llimagegl.cpp

Go to the documentation of this file.

// TODO: create 2 classes for images w/ and w/o discard levels?

#include "linden_common.h"

#include "llimagegl.h"

#include "llerror.h"
#include "llimage.h"

#include "llmath.h"
#include "llgl.h"

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

const F32 MIN_TEXTURE_LIFETIME = 10.f;

//statics
LLGLuint LLImageGL::sCurrentBoundTextures[MAX_GL_TEXTURE_UNITS] = { 0 };

S32 LLImageGL::sGlobalTextureMemory             = 0;
S32 LLImageGL::sBoundTextureMemory              = 0;
S32 LLImageGL::sCurBoundTextureMemory   = 0;
S32 LLImageGL::sCount                                   = 0;

BOOL LLImageGL::sGlobalUseAnisotropic   = FALSE;
F32 LLImageGL::sLastFrameTime                   = 0.f;

std::set<LLImageGL*> LLImageGL::sImageList;

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

//static
S32 LLImageGL::dataFormatBits(S32 dataformat)
{
        switch (dataformat)
        {
          case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:        return 4;
          case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:        return 8;
          case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:        return 8;
          case GL_LUMINANCE:                                            return 8;
          case GL_ALPHA:                                                        return 8;
          case GL_COLOR_INDEX:                                          return 8;
          case GL_LUMINANCE_ALPHA:                                      return 16;
          case GL_RGB:                                                          return 24;
          case GL_RGB8:                                                         return 24;
          case GL_RGBA:                                                         return 32;
          case GL_BGRA:                                                         return 32;              // Used for QuickTime media textures on the Mac
          default:
                llerrs << "LLImageGL::Unknown format: " << dataformat << llendl;
                return 0;
        }
}

//static
S32 LLImageGL::dataFormatBytes(S32 dataformat, S32 width, S32 height)
{
        if (dataformat >= GL_COMPRESSED_RGB_S3TC_DXT1_EXT &&
                dataformat <= GL_COMPRESSED_RGBA_S3TC_DXT5_EXT)
        {
                if (width < 4) width = 4;
                if (height < 4) height = 4;
        }
        S32 bytes ((width*height*dataFormatBits(dataformat)+7)>>3);
        S32 aligned = (bytes+3)&~3;
        return aligned;
}

//static
S32 LLImageGL::dataFormatComponents(S32 dataformat)
{
        switch (dataformat)
        {
          case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:        return 3;
          case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:        return 4;
          case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:        return 4;
          case GL_LUMINANCE:                                            return 1;
          case GL_ALPHA:                                                        return 1;
          case GL_COLOR_INDEX:                                          return 1;
          case GL_LUMINANCE_ALPHA:                                      return 2;
          case GL_RGB:                                                          return 3;
          case GL_RGBA:                                                         return 4;
          case GL_BGRA:                                                         return 4;               // Used for QuickTime media textures on the Mac
          default:
                llerrs << "LLImageGL::Unknown format: " << dataformat << llendl;
                return 0;
        }
}

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

// static
void LLImageGL::bindExternalTexture(LLGLuint gl_name, S32 stage, LLGLenum bind_target )
{
        glActiveTextureARB(GL_TEXTURE0_ARB + stage);
        glClientActiveTextureARB(GL_TEXTURE0_ARB + stage);
        glBindTexture(bind_target, gl_name);
        sCurrentBoundTextures[stage] = gl_name;
}

// static
void LLImageGL::unbindTexture(S32 stage, LLGLenum bind_target)
{
        // LLGLSLShader can return -1
        if (stage >= 0)
        {
                glActiveTextureARB(GL_TEXTURE0_ARB + stage);
                glClientActiveTextureARB(GL_TEXTURE0_ARB + stage);
                glBindTexture(bind_target, 0);
                sCurrentBoundTextures[stage] = 0;
        }
}

// static (duplicated for speed and to avoid GL_TEXTURE_2D default argument which requires GL header dependency)
void LLImageGL::unbindTexture(S32 stage)
{
        // LLGLSLShader can return -1
        if (stage >= 0)
        {
                glActiveTextureARB(GL_TEXTURE0_ARB + stage);
                glClientActiveTextureARB(GL_TEXTURE0_ARB + stage);
                glBindTexture(GL_TEXTURE_2D, 0);
                sCurrentBoundTextures[stage] = 0;
        }
}

// static
void LLImageGL::updateStats(F32 current_time)
{
        sLastFrameTime = current_time;
        sBoundTextureMemory = sCurBoundTextureMemory;
        sCurBoundTextureMemory = 0;
}

//static
S32 LLImageGL::updateBoundTexMem(const S32 delta)
{
        LLImageGL::sCurBoundTextureMemory += delta;
        return LLImageGL::sCurBoundTextureMemory;
}

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

//static 
void LLImageGL::destroyGL(BOOL save_state)
{
        for (S32 stage = 0; stage < gGLManager.mNumTextureUnits; stage++)
        {
                LLImageGL::unbindTexture(stage, GL_TEXTURE_2D);
        }
        for (std::set<LLImageGL*>::iterator iter = sImageList.begin();
                 iter != sImageList.end(); iter++)
        {
                LLImageGL* glimage = *iter;
                if (glimage->mTexName && glimage->mComponents)
                {
                        if (save_state)
                        {
                                glimage->mSaveData = new LLImageRaw;
                                glimage->readBackRaw(glimage->mCurrentDiscardLevel, glimage->mSaveData, false);
                        }
                        glimage->destroyGLTexture();
                        stop_glerror();
                }
        }
}

//static 
void LLImageGL::restoreGL()
{
        for (std::set<LLImageGL*>::iterator iter = sImageList.begin();
                 iter != sImageList.end(); iter++)
        {
                LLImageGL* glimage = *iter;
                if (glimage->mSaveData.notNull() && glimage->mSaveData->getComponents())
                {
                        if (glimage->getComponents())
                        {
                                glimage->createGLTexture(glimage->mCurrentDiscardLevel, glimage->mSaveData);
                                stop_glerror();
                        }
                        glimage->mSaveData = NULL; // deletes data
                }
        }
}

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

//static 
BOOL LLImageGL::create(LLPointer<LLImageGL>& dest, BOOL usemipmaps)
{
        dest = new LLImageGL(usemipmaps);
        return TRUE;
}

BOOL LLImageGL::create(LLPointer<LLImageGL>& dest, U32 width, U32 height, U8 components, BOOL usemipmaps)
{
        dest = new LLImageGL(width, height, components, usemipmaps);
        return TRUE;
}

BOOL LLImageGL::create(LLPointer<LLImageGL>& dest, const LLImageRaw* imageraw, BOOL usemipmaps)
{
        dest = new LLImageGL(imageraw, usemipmaps);
        return TRUE;
}

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

LLImageGL::LLImageGL(BOOL usemipmaps)
        : mSaveData(0)
{
        init(usemipmaps);
        setSize(0, 0, 0);
        sImageList.insert(this);
        sCount++;
}

LLImageGL::LLImageGL(U32 width, U32 height, U8 components, BOOL usemipmaps)
        : mSaveData(0)
{
        llassert( components <= 4 );
        init(usemipmaps);
        setSize(width, height, components);
        sImageList.insert(this);
        sCount++;
}

LLImageGL::LLImageGL(const LLImageRaw* imageraw, BOOL usemipmaps)
        : mSaveData(0)
{
        init(usemipmaps);
        setSize(0, 0, 0);
        sImageList.insert(this);
        sCount++;
        createGLTexture(0, imageraw); 
}

LLImageGL::~LLImageGL()
{
        LLImageGL::cleanup();
        sImageList.erase(this);
        sCount--;
}

void LLImageGL::init(BOOL usemipmaps)
{
#ifdef DEBUG_MISS
        mMissed                         = FALSE;
#endif

        mTextureMemory    = 0;
        mLastBindTime     = 0.f;

        mTarget                   = GL_TEXTURE_2D;
        mBindTarget               = GL_TEXTURE_2D;
        mUseMipMaps               = usemipmaps;
        mHasMipMaps               = FALSE;
        mAutoGenMips      = FALSE;
        mTexName          = 0;
        mIsResident       = 0;
        mClampS                   = FALSE;
        mClampT                   = FALSE;
        mMipFilterNearest  = FALSE;
        mWidth                          = 0;
        mHeight                         = 0;
        mComponents                     = 0;
        
        mMaxDiscardLevel = MAX_DISCARD_LEVEL;
        mCurrentDiscardLevel = -1;
        mDontDiscard = FALSE;
        
        mFormatInternal = -1;
        mFormatPrimary = (LLGLenum) 0;
        mFormatType = GL_UNSIGNED_BYTE;
        mFormatSwapBytes = FALSE;
        mHasExplicitFormat = FALSE;
}

void LLImageGL::cleanup()
{
        if (!gGLManager.mIsDisabled)
        {
                destroyGLTexture();
        }
        mSaveData = NULL; // deletes data
}

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

static bool check_power_of_two(S32 dim)
{
        while(dim > 1)
        {
                if (dim & 1)
                {
                        return false;
                }
                dim >>= 1;
        }
        return true;
}

//static
bool LLImageGL::checkSize(S32 width, S32 height)
{
        return check_power_of_two(width) && check_power_of_two(height);
}

void LLImageGL::setSize(S32 width, S32 height, S32 ncomponents)
{
        if (width != mWidth || height != mHeight || ncomponents != mComponents)
        {
                // Check if dimensions are a power of two!
                if (!checkSize(width,height))
                {
                        llerrs << llformat("Texture has non power of two dimention: %dx%d",width,height) << llendl;
                }
                
                if (mTexName)
                {
//                      llwarns << "Setting Size of LLImageGL with existing mTexName = " << mTexName << llendl;
                        destroyGLTexture();
                }
                
                mWidth = width;
                mHeight = height;
                mComponents = ncomponents;
                if (ncomponents > 0)
                {
                        mMaxDiscardLevel = 0;
                        while (width > 1 && height > 1 && mMaxDiscardLevel < MAX_DISCARD_LEVEL)
                        {
                                mMaxDiscardLevel++;
                                width >>= 1;
                                height >>= 1;
                        }
                }
                else
                {
                        mMaxDiscardLevel = MAX_DISCARD_LEVEL;
                }
        }
}

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

// virtual
void LLImageGL::dump()
{
        llinfos << "mMaxDiscardLevel " << S32(mMaxDiscardLevel)
                        << " mLastBindTime " << mLastBindTime
                        << " mTarget " << S32(mTarget)
                        << " mBindTarget " << S32(mBindTarget)
                        << " mUseMipMaps " << S32(mUseMipMaps)
                        << " mHasMipMaps " << S32(mHasMipMaps)
                        << " mCurrentDiscardLevel " << S32(mCurrentDiscardLevel)
                        << " mFormatInternal " << S32(mFormatInternal)
                        << " mFormatPrimary " << S32(mFormatPrimary)
                        << " mFormatType " << S32(mFormatType)
                        << " mFormatSwapBytes " << S32(mFormatSwapBytes)
                        << " mHasExplicitFormat " << S32(mHasExplicitFormat)
#if DEBUG_MISS
                        << " mMissed " << mMissed
#endif
                        << llendl;

        llinfos << " mTextureMemory " << mTextureMemory
                        << " mTexNames " << mTexName
                        << " mIsResident " << S32(mIsResident)
                        << llendl;
}

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

BOOL LLImageGL::bindTextureInternal(const S32 stage) const
{
        if (gGLManager.mIsDisabled)
        {
                llwarns << "Trying to bind a texture while GL is disabled!" << llendl;
        }

        glActiveTextureARB(GL_TEXTURE0_ARB + stage);
                
        if (sCurrentBoundTextures[stage] && sCurrentBoundTextures[stage] == mTexName)
        {
                // already set!
                return TRUE;
        }

        if (mTexName != 0)
        {
#ifdef DEBUG_MISS
                mMissed = ! getIsResident(TRUE);
#endif

                glBindTexture(mBindTarget, mTexName);
                sCurrentBoundTextures[stage] = mTexName;

                if (mLastBindTime != sLastFrameTime)
                {
                        // we haven't accounted for this texture yet this frame
                        updateBoundTexMem(mTextureMemory);
                        mLastBindTime = sLastFrameTime;
                }
                
                return TRUE;
        }
        else
        {
                glBindTexture(mBindTarget, 0);
                sCurrentBoundTextures[stage] = 0;
                return FALSE;
        }
}

//virtual
BOOL LLImageGL::bind(const S32 stage) const
{
        if (stage == -1)
        {
                return FALSE;
        }
        BOOL res = bindTextureInternal(stage);
        //llassert(res);
        return res;
}

void LLImageGL::setExplicitFormat( LLGLint internal_format, LLGLenum primary_format, LLGLenum type_format, BOOL swap_bytes )
{
        // Note: must be called before createTexture()
        // Note: it's up to the caller to ensure that the format matches the number of components.
        mHasExplicitFormat = TRUE;
        mFormatInternal = internal_format;
        mFormatPrimary = primary_format;
        if(type_format == 0)
                mFormatType = GL_UNSIGNED_BYTE;
        else
                mFormatType = type_format;
        mFormatSwapBytes = swap_bytes;
}

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

void LLImageGL::setImage(const LLImageRaw* imageraw)
{
        llassert((imageraw->getWidth() == getWidth(mCurrentDiscardLevel)) &&
                         (imageraw->getHeight() == getHeight(mCurrentDiscardLevel)) &&
                         (imageraw->getComponents() == getComponents()));
        const U8* rawdata = imageraw->getData();
        setImage(rawdata, FALSE);
}

void LLImageGL::setImage(const U8* data_in, BOOL data_hasmips)
{
//      LLFastTimer t1(LLFastTimer::FTM_TEMP1);
        
        bool is_compressed = false;
        if (mFormatPrimary >= GL_COMPRESSED_RGBA_S3TC_DXT1_EXT && mFormatPrimary <= GL_COMPRESSED_RGBA_S3TC_DXT5_EXT)
        {
                is_compressed = true;
        }

        {
//              LLFastTimer t2(LLFastTimer::FTM_TEMP2);
                llverify(bindTextureInternal(0));
        }
        
        if (mUseMipMaps)
        {
//              LLFastTimer t2(LLFastTimer::FTM_TEMP3);
                if (data_hasmips)
                {
                        // NOTE: data_in points to largest image; smaller images
                        // are stored BEFORE the largest image
                        for (S32 d=mCurrentDiscardLevel; d<=mMaxDiscardLevel; d++)
                        {
                                S32 w = getWidth(d);
                                S32 h = getHeight(d);
                                S32 gl_level = d-mCurrentDiscardLevel;
                                if (d > mCurrentDiscardLevel)
                                {
                                        data_in -= dataFormatBytes(mFormatPrimary, w, h); // see above comment
                                }
                                if (is_compressed)
                                {
//                                      LLFastTimer t2(LLFastTimer::FTM_TEMP4);
                                        S32 tex_size = dataFormatBytes(mFormatPrimary, w, h);
                                        glCompressedTexImage2DARB(mTarget, gl_level, mFormatPrimary, w, h, 0, tex_size, (GLvoid *)data_in);
                                        stop_glerror();
                                }
                                else
                                {
//                                      LLFastTimer t2(LLFastTimer::FTM_TEMP4);

                                        if(mFormatSwapBytes)
                                        {
                                                glPixelStorei(GL_UNPACK_SWAP_BYTES, 1);
                                                stop_glerror();
                                        }
                                                
                                        glTexImage2D(mTarget, gl_level, mFormatInternal, w, h, 0, mFormatPrimary, GL_UNSIGNED_BYTE, (GLvoid*)data_in);
                                        
                                        if(mFormatSwapBytes)
                                        {
                                                glPixelStorei(GL_UNPACK_SWAP_BYTES, 0);
                                                stop_glerror();
                                        }
                                                
                                        stop_glerror();
                                }
                                stop_glerror();
                        }                       
                }
                else if (!is_compressed)
                {
                        if (mAutoGenMips)
                        {
                                glTexParameteri(mBindTarget, GL_GENERATE_MIPMAP_SGIS, TRUE);
                                stop_glerror();
                                {
//                                      LLFastTimer t2(LLFastTimer::FTM_TEMP4);

                                        if(mFormatSwapBytes)
                                        {
                                                glPixelStorei(GL_UNPACK_SWAP_BYTES, 1);
                                                stop_glerror();
                                        }

                                        glTexImage2D(mTarget, 0, mFormatInternal,
                                                                 getWidth(mCurrentDiscardLevel), getHeight(mCurrentDiscardLevel), 0,
                                                                 mFormatPrimary, mFormatType,
                                                                 data_in);
                                        stop_glerror();

                                        if(mFormatSwapBytes)
                                        {
                                                glPixelStorei(GL_UNPACK_SWAP_BYTES, 0);
                                                stop_glerror();
                                        }
                                }
                        }
                        else
                        {
                                // Create mips by hand
                                // about 30% faster than autogen on ATI 9800, 50% slower on nVidia 4800
                                // ~4x faster than gluBuild2DMipmaps
                                S32 width = getWidth(mCurrentDiscardLevel);
                                S32 height = getHeight(mCurrentDiscardLevel);
                                S32 nummips = mMaxDiscardLevel - mCurrentDiscardLevel + 1;
                                S32 w = width, h = height;
                                const U8* prev_mip_data = 0;
                                const U8* cur_mip_data = 0;
                                for (int m=0; m<nummips; m++)
                                {
                                        if (m==0)
                                        {
                                                cur_mip_data = data_in;
                                        }
                                        else
                                        {
                                                S32 bytes = w * h * mComponents;
                                                U8* new_data = new U8[bytes];
                                                LLImageBase::generateMip(prev_mip_data, new_data, w, h, mComponents);
                                                cur_mip_data = new_data;
                                        }
                                        llassert(w > 0 && h > 0 && cur_mip_data);
                                        {
//                                              LLFastTimer t1(LLFastTimer::FTM_TEMP4);
                                                if(mFormatSwapBytes)
                                                {
                                                        glPixelStorei(GL_UNPACK_SWAP_BYTES, 1);
                                                        stop_glerror();
                                                }

                                                glTexImage2D(mTarget, m, mFormatInternal, w, h, 0, mFormatPrimary, mFormatType, cur_mip_data);
                                                stop_glerror();

                                                if(mFormatSwapBytes)
                                                {
                                                        glPixelStorei(GL_UNPACK_SWAP_BYTES, 0);
                                                        stop_glerror();
                                                }
                                        }
                                        if (prev_mip_data && prev_mip_data != data_in)
                                        {
                                                delete[] prev_mip_data;
                                        }
                                        prev_mip_data = cur_mip_data;
                                        w >>= 1;
                                        h >>= 1;
                                }
                                if (prev_mip_data && prev_mip_data != data_in)
                                {
                                        delete[] prev_mip_data;
                                }
                        }
                }
                else
                {
                        llerrs << "Compressed Image has mipmaps but data does not (can not auto generate compressed mips)" << llendl;
                }
                mHasMipMaps = TRUE;
        }
        else
        {
//              LLFastTimer t2(LLFastTimer::FTM_TEMP5);
                S32 w = getWidth();
                S32 h = getHeight();
                if (is_compressed)
                {
                        S32 tex_size = dataFormatBytes(mFormatPrimary, w, h);
                        glCompressedTexImage2DARB(mTarget, 0, mFormatPrimary, w, h, 0, tex_size, (GLvoid *)data_in);
                        stop_glerror();
                }
                else
                {
                        if(mFormatSwapBytes)
                        {
                                glPixelStorei(GL_UNPACK_SWAP_BYTES, 1);
                                stop_glerror();
                        }

                        glTexImage2D(mTarget, 0, mFormatInternal, w, h, 0,
                                                 mFormatPrimary, mFormatType, (GLvoid *)data_in);
                        stop_glerror();

                        if(mFormatSwapBytes)
                        {
                                glPixelStorei(GL_UNPACK_SWAP_BYTES, 0);
                                stop_glerror();
                        }

                }
                mHasMipMaps = FALSE;
        }
        glFlush();
        stop_glerror();
}

BOOL LLImageGL::setSubImage(const U8* datap, S32 data_width, S32 data_height, S32 x_pos, S32 y_pos, S32 width, S32 height)
{
        if (!width || !height)
        {
                return TRUE;
        }
        if (mTexName == 0)
        {
                llwarns << "Setting subimage on image without GL texture" << llendl;
                return FALSE;
        }
        if (datap == NULL)
        {
                llwarns << "Setting subimage on image with NULL datap" << llendl;
                return FALSE;
        }
        
        if (x_pos == 0 && y_pos == 0 && width == getWidth() && height == getHeight())
        {
                setImage(datap, FALSE);
        }
        else
        {
                if (mUseMipMaps)
                {
                        dump();
                        llerrs << "setSubImage called with mipmapped image (not supported)" << llendl;
                }
                llassert_always(mCurrentDiscardLevel == 0);
                llassert_always(x_pos >= 0 && y_pos >= 0);
                
                if (((x_pos + width) > getWidth()) || 
                        (y_pos + height) > getHeight())
                {
                        dump();
                        llerrs << "Subimage not wholly in target image!" 
                                   << " x_pos " << x_pos
                                   << " y_pos " << y_pos
                                   << " width " << width
                                   << " height " << height
                                   << " getWidth() " << getWidth()
                                   << " getHeight() " << getHeight()
                                   << llendl;
                }

                if ((x_pos + width) > data_width || 
                        (y_pos + height) > data_height)
                {
                        dump();
                        llerrs << "Subimage not wholly in source image!" 
                                   << " x_pos " << x_pos
                                   << " y_pos " << y_pos
                                   << " width " << width
                                   << " height " << height
                                   << " source_width " << data_width
                                   << " source_height " << data_height
                                   << llendl;
                }


                glPixelStorei(GL_UNPACK_ROW_LENGTH, data_width);
                stop_glerror();

                if(mFormatSwapBytes)
                {
                        glPixelStorei(GL_UNPACK_SWAP_BYTES, 1);
                        stop_glerror();
                }

                datap += (y_pos * data_width + x_pos) * getComponents();
                // Update the GL texture
                BOOL res = bindTextureInternal(0);
                if (!res) llerrs << "LLImageGL::setSubImage(): bindTexture failed" << llendl;
                stop_glerror();

                LLGLEnable tex( GL_TEXTURE_2D ); 

                glTexSubImage2D(mTarget, 0, x_pos, y_pos, 
                                                width, height, mFormatPrimary, mFormatType, datap);
                stop_glerror();

                if(mFormatSwapBytes)
                {
                        glPixelStorei(GL_UNPACK_SWAP_BYTES, 0);
                        stop_glerror();
                }

                glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
                stop_glerror();
        }
        glFlush();
        return TRUE;
}

BOOL LLImageGL::setSubImage(const LLImageRaw* imageraw, S32 x_pos, S32 y_pos, S32 width, S32 height)
{
        return setSubImage(imageraw->getData(), imageraw->getWidth(), imageraw->getHeight(), x_pos, y_pos, width, height);
}

// Copy sub image from frame buffer
BOOL LLImageGL::setSubImageFromFrameBuffer(S32 fb_x, S32 fb_y, S32 x_pos, S32 y_pos, S32 width, S32 height)
{
        if (bindTextureInternal(0))
        {
                glCopyTexSubImage2D(GL_TEXTURE_2D, 0, fb_x, fb_y, x_pos, y_pos, width, height);
                stop_glerror();
                return TRUE;
        }
        else
        {
                return FALSE;
        }
}

BOOL LLImageGL::createGLTexture(S32 discard_level, const LLImageRaw* imageraw, S32 usename/*=0*/)
{
        if (gGLManager.mIsDisabled)
        {
                llwarns << "Trying to create a texture while GL is disabled!" << llendl;
                return FALSE;
        }
        llassert(gGLManager.mInited || gNoRender);
        stop_glerror();

        if (discard_level < 0)
        {
                llassert(mCurrentDiscardLevel >= 0);
                discard_level = mCurrentDiscardLevel;
        }
        discard_level = llclamp(discard_level, 0, (S32)mMaxDiscardLevel);

        // Actual image width/height = raw image width/height * 2^discard_level
        S32 w = imageraw->getWidth() << discard_level;
        S32 h = imageraw->getHeight() << discard_level;

        // setSize may call destroyGLTexture if the size does not match
        setSize(w, h, imageraw->getComponents());

        if( !mHasExplicitFormat )
        {
                switch (mComponents)
                {
                  case 1:
                        // Use luminance alpha (for fonts)
                        mFormatInternal = GL_LUMINANCE8;
                        mFormatPrimary = GL_LUMINANCE;
                        mFormatType = GL_UNSIGNED_BYTE;
                        break;
                  case 2:
                        // Use luminance alpha (for fonts)
                        mFormatInternal = GL_LUMINANCE8_ALPHA8;
                        mFormatPrimary = GL_LUMINANCE_ALPHA;
                        mFormatType = GL_UNSIGNED_BYTE;
                        break;
                  case 3:
                        mFormatInternal = GL_RGB8;
                        mFormatPrimary = GL_RGB;
                        mFormatType = GL_UNSIGNED_BYTE;
                        break;
                  case 4:
                        mFormatInternal = GL_RGBA8;
                        mFormatPrimary = GL_RGBA;
                        mFormatType = GL_UNSIGNED_BYTE;
                        break;
                  default:
                        llerrs << "Bad number of components for texture: " << (U32)getComponents() << llendl;
                }
        }

        const U8* rawdata = imageraw->getData();
        return createGLTexture(discard_level, rawdata, FALSE, usename);
}

BOOL LLImageGL::createGLTexture(S32 discard_level, const U8* data_in, BOOL data_hasmips, S32 usename)
{
        llassert(data_in);

        if (discard_level < 0)
        {
                llassert(mCurrentDiscardLevel >= 0);
                discard_level = mCurrentDiscardLevel;
        }
        discard_level = llclamp(discard_level, 0, (S32)mMaxDiscardLevel);

        if (mTexName != 0 && discard_level == mCurrentDiscardLevel)
        {
                // This will only be true if the size has not changed
                setImage(data_in, data_hasmips);
                return TRUE;
        }
        
        GLuint old_name = mTexName;
//      S32 old_discard = mCurrentDiscardLevel;
        
        if (usename != 0)
        {
                mTexName = usename;
        }
        else
        {
                glGenTextures(1, (GLuint*)&mTexName);
                stop_glerror();
                {
//                      LLFastTimer t1(LLFastTimer::FTM_TEMP6);
                        llverify(bindTextureInternal(0));
                        glTexParameteri(mBindTarget, GL_TEXTURE_BASE_LEVEL, 0);
                        glTexParameteri(mBindTarget, GL_TEXTURE_MAX_LEVEL,  mMaxDiscardLevel-discard_level);
                }
        }
        if (!mTexName)
        {
                llerrs << "LLImageGL::createGLTexture failed to make texture" << llendl;
        }

        if (mUseMipMaps)
        {
                mAutoGenMips = gGLManager.mHasMipMapGeneration;
#if LL_DARWIN
                // On the Mac GF2 and GF4MX drivers, auto mipmap generation doesn't work right with alpha-only textures.
                if(gGLManager.mIsGF2or4MX && (mFormatInternal == GL_ALPHA8) && (mFormatPrimary == GL_ALPHA))
                {
                        mAutoGenMips = FALSE;
                }
#endif
        }

        mCurrentDiscardLevel = discard_level;

        setImage(data_in, data_hasmips);

        setClamp(mClampS, mClampT);
        setMipFilterNearest(mMipFilterNearest);
        
        // things will break if we don't unbind after creation
        unbindTexture(0, mBindTarget);
        stop_glerror();

        if (old_name != 0)
        {
                sGlobalTextureMemory -= mTextureMemory;
                glDeleteTextures(1, &old_name);
                stop_glerror();
        }

        mTextureMemory = getMipBytes(discard_level);
        sGlobalTextureMemory += mTextureMemory;
                
        // mark this as bound at this point, so we don't throw it out immediately
        mLastBindTime = sLastFrameTime;

        return TRUE;
}

BOOL LLImageGL::setDiscardLevel(S32 discard_level)
{
        llassert(discard_level >= 0);
        llassert(mCurrentDiscardLevel >= 0);

        discard_level = llclamp(discard_level, 0, (S32)mMaxDiscardLevel);       

        if (mDontDiscard)
        {
                // don't discard!
                return FALSE;
        }
        else if (discard_level == mCurrentDiscardLevel)
        {
                // nothing to do
                return FALSE;
        }
        else if (discard_level < mCurrentDiscardLevel)
        {
                // larger image
                dump();
                llerrs << "LLImageGL::setDiscardLevel() called with larger discard level; use createGLTexture()" << llendl;
                return FALSE;
        }
        else if (mUseMipMaps)
        {
                LLPointer<LLImageRaw> imageraw = new LLImageRaw;
                while(discard_level > mCurrentDiscardLevel)
                {
                        if (readBackRaw(discard_level, imageraw, false))
                        {
                                break;
                        }
                        discard_level--;
                }
                if (discard_level == mCurrentDiscardLevel)
                {
                        // unable to increase the discard level
                        return FALSE;
                }
                return createGLTexture(discard_level, imageraw);
        }
        else
        {
#if !LL_LINUX && !LL_SOLARIS
                 // *FIX: This should not be skipped for the linux client.
                llerrs << "LLImageGL::setDiscardLevel() called on image without mipmaps" << llendl;
#endif
                return FALSE;
        }
}

BOOL LLImageGL::readBackRaw(S32 discard_level, LLImageRaw* imageraw, bool compressed_ok)
{
        if (discard_level < 0)
        {
                discard_level = mCurrentDiscardLevel;
        }
        
        if (mTexName == 0 || discard_level < mCurrentDiscardLevel)
        {
                return FALSE;
        }

        S32 gl_discard = discard_level - mCurrentDiscardLevel;

        llverify(bindTextureInternal(0));
        
        LLGLint glwidth = 0;
        glGetTexLevelParameteriv(mTarget, gl_discard, GL_TEXTURE_WIDTH, (GLint*)&glwidth);
        if (glwidth == 0)
        {
                // No mip data smaller than current discard level
                return FALSE;
        }

        S32 width = getWidth(discard_level);
        S32 height = getHeight(discard_level);
        S32 ncomponents = getComponents();
        if (ncomponents == 0)
        {
                return FALSE;
        }

        if (width <= 0 || width > 2048 || height <= 0 || height > 2048 || ncomponents < 1 || ncomponents > 4)
        {
                llerrs << llformat("LLImageGL::readBackRaw: bogus params: %d x %d x %d",width,height,ncomponents) << llendl;
        }
        
        LLGLint is_compressed = 0;
        if (compressed_ok)
        {
                glGetTexLevelParameteriv(mTarget, is_compressed, GL_TEXTURE_COMPRESSED, (GLint*)&is_compressed);
        }
        if (is_compressed)
        {
                LLGLint glbytes;
                glGetTexLevelParameteriv(mTarget, gl_discard, GL_TEXTURE_COMPRESSED_IMAGE_SIZE, (GLint*)&glbytes);
                imageraw->allocateDataSize(width, height, ncomponents, glbytes);
                glGetCompressedTexImageARB(mTarget, gl_discard, (GLvoid*)(imageraw->getData()));
                stop_glerror();
        }
        else
        {
                imageraw->allocateDataSize(width, height, ncomponents);
                glGetTexImage(GL_TEXTURE_2D, gl_discard, mFormatPrimary, mFormatType, (GLvoid*)(imageraw->getData()));
                stop_glerror();
        }
                
        return TRUE;
}

void LLImageGL::destroyGLTexture()
{
        stop_glerror();

        if (mTexName != 0)
        {
                for (int i = 0; i < gGLManager.mNumTextureUnits; i++)
                {
                        if (sCurrentBoundTextures[i] == mTexName)
                        {
                                unbindTexture(i, GL_TEXTURE_2D);
                                stop_glerror();
                        }
                }

                sGlobalTextureMemory -= mTextureMemory;
                mTextureMemory = 0;

                glDeleteTextures(1, (GLuint*)&mTexName);
                mTexName = 0;

                stop_glerror();
        }
}

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

void LLImageGL::setClamp(BOOL clamps, BOOL clampt)
{
        mClampS = clamps;
        mClampT = clampt;
        if (mTexName != 0)
        {
                glTexParameteri(mBindTarget, GL_TEXTURE_WRAP_S, clamps ? GL_CLAMP_TO_EDGE : GL_REPEAT);
                glTexParameteri(mBindTarget, GL_TEXTURE_WRAP_T, clampt ? GL_CLAMP_TO_EDGE : GL_REPEAT);
        }
        stop_glerror();
}

