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-rw-r--r--indra/llimage/llpngwrapper.cpp823
1 files changed, 415 insertions, 408 deletions
diff --git a/indra/llimage/llpngwrapper.cpp b/indra/llimage/llpngwrapper.cpp
index baf1330011..e9c11270c8 100644
--- a/indra/llimage/llpngwrapper.cpp
+++ b/indra/llimage/llpngwrapper.cpp
@@ -1,408 +1,415 @@
-/*
- * @file llpngwrapper.cpp
- * @brief Encapsulates libpng read/write functionality.
- *
- * $LicenseInfo:firstyear=2007&license=viewerlgpl$
- * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License only.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
- * $/LicenseInfo$
- */
-
-#include "linden_common.h"
-#include "stdtypes.h"
-#include "llerror.h"
-
-#include "llimage.h"
-#include "llpngwrapper.h"
-
-#include "llexception.h"
-
-namespace {
-// Failure to load an image shouldn't crash the whole viewer.
-struct PngError: public LLContinueError
-{
- PngError(png_const_charp msg): LLContinueError(msg) {}
-};
-} // anonymous namespace
-
-// ---------------------------------------------------------------------------
-// LLPngWrapper
-// ---------------------------------------------------------------------------
-
-LLPngWrapper::LLPngWrapper()
- : mReadPngPtr( NULL ),
- mReadInfoPtr( NULL ),
- mWritePngPtr( NULL ),
- mWriteInfoPtr( NULL ),
- mRowPointers( NULL ),
- mWidth( 0 ),
- mHeight( 0 ),
- mBitDepth( 0 ),
- mColorType( 0 ),
- mChannels( 0 ),
- mInterlaceType( 0 ),
- mCompressionType( 0 ),
- mFilterMethod( 0 ),
- mFinalSize( 0 ),
- mGamma(0.f)
-{
-}
-
-LLPngWrapper::~LLPngWrapper()
-{
- releaseResources();
-}
-
-// Checks the src for a valid PNG header
-bool LLPngWrapper::isValidPng(U8* src)
-{
- const int PNG_BYTES_TO_CHECK = 8;
-
- int sig = png_sig_cmp((png_bytep)src, (png_size_t)0, PNG_BYTES_TO_CHECK);
- if (sig != 0)
- {
- mErrorMessage = "Invalid or corrupt PNG file";
- return false;
- }
-
- return true;
-}
-
-// Called by the libpng library when a fatal encoding or decoding error
-// occurs. We throw PngError and let our try/catch block clean up.
-void LLPngWrapper::errorHandler(png_structp png_ptr, png_const_charp msg)
-{
- LLTHROW(PngError(msg));
-}
-
-// Called by the libpng library when reading (decoding) the PNG file. We
-// copy the PNG data from our internal buffer into the PNG's data buffer.
-void LLPngWrapper::readDataCallback(png_structp png_ptr, png_bytep dest, png_size_t length)
-{
- PngDataInfo *dataInfo = (PngDataInfo *) png_get_io_ptr(png_ptr);
- if(dataInfo->mOffset + length > dataInfo->mDataSize)
- {
- png_error(png_ptr, "Data read error. Requested data size exceeds available data size.");
- return;
- }
-
- U8 *src = &dataInfo->mData[dataInfo->mOffset];
- memcpy(dest, src, length);
- dataInfo->mOffset += static_cast<U32>(length);
-}
-
-// Called by the libpng library when writing (encoding) the PNG file. We
-// copy the encoded result into our data buffer.
