llimage.cpp

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#include "linden_common.h"

#include "llimage.h"

#include "llmath.h"
#include "v4coloru.h"
#include "llmemtype.h"

#include "llimagebmp.h"
#include "llimagetga.h"
#include "llimagej2c.h"
#if JPEG_SUPPORT
#include "llimagejpeg.h"
#endif
#include "llimagedxt.h"

//---------------------------------------------------------------------------
// LLImageBase
//---------------------------------------------------------------------------

LLImageBase::LLImageBase()
        : mData(NULL),
          mDataSize(0),
          mWidth(0),
          mHeight(0),
          mComponents(0),
          mMemType(LLMemType::MTYPE_IMAGEBASE)
{
}

// virtual
LLImageBase::~LLImageBase()
{
        deleteData(); // virtual
}

// virtual
void LLImageBase::dump()
{
        llinfos << "LLImageBase mComponents " << mComponents
                << " mData " << mData
                << " mDataSize " << mDataSize
                << " mWidth " << mWidth
                << " mHeight " << mHeight
                << llendl;
}

// virtual
void LLImageBase::sanityCheck()
{
        if (mWidth > MAX_IMAGE_SIZE
                || mHeight > MAX_IMAGE_SIZE
                || mDataSize > (S32)MAX_IMAGE_DATA_SIZE
                || mComponents > (S8)MAX_IMAGE_COMPONENTS
                )
        {
                llerrs << "Failed LLImageBase::sanityCheck "
                           << "width " << mWidth
                           << "height " << mHeight
                           << "datasize " << mDataSize
                           << "components " << mComponents
                           << "data " << mData
                           << llendl;
        }
}

LLString LLImageBase::sLastErrorMessage;
BOOL LLImageBase::sSizeOverride = FALSE;

BOOL LLImageBase::setLastError(const LLString& message, const LLString& filename) 
{
        sLastErrorMessage = message;
        if (filename != "")
        {
                sLastErrorMessage += LLString(" FILE:");
                sLastErrorMessage += filename;
        }
        llwarns << sLastErrorMessage << llendl;
        return FALSE;
}

// virtual
void LLImageBase::deleteData()
{
        delete[] mData;
        mData = NULL;
        mDataSize = 0;
}

// virtual
U8* LLImageBase::allocateData(S32 size)
{
        LLMemType mt1((LLMemType::EMemType)mMemType);
        
        if (size < 0)
        {
                size = mWidth * mHeight * mComponents;
                if (size <= 0)
                {
                        llerrs << llformat("LLImageBase::allocateData called with bad dimentions: %dx%dx%d",mWidth,mHeight,mComponents) << llendl;
                }
        }
        else if (size <= 0 || (size > 4096*4096*16 && sSizeOverride == FALSE))
        {
                llerrs << "LLImageBase::allocateData: bad size: " << size << llendl;
        }
        
        resetLastError();

        if (!mData || size != mDataSize)
        {
                deleteData(); // virtual
                mData = new U8[size];
                if (!mData)
                {
                        llerrs << "allocate image data: " << size << llendl;
                }
                mDataSize = size;
        }

        return mData;
}

// virtual
U8* LLImageBase::reallocateData(S32 size)
{
        LLMemType mt1((LLMemType::EMemType)mMemType);
        U8 *new_datap = new U8[size];
        if (!new_datap)
        {
                llwarns << "Out of memory in LLImageBase::reallocateData" << llendl;
                return 0;
        }
        if (mData)
        {
                S32 bytes = llmin(mDataSize, size);
                memcpy(new_datap, mData, bytes);        /* Flawfinder: ignore */
                delete[] mData;
        }
        mData = new_datap;
        mDataSize = size;
        return mData;
}


void LLImageBase::setSize(S32 width, S32 height, S32 ncomponents)
{
        mWidth = width;
        mHeight = height;
        mComponents = ncomponents;
}

U8* LLImageBase::allocateDataSize(S32 width, S32 height, S32 ncomponents, S32 size)
{
        setSize(width, height, ncomponents);
        return allocateData(size); // virtual
}

//---------------------------------------------------------------------------
// LLImageRaw
//---------------------------------------------------------------------------

S32 LLImageRaw::sGlobalRawMemory = 0;
S32 LLImageRaw::sRawImageCount = 0;

LLImageRaw::LLImageRaw()
        : LLImageBase()
{
        mMemType = LLMemType::MTYPE_IMAGERAW;
        ++sRawImageCount;
}

LLImageRaw::LLImageRaw(U16 width, U16 height, S8 components)
        : LLImageBase()
{
        mMemType = LLMemType::MTYPE_IMAGERAW;
        llassert( S32(width) * S32(height) * S32(components) <= MAX_IMAGE_DATA_SIZE );
        allocateDataSize(width, height, components);
        ++sRawImageCount;
}

LLImageRaw::LLImageRaw(U8 *data, U16 width, U16 height, S8 components)
        : LLImageBase()
{
        mMemType = LLMemType::MTYPE_IMAGERAW;
        allocateDataSize(width, height, components);
        memcpy(getData(), data, width*height*components);
        ++sRawImageCount;
}

LLImageRaw::LLImageRaw(const LLString &filename, bool j2c_lowest_mip_only)
        : LLImageBase()
{
        createFromFile(filename, j2c_lowest_mip_only);
}

LLImageRaw::~LLImageRaw()
{
        // NOTE: ~LLimageBase() call to deleteData() calls LLImageBase::deleteData()
        //        NOT LLImageRaw::deleteData()
        deleteData();
        --sRawImageCount;
}

// virtual
U8* LLImageRaw::allocateData(S32 size)
{
        U8* res = LLImageBase::allocateData(size);
        sGlobalRawMemory += getDataSize();
        return res;
}

// virtual
U8* LLImageRaw::reallocateData(S32 size)
{
        sGlobalRawMemory -= getDataSize();
        U8* res = LLImageBase::reallocateData(size);
        sGlobalRawMemory += getDataSize();
        return res;
}

