llimagebmp.cpp
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- /**
- * @file llimagebmp.cpp
- *
- * $LicenseInfo:firstyear=2001&license=viewergpl$
- *
- * Copyright (c) 2001-2010, Linden Research, Inc.
- *
- * Second Life Viewer Source Code
- * The source code in this file ("Source Code") is provided by Linden Lab
- * to you under the terms of the GNU General Public License, version 2.0
- * ("GPL"), unless you have obtained a separate licensing agreement
- * ("Other License"), formally executed by you and Linden Lab. Terms of
- * the GPL can be found in doc/GPL-license.txt in this distribution, or
- * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
- *
- * There are special exceptions to the terms and conditions of the GPL as
- * it is applied to this Source Code. View the full text of the exception
- * in the file doc/FLOSS-exception.txt in this software distribution, or
- * online at
- * http://secondlifegrid.net/programs/open_source/licensing/flossexception
- *
- * By copying, modifying or distributing this software, you acknowledge
- * that you have read and understood your obligations described above,
- * and agree to abide by those obligations.
- *
- * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
- * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
- * COMPLETENESS OR PERFORMANCE.
- * $/LicenseInfo$
- */
- #include "linden_common.h"
- #include "llimagebmp.h"
- #include "llerror.h"
- #include "llendianswizzle.h"
- /**
- * @struct LLBMPHeader
- *
- * This struct helps deal with bmp files.
- */
- struct LLBMPHeader
- {
- S32 mSize;
- S32 mWidth;
- S32 mHeight;
- S16 mPlanes;
- S16 mBitsPerPixel;
- S16 mCompression;
- S16 mAlignmentPadding; // pads out to next word boundary
- S32 mImageSize;
- S32 mHorzPelsPerMeter;
- S32 mVertPelsPerMeter;
- S32 mNumColors;
- S32 mNumColorsImportant;
- };
- /**
- * @struct Win95BmpHeaderExtension
- */
- struct Win95BmpHeaderExtension
- {
- U32 mReadMask;
- U32 mGreenMask;
- U32 mBlueMask;
- U32 mAlphaMask;
- U32 mColorSpaceType;
- U16 mRed[3]; // Red CIE endpoint
- U16 mGreen[3]; // Green CIE endpoint
- U16 mBlue[3]; // Blue CIE endpoint
- U32 mGamma[3]; // Gamma scale for r g and b
- };
- /**
- * LLImageBMP
- */
- LLImageBMP::LLImageBMP()
- :
- LLImageFormatted(IMG_CODEC_BMP),
- mColorPaletteColors( 0 ),
- mColorPalette( NULL ),
- mBitmapOffset( 0 ),
- mBitsPerPixel( 0 ),
- mOriginAtTop( FALSE )
- {
- mBitfieldMask[0] = 0;
- mBitfieldMask[1] = 0;
- mBitfieldMask[2] = 0;
- mBitfieldMask[3] = 0;
- }
- LLImageBMP::~LLImageBMP()
- {
- delete[] mColorPalette;
- }
- BOOL LLImageBMP::updateData()
- {
- resetLastError();
- // Check to make sure that this instance has been initialized with data
- U8* mdata = getData();
- if (!mdata || (0 == getDataSize()))
- {
- setLastError("Uninitialized instance of LLImageBMP");
- return FALSE;
- }
- // Read the bitmap headers in order to get all the useful info
- // about this image
- ////////////////////////////////////////////////////////////////////
- // Part 1: "File Header"
- // 14 bytes consisting of
- // 2 bytes: either BM or BA
- // 4 bytes: file size in bytes
- // 4 bytes: reserved (always 0)
- // 4 bytes: bitmap offset (starting position of image data in bytes)
- const S32 FILE_HEADER_SIZE = 14;
- if ((mdata[0] != 'B') || (mdata[1] != 'M'))
- {
- if ((mdata[0] != 'B') || (mdata[1] != 'A'))
- {
- setLastError("OS/2 bitmap array BMP files are not supported");
- return FALSE;
- }
- else
- {
- setLastError("Does not appear to be a bitmap file");
- return FALSE;
- }
- }
- mBitmapOffset = mdata[13];
- mBitmapOffset <<= 8; mBitmapOffset += mdata[12];
- mBitmapOffset <<= 8; mBitmapOffset += mdata[11];
- mBitmapOffset <<= 8; mBitmapOffset += mdata[10];
- ////////////////////////////////////////////////////////////////////
- // Part 2: "Bitmap Header"
- const S32 BITMAP_HEADER_SIZE = 40;
- LLBMPHeader header;
- llassert( sizeof( header ) == BITMAP_HEADER_SIZE );
- memcpy( /* Flawfinder: ignore */
- (void*)&header,
- mdata + FILE_HEADER_SIZE,
- BITMAP_HEADER_SIZE);
- // convert BMP header from little endian (no-op on little endian builds)
- llendianswizzleone(header.mSize);
- llendianswizzleone(header.mWidth);
- llendianswizzleone(header.mHeight);
- llendianswizzleone(header.mPlanes);
- llendianswizzleone(header.mBitsPerPixel);
- llendianswizzleone(header.mCompression);
- llendianswizzleone(header.mAlignmentPadding);
- llendianswizzleone(header.mImageSize);
- llendianswizzleone(header.mHorzPelsPerMeter);
- llendianswizzleone(header.mVertPelsPerMeter);
- llendianswizzleone(header.mNumColors);
- llendianswizzleone(header.mNumColorsImportant);
- BOOL windows_nt_version = FALSE;
- BOOL windows_95_version = FALSE;
- if( 12 == header.mSize )
- {
- setLastError("Windows 2.x and OS/2 1.x BMP files are not supported");
- return FALSE;
- }
- else
- if( 40 == header.mSize )
- {
- if( 3 == header.mCompression )
- {
- // Windows NT
- windows_nt_version = TRUE;
- }
- else
- {
- // Windows 3.x
- }
- }
- else
- if( 12 <= header.mSize && 64 <= header.mSize )
- {
- setLastError("OS/2 2.x BMP files are not supported");
- return FALSE;
- }
- else
- if( 108 == header.mSize )
- {
- // BITMAPV4HEADER
- windows_95_version = TRUE;
- }
- else
- if( 108 < header.mSize )
- {
- // BITMAPV5HEADER or greater
- // Should work as long at Microsoft maintained backwards compatibility (which they did in V4 and V5)
- windows_95_version = TRUE;
- }
- S32 width = header.mWidth;
- S32 height = header.mHeight;
- if (height < 0)
- {
- mOriginAtTop = TRUE;
- height = -height;
- }
- else
- {
- mOriginAtTop = FALSE;
- }
- mBitsPerPixel = header.mBitsPerPixel;
- S32 components;
- switch( mBitsPerPixel )
- {
- case 8:
- components = 1;
- break;
- case 24:
- case 32:
- components = 3;
- break;
- case 1:
- case 4:
- case 16: // Started work on 16, but doesn't work yet
- // These are legal, but we don't support them yet.
- setLastError("Unsupported bit depth");
- return FALSE;
- default:
- setLastError("Unrecognized bit depth");
- return FALSE;
- }
- setSize(width, height, components);
-
- switch( header.mCompression )
- {
- case 0:
- // Uncompressed
- break;
- case 1:
- setLastError("8 bit RLE compression not supported.");
- return FALSE;
- case 2:
- setLastError("4 bit RLE compression not supported.");
- return FALSE;
- case 3:
- // Windows NT or Windows 95
- break;
- default:
- setLastError("Unsupported compression format.");
- return FALSE;
- }
- ////////////////////////////////////////////////////////////////////
- // Part 3: Bitfield Masks and other color data
- S32 extension_size = 0;
- if( windows_nt_version )
- {
- if( (16 != header.mBitsPerPixel) && (32 != header.mBitsPerPixel) )
- {
- setLastError("Bitfield encoding requires 16 or 32 bits per pixel.");
- return FALSE;
- }
- if( 0 != header.mNumColors )
- {
- setLastError("Bitfield encoding is not compatible with a color table.");
- return FALSE;
- }
-
- extension_size = 4 * 3;
- memcpy( mBitfieldMask, mdata + FILE_HEADER_SIZE + BITMAP_HEADER_SIZE, extension_size); /* Flawfinder: ignore */
- }
- else
- if( windows_95_version )
- {
- Win95BmpHeaderExtension win_95_extension;
- extension_size = sizeof( win_95_extension );
- llassert( sizeof( win_95_extension ) + BITMAP_HEADER_SIZE == 108 );
- memcpy( &win_95_extension, mdata + FILE_HEADER_SIZE + BITMAP_HEADER_SIZE, sizeof( win_95_extension ) ); /* Flawfinder: ignore */
- if( 3 == header.mCompression )
- {
- memcpy( mBitfieldMask, mdata + FILE_HEADER_SIZE + BITMAP_HEADER_SIZE, 4 * 4); /* Flawfinder: ignore */
- }
- // Color correction ignored for now
- }
-
- ////////////////////////////////////////////////////////////////////
- // Part 4: Color Palette (optional)
- // Note: There's no color palette if there are 16 or more bits per pixel
- S32 color_palette_size = 0;
- mColorPaletteColors = 0;
- if( header.mBitsPerPixel < 16 )
- {
- if( 0 == header.mNumColors )
- {
- mColorPaletteColors = (1 << header.mBitsPerPixel);
- }
- else
- {
- mColorPaletteColors = header.mNumColors;
- }
- }
- color_palette_size = mColorPaletteColors * 4;
- if( 0 != mColorPaletteColors )
- {
- mColorPalette = new U8[color_palette_size];
- if (!mColorPalette)
- {
- llerrs << "Out of memory in LLImageBMP::updateData()" << llendl;
- return FALSE;
- }
- memcpy( mColorPalette, mdata + FILE_HEADER_SIZE + BITMAP_HEADER_SIZE + extension_size, color_palette_size ); /* Flawfinder: ignore */
- }
- return TRUE;
- }
- BOOL LLImageBMP::decode(LLImageRaw* raw_image, F32 decode_time)
- {
- llassert_always(raw_image);
-
- resetLastError();
- // Check to make sure that this instance has been initialized with data
- U8* mdata = getData();
- if (!mdata || (0 == getDataSize()))
- {
- setLastError("llimagebmp trying to decode an image with no data!");
- return FALSE;
- }
-
- raw_image->resize(getWidth(), getHeight(), 3);
- U8* src = mdata + mBitmapOffset;
- U8* dst = raw_image->getData();
- BOOL success = FALSE;
- switch( mBitsPerPixel )
- {
- case 8:
- if( mColorPaletteColors >= 256 )
- {
- success = decodeColorTable8( dst, src );
- }
- break;
-
- case 16:
- success = decodeColorMask16( dst, src );
- break;
-
- case 24:
- success = decodeTruecolor24( dst, src );
- break;
- case 32:
- success = decodeColorMask32( dst, src );
- break;
- }
- if( success && mOriginAtTop )
- {
- raw_image->verticalFlip();
- }
- return success;
- }
- U32 LLImageBMP::countTrailingZeros( U32 m )
- {
- U32 shift_count = 0;
- while( !(m & 1) )
- {
- shift_count++;
- m >>= 1;
- }
- return shift_count;
- }
- BOOL LLImageBMP::decodeColorMask16( U8* dst, U8* src )
- {
- llassert( 16 == mBitsPerPixel );
- if( !mBitfieldMask[0] && !mBitfieldMask[1] && !mBitfieldMask[2] )
- {
- // Use default values
- mBitfieldMask[0] = 0x00007C00;
- mBitfieldMask[1] = 0x000003E0;
- mBitfieldMask[2] = 0x0000001F;
- }
- S32 src_row_span = getWidth() * 2;
- S32 alignment_bytes = (3 * src_row_span) % 4; // round up to nearest multiple of 4
- U32 r_shift = countTrailingZeros( mBitfieldMask[2] );
- U32 g_shift = countTrailingZeros( mBitfieldMask[1] );
- U32 b_shift = countTrailingZeros( mBitfieldMask[0] );
- for( S32 row = 0; row < getHeight(); row++ )
- {
- for( S32 col = 0; col < getWidth(); col++ )
- {
- U32 value = *((U16*)src);
- dst[0] = U8((value & mBitfieldMask[2]) >> r_shift); // Red
- dst[1] = U8((value & mBitfieldMask[1]) >> g_shift); // Green
- dst[2] = U8((value & mBitfieldMask[0]) >> b_shift); // Blue
- src += 2;
- dst += 3;
- }
- src += alignment_bytes;
- }
- return TRUE;
- }
- BOOL LLImageBMP::decodeColorMask32( U8* dst, U8* src )
- {
- // Note: alpha is not supported
- llassert( 32 == mBitsPerPixel );
- if( !mBitfieldMask[0] && !mBitfieldMask[1] && !mBitfieldMask[2] )
- {
- // Use default values
- mBitfieldMask[0] = 0x00FF0000;
- mBitfieldMask[1] = 0x0000FF00;
- mBitfieldMask[2] = 0x000000FF;
- }
- S32 src_row_span = getWidth() * 4;
- S32 alignment_bytes = (3 * src_row_span) % 4; // round up to nearest multiple of 4
- U32 r_shift = countTrailingZeros( mBitfieldMask[0] );
- U32 g_shift = countTrailingZeros( mBitfieldMask[1] );
- U32 b_shift = countTrailingZeros( mBitfieldMask[2] );
- for( S32 row = 0; row < getHeight(); row++ )
- {
- for( S32 col = 0; col < getWidth(); col++ )
- {
- U32 value = *((U32*)src);
- dst[0] = U8((value & mBitfieldMask[0]) >> r_shift); // Red
- dst[1] = U8((value & mBitfieldMask[1]) >> g_shift); // Green
- dst[2] = U8((value & mBitfieldMask[2]) >> b_shift); // Blue
- src += 4;
- dst += 3;
- }
- src += alignment_bytes;
- }
- return TRUE;
- }
- BOOL LLImageBMP::decodeColorTable8( U8* dst, U8* src )
- {
- llassert( (8 == mBitsPerPixel) && (mColorPaletteColors >= 256) );
- S32 src_row_span = getWidth() * 1;
- S32 alignment_bytes = (3 * src_row_span) % 4; // round up to nearest multiple of 4
- for( S32 row = 0; row < getHeight(); row++ )
- {
- for( S32 col = 0; col < getWidth(); col++ )
- {
- S32 index = 4 * src[0];
- dst[0] = mColorPalette[index + 2]; // Red
- dst[1] = mColorPalette[index + 1]; // Green
- dst[2] = mColorPalette[index + 0]; // Blue
- src++;
- dst += 3;
- }
- src += alignment_bytes;
- }
- return TRUE;
- }
- BOOL LLImageBMP::decodeTruecolor24( U8* dst, U8* src )
- {
- llassert( 24 == mBitsPerPixel );
- llassert( 3 == getComponents() );
- S32 src_row_span = getWidth() * 3;
- S32 alignment_bytes = (3 * src_row_span) % 4; // round up to nearest multiple of 4
- for( S32 row = 0; row < getHeight(); row++ )
- {
- for( S32 col = 0; col < getWidth(); col++ )
- {
- dst[0] = src[2]; // Red
- dst[1] = src[1]; // Green
- dst[2] = src[0]; // Blue
- src += 3;
- dst += 3;
- }
- src += alignment_bytes;
- }
- return TRUE;
- }
- BOOL LLImageBMP::encode(const LLImageRaw* raw_image, F32 encode_time)
- {
- llassert_always(raw_image);
-
- resetLastError();
- S32 src_components = raw_image->getComponents();
- S32 dst_components = ( src_components < 3 ) ? 1 : 3;
- if( (2 == src_components) || (4 == src_components) )
- {
- llinfos << "Dropping alpha information during BMP encoding" << llendl;
- }
- setSize(raw_image->getWidth(), raw_image->getHeight(), dst_components);
-
- U8 magic[14];
- LLBMPHeader header;
- int header_bytes = 14+sizeof(header);
- llassert(header_bytes == 54);
- if (getComponents() == 1)
- {
- header_bytes += 1024; // Need colour LUT.