-void LLPngWrapper::writeDataCallback(png_structp png_ptr, png_bytep src, png_size_t length)
-{
- PngDataInfo *dataInfo = (PngDataInfo *) png_get_io_ptr(png_ptr);
- if (dataInfo->mOffset + length > dataInfo->mDataSize)
- {
- png_error(png_ptr, "Data write error. Requested data size exceeds available data size.");
- return;
- }
- U8 *dest = &dataInfo->mData[dataInfo->mOffset];
- memcpy(dest, src, length);
- dataInfo->mOffset += static_cast<U32>(length);
-}
-
-// Flush the write output pointer
-void LLPngWrapper::writeFlush(png_structp png_ptr)
-{
- // no-op since we're just writing to memory
-}
-
-// Read the PNG file using the libpng. The low-level interface is used here
-// because we want to do various transformations (including applying gama)
-// which can't be done with the high-level interface.
-// The scanline also begins at the bottom of
-// the image (per SecondLife conventions) instead of at the top, so we
-// must assign row-pointers in "reverse" order.
-bool LLPngWrapper::readPng(U8* src, S32 dataSize, LLImageRaw* rawImage, ImageInfo *infop)
-{
- try
- {
- // Create and initialize the png structures
- mReadPngPtr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
- this, &errorHandler, NULL);
- if (mReadPngPtr == NULL)
- {
- LLTHROW(PngError("Problem creating png read structure"));
- }
-
- // Allocate/initialize the memory for image information.
- mReadInfoPtr = png_create_info_struct(mReadPngPtr);
-
- // Set up the input control
- PngDataInfo dataPtr;
- dataPtr.mData = src;
- dataPtr.mOffset = 0;
- dataPtr.mDataSize = dataSize;
-
- png_set_read_fn(mReadPngPtr, &dataPtr, &readDataCallback);
- png_set_sig_bytes(mReadPngPtr, 0);
-
- // setup low-level read and get header information
- png_read_info(mReadPngPtr, mReadInfoPtr);
- png_get_IHDR(mReadPngPtr, mReadInfoPtr, &mWidth, &mHeight,
- &mBitDepth, &mColorType, &mInterlaceType,
- &mCompressionType, &mFilterMethod);
-
- // Normalize the image, then get updated image information
- // after transformations have been applied
- normalizeImage();
- updateMetaData();
-
- // If a raw object is supplied, read the PNG image into its
- // data space
- if (rawImage != NULL)
- {
- LLImageDataLock lock(rawImage);
-
- if (!rawImage->resize(static_cast<U16>(mWidth),
- static_cast<U16>(mHeight), mChannels))
- {
- LLTHROW(PngError("Failed to resize image"));
- }
- U8 *dest = rawImage->getData();
- int offset = mWidth * mChannels;
-
- // Set up the row pointers and read the image
- mRowPointers = new U8* [mHeight];
- for (U32 i=0; i < mHeight; i++)
- {
- mRowPointers[i] = &dest[(mHeight-i-1)*offset];
- }
-
- png_read_image(mReadPngPtr, mRowPointers);
-
- // Finish up, ensures all metadata are updated
- png_read_end(mReadPngPtr, NULL);
- }
-
- // If an info object is supplied, copy the relevant info
- if (infop != NULL)
- {
- infop->mHeight = static_cast<U16>(mHeight);
- infop->mWidth = static_cast<U16>(mWidth);
- infop->mComponents = mChannels;
- }
-
- mFinalSize = dataPtr.mOffset;
- }
- catch (const PngError& msg)
- {
- mErrorMessage = msg.what();
- releaseResources();
- return (false);
- }
- catch (std::bad_alloc&)
