, 0);

   F32 yCoeff = (F32) height / (F32) newHeight;
   F32 xCoeff = (F32) width / (F32) newWidth;

   F32 currY = 0.0f;
   for (U32 y = 0; y < newHeight; y++)
   {
      F32 currX = 0.0f;
      //U32 yDestOffset = (pReturn->mWidth * pReturn->mBytesPerPixel) * y;
      //U32 xDestOffset = 0;
      //U32 ySourceOffset = (U32)((mWidth * mBytesPerPixel) * currY);
      //F32 xSourceOffset = 0.0f;
      for (U32 x = 0; x < newWidth; x++)
      {
         pDest = (U8*) pReturn->getAddress(x, y);
         pSrc = (U8*) getAddress((S32)currX, (S32)currY);
         for (U32 p = 0; p < pReturn->mBytesPerPixel; p++) 
         {
            pDest[p] = pSrc[p];
         }
         currX += xCoeff;
      }
      currY += yCoeff;
   }

   return pReturn;
}

void GBitmap::copyChannel( U32 index, GBitmap *outBitmap ) const
{
   AssertFatal( index < mBytesPerPixel, "GBitmap::copyChannel() - Bad channel offset!" );
   AssertFatal( outBitmap, "GBitmap::copyChannel() - Null output bitmap!" );   
   AssertFatal( outBitmap->getWidth() == getWidth(), "GBitmap::copyChannel() - Width mismatch!" );
   AssertFatal( outBitmap->getHeight() == getHeight(), "GBitmap::copyChannel() - Height mismatch!" );

   U8 *outBits = outBitmap->getWritableBits();
   const U32 outBytesPerPixel = outBitmap->getBytesPerPixel();
   const U8 *srcBits = getBits() + index;
   const U8 *endBits = getBits() + mByteSize;

   for (  ; srcBits < endBits;  )
   {
      *outBits = *srcBits;
      outBits += outBytesPerPixel;
      srcBits += mBytesPerPixel;
   }
}

//------------------------------------------------------------------------------

bool GBitmap::read(Stream& io_rStream)
{
   PROFILE_SCOPE(GBitmap_Read);
   // Handle versioning
   U32 version;
   io_rStream.read(&version);
   AssertFatal(version == csFileVersion, "Bitmap::read: incorrect file version");

   //-------------------------------------- Read the object
   U32 fmt;
   io_rStream.read(&fmt);
   mInternalFormat = GFXFormat(fmt);
   mBytesPerPixel = getFormatBytesPerPixel(mInternalFormat);

   io_rStream.read(&mByteSize);

   mBits = new U8[mByteSize];
   io_rStream.read(mByteSize, mBits);

   io_rStream.read(&mWidth);
   io_rStream.read(&mHeight);

   io_rStream.read(&mNumMipLevels);
   for (U32 i = 0; i < c_maxMipLevels; i++)
      io_rStream.read(&mMipLevelOffsets[i]);

   checkForTransparency();

   return (io_rStream.getStatus() == Stream::Ok);
}

bool GBitmap::write(Stream& io_rStream) const
{
   PROFILE_SCOPE(GBitmap_Write);
   // Handle versioning
   io_rStream.write(csFileVersion);

   //-------------------------------------- Write the object
   io_rStream.write(U32(mInternalFormat));

   io_rStream.write(mByteSize);
   io_rStream.write(mByteSize, mBits);

   io_rStream.write(mWidth);
   io_rStream.write(mHeight);

   io_rStream.write(mNumMipLevels);
   for (U32 i = 0; i < c_maxMipLevels; i++)
      io_rStream.write(mMipLevelOffsets[i]);

   return (io_rStream.getStatus() == Stream::Ok);
}

//------------------------------------------------------------------------------
//-------------------------------------- Persistent I/O
//

bool  GBitmap::readBitmap(const String& bmType, const Torque::Path& path)
{
   PROFILE_SCOPE(ResourceGBitmap_readBitmap);
   const GBitmap::Registration   *regInfo = GBitmap::sFindRegInfo( bmType );

   if ( regInfo == NULL )
   {
      Con::errorf( "[GBitmap::readBitmap] unable to find registration for extension [%s]", bmType.c_str() );
      return false;
   }

   return regInfo->readFunc(path, this);
}

bool GBitmap::readBitmapStream(const String& bmType, Stream& ioStream, U32 len)
{
   PROFILE_SCOPE(ResourceGBitmap_readBitmapStream);
   const GBitmap::Registration* regInfo = GBitmap::sFindRegInfo(bmType);

   if (regInfo == NULL)
   {
      Con::errorf("[GBitmap::readBitmap] unable to find registration for extension [%s]", bmType.c_str());
      return false;
   }

   return regInfo->readStreamFunc(ioStream, this, len);
}

bool  GBitmap::writeBitmap( const String &bmType, const Torque::Path& path, U32 compressionLevel )
{
   FileStream stream;
   if (!stream.open(path, Torque::FS::File::Write))
   {
      Con::errorf("GBitmap::writeBitmap failed to open path %s", path.getFullFileName().c_str());
      stream.close();
      return false;
   }

   // free file for stb
   stream.close();

   const GBitmap::Registration   *regInfo = GBitmap::sFindRegInfo( bmType );

   if ( regInfo == NULL )
   {
      Con::errorf( "[GBitmap::writeBitmap] unable to find registration for extension [%s]", bmType.c_str() );
      return false;
   }

   return regInfo->writeFunc(path, this, (compressionLevel == U32_MAX) ? regInfo->defaultCompression : compressionLevel );
}

bool GBitmap::writeBitmapStream(const String& bmType, Stream& ioStream, U32 compressionLevel)
{
   const GBitmap::Registration* regInfo = GBitmap::sFindRegInfo(bmType);

   if (regInfo == NULL)
   {
      Con::errorf("[GBitmap::writeBitmap] unable to find registration for extension [%s]", bmType.c_str());
      return false;
   }

   return regInfo->writeStreamFunc(bmType, ioStream, this, (compressionLevel == U32_MAX) ? regInfo->defaultCompression : compressionLevel);
}

template<> void *Resource<GBitmap>::create(const Torque::Path &path)
{
   PROFILE_SCOPE( ResourceGBitmap_create );

#ifdef TORQUE_DEBUG_RES_MANAGER
   Con::printf( "Resource<GBitmap>::create - [%s]", path.getFullPath().c_str() );
#endif

   GBitmap* bmp = new GBitmap;
   FileStream  stream;

   Torque::Path dbm = path;
   dbm.setExtension("dbm");
   if (Torque::FS::IsFile(dbm))
   {

      Torque::FS::FileNodeRef assetFile = Torque::FS::GetFileNode(path);
      Torque::FS::FileNodeRef compiledFile = Torque::FS::GetFileNode(dbm);

      if (assetFile != NULL && compiledFile != NULL)
      {
         if (compiledFile->getModifiedTime() >= assetFile->getModifiedTime())
         {
#ifdef TORQUE_DEBUG_RES_MANAGER
            Con::printf("Resource<GBitmap>::create - Loading cached image file: %s", dbm.getFullPath().c_str());
#endif
            stream.open(dbm.getFullPath(), Torque::FS::File::Read);
            bmp->read(stream);
            return bmp;
         }
      }
   }

   stream.open( path.getFullPath(), Torque::FS::File::Read );

   if ( stream.getStatus() != Stream::Ok )
   {
      Con::errorf( "Resource<GBitmap>::create - failed to open '%s'", path.getFullPath().c_str() );
      return NULL;
   }

   const String extension = path.getExtension();
   if( !bmp->readBitmap( extension, path ) )
   {
      // we can only get here if the stream was successful, so attempt to read the stream.
      Con::warnf("Was unable to load as file, going to try the stream instead.");
      if (!bmp->readBitmapStream(extension, stream, stream.getStreamSize()))
      {
         Con::errorf("Resource<GBitmap>::create - error reading '%s'", path.getFullPath().c_str());
         delete bmp;
         bmp = NULL;
      }
   }

   return bmp;
}

template<> ResourceBase::Signature  Resource<GBitmap>::signature()
{
   return MakeFourCC('b','i','t','m');
}

Resource<GBitmap> GBitmap::load(const Torque::Path &path)
{
   Resource<GBitmap> ret = _load( path );
   if ( ret != NULL )
      return ret;

   // Do a recursive search.
   return _search( path );
}

Resource<GBitmap> GBitmap::_load(const Torque::Path &path)
{
   PROFILE_SCOPE( GBitmap_load );

   if ( Torque::FS::IsFile( path ) )
      return ResourceManager::get().load( path );
  
   Path foundPath;
   if ( GBitmap::sFindFile( path, &foundPath ) )
   {
      Resource<GBitmap> ret = ResourceManager::get().load( foundPath );
      if ( ret != NULL )
         return ret;
   }

   return Resource< GBitmap >( NULL );
}

Resource<GBitmap> GBitmap::_search(const Torque::Path &path)
{
   PROFILE_SCOPE( GBitmap_search );

