229 lines
8.4 KiB
C++
229 lines
8.4 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
|
|
/*
|
|
* Copyright the Collabora Online contributors.
|
|
*
|
|
* SPDX-License-Identifier: MPL-2.0
|
|
*
|
|
* 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
|
|
|
|
#define LOK_USE_UNSTABLE_API
|
|
#include <LibreOfficeKit/LibreOfficeKitInit.h>
|
|
#include <LibreOfficeKit/LibreOfficeKit.hxx>
|
|
#include <LibreOfficeKit/LibreOfficeKitEnums.h>
|
|
#include <vector>
|
|
#include <Log.hpp>
|
|
#include <cstdlib>
|
|
#include <string>
|
|
#include <cmath>
|
|
#include <unordered_map>
|
|
|
|
class Watermark final
|
|
{
|
|
public:
|
|
Watermark(const std::shared_ptr<lok::Document>& loKitDoc, const std::string& text,
|
|
double opacity)
|
|
: _loKitDoc(loKitDoc)
|
|
, _text(Util::replace(text, "\\n", "\n"))
|
|
, _font("Carlito")
|
|
, _alphaLevel(opacity)
|
|
{
|
|
if (_loKitDoc == nullptr)
|
|
{
|
|
LOG_ERR("Watermark rendering requested without a valid document. Watermarking will be disabled.");
|
|
assert(_loKitDoc && "Valid loKitDoc is required for Watermark.");
|
|
}
|
|
}
|
|
|
|
void blending(unsigned char* tilePixmap,
|
|
int offsetX, int offsetY,
|
|
int tilesPixmapWidth, int tilesPixmapHeight,
|
|
int tileWidth, int tileHeight,
|
|
LibreOfficeKitTileMode /*mode*/)
|
|
{
|
|
// set requested watermark size a little bit smaller than tile size
|
|
const int width = tileWidth * 0.8;
|
|
const int height = tileHeight * 0.8;
|
|
|
|
const std::vector<unsigned char>* pixmap = getPixmap(width, height);
|
|
|
|
if (pixmap && tilePixmap)
|
|
{
|
|
// center watermark
|
|
const int maxX = std::min(tileWidth, width);
|
|
const int maxY = std::min(tileHeight, height);
|
|
offsetX += (tileWidth - maxX) / 2;
|
|
offsetY += (tileHeight - maxY) / 2;
|
|
alphaBlend(*pixmap, width, height, offsetX, offsetY, tilePixmap, tilesPixmapWidth, tilesPixmapHeight, false);
|
|
}
|
|
}
|
|
|
|
private:
|
|
/// Alpha blend pixels from 'from' over the 'to'.
|
|
void alphaBlend(const std::vector<unsigned char>& from, int from_width, int from_height, int from_offset_x, int from_offset_y,
|
|
unsigned char* to, int to_width, int to_height, const bool isFontBlending)
|
|
{
|
|
bool isCalc = (_loKitDoc->getDocumentType() == LOK_DOCTYPE_SPREADSHEET);
|
|
for (int to_y = from_offset_y, from_y = 0; (to_y < to_height) && (from_y < from_height) ; ++to_y, ++from_y)
|
|
for (int to_x = from_offset_x, from_x = 0; (to_x < to_width) && (from_x < from_width); ++to_x, ++from_x)
|
|
{
|
|
unsigned char* t = to + 4 * (to_y * to_width + to_x);
|
|
|
|
if (!isFontBlending && !isCalc && t[3] != 255)
|
|
continue;
|
|
|
|
double dst_r = t[0];
|
|
double dst_g = t[1];
|
|
double dst_b = t[2];
|
|
double dst_a = t[3] / 255.0;
|
|
|
|
const unsigned char* f = from.data() + 4 * (from_y * from_width + from_x);
|
|
double src_r = f[0];
|
|
double src_g = f[1];
|
|
double src_b = f[2];
|
|
double src_a = f[3] / 255.0;
|
|
|
|
double out_a = src_a + dst_a * (1.0 - src_a);
|
|
unsigned char out_r = src_r + dst_r * (1.0 - src_a);
|
|
unsigned char out_g = src_g + dst_g * (1.0 - src_a);
|
|
unsigned char out_b = src_b + dst_b * (1.0 - src_a);
|
|
|
|
t[0] = out_r;
|
|
t[1] = out_g;
|
|
t[2] = out_b;
|
|
t[3] = static_cast<unsigned char>(out_a * 255.0);
|
|
}
|
|
}
|
|
|
|
/// Create bitmap that we later use as the watermark for every tile.
|
|
const std::vector<unsigned char>* getPixmap(int width, int height)
|
|
{
|
|
if (_loKitDoc == nullptr)
|
|
{
|
|
return nullptr;
|
|
}
|
|
|
|
const size_t key = width + height * 10000;
|
|
|
|
if (_pixmaps.find(key) != _pixmaps.end())
|
|
{
|
|
return &_pixmaps[key];
|
|
}
|
|
|
|
// renderFont returns a buffer based on RGBA mode, where r, g, b
|
|
// are always set to 0 (black) and the alpha level is 0 everywhere
|
|
// except on the text area; the alpha level take into account of
|
|
// performing anti-aliasing over the text edges.
|
|
unsigned char* textPixels = _loKitDoc->renderFont(_font.c_str(), _text.c_str(), &width, &height, 0);
|
|
|
|
if (!textPixels)
|
|
{
|
|
LOG_ERR("Watermark: rendering failed.");
|
|
return nullptr;
|
|
}
|
|
|
|
const unsigned int pixel_count = width * height * 4;
|
|
|
|
std::vector<unsigned char> text(textPixels, textPixels + pixel_count);
|
|
// No longer needed.
|
|
std::free(textPixels);
|
|
|
|
_pixmaps.emplace(key, std::vector<unsigned char>(pixel_count));
|
|
std::vector<unsigned char>& _pixmap = _pixmaps[key];
|
|
|
|
/*
|
|
apply 2d rotation transformation (counter-clockwise):
|
|
| cos(a) -sin(a) | | x |
|
|
| sin(a) cos(a) | | y |
|