- {
- mErrorMessage = "LLPngWrapper";
- releaseResources();
- return (false);
- }
-
- // Clean up and return
- releaseResources();
- return (true);
-}
-
-// Do transformations to normalize the input to 8-bpp RGBA
-void LLPngWrapper::normalizeImage()
-{
- // 1. Expand any palettes
- // 2. Convert grayscales to RGB
- // 3. Create alpha layer from transparency
- // 4. Ensure 8-bpp for all images
- // 5. Set (or guess) gamma
-
- if (mColorType == PNG_COLOR_TYPE_PALETTE)
- {
- png_set_palette_to_rgb(mReadPngPtr);
- }
- if (mColorType == PNG_COLOR_TYPE_GRAY && mBitDepth < 8)
- {
- png_set_expand_gray_1_2_4_to_8(mReadPngPtr);
- }
- if (mColorType == PNG_COLOR_TYPE_GRAY
- || mColorType == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- png_set_gray_to_rgb(mReadPngPtr);
- }
- if (png_get_valid(mReadPngPtr, mReadInfoPtr, PNG_INFO_tRNS))
- {
- png_set_tRNS_to_alpha(mReadPngPtr);
- }
- if (mBitDepth < 8)
- {
- png_set_packing(mReadPngPtr);
- }
- else if (mBitDepth == 16)
- {
- png_set_strip_16(mReadPngPtr);
- }
-
- const F64 SCREEN_GAMMA = 2.2;
- if (png_get_gAMA(mReadPngPtr, mReadInfoPtr, &mGamma))
- {
- png_set_gamma(mReadPngPtr, SCREEN_GAMMA, mGamma);
- }
- else
- {
- png_set_gamma(mReadPngPtr, SCREEN_GAMMA, 1/SCREEN_GAMMA);
- }
-}
-
-// Read out the image meta-data
-void LLPngWrapper::updateMetaData()
-{
- png_read_update_info(mReadPngPtr, mReadInfoPtr);
- mWidth = png_get_image_width(mReadPngPtr, mReadInfoPtr);
- mHeight = png_get_image_height(mReadPngPtr, mReadInfoPtr);
- mBitDepth = png_get_bit_depth(mReadPngPtr, mReadInfoPtr);
- mColorType = png_get_color_type(mReadPngPtr, mReadInfoPtr);
- mChannels = png_get_channels(mReadPngPtr, mReadInfoPtr);
-}
-
-// Method to write raw image into PNG at dest. The raw scanline begins
-// at the bottom of the image per SecondLife conventions.
-bool LLPngWrapper::writePng(const LLImageRaw* rawImage, U8* dest, size_t destSize)
-{
- try
- {
- S8 numComponents = rawImage->getComponents();
- switch (numComponents)
- {
- case 1:
- mColorType = PNG_COLOR_TYPE_GRAY;
- break;
- case 2:
- mColorType = PNG_COLOR_TYPE_GRAY_ALPHA;
- break;
- case 3:
- mColorType = PNG_COLOR_TYPE_RGB;
- break;
- case 4:
- mColorType = PNG_COLOR_TYPE_RGB_ALPHA;
- break;
- default:
- mColorType = -1;
- }
-
- if (mColorType == -1)
- {
- LLTHROW(PngError("Unsupported image: unexpected number of channels"));
- }
-
- mWritePngPtr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
- NULL, &errorHandler, NULL);
- if (!mWritePngPtr)
- {
- LLTHROW(PngError("Problem creating png write structure"));
- }
-
- mWriteInfoPtr = png_create_info_struct(mWritePngPtr);
-
- // Setup write function
- PngDataInfo dataPtr;
- dataPtr.mData = dest;
- dataPtr.mOffset = 0;
- dataPtr.mDataSize = destSize;
- png_set_write_fn(mWritePngPtr, &dataPtr, &writeDataCallback, &writeFlush);
-
- // Setup image params
- mWidth = rawImage->getWidth();
- mHeight = rawImage->getHeight();
- mBitDepth = 8; // Fixed to 8-bpp in SL
- mChannels = numComponents;
- mInterlaceType = PNG_INTERLACE_NONE;
- mCompressionType = PNG_COMPRESSION_TYPE_DEFAULT;
- mFilterMethod = PNG_FILTER_TYPE_DEFAULT;