- }
- int line_bytes = getComponents() * getWidth();
- int alignment_bytes = (3 * line_bytes) % 4;
- line_bytes += alignment_bytes;
- int file_bytes = line_bytes*getHeight() + header_bytes;
- // Allocate the new buffer for the data.
- if(!allocateData(file_bytes)) //memory allocation failed
- {
- return FALSE ;
- }
- magic[0] = 'B'; magic[1] = 'M';
- magic[2] = (U8) file_bytes;
- magic[3] = (U8)(file_bytes>>8);
- magic[4] = (U8)(file_bytes>>16);
- magic[5] = (U8)(file_bytes>>24);
- magic[6] = magic[7] = magic[8] = magic[9] = 0;
- magic[10] = (U8) header_bytes;
- magic[11] = (U8)(header_bytes>>8);
- magic[12] = (U8)(header_bytes>>16);
- magic[13] = (U8)(header_bytes>>24);
- header.mSize = 40;
- header.mWidth = getWidth();
- header.mHeight = getHeight();
- header.mPlanes = 1;
- header.mBitsPerPixel = (getComponents()==1)?8:24;
- header.mCompression = 0;
- header.mAlignmentPadding = 0;
- header.mImageSize = 0;
- #if LL_DARWIN
- header.mHorzPelsPerMeter = header.mVertPelsPerMeter = 2834; // 72dpi
- #else
- header.mHorzPelsPerMeter = header.mVertPelsPerMeter = 0;
- #endif
- header.mNumColors = header.mNumColorsImportant = 0;
- // convert BMP header to little endian (no-op on little endian builds)
- llendianswizzleone(header.mSize);
- llendianswizzleone(header.mWidth);
- llendianswizzleone(header.mHeight);
- llendianswizzleone(header.mPlanes);
- llendianswizzleone(header.mBitsPerPixel);
- llendianswizzleone(header.mCompression);
- llendianswizzleone(header.mAlignmentPadding);
- llendianswizzleone(header.mImageSize);
- llendianswizzleone(header.mHorzPelsPerMeter);
- llendianswizzleone(header.mVertPelsPerMeter);
- llendianswizzleone(header.mNumColors);
- llendianswizzleone(header.mNumColorsImportant);
- U8* mdata = getData();
-
- // Output magic, then header, then the palette table, then the data.
- U32 cur_pos = 0;
- memcpy(mdata, magic, 14);
- cur_pos += 14;
- memcpy(mdata+cur_pos, &header, 40); /* Flawfinder: ignore */
- cur_pos += 40;
- if (getComponents() == 1)
- {
- S32 n;
- for (n=0; n < 256; n++)
- {
- mdata[cur_pos++] = (U8)n;
- mdata[cur_pos++] = (U8)n;
- mdata[cur_pos++] = (U8)n;
- mdata[cur_pos++] = 0;
- }
- }
-
- // Need to iterate through, because we need to flip the RGB.
- const U8* src = raw_image->getData();
- U8* dst = mdata + cur_pos;
- for( S32 row = 0; row < getHeight(); row++ )
- {
- for( S32 col = 0; col < getWidth(); col++ )
- {
- switch( src_components )
- {
- case 1:
- *dst++ = *src++;
- break;
- case 2:
- {
- U32 lum = src[0];
- U32 alpha = src[1];
- *dst++ = (U8)(lum * alpha / 255);
- src += 2;
- break;
- }
- case 3:
- case 4:
- dst[0] = src[2];
- dst[1] = src[1];
- dst[2] = src[0];
- src += src_components;
- dst += 3;
- break;
- }
- }
- for( S32 i = 0; i < alignment_bytes; i++ )
- {
- *dst++ = 0;
- }
- }
- return TRUE;
- }