// virtual
void LLImageRaw::deleteData()
{
        sGlobalRawMemory -= getDataSize();
        LLImageBase::deleteData();
}

BOOL LLImageRaw::resize(U16 width, U16 height, S8 components)
{
        if ((getWidth() == width) && (getHeight() == height) && (getComponents() == components))
        {
                return TRUE;
        }
        // Reallocate the data buffer.
        deleteData();

        allocateDataSize(width,height,components);

        return TRUE;
}

U8 * LLImageRaw::getSubImage(U32 x_pos, U32 y_pos, U32 width, U32 height) const
{
        LLMemType mt1((LLMemType::EMemType)mMemType);
        U8 *data = new U8[width*height*getComponents()];

        // Should do some simple bounds checking
        if (!data)
        {
                llerrs << "Out of memory in LLImageRaw::getSubImage" << llendl;
                return NULL;
        }

        U32 i;
        for (i = y_pos; i < y_pos+height; i++)
        {
                memcpy(data + i*width*getComponents(),          /* Flawfinder: ignore */
                                getData() + ((y_pos + i)*getWidth() + x_pos)*getComponents(), getComponents()*width);
        }
        return data;
}

BOOL LLImageRaw::setSubImage(U32 x_pos, U32 y_pos, U32 width, U32 height,
                                                         const U8 *data, U32 stride, BOOL reverse_y)
{
        if (!getData())
        {
                return FALSE;
        }
        if (!data)
        {
                return FALSE;
        }

        // Should do some simple bounds checking

        U32 i;
        for (i = 0; i < height; i++)
        {
                const U32 row = reverse_y ? height - 1 - i : i;
                const U32 from_offset = row * ((stride == 0) ? width*getComponents() : stride);
                const U32 to_offset = (y_pos + i)*getWidth() + x_pos;
                memcpy(getData() + to_offset*getComponents(),           /* Flawfinder: ignore */
                                data + from_offset, getComponents()*width);
        }

        return TRUE;
}

void LLImageRaw::clear(U8 r, U8 g, U8 b, U8 a)
{
        llassert( getComponents() <= 4 );
        // This is fairly bogus, but it'll do for now.
        U8 *pos = getData();
        U32 x, y;
        for (x = 0; x < getWidth(); x++)
        {
                for (y = 0; y < getHeight(); y++)
                {
                        *pos = r;
                        pos++;
                        if (getComponents() == 1)
                        {
                                continue;
                        }
                        *pos = g;
                        pos++;
                        if (getComponents() == 2)
                        {
                                continue;
                        }
                        *pos = b;
                        pos++;
                        if (getComponents() == 3)
                        {
                                continue;
                        }
                        *pos = a;
                        pos++;
                }
        }
}

// Reverses the order of the rows in the image
void LLImageRaw::verticalFlip()
{
        LLMemType mt1((LLMemType::EMemType)mMemType);
        S32 row_bytes = getWidth() * getComponents();
        U8* line_buffer = new U8[row_bytes];
        if (!line_buffer )
        {
                llerrs << "Out of memory in LLImageRaw::verticalFlip()" << llendl;
                return;
        }
        S32 mid_row = getHeight() / 2;
        for( S32 row = 0; row < mid_row; row++ )
        {
                U8* row_a_data = getData() + row * row_bytes;
                U8* row_b_data = getData() + (getHeight() - 1 - row) * row_bytes;
                memcpy( line_buffer, row_a_data,  row_bytes );  /* Flawfinder: ignore */
                memcpy( row_a_data,  row_b_data,  row_bytes );  /* Flawfinder: ignore */
                memcpy( row_b_data,  line_buffer, row_bytes );  /* Flawfinder: ignore */
        }
        delete[] line_buffer;
}


void LLImageRaw::expandToPowerOfTwo(S32 max_dim, BOOL scale_image)
{
        // Find new sizes
        S32 new_width = MIN_IMAGE_SIZE;
        S32 new_height = MIN_IMAGE_SIZE;

        while( (new_width < getWidth()) && (new_width < max_dim) )
        {
                new_width <<= 1;
        }

        while( (new_height < getHeight()) && (new_height < max_dim) )
        {
                new_height <<= 1;
        }

        scale( new_width, new_height, scale_image );
}

void LLImageRaw::contractToPowerOfTwo(S32 max_dim, BOOL scale_image)
{
        // Find new sizes
        S32 new_width = max_dim;
        S32 new_height = max_dim;

        while( (new_width > getWidth()) && (new_width > MIN_IMAGE_SIZE) )
        {
                new_width >>= 1;
        }

        while( (new_height > getHeight()) && (new_height > MIN_IMAGE_SIZE) )
        {
                new_height >>= 1;
        }

        scale( new_width, new_height, scale_image );
}

void LLImageRaw::biasedScaleToPowerOfTwo(S32 max_dim)
{
        // Strong bias towards rounding down (to save bandwidth)
        // No bias would mean THRESHOLD == 1.5f;
        const F32 THRESHOLD = 1.75f; 

        // Find new sizes
        S32 larger_w = max_dim; // 2^n >= mWidth
        S32 smaller_w = max_dim;        // 2^(n-1) <= mWidth
        while( (smaller_w > getWidth()) && (smaller_w > MIN_IMAGE_SIZE) )
        {
                larger_w = smaller_w;
                smaller_w >>= 1;
        }
        S32 new_width = ( (F32)getWidth() / smaller_w > THRESHOLD ) ? larger_w : smaller_w;


        S32 larger_h = max_dim; // 2^m >= mHeight
        S32 smaller_h = max_dim;        // 2^(m-1) <= mHeight
        while( (smaller_h > getHeight()) && (smaller_h > MIN_IMAGE_SIZE) )
        {
                larger_h = smaller_h;
                smaller_h >>= 1;
        }
        S32 new_height = ( (F32)getHeight() / smaller_h > THRESHOLD ) ? larger_h : smaller_h;


        scale( new_width, new_height );
}




// Calculates (U8)(255*(a/255.f)*(b/255.f) + 0.5f).  Thanks, Jim Blinn!
inline U8 LLImageRaw::fastFractionalMult( U8 a, U8 b )
{
        U32 i = a * b + 128;
        return U8((i + (i>>8)) >> 8);
}


void LLImageRaw::composite( LLImageRaw* src )
{
        LLImageRaw* dst = this;  // Just for clarity.