-
- // Write header
- png_set_IHDR(mWritePngPtr, mWriteInfoPtr, mWidth, mHeight,
- mBitDepth, mColorType, mInterlaceType,
- mCompressionType, mFilterMethod);
-
- // Get data and compute row size
- const U8* data = rawImage->getData();
- int offset = mWidth * mChannels;
-
- // Ready to write, start with the header
- png_write_info(mWritePngPtr, mWriteInfoPtr);
-
- // Write image (sorry, must const-cast for libpng)
- const U8 * rowPointer;
- for (U32 i=0; i < mHeight; i++)
- {
- rowPointer = &data[(mHeight-1-i)*offset];
- png_write_row(mWritePngPtr, const_cast<png_bytep>(rowPointer));
- }
-
- // Finish up
- png_write_end(mWritePngPtr, mWriteInfoPtr);
- mFinalSize = dataPtr.mOffset;
- }
- catch (const PngError& msg)
- {
- mErrorMessage = msg.what();
- releaseResources();
- return (false);
- }
-
- releaseResources();
- return true;
-}
-
-// Cleanup various internal structures
-void LLPngWrapper::releaseResources()
-{
- if (mReadPngPtr || mReadInfoPtr)
- {
- png_destroy_read_struct(&mReadPngPtr, &mReadInfoPtr, NULL);
- mReadPngPtr = NULL;
- mReadInfoPtr = NULL;
- }
-
- if (mWritePngPtr || mWriteInfoPtr)
- {
- png_destroy_write_struct(&mWritePngPtr, &mWriteInfoPtr);
- mWritePngPtr = NULL;
- mWriteInfoPtr = NULL;
- }
-
- if (mRowPointers)
- {
- delete[] mRowPointers;
- mRowPointers = NULL;
- }
-}
-
-// Get final image size after compression
-U32 LLPngWrapper::getFinalSize()
-{
- return mFinalSize;
-}
-
-// Get last error message, if any
-const std::string& LLPngWrapper::getErrorMessage()
-{
- return mErrorMessage;
-}
+/*
+ * @file llpngwrapper.cpp
+ * @brief Encapsulates libpng read/write functionality.
+ *
+ * $LicenseInfo:firstyear=2007&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+#include "stdtypes.h"
+#include "llerror.h"
+
+#include "llimage.h"
+#include "llpngwrapper.h"
+
+#include "llexception.h"
+
+namespace {
+// Failure to load an image shouldn't crash the whole viewer.
+struct PngError: public LLContinueError
+{
+ PngError(png_const_charp msg): LLContinueError(msg) {}
+};
+} // anonymous namespace
+
+// ---------------------------------------------------------------------------
+// LLPngWrapper
+// ---------------------------------------------------------------------------
+
+LLPngWrapper::LLPngWrapper()
+ : mReadPngPtr( NULL ),
+ mReadInfoPtr( NULL ),
+ mWritePngPtr( NULL ),
+ mWriteInfoPtr( NULL ),
+ mRowPointers( NULL ),
+ mWidth( 0 ),
+ mHeight( 0 ),
+ mBitDepth( 0 ),
+ mColorType( 0 ),
+ mChannels( 0 ),
+ mInterlaceType( 0 ),
+ mCompressionType( 0 ),
+ mFilterMethod( 0 ),
+ mFinalSize( 0 ),
+ mGamma(0.f)
+{
+}
+
+LLPngWrapper::~LLPngWrapper()
+{
+ releaseResources();
+}
+
+// Checks the src for a valid PNG header
+bool LLPngWrapper::isValidPng(U8* src)
+{
+ const int PNG_BYTES_TO_CHECK = 8;
+
+ int sig = png_sig_cmp((png_bytep)src, (png_size_t)0, PNG_BYTES_TO_CHECK);
+ if (sig != 0)
+ {
+ mErrorMessage = "Invalid or corrupt PNG file";
+ return false;
+ }
+
+ return true;
+}
+
+// Called by the libpng library when a fatal encoding or decoding error
+// occurs. We throw PngError and let our try/catch block clean up.
+void LLPngWrapper::errorHandler(png_structp png_ptr, png_const_charp msg)
+{
+ LLTHROW(PngError(msg));
+}
+
+// Called by the libpng library when reading (decoding) the PNG file. We
+// copy the PNG data from our internal buffer into the PNG's data buffer.
+void LLPngWrapper::readDataCallback(png_structp png_ptr, png_bytep dest, png_size_t length)
+{
+ PngDataInfo *dataInfo = (PngDataInfo *) png_get_io_ptr(png_ptr);
+ if(dataInfo->mOffset + length > dataInfo->mDataSize)
+ {
+ png_error(png_ptr, "Data read error. Requested data size exceeds available data size.");
+ return;
+ }
+
+ U8 *src = &dataInfo->mData[dataInfo->mOffset];
+ memcpy(dest, src, length);
+ dataInfo->mOffset += static_cast<U32>(length);
+}
+
+// Called by the libpng library when writing (encoding) the PNG file. We
+// copy the encoded result into our data buffer.
+void LLPngWrapper::writeDataCallback(png_structp png_ptr, png_bytep src, png_size_t length)
+{
+ PngDataInfo *dataInfo = (PngDataInfo *) png_get_io_ptr(png_ptr);
+ if (dataInfo->mOffset + length > dataInfo->mDataSize)
+ {
+ png_error(png_ptr, "Data write error. Requested data size exceeds available data size.");
+ return;
+ }
+ U8 *dest = &dataInfo->mData[dataInfo->mOffset];
+ memcpy(dest, src, length);
+ dataInfo->mOffset += static_cast<U32>(length);
+}
+
+// Flush the write output pointer
+void LLPngWrapper::writeFlush(png_structp png_ptr)
+{
+ // no-op since we're just writing to memory
+}
+
+// Read the PNG file using the libpng. The low-level interface is used here
+// because we want to do various transformations (including applying gama)
+// which can't be done with the high-level interface.
+// The scanline also begins at the bottom of
+// the image (per SecondLife conventions) instead of at the top, so we
+// must assign row-pointers in "reverse" order.
+bool LLPngWrapper::readPng(U8* src, S32 dataSize, LLImageRaw* rawImage, ImageInfo *infop)
+{
+ try
+ {
+ // Create and initialize the png structures
+ mReadPngPtr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
+ this, &errorHandler, NULL);
+ if (mReadPngPtr == NULL)
+ {
+ LLTHROW(PngError("Problem creating png read structure"));
+ }
+
+ // Allocate/initialize the memory for image information.
+ mReadInfoPtr = png_create_info_struct(mReadPngPtr);
+
+ // Set up the input control
+ PngDataInfo dataPtr;
+ dataPtr.mData = src;
+ dataPtr.mOffset = 0;
+ dataPtr.mDataSize = dataSize;
+
+ png_set_read_fn(mReadPngPtr, &dataPtr, &readDataCallback);
+ png_set_sig_bytes(mReadPngPtr, 0);
+
+ // setup low-level read and get header information
+ png_read_info(mReadPngPtr, mReadInfoPtr);
+ png_get_IHDR(mReadPngPtr, mReadInfoPtr, &mWidth, &mHeight,
+ &mBitDepth, &mColorType, &mInterlaceType,
+ &mCompressionType, &mFilterMethod);
+
+ // Normalize the image, then get updated image information
+ // after transformations have been applied
+ normalizeImage();
+ updateMetaData();
+
+ // If a raw object is supplied, read the PNG image into its
+ // data space
+ if (rawImage != NULL)
+ {
+ LLImageDataLock lock(rawImage);
+
+ if (!rawImage->resize(static_cast<U16>(mWidth),
+ static_cast<U16>(mHeight), mChannels))
+ {
+ LLTHROW(PngError("Failed to resize image"));
+ }
+ U8 *dest = rawImage->getData();
+ int offset = mWidth * mChannels;
+
+ // Set up the row pointers and read the image
+ mRowPointers = new U8* [mHeight];
+ for (U32 i=0; i < mHeight; i++)
+ {
+ mRowPointers[i] = &dest[(mHeight-i-1)*offset];
+ }
+
+ png_read_image(mReadPngPtr, mRowPointers);
+
+ // Finish up, ensures all metadata are updated
+ png_read_end(mReadPngPtr, NULL);
+ }
+
+ // If an info object is supplied, copy the relevant info
+ if (infop != NULL)
+ {
+ infop->mHeight = static_cast<U16>(mHeight);
+ infop->mWidth = static_cast<U16>(mWidth);
+ infop->mComponents = mChannels;
+ }
+
+ mFinalSize = dataPtr.mOffset;
+ }
+ catch (const PngError& msg)
+ {
+ mErrorMessage = msg.what();
+ releaseResources();
+ return (false);
+ }
+ catch (std::bad_alloc&)
+ {
+ mErrorMessage = "LLPngWrapper";
+ releaseResources();
+ return (false);
+ }
+ catch (...)
+ {
+ mErrorMessage = "LLPngWrapper";
+ releaseResources();
+ LOG_UNHANDLED_EXCEPTION("");
+ return (false);
+ }
+
+ // Clean up and return
+ releaseResources();
+ return (true);
+}
+
+// Do transformations to normalize the input to 8-bpp RGBA
+void LLPngWrapper::normalizeImage()
+{
+ // 1. Expand any palettes
+ // 2. Convert grayscales to RGB
+ // 3. Create alpha layer from transparency
+ // 4. Ensure 8-bpp for all images
+ // 5. Set (or guess) gamma
+
+ if (mColorType == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_set_palette_to_rgb(mReadPngPtr);
+ }
+ if (mColorType == PNG_COLOR_TYPE_GRAY && mBitDepth < 8)
+ {
+ png_set_expand_gray_1_2_4_to_8(mReadPngPtr);
+ }
+ if (mColorType == PNG_COLOR_TYPE_GRAY
+ || mColorType == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ png_set_gray_to_rgb(mReadPngPtr);
+ }
+ if (png_get_valid(mReadPngPtr, mReadInfoPtr, PNG_INFO_tRNS))
+ {
+ png_set_tRNS_to_alpha(mReadPngPtr);
+ }
+ if (mBitDepth < 8)
+ {
+ png_set_packing(mReadPngPtr);
+ }
+ else if (mBitDepth == 16)
+ {
+ png_set_strip_16(mReadPngPtr);
+ }
+
+ const F64 SCREEN_GAMMA = 2.2;
+ if (png_get_gAMA(mReadPngPtr, mReadInfoPtr, &mGamma))
+ {
+ png_set_gamma(mReadPngPtr, SCREEN_GAMMA, mGamma);
+ }
+ else
+ {
+ png_set_gamma(mReadPngPtr, SCREEN_GAMMA, 1/SCREEN_GAMMA);
+ }
+}
+
+// Read out the image meta-data
+void LLPngWrapper::updateMetaData()
+{
+ png_read_update_info(mReadPngPtr, mReadInfoPtr);
+ mWidth = png_get_image_width(mReadPngPtr, mReadInfoPtr);
+ mHeight = png_get_image_height(mReadPngPtr, mReadInfoPtr);
+ mBitDepth = png_get_bit_depth(mReadPngPtr, mReadInfoPtr);
+ mColorType = png_get_color_type(mReadPngPtr, mReadInfoPtr);
+ mChannels = png_get_channels(mReadPngPtr, mReadInfoPtr);
+}
+
+// Method to write raw image into PNG at dest. The raw scanline begins
+// at the bottom of the image per SecondLife conventions.