   // If unable to load texture in current directory
   // look in the parent directory.  But never look in the root.
   Path newPath( path );
   while ( true )
   {
      String filePath = newPath.getPath();
      String::SizeType slash = filePath.find( '/', filePath.length(), String::Right );

      if ( slash == String::NPos )
         break;

      slash = filePath.find( '/', filePath.length(), String::Right );
      if ( slash == String::NPos )
         break;

      String truncPath = filePath.substr( 0, slash );
      newPath.setPath( truncPath );

      Resource<GBitmap> ret = _load( newPath );
      if ( ret != NULL )
         return ret;
   }

   return Resource< GBitmap >( NULL );
}

U32 GBitmap::getSurfaceSize(const U32 mipLevel) const
{
   // Bump by the mip level.
   U32 height = getMax(U32(1), mHeight >> mipLevel);
   U32 width = getMax(U32(1), mWidth >> mipLevel);

   if (mInternalFormat >= GFXFormatBC1 && mInternalFormat <= GFXFormatBC3)
   {
      // From the directX docs:
      // max(1, width / 4) x max(1, height / 4) x 8(DXT1) or 16(DXT2-5)

      U32 sizeMultiple = 0;

      switch (mInternalFormat)
      {
      case GFXFormatBC1:
         sizeMultiple = 8;
         break;
      case GFXFormatBC2:
      case GFXFormatBC3:
         sizeMultiple = 16;
         break;
      default:
         AssertISV(false, "DDSFile::getSurfaceSize - invalid compressed texture format, we only support DXT1-5 right now.");
         break;
      }

      return getMax(U32(1), width / 4) * getMax(U32(1), height / 4) * sizeMultiple;
   }
   else
   {
      return height * width* mBytesPerPixel;
   }
}

DefineEngineFunction( getBitmapInfo, String, ( const char *filename ),,
   "Returns image info in the following format: width TAB height TAB bytesPerPixel TAB format. "
   "It will return an empty string if the file is not found.\n"
   "@ingroup Rendering\n" )
{
   Resource<GBitmap> image = GBitmap::load( filename );
   if ( !image )
      return String::EmptyString;

   return String::ToString( "%d\t%d\t%d\t%d", image->getWidth(), 
                                          image->getHeight(),
                                          image->getBytesPerPixel(),
                                          image->getFormat());
}

DefineEngineFunction(saveScaledImage, bool, (const char* bitmapSource, const char* bitmapDest, S32 resolutionSize), ("", "", 256),
   "Loads an image from the source path, and scales it down to the target resolution before"
   "Saving it out to the destination path.\n")
{
   bool isDDS = false;
   bool isHDR = false;

   if (bitmapSource == 0 || bitmapSource[0] == '\0' || bitmapDest == 0 || bitmapDest[0] == '\0')
   {
      return false;
   }

   if (!Platform::isFile(bitmapSource))
   {
      return false;
   }

   //First, gotta check the extension, as we have some extra work to do if it's
   //a DDS file
   const char* ret = dStrrchr(bitmapSource, '.');
   if (ret)
   {
      if (String::ToLower(ret) == String(".dds"))
         isDDS = true;

      if (String::ToLower(ret) == String(".hdr"))
         isHDR = true;
   }
   else
   {
      return false; //no extension? bail out
   }

   GBitmap* image = NULL;
   if (isDDS)
   {
      Resource<DDSFile> dds = DDSFile::load(bitmapSource, 0);
      if (dds != NULL)
      {
         image = new GBitmap();
         if (!dds->decompressToGBitmap(image))
         {
            delete image;
            image = NULL;
         }
      }
   }
   else
   {
      Resource<GBitmap> resImage = GBitmap::load(bitmapSource);
      image = new GBitmap(*resImage);
   }

   if (!image)
      return false;
   Torque::Path sourcePath = Torque::Path(bitmapSource);

   if (isPow2(image->getWidth()) && isPow2(image->getHeight()))
      image->extrudeMipLevels();

   image->setFormat(GFXFormatR8G8B8A8);

   U32 mipCount = image->getNumMipLevels();
   U32 targetMips = mFloor(mLog2((F32)(resolutionSize ? resolutionSize : 256))) + 1;

   if (mipCount > targetMips)
   {
      image->chopTopMips(mipCount - targetMips);
   }

   //TODO: support different format targets, for now we just force
   //to png for simplicity
   Torque::Path destinationPath = Torque::Path(bitmapDest);
   destinationPath.setExtension("png");

   if(!image->writeBitmap("png", destinationPath.getFullPath()))
   {
      Con::errorf("saveScaledImage() - Error writing %s !", bitmapDest);
      delete image;
      return false;
   }

   
   delete image;
   return true;
}