        llassert( (3 == src->getComponents()) || (4 == src->getComponents()) );
        llassert( (3 == dst->getComponents()) || (4 == dst->getComponents()) );

        if( 3 == dst->getComponents() )
        {
                if( (src->getWidth() == dst->getWidth()) && (src->getHeight() == dst->getHeight()) )
                {
                        // No scaling needed
                        if( 3 == src->getComponents() )
                        {
                                copyUnscaled( src );  // alpha is one so just copy the data.
                        }
                        else
                        {
                                compositeUnscaled4onto3( src );
                        }
                }
                else
                {
                        if( 3 == src->getComponents() )
                        {
                                copyScaled( src );  // alpha is one so just copy the data.
                        }
                        else
                        {
                                compositeScaled4onto3( src );
                        }
                }
        }
        else
        {
                // 4 == dst->mComponents
                llassert(0); // not implemented yet.
        }
}

// Src and dst can be any size.  Src has 4 components.  Dst has 3 components.
void LLImageRaw::compositeScaled4onto3(LLImageRaw* src)
{
        LLMemType mt1((LLMemType::EMemType)mMemType);
        llinfos << "compositeScaled4onto3" << llendl;

        LLImageRaw* dst = this;  // Just for clarity.

        llassert( (4 == src->getComponents()) && (3 == dst->getComponents()) );

        // Vertical: scale but no composite
        S32 temp_data_size = src->getWidth() * dst->getHeight() * src->getComponents();
        U8* temp_buffer = new U8[ temp_data_size ];
        for( S32 col = 0; col < src->getWidth(); col++ )
        {
                copyLineScaled( src->getData() + (src->getComponents() * col), temp_buffer + (src->getComponents() * col), src->getHeight(), dst->getHeight(), src->getWidth(), src->getWidth() );
        }

        // Horizontal: scale and composite
        for( S32 row = 0; row < dst->getHeight(); row++ )
        {
                compositeRowScaled4onto3( temp_buffer + (src->getComponents() * src->getWidth() * row), dst->getData() + (dst->getComponents() * dst->getWidth() * row), src->getWidth(), dst->getWidth() );
        }

        // Clean up
        delete[] temp_buffer;
}


// Src and dst are same size.  Src has 4 components.  Dst has 3 components.
void LLImageRaw::compositeUnscaled4onto3( LLImageRaw* src )
{
        /*
        //test fastFractionalMult()
        {
                U8 i = 255;
                U8 j = 255;
                do
                {
                        do
                        {
                                llassert( fastFractionalMult(i, j) == (U8)(255*(i/255.f)*(j/255.f) + 0.5f) );
                        } while( j-- );
                } while( i-- );
        }
        */

        LLImageRaw* dst = this;  // Just for clarity.

        llassert( (3 == src->getComponents()) || (4 == src->getComponents()) );
        llassert( (src->getWidth() == dst->getWidth()) && (src->getHeight() == dst->getHeight()) );


        U8* src_data = src->getData();
        U8* dst_data = dst->getData();
        S32 pixels = getWidth() * getHeight();
        while( pixels-- )
        {
                U8 alpha = src_data[3];
                if( alpha )
                {
                        if( 255 == alpha )
                        {
                                dst_data[0] = src_data[0];
                                dst_data[1] = src_data[1];
                                dst_data[2] = src_data[2];
                        }
                        else
                        {

                                U8 transparency = 255 - alpha;
                                dst_data[0] = fastFractionalMult( dst_data[0], transparency ) + fastFractionalMult( src_data[0], alpha );
                                dst_data[1] = fastFractionalMult( dst_data[1], transparency ) + fastFractionalMult( src_data[1], alpha );
                                dst_data[2] = fastFractionalMult( dst_data[2], transparency ) + fastFractionalMult( src_data[2], alpha );
                        }
                }

                src_data += 4;
                dst_data += 3;
        }
}

// Fill the buffer with a constant color
void LLImageRaw::fill( const LLColor4U& color )
{
        S32 pixels = getWidth() * getHeight();
        if( 4 == getComponents() )
        {
                U32* data = (U32*) getData();
                for( S32 i = 0; i < pixels; i++ )
                {
                        data[i] = color.mAll;
                }
        }
        else
        if( 3 == getComponents() )
        {
                U8* data = getData();
                for( S32 i = 0; i < pixels; i++ )
                {
                        data[0] = color.mV[0];
                        data[1] = color.mV[1];
                        data[2] = color.mV[2];
                        data += 3;
                }
        }
}




// Src and dst can be any size.  Src and dst can each have 3 or 4 components.
void LLImageRaw::copy(LLImageRaw* src)
{
        LLImageRaw* dst = this;  // Just for clarity.

        llassert( (3 == src->getComponents()) || (4 == src->getComponents()) );
        llassert( (3 == dst->getComponents()) || (4 == dst->getComponents()) );

        if( (src->getWidth() == dst->getWidth()) && (src->getHeight() == dst->getHeight()) )
        {
                // No scaling needed
                if( src->getComponents() == dst->getComponents() )
                {
                        copyUnscaled( src );
                }
                else
                if( 3 == src->getComponents() )
                {
                        copyUnscaled3onto4( src );
                }
                else
                {
                        // 4 == src->getComponents()
                        copyUnscaled4onto3( src );
                }
        }
        else
        {
                // Scaling needed
                // No scaling needed
                if( src->getComponents() == dst->getComponents() )
                {
                        copyScaled( src );
                }
                else
                if( 3 == src->getComponents() )
                {
                        copyScaled3onto4( src );
                }
                else
                {
                        // 4 == src->getComponents()
                        copyScaled4onto3( src );
                }
        }
}

// Src and dst are same size.  Src and dst have same number of components.
void LLImageRaw::copyUnscaled(LLImageRaw* src)
{
        LLImageRaw* dst = this;  // Just for clarity.