+bool LLPngWrapper::writePng(const LLImageRaw* rawImage, U8* dest, size_t destSize)
+{
+ try
+ {
+ S8 numComponents = rawImage->getComponents();
+ switch (numComponents)
+ {
+ case 1:
+ mColorType = PNG_COLOR_TYPE_GRAY;
+ break;
+ case 2:
+ mColorType = PNG_COLOR_TYPE_GRAY_ALPHA;
+ break;
+ case 3:
+ mColorType = PNG_COLOR_TYPE_RGB;
+ break;
+ case 4:
+ mColorType = PNG_COLOR_TYPE_RGB_ALPHA;
+ break;
+ default:
+ mColorType = -1;
+ }
+
+ if (mColorType == -1)
+ {
+ LLTHROW(PngError("Unsupported image: unexpected number of channels"));
+ }
+
+ mWritePngPtr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+ NULL, &errorHandler, NULL);
+ if (!mWritePngPtr)
+ {
+ LLTHROW(PngError("Problem creating png write structure"));
+ }
+
+ mWriteInfoPtr = png_create_info_struct(mWritePngPtr);
+
+ // Setup write function
+ PngDataInfo dataPtr;
+ dataPtr.mData = dest;
+ dataPtr.mOffset = 0;
+ dataPtr.mDataSize = destSize;
+ png_set_write_fn(mWritePngPtr, &dataPtr, &writeDataCallback, &writeFlush);
+
+ // Setup image params
+ mWidth = rawImage->getWidth();
+ mHeight = rawImage->getHeight();
+ mBitDepth = 8; // Fixed to 8-bpp in SL
+ mChannels = numComponents;
+ mInterlaceType = PNG_INTERLACE_NONE;
+ mCompressionType = PNG_COMPRESSION_TYPE_DEFAULT;
+ mFilterMethod = PNG_FILTER_TYPE_DEFAULT;
+
+ // Write header
+ png_set_IHDR(mWritePngPtr, mWriteInfoPtr, mWidth, mHeight,
+ mBitDepth, mColorType, mInterlaceType,
+ mCompressionType, mFilterMethod);
+
+ // Get data and compute row size
+ const U8* data = rawImage->getData();
+ int offset = mWidth * mChannels;
+
+ // Ready to write, start with the header
+ png_write_info(mWritePngPtr, mWriteInfoPtr);
+
+ // Write image (sorry, must const-cast for libpng)
+ const U8 * rowPointer;
+ for (U32 i=0; i < mHeight; i++)
+ {
+ rowPointer = &data[(mHeight-1-i)*offset];
+ png_write_row(mWritePngPtr, const_cast<png_bytep>(rowPointer));
+ }
+
+ // Finish up
+ png_write_end(mWritePngPtr, mWriteInfoPtr);
+ mFinalSize = dataPtr.mOffset;
+ }
+ catch (const PngError& msg)
+ {
+ mErrorMessage = msg.what();
+ releaseResources();
+ return (false);
+ }
+
+ releaseResources();
+ return true;
+}
+
+// Cleanup various internal structures
+void LLPngWrapper::releaseResources()
+{
+ if (mReadPngPtr || mReadInfoPtr)
+ {
+ png_destroy_read_struct(&mReadPngPtr, &mReadInfoPtr, NULL);
+ mReadPngPtr = NULL;
+ mReadInfoPtr = NULL;
+ }
+
+ if (mWritePngPtr || mWriteInfoPtr)
+ {
+ png_destroy_write_struct(&mWritePngPtr, &mWriteInfoPtr);
+ mWritePngPtr = NULL;
+ mWriteInfoPtr = NULL;
+ }
+
+ if (mRowPointers)
+ {
+ delete[] mRowPointers;
+ mRowPointers = NULL;
+ }
+}
+
+// Get final image size after compression
+U32 LLPngWrapper::getFinalSize()
+{
+ return mFinalSize;
+}
+
+// Get last error message, if any
+const std::string& LLPngWrapper::getErrorMessage()
+{
+ return mErrorMessage;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 00:00:09 +0000