void LLImageGL::setMipFilterNearest(BOOL nearest, BOOL min_nearest)
{
        mMipFilterNearest = nearest;

        if (mTexName != 0)
        {
                if (min_nearest)
                {
                        glTexParameteri(mBindTarget, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
                }
                else if (mHasMipMaps)
                {
                        glTexParameteri(mBindTarget, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
                }
                else
                {
                        glTexParameteri(mBindTarget, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
                }
                if (mMipFilterNearest)
                {
                        glTexParameteri(mBindTarget, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
                }
                else 
                {
                        glTexParameteri(mBindTarget, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
                }
                if (gGLManager.mHasAnisotropic)
                {
                        if (sGlobalUseAnisotropic && !mMipFilterNearest)
                        {
                                F32 largest_anisotropy;
                                glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &largest_anisotropy);
                                glTexParameterf(mBindTarget, GL_TEXTURE_MAX_ANISOTROPY_EXT, largest_anisotropy);
                        }
                        else
                        {
                                glTexParameterf(mBindTarget, GL_TEXTURE_MAX_ANISOTROPY_EXT, 1.f);
                        }
                }
        }
        
        stop_glerror();
}

BOOL LLImageGL::getIsResident(BOOL test_now)
{
        if (test_now)
        {
                if (mTexName != 0)
                {
                        glAreTexturesResident(1, (GLuint*)&mTexName, &mIsResident);
                }
                else
                {
                        mIsResident = FALSE;
                }
        }

        return mIsResident;
}

S32 LLImageGL::getHeight(S32 discard_level) const
{
        if (discard_level < 0)
        {
                discard_level = mCurrentDiscardLevel;
        }
        S32 height = mHeight >> discard_level;
        if (height < 1) height = 1;
        return height;
}

S32 LLImageGL::getWidth(S32 discard_level) const
{
        if (discard_level < 0)
        {
                discard_level = mCurrentDiscardLevel;
        }
        S32 width = mWidth >> discard_level;
        if (width < 1) width = 1;
        return width;
}

S32 LLImageGL::getBytes(S32 discard_level) const
{
        if (discard_level < 0)
        {
                discard_level = mCurrentDiscardLevel;
        }
        S32 w = mWidth>>discard_level;
        S32 h = mHeight>>discard_level;
        if (w == 0) w = 1;
        if (h == 0) h = 1;
        return dataFormatBytes(mFormatPrimary, w, h);
}

S32 LLImageGL::getMipBytes(S32 discard_level) const
{
        if (discard_level < 0)
        {
                discard_level = mCurrentDiscardLevel;
        }
        S32 w = mWidth>>discard_level;
        S32 h = mHeight>>discard_level;
        S32 res = dataFormatBytes(mFormatPrimary, w, h);
        if (mUseMipMaps)
        {
                while (w > 1 && h > 1)
                {
                        w >>= 1; if (w == 0) w = 1;
                        h >>= 1; if (h == 0) h = 1;
                        res += dataFormatBytes(mFormatPrimary, w, h);
                }
        }
        return res;
}

BOOL LLImageGL::getBoundRecently() const
{
        return (BOOL)(sLastFrameTime - mLastBindTime < MIN_TEXTURE_LIFETIME);
}

void LLImageGL::setTarget(const LLGLenum target, const LLGLenum bind_target)
{
        mTarget = target;
        mBindTarget = bind_target;
}

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

// Manual Mip Generation
/*
                S32 width = getWidth(discard_level);
                S32 height = getHeight(discard_level);
                S32 w = width, h = height;
                S32 nummips = 1;
                while (w > 4 && h > 4)
                {
                        w >>= 1; h >>= 1;
                        nummips++;
                }
                stop_glerror();
                w = width, h = height;
                const U8* prev_mip_data = 0;
                const U8* cur_mip_data = 0;
                for (int m=0; m<nummips; m++)
                {
                        if (m==0)
                        {
                                cur_mip_data = rawdata;
                        }
                        else
                        {
                                S32 bytes = w * h * mComponents;
                                U8* new_data = new U8[bytes];
                                LLImageBase::generateMip(prev_mip_data, new_data, w, h, mComponents);
                                cur_mip_data = new_data;
                        }
                        llassert(w > 0 && h > 0 && cur_mip_data);
                        U8 test = cur_mip_data[w*h*mComponents-1];
                        {
                                glTexImage2D(mTarget, m, mFormatInternal, w, h, 0, mFormatPrimary, mFormatType, cur_mip_data);
                                stop_glerror();
                        }
                        if (prev_mip_data && prev_mip_data != rawdata)
                        {
                                delete prev_mip_data;
                        }
                        prev_mip_data = cur_mip_data;
                        w >>= 1;
                        h >>= 1;
                }
                if (prev_mip_data && prev_mip_data != rawdata)
                {
                        delete prev_mip_data;
                }
                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL,  nummips);
*/  

---