        llassert( (3 == src->getComponents()) || (4 == src->getComponents()) );
        llassert( src->getComponents() == dst->getComponents() );
        llassert( (src->getWidth() == dst->getWidth()) && (src->getHeight() == dst->getHeight()) );

        memcpy( dst->getData(), src->getData(), getWidth() * getHeight() * getComponents() );   /* Flawfinder: ignore */
}


// Src and dst can be any size.  Src has 3 components.  Dst has 4 components.
void LLImageRaw::copyScaled3onto4(LLImageRaw* src)
{
        llassert( (3 == src->getComponents()) && (4 == getComponents()) );

        // Slow, but simple.  Optimize later if needed.
        LLImageRaw temp( src->getWidth(), src->getHeight(), 4);
        temp.copyUnscaled3onto4( src );
        copyScaled( &temp );
}


// Src and dst can be any size.  Src has 4 components.  Dst has 3 components.
void LLImageRaw::copyScaled4onto3(LLImageRaw* src)
{
        llassert( (4 == src->getComponents()) && (3 == getComponents()) );

        // Slow, but simple.  Optimize later if needed.
        LLImageRaw temp( src->getWidth(), src->getHeight(), 3);
        temp.copyUnscaled4onto3( src );
        copyScaled( &temp );
}


// Src and dst are same size.  Src has 4 components.  Dst has 3 components.
void LLImageRaw::copyUnscaled4onto3( LLImageRaw* src )
{
        LLImageRaw* dst = this;  // Just for clarity.

        llassert( (3 == dst->getComponents()) && (4 == src->getComponents()) );
        llassert( (src->getWidth() == dst->getWidth()) && (src->getHeight() == dst->getHeight()) );

        S32 pixels = getWidth() * getHeight();
        U8* src_data = src->getData();
        U8* dst_data = dst->getData();
        for( S32 i=0; i<pixels; i++ )
        {
                dst_data[0] = src_data[0];
                dst_data[1] = src_data[1];
                dst_data[2] = src_data[2];
                src_data += 4;
                dst_data += 3;
        }
}


// Src and dst are same size.  Src has 3 components.  Dst has 4 components.
void LLImageRaw::copyUnscaled3onto4( LLImageRaw* src )
{
        LLImageRaw* dst = this;  // Just for clarity.
        llassert( 3 == src->getComponents() );
        llassert( 4 == dst->getComponents() );
        llassert( (src->getWidth() == dst->getWidth()) && (src->getHeight() == dst->getHeight()) );

        S32 pixels = getWidth() * getHeight();
        U8* src_data = src->getData();
        U8* dst_data = dst->getData();
        for( S32 i=0; i<pixels; i++ )
        {
                dst_data[0] = src_data[0];
                dst_data[1] = src_data[1];
                dst_data[2] = src_data[2];
                dst_data[3] = 255;
                src_data += 3;
                dst_data += 4;
        }
}


// Src and dst can be any size.  Src and dst have same number of components.
void LLImageRaw::copyScaled( LLImageRaw* src )
{
        LLMemType mt1((LLMemType::EMemType)mMemType);
        LLImageRaw* dst = this;  // Just for clarity.

        llassert( (3 == src->getComponents()) || (4 == src->getComponents()) );
        llassert( src->getComponents() == dst->getComponents() );

        if( (src->getWidth() == dst->getWidth()) && (src->getHeight() == dst->getHeight()) )
        {
                memcpy( dst->getData(), src->getData(), getWidth() * getHeight() * getComponents() );   /* Flawfinder: ignore */
                return;
        }

        // Vertical
        S32 temp_data_size = src->getWidth() * dst->getHeight() * getComponents();
        U8* temp_buffer = new U8[ temp_data_size ];
        for( S32 col = 0; col < src->getWidth(); col++ )
        {
                copyLineScaled( src->getData() + (getComponents() * col), temp_buffer + (getComponents() * col), src->getHeight(), dst->getHeight(), src->getWidth(), src->getWidth() );
        }

        // Horizontal
        for( S32 row = 0; row < dst->getHeight(); row++ )
        {
                copyLineScaled( temp_buffer + (getComponents() * src->getWidth() * row), dst->getData() + (getComponents() * dst->getWidth() * row), src->getWidth(), dst->getWidth(), 1, 1 );
        }

        // Clean up
        delete[] temp_buffer;
}


void LLImageRaw::scale( S32 new_width, S32 new_height, BOOL scale_image_data )
{
        LLMemType mt1((LLMemType::EMemType)mMemType);
        llassert( (3 == getComponents()) || (4 == getComponents()) );

        S32 old_width = getWidth();
        S32 old_height = getHeight();
        
        if( (old_width == new_width) && (old_height == new_height) )
        {
                return;  // Nothing to do.
        }

        // Reallocate the data buffer.

        if (scale_image_data)
        {
                // Vertical
                S32 temp_data_size = old_width * new_height * getComponents();
                U8* temp_buffer = new U8[ temp_data_size ];
                for( S32 col = 0; col < old_width; col++ )
                {
                        copyLineScaled( getData() + (getComponents() * col), temp_buffer + (getComponents() * col), old_height, new_height, old_width, old_width );
                }

                deleteData();

                U8* new_buffer = allocateDataSize(new_width, new_height, getComponents());

                // Horizontal
                for( S32 row = 0; row < new_height; row++ )
                {
                        copyLineScaled( temp_buffer + (getComponents() * old_width * row), new_buffer + (getComponents() * new_width * row), old_width, new_width, 1, 1 );
                }

                // Clean up
                delete[] temp_buffer;
        }
        else
        {
                // copy out     existing image data
                S32     temp_data_size = old_width * old_height * getComponents();
                U8*     temp_buffer     = new U8[ temp_data_size ];
                if (!temp_buffer)
                {
                        llerrs << "Out of memory in LLImageRaw::scale( S32 new_width, S32 new_height, BOOL scale_image_data )" << llendl;
                        return;
                }
                memcpy(temp_buffer,     getData(), temp_data_size);     /* Flawfinder: ignore */

                // allocate     new     image data,     will delete     old     data
                U8*     new_buffer = allocateDataSize(new_width, new_height, getComponents());

                for( S32 row = 0; row < new_height;     row++ )
                {
                        if (row < old_height)
                        {
                                memcpy(new_buffer +     (new_width * row * getComponents()), temp_buffer + (old_width * row     * getComponents()),     getComponents() * llmin(old_width, new_width)); /* Flawfinder: ignore */
                                if (old_width < new_width)
                                {
                                        // pad out rest of row with     black
                                        memset(new_buffer +     (getComponents() * ((new_width * row) + old_width)), 0, getComponents() * (new_width - old_width));
                                }
                        }
                        else
                        {
                                // pad remaining rows with black
                                memset(new_buffer +     (new_width * row * getComponents()), 0, new_width *     getComponents());
                        }
                }

                // Clean up
                delete[] temp_buffer;
        }
}

void LLImageRaw::copyLineScaled( U8* in, U8* out, S32 in_pixel_len, S32 out_pixel_len, S32 in_pixel_step, S32 out_pixel_step )
{
        const S32 components = getComponents();
        llassert( components >= 1 && components <= 4 );

        const F32 ratio = F32(in_pixel_len) / out_pixel_len; // ratio of old to new
        const F32 norm_factor = 1.f / ratio;

        S32 goff = components >= 2 ? 1 : 0;
        S32 boff = components >= 3 ? 2 : 0;
        for( S32 x = 0; x < out_pixel_len; x++ )
        {
                // Sample input pixels in range from sample0 to sample1.
                // Avoid floating point accumulation error... don't just add ratio each time.  JC
                const F32 sample0 = x * ratio;
                const F32 sample1 = (x+1) * ratio;
                const S32 index0 = llfloor(sample0);                    // left integer (floor)
                const S32 index1 = llfloor(sample1);                    // right integer (floor)
                const F32 fract0 = 1.f - (sample0 - F32(index0));       // spill over on left
                const F32 fract1 = sample1 - F32(index1);                       // spill-over on right

                if( index0 == index1 )
                {
                        // Interval is embedded in one input pixel
                        S32 t0 = x * out_pixel_step * components;
                        S32 t1 = index0 * in_pixel_step * components;
                        U8* outp = out + t0;
                        U8* inp = in + t1;
                        for (S32 i = 0; i < components; ++i)
                        {
                                *outp = *inp;
                                ++outp;
                                ++inp;
                        }
                }
                else
                {
                        // Left straddle
                        S32 t1 = index0 * in_pixel_step * components;
                        F32 r = in[t1 + 0] * fract0;
                        F32 g = in[t1 + goff] * fract0;
                        F32 b = in[t1 + boff] * fract0;
                        F32 a = 0;
                        if( components == 4)
                        {
                                a = in[t1 + 3] * fract0;
                        }
                
                        // Central interval
                        if (components < 4)
                        {
                                for( S32 u = index0 + 1; u < index1; u++ )
                                {
                                        S32 t2 = u * in_pixel_step * components;
                                        r += in[t2 + 0];
                                        g += in[t2 + goff];
                                        b += in[t2 + boff];
                                }
                        }
                        else
                        {
                                for( S32 u = index0 + 1; u < index1; u++ )
                                {
                                        S32 t2 = u * in_pixel_step * components;
                                        r += in[t2 + 0];
                                        g += in[t2 + 1];
                                        b += in[t2 + 2];
                                        a += in[t2 + 3];
                                }
                        }

                        // right straddle
                        // Watch out for reading off of end of input array.
                        if( fract1 && index1 < in_pixel_len )
                        {
                                S32 t3 = index1 * in_pixel_step * components;
                                if (components < 4)
                                {
                                        U8 in0 = in[t3 + 0];
                                        U8 in1 = in[t3 + goff];
                                        U8 in2 = in[t3 + boff];
                                        r += in0 * fract1;
                                        g += in1 * fract1;
                                        b += in2 * fract1;
                                }
                                else
                                {
                                        U8 in0 = in[t3 + 0];
                                        U8 in1 = in[t3 + 1];
                                        U8 in2 = in[t3 + 2];
                                        U8 in3 = in[t3 + 3];
                                        r += in0 * fract1;
                                        g += in1 * fract1;
                                        b += in2 * fract1;
                                        a += in3 * fract1;
                                }
                        }

                        r *= norm_factor;
                        g *= norm_factor;
                        b *= norm_factor;
                        a *= norm_factor;  // skip conditional

                        S32 t4 = x * out_pixel_step * components;
                        out[t4 + 0] = U8(llround(r));
                        if (components >= 2)
                                out[t4 + 1] = U8(llround(g));
                        if (components >= 3)
                                out[t4 + 2] = U8(llround(b));
                        if( components == 4)
                                out[t4 + 3] = U8(llround(a));
                }
        }
}

void LLImageRaw::compositeRowScaled4onto3( U8* in, U8* out, S32 in_pixel_len, S32 out_pixel_len )
{
        llassert( getComponents() == 3 );

        const S32 IN_COMPONENTS = 4;
        const S32 OUT_COMPONENTS = 3;

        const F32 ratio = F32(in_pixel_len) / out_pixel_len; // ratio of old to new
        const F32 norm_factor = 1.f / ratio;

        for( S32 x = 0; x < out_pixel_len; x++ )
        {
                // Sample input pixels in range from sample0 to sample1.
                // Avoid floating point accumulation error... don't just add ratio each time.  JC
                const F32 sample0 = x * ratio;
                const F32 sample1 = (x+1) * ratio;
                const S32 index0 = S32(sample0);                        // left integer (floor)
                const S32 index1 = S32(sample1);                        // right integer (floor)
                const F32 fract0 = 1.f - (sample0 - F32(index0));       // spill over on left
                const F32 fract1 = sample1 - F32(index1);                       // spill-over on right

                U8 in_scaled_r;
                U8 in_scaled_g;
                U8 in_scaled_b;
                U8 in_scaled_a;

                if( index0 == index1 )
                {
                        // Interval is embedded in one input pixel
                        S32 t1 = index0 * IN_COMPONENTS;
                        in_scaled_r = in[t1 + 0];
                        in_scaled_g = in[t1 + 0];
                        in_scaled_b = in[t1 + 0];
                        in_scaled_a = in[t1 + 0];
                }
                else
                {
                        // Left straddle
                        S32 t1 = index0 * IN_COMPONENTS;
                        F32 r = in[t1 + 0] * fract0;
                        F32 g = in[t1 + 1] * fract0;
                        F32 b = in[t1 + 2] * fract0;
                        F32 a = in[t1 + 3] * fract0;
                
                        // Central interval
                        for( S32 u = index0 + 1; u < index1; u++ )
                        {
                                S32 t2 = u * IN_COMPONENTS;
                                r += in[t2 + 0];
                                g += in[t2 + 1];
                                b += in[t2 + 2];
                                a += in[t2 + 3];
                        }

                        // right straddle
                        // Watch out for reading off of end of input array.
                        if( fract1 && index1 < in_pixel_len )
                        {
                                S32 t3 = index1 * IN_COMPONENTS;
                                r += in[t3 + 0] * fract1;
                                g += in[t3 + 1] * fract1;
                                b += in[t3 + 2] * fract1;
                                a += in[t3 + 3] * fract1;
                        }

                        r *= norm_factor;
                        g *= norm_factor;
                        b *= norm_factor;
                        a *= norm_factor;

                        in_scaled_r = U8(llround(r));
                        in_scaled_g = U8(llround(g));
                        in_scaled_b = U8(llround(b));
                        in_scaled_a = U8(llround(a));
                }

                if( in_scaled_a )
                {
                        if( 255 == in_scaled_a )
                        {
                                out[0] = in_scaled_r;
                                out[1] = in_scaled_g;
                                out[2] = in_scaled_b;
                        }
                        else
                        {
                                U8 transparency = 255 - in_scaled_a;
                                out[0] = fastFractionalMult( out[0], transparency ) + fastFractionalMult( in_scaled_r, in_scaled_a );
                                out[1] = fastFractionalMult( out[1], transparency ) + fastFractionalMult( in_scaled_g, in_scaled_a );
                                out[2] = fastFractionalMult( out[2], transparency ) + fastFractionalMult( in_scaled_b, in_scaled_a );
                        }
                }
                out += OUT_COMPONENTS;
        }
}


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

static struct
{
        const char* exten;
        S8 codec;
}
file_extensions[] =
{
        { "bmp", IMG_CODEC_BMP },
        { "tga", IMG_CODEC_TGA },
        { "j2c", IMG_CODEC_J2C },
        { "jp2", IMG_CODEC_J2C },
        { "texture", IMG_CODEC_J2C },
        { "jpg", IMG_CODEC_JPEG },
        { "jpeg", IMG_CODEC_JPEG },
        { "mip", IMG_CODEC_DXT },
        { "dxt", IMG_CODEC_DXT },
        { "png", IMG_CODEC_PNG }
};
#define NUM_FILE_EXTENSIONS sizeof(file_extensions)/sizeof(file_extensions[0])

static LLString find_file(LLString &name, S8 *codec)
{
        LLString tname;
        for (int i=0; i<(int)(NUM_FILE_EXTENSIONS); i++)
        {
                tname = name + "." + LLString(file_extensions[i].exten);
                llifstream ifs(tname.c_str(), llifstream::binary);
                if (ifs.is_open())
                {
                        ifs.close();
                        if (codec)
                                *codec = file_extensions[i].codec;
                        return LLString(file_extensions[i].exten);
                }
        }
        return LLString("");
}

static S8 get_codec(const LLString& exten)
{
        for (int i=0; i<(int)(NUM_FILE_EXTENSIONS); i++)
        {
                if (exten == file_extensions[i].exten)
                        return file_extensions[i].codec;
        }
        return IMG_CODEC_INVALID;
}

bool LLImageRaw::createFromFile(const LLString &filename, bool j2c_lowest_mip_only)
{
        LLString name = filename;
        size_t dotidx = name.rfind('.');
        S8 codec = IMG_CODEC_INVALID;
        LLString exten;
        
        deleteData(); // delete any existing data

        if (dotidx != LLString::npos)
        {
                exten = name.substr(dotidx+1);
                LLString::toLower(exten);
                codec = get_codec(exten);
        }
        else
        {
                exten = find_file(name, &codec);
                name = name + "." + exten;
        }
        if (codec == IMG_CODEC_INVALID)
        {
                return false; // format not recognized
        }

        llifstream ifs(name.c_str(), llifstream::binary);
        if (!ifs.is_open())
        {
                // SJB: changed from llinfos to lldebugs to reduce spam
                lldebugs << "Unable to open image file: " << name << llendl;
                return false;
        }
        
        ifs.seekg (0, std::ios::end);
        int length = ifs.tellg();
        if (j2c_lowest_mip_only && length > 2048)
        {
                length = 2048;
        }
        ifs.seekg (0, std::ios::beg);

        if (!length)
        {
                llinfos << "Zero length file file: " << name << llendl;
                return false;
        }
        
        LLPointer<LLImageFormatted> image;
        switch(codec)
        {
          //case IMG_CODEC_RGB:
          case IMG_CODEC_BMP:
                image = new LLImageBMP();
                break;
          case IMG_CODEC_TGA:
                image = new LLImageTGA();
                break;
#if JPEG_SUPPORT
          case IMG_CODEC_JPEG:
                image = new LLImageJPEG();
                break;
#endif
          case IMG_CODEC_J2C:
                image = new LLImageJ2C();
                break;
          case IMG_CODEC_DXT:
                image = new LLImageDXT();
                break;
          default:
                return false;
        }
        llassert(image.notNull());

        U8 *buffer = image->allocateData(length);
        ifs.read ((char*)buffer, length);       /* Flawfinder: ignore */
        ifs.close();
        
        image->updateData();
        
        if (j2c_lowest_mip_only && codec == IMG_CODEC_J2C)
        {
                S32 width = image->getWidth();
                S32 height = image->getHeight();
                S32 discard_level = 0;
                while (width > 1 && height > 1 && discard_level < MAX_DISCARD_LEVEL)
                {
                        width >>= 1;
                        height >>= 1;
                        discard_level++;
                }
                ((LLImageJ2C *)((LLImageFormatted*)image))->setDiscardLevel(discard_level);
        }
        
        BOOL success = image->decode(this, 100000.0f);
        image = NULL; // deletes image

        if (!success)
        {
                deleteData();
                llwarns << "Unable to decode image" << name << llendl;
                return false;
        }

        return true;
}

//---------------------------------------------------------------------------
// LLImageFormatted
//---------------------------------------------------------------------------

//static
S32 LLImageFormatted::sGlobalFormattedMemory = 0;

LLImageFormatted::LLImageFormatted(S8 codec)
        : LLImageBase(),
          mCodec(codec),
          mDecoding(0),
          mDecoded(0),
          mDiscardLevel(0)
{
        mMemType = LLMemType::MTYPE_IMAGEFORMATTED;
}

// virtual
LLImageFormatted::~LLImageFormatted()
{
        // NOTE: ~LLimageBase() call to deleteData() calls LLImageBase::deleteData()
        //        NOT LLImageFormatted::deleteData()
        deleteData();
}

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

// static
LLImageFormatted* LLImageFormatted::createFromType(S8 codec)
{
        LLImageFormatted* image;
        switch(codec)
        {
          case IMG_CODEC_BMP:
                image = new LLImageBMP();
                break;
          case IMG_CODEC_TGA:
                image = new LLImageTGA();
                break;
#if JPEG_SUPPORT
          case IMG_CODEC_JPEG:
                image = new LLImageJPEG();
                break;
#endif
          case IMG_CODEC_J2C:
                image = new LLImageJ2C();
                break;
          case IMG_CODEC_DXT:
                image = new LLImageDXT();
                break;
          default:
                image = NULL;
                break;
        }
        return image;
}

// static
LLImageFormatted* LLImageFormatted::createFromExtension(const LLString& instring)
{
        LLString exten;
        size_t dotidx = instring.rfind('.');
        if (dotidx != LLString::npos)
        {
                exten = instring.substr(dotidx+1);
        }
        else
        {
                exten = instring;
        }
        S8 codec = get_codec(exten);
        return createFromType(codec);
}
//----------------------------------------------------------------------------

// virtual
void LLImageFormatted::dump()
{
        LLImageBase::dump();

        llinfos << "LLImageFormatted"
                        << " mDecoding " << mDecoding
                        << " mCodec " << S32(mCodec)
                        << " mDecoded " << mDecoded
                        << llendl;
}

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

S32 LLImageFormatted::calcDataSize(S32 discard_level)
{
        if (discard_level < 0)
        {
                discard_level = mDiscardLevel;
        }
        S32 w = getWidth() >> discard_level;
        S32 h = getHeight() >> discard_level;
        w = llmax(w, 1);
        h = llmax(h, 1);
        return w * h * getComponents();
}

S32 LLImageFormatted::calcDiscardLevelBytes(S32 bytes)
{
        llassert(bytes >= 0);
        S32 discard_level = 0;
        while (1)
        {
                S32 bytes_needed = calcDataSize(discard_level); // virtual
                if (bytes_needed <= bytes)
                {
                        break;
                }
                discard_level++;
                if (discard_level > MAX_IMAGE_MIP)
                {
                        return -1;
                }
        }
        return discard_level;
}


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

// Subclasses that can handle more than 4 channels should override this function.
BOOL LLImageFormatted::decode(LLImageRaw* raw_image,F32  decode_time, S32 first_channel, S32 max_channel)
{
        llassert( (first_channel == 0) && (max_channel == 4) );
        return decode( raw_image, decode_time );  // Loads first 4 channels by default.
} 

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

// virtual
U8* LLImageFormatted::allocateData(S32 size)
{
        U8* res = LLImageBase::allocateData(size); // calls deleteData()
        sGlobalFormattedMemory += getDataSize();
        return res;
}

// virtual
U8* LLImageFormatted::reallocateData(S32 size)
{
        sGlobalFormattedMemory -= getDataSize();
        U8* res = LLImageBase::reallocateData(size);
        sGlobalFormattedMemory += getDataSize();
        return res;
}

// virtual
void LLImageFormatted::deleteData()
{
        sGlobalFormattedMemory -= getDataSize();
        LLImageBase::deleteData();
}

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

// virtual
void LLImageFormatted::sanityCheck()
{
        LLImageBase::sanityCheck();

        if (mCodec >= IMG_CODEC_EOF)
        {
                llerrs << "Failed LLImageFormatted::sanityCheck "
                           << "decoding " << S32(mDecoding)
                           << "decoded " << S32(mDecoded)
                           << "codec " << S32(mCodec)
                           << llendl;
        }
}

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

BOOL LLImageFormatted::copyData(U8 *data, S32 size)
{
        if ( data && ((data != getData()) || (size != getDataSize())) )
        {
                deleteData();
                allocateData(size);
                memcpy(getData(), data, size);  /* Flawfinder: ignore */
        }
        return TRUE;
}

// LLImageFormatted becomes the owner of data
void LLImageFormatted::setData(U8 *data, S32 size)
{
        if (data && data != getData())
        {
                deleteData();
                setDataAndSize(data, size); // Access private LLImageBase members
                sGlobalFormattedMemory += getDataSize();
        }
}

void LLImageFormatted::appendData(U8 *data, S32 size)
{
        if (data)
        {
                if (!getData())
                {
                        setData(data, size);
                }
                else 
                {
                        S32 cursize = getDataSize();
                        S32 newsize = cursize + size;
                        reallocateData(newsize);
                        memcpy(getData() + cursize, data, size);
                }
        }
}

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

BOOL LLImageFormatted::load(const LLString &filename)
{
        resetLastError();

