libreoffice-online/common/Png.hpp
Tor Lillqvist 64675d2926 Add ProfileZone to encodeSubBufferToPNG
Signed-off-by: Tor Lillqvist <tml@collabora.com>
Change-Id: I7363ea929ba703ce34a5c2411687f120ac5ba59e
2021-06-22 16:43:40 +03:00

344 lines
11 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#pragma once
/* cairo - a vector graphics library with display and print output
*
* Copyright © 2003 University of Southern California
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is University of Southern
* California.
*
* Contributor(s):
* Carl D. Worth <cworth@cworth.org>
* Kristian Høgsberg <krh@redhat.com>
* Chris Wilson <chris@chris-wilson.co.uk>
*/
#define PNG_SKIP_SETJMP_CHECK
#include <png.h>
#include <zlib.h>
#include <cassert>
#include <chrono>
#include <iomanip>
#ifdef IOS
#include <Foundation/Foundation.h>
#endif
#include "Log.hpp"
#include "SpookyV2.h"
#include "TraceEvent.hpp"
namespace Png
{
// Callback functions for libpng
extern "C"
{
static void user_write_status_fn(png_structp, png_uint_32, int)
{
}
static void user_write_fn(png_structp png_ptr, png_bytep data, png_size_t length)
{
std::vector<char>* outputp = static_cast<std::vector<char>*>(png_get_io_ptr(png_ptr));
const size_t oldsize = outputp->size();
outputp->resize(oldsize + length);
std::memcpy(outputp->data() + oldsize, data, length);
}
static void user_flush_fn(png_structp)
{
}
}
/* Unpremultiplies data and converts native endian ARGB => RGBA bytes */
static void
unpremultiply_data (png_structp /*png*/, png_row_infop row_info, png_bytep data)
{
unsigned int i;
for (i = 0; i < row_info->rowbytes; i += 4)
{
uint8_t *b = &data[i];
uint32_t pix;
uint8_t alpha;
std::memcpy (&pix, b, sizeof (uint32_t));
alpha = (pix & 0xff000000) >> 24;
if (alpha == 255)
{
b[0] = ((pix & 0xff0000) >> 16);
b[1] = ((pix & 0x00ff00) >> 8);
b[2] = ((pix & 0x0000ff) >> 0);
b[3] = 255;
}
else if (alpha == 0)
{
b[0] = b[1] = b[2] = b[3] = 0;
}
else
{
b[0] = (((pix & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
b[1] = (((pix & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha;
b[2] = (((pix & 0x0000ff) >> 0) * 255 + alpha / 2) / alpha;
b[3] = alpha;
}
}
}
/// This function uses setjmp which may clobbers non-trivial objects.
/// So we can't use logging or create complex C++ objects in this frame.
/// Specifically, logging uses std::string objects, and GCC gives the following:
/// error: variable __capacity might be clobbered by longjmp or vfork [-Werror=clobbered]
/// In practice, this is bogus, since __capacity is has a trivial type, but this error
/// shows up with the sanitizers. But technically we shouldn't mix C++ objects with setjmp.
/// Sadly, older libpng headers don't use const for the pixmap pointer parameter to
/// png_write_row(), so can't use const here for pixmap.
inline bool impl_encodeSubBufferToPNG(unsigned char* pixmap, size_t startX, size_t startY,
int width, int height, int bufferWidth, int bufferHeight,
std::vector<char>& output, LibreOfficeKitTileMode mode)
{
if (bufferWidth < width || bufferHeight < height)
{
return false;
}
png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
png_infop info_ptr = png_create_info_struct(png_ptr);
if (setjmp(png_jmpbuf(png_ptr)))
{
png_destroy_write_struct(&png_ptr, nullptr);
return false;
}
#if MOBILEAPP
png_set_compression_level(png_ptr, Z_BEST_SPEED);
#else
// Level 4 gives virtually identical compression
// ratio to level 6, but is between 5-10% faster.
// Level 3 runs almost twice as fast, but the
// output is typically 2-3x larger.
png_set_compression_level(png_ptr, 4);
#endif
#ifdef IOS
auto initialSize = output.size();
#endif
png_set_IHDR(png_ptr, info_ptr, width, height, 8, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_set_write_fn(png_ptr, &output, user_write_fn, user_flush_fn);
png_set_write_status_fn(png_ptr, user_write_status_fn);
png_write_info(png_ptr, info_ptr);
if (mode == LOK_TILEMODE_BGRA)
{
png_set_write_user_transform_fn (png_ptr, unpremultiply_data);
}
for (int y = 0; y < height; ++y)
{
size_t position = ((startY + y) * bufferWidth * 4) + (startX * 4);
png_write_row(png_ptr, pixmap + position);
}
png_write_end(png_ptr, info_ptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
#ifdef IOS
auto base64 = [[NSData dataWithBytesNoCopy:output.data() + initialSize length:(output.size() - initialSize) freeWhenDone:NO] base64EncodedDataWithOptions:0];
const char dataURLStart[] = "data:image/png;base64,";
output.resize(initialSize);
output.insert(output.end(), dataURLStart, dataURLStart + sizeof(dataURLStart)-1);
output.insert(output.end(), (char*)base64.bytes, (char*)base64.bytes + base64.length);
#endif
return true;
}
/// Sadly, older libpng headers don't use const for the pixmap pointer parameter to
/// png_write_row(), so can't use const here for pixmap.