        S32 file_size = 0;
        apr_file_t* apr_file = ll_apr_file_open(filename, LL_APR_RB, &file_size);
        if (!apr_file)
        {
                setLastError("Unable to open file for reading", filename);
                return FALSE;
        }
        if (file_size == 0)
        {
                setLastError("File is empty",filename);
                apr_file_close(apr_file);
                return FALSE;
        }

        BOOL res;
        U8 *data = allocateData(file_size);
        apr_size_t bytes_read = file_size;
        apr_status_t s = apr_file_read(apr_file, data, &bytes_read); // modifies bytes_read
        if (s != APR_SUCCESS || (S32) bytes_read != file_size)
        {
                deleteData();
                setLastError("Unable to read entire file",filename);
                res = FALSE;
        }
        else
        {
                res = updateData();
        }
        apr_file_close(apr_file);

        return res;
}

BOOL LLImageFormatted::save(const LLString &filename)
{
        resetLastError();

        apr_file_t* apr_file = ll_apr_file_open(filename, LL_APR_WB);
        if (!apr_file)
        {
                setLastError("Unable to open file for reading", filename);
                return FALSE;
        }
        
        ll_apr_file_write(apr_file, getData(),  getDataSize());
        apr_file_close(apr_file);

        return TRUE;
}

// BOOL LLImageFormatted::save(LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type)
// Depricated to remove VFS dependency.
// Use:
// LLVFile::writeFile(image->getData(), image->getDataSize(), vfs, uuid, type);

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

S8 LLImageFormatted::getCodec() const
{
        return mCodec;
}

//============================================================================

static void avg4_colors4(const U8* a, const U8* b, const U8* c, const U8* d, U8* dst)
{
        dst[0] = (U8)(((U32)(a[0]) + b[0] + c[0] + d[0])>>2);
        dst[1] = (U8)(((U32)(a[1]) + b[1] + c[1] + d[1])>>2);
        dst[2] = (U8)(((U32)(a[2]) + b[2] + c[2] + d[2])>>2);
        dst[3] = (U8)(((U32)(a[3]) + b[3] + c[3] + d[3])>>2);
}

static void avg4_colors3(const U8* a, const U8* b, const U8* c, const U8* d, U8* dst)
{
        dst[0] = (U8)(((U32)(a[0]) + b[0] + c[0] + d[0])>>2);
        dst[1] = (U8)(((U32)(a[1]) + b[1] + c[1] + d[1])>>2);
        dst[2] = (U8)(((U32)(a[2]) + b[2] + c[2] + d[2])>>2);
}

static void avg4_colors2(const U8* a, const U8* b, const U8* c, const U8* d, U8* dst)
{
        dst[0] = (U8)(((U32)(a[0]) + b[0] + c[0] + d[0])>>2);
        dst[1] = (U8)(((U32)(a[1]) + b[1] + c[1] + d[1])>>2);
}

//static
void LLImageBase::generateMip(const U8* indata, U8* mipdata, S32 width, S32 height, S32 nchannels)
{
        llassert(width > 0 && height > 0);
        U8* data = mipdata;
        S32 in_width = width*2;
        for (S32 h=0; h<height; h++)
        {
                for (S32 w=0; w<width; w++)
                {
                        switch(nchannels)
                        {
                          case 4:
                                avg4_colors4(indata, indata+4, indata+4*in_width, indata+4*in_width+4, data);
                                break;
                          case 3:
                                avg4_colors3(indata, indata+3, indata+3*in_width, indata+3*in_width+3, data);
                                break;
                          case 2:
                                avg4_colors2(indata, indata+2, indata+2*in_width, indata+2*in_width+2, data);
                                break;
                          case 1:
                                *(U8*)data = (U8)(((U32)(indata[0]) + indata[1] + indata[in_width] + indata[in_width+1])>>2);
                                break;
                          default:
                                llerrs << "generateMmip called with bad num channels" << llendl;
                        }
                        indata += nchannels*2;
                        data += nchannels;
                }
                indata += nchannels*in_width; // skip odd lines
        }
}


//============================================================================

//static
F32 LLImageBase::calc_download_priority(F32 virtual_size, F32 visible_pixels, S32 bytes_sent)
{
        F32 w_priority;

        F32 bytes_weight = 1.f;
        if (!bytes_sent)
        {
                bytes_weight = 20.f;
        }
        else if (bytes_sent < 1000)
        {
                bytes_weight = 1.f;
        }
        else if (bytes_sent < 2000)
        {
                bytes_weight = 1.f/1.5f;
        }
        else if (bytes_sent < 4000)
        {
                bytes_weight = 1.f/3.f;
        }
        else if (bytes_sent < 8000)
        {
                bytes_weight = 1.f/6.f;
        }
        else if (bytes_sent < 16000)
        {
                bytes_weight = 1.f/12.f;
        }
        else if (bytes_sent < 32000)
        {
                bytes_weight = 1.f/20.f;
        }
        else if (bytes_sent < 64000)
        {
                bytes_weight = 1.f/32.f;
        }
        else
        {
                bytes_weight = 1.f/64.f;
        }
        bytes_weight *= bytes_weight;


        //llinfos << "VS: " << virtual_size << llendl;
        F32 virtual_size_factor = virtual_size / (10.f*10.f);

        // The goal is for weighted priority to be <= 0 when we've reached a point where
        // we've sent enough data.
        //llinfos << "BytesSent: " << bytes_sent << llendl;
        //llinfos << "BytesWeight: " << bytes_weight << llendl;
        //llinfos << "PreLog: " << bytes_weight * virtual_size_factor << llendl;
        w_priority = (F32)log10(bytes_weight * virtual_size_factor);

        //llinfos << "PreScale: " << w_priority << llendl;

        // We don't want to affect how MANY bytes we send based on the visible pixels, but the order
        // in which they're sent.  We post-multiply so we don't change the zero point.
        if (w_priority > 0.f)
        {
                F32 pixel_weight = (F32)log10(visible_pixels + 1)*3.0f;
                w_priority *= pixel_weight;
        }

        return w_priority;
}

//============================================================================

---