inline bool encodeSubBufferToPNG(unsigned char* pixmap, size_t startX, size_t startY, int width,
int height, int bufferWidth, int bufferHeight,
std::vector<char>& output, LibreOfficeKitTileMode mode)
{
ProfileZone pz("encodeSubBufferToPNG");
const auto start = std::chrono::steady_clock::now();
const bool res = impl_encodeSubBufferToPNG(pixmap, startX, startY, width, height, bufferWidth,
bufferHeight, output, mode);
if (Log::traceEnabled())
{
const auto end = std::chrono::steady_clock::now();
std::chrono::milliseconds duration
= std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
static std::chrono::milliseconds totalDuration;
static int nCalls = 0;
totalDuration += duration;
++nCalls;
static uint64_t totalPixelBytes = 0;
static uint64_t totalOutputBytes = 0;
totalPixelBytes += (width * height * 4);
totalOutputBytes += output.size();
LOG_TRC("PNG compression took "
<< duration << " (" << output.size() << " bytes from " << (width * height * 4) << "). Average after " << nCalls
<< " calls: " << (totalDuration.count() / static_cast<double>(nCalls)) << "ms, "
<< (totalOutputBytes / static_cast<double>(nCalls)) << " bytes, "
<< std::setprecision(2) << (100. * totalOutputBytes / totalPixelBytes) << "% compression.");
}
return res;
}
inline
bool encodeBufferToPNG(unsigned char* pixmap, int width, int height,
std::vector<char>& output, LibreOfficeKitTileMode mode)
{
return encodeSubBufferToPNG(pixmap, 0, 0, width, height, width, height, output, mode);
}
inline
uint64_t hashSubBuffer(unsigned char* pixmap, size_t startX, size_t startY,
long width, long height, int bufferWidth, int bufferHeight)
{
if (bufferWidth < width || bufferHeight < height)
return 0; // magic invalid hash.
// assume a consistent mode - RGBA vs. BGRA for process
SpookyHash hash;
hash.Init(1073741789, 1073741789); // Seeds can be anything.
for (long y = 0; y < height; ++y)
{
const size_t position = ((startY + y) * bufferWidth * 4) + (startX * 4);
hash.Update(pixmap + position, width * 4);
}
uint64_t hash1;
uint64_t hash2;
hash.Final(&hash1, &hash2);
return hash1;
}
static
void readTileData(png_structp png_ptr, png_bytep data, png_size_t length)
{
png_voidp io_ptr = png_get_io_ptr(png_ptr);
assert(io_ptr);
std::stringstream& streamTile = *static_cast<std::stringstream*>(io_ptr);
streamTile.read(reinterpret_cast<char*>(data), length);
}
inline
std::vector<png_bytep> decodePNG(std::stringstream& stream, png_uint_32& height, png_uint_32& width, png_uint_32& rowBytes)
{
png_byte signature[0x08];
stream.read(reinterpret_cast<char *>(signature), 0x08);
if (png_sig_cmp(signature, 0x00, 0x08))
{
throw std::runtime_error("Invalid PNG signature.");
}
png_structp ptrPNG = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
if (ptrPNG == nullptr)
{
throw std::runtime_error("png_create_read_struct failed.");
}
png_infop ptrInfo = png_create_info_struct(ptrPNG);
if (ptrInfo == nullptr)
{
throw std::runtime_error("png_create_info_struct failed.");
}
png_infop ptrEnd = png_create_info_struct(ptrPNG);
if (ptrEnd == nullptr)
{
throw std::runtime_error("png_create_info_struct failed.");
}
png_set_read_fn(ptrPNG, &stream, readTileData);
png_set_sig_bytes(ptrPNG, 0x08);
png_read_info(ptrPNG, ptrInfo);
width = png_get_image_width(ptrPNG, ptrInfo);
height = png_get_image_height(ptrPNG, ptrInfo);
png_set_interlace_handling(ptrPNG);
png_read_update_info(ptrPNG, ptrInfo);
rowBytes = png_get_rowbytes(ptrPNG, ptrInfo);
assert(width == rowBytes / 4);
const size_t dataSize = (rowBytes + sizeof(png_bytep)) * height / sizeof(png_bytep);
const size_t size = dataSize + height + sizeof(png_bytep);
std::vector<png_bytep> rows;
rows.resize(size);
// rows
for (png_uint_32 itRow = 0; itRow < height; itRow++)
{
const size_t index = height + (itRow * rowBytes + sizeof(png_bytep) - 1) / sizeof(png_bytep);
rows[itRow] = reinterpret_cast<png_bytep>(&rows[index]);
}
png_read_image(ptrPNG, rows.data());
png_read_end(ptrPNG, ptrEnd);
png_destroy_read_struct(&ptrPNG, &ptrInfo, &ptrEnd);
return rows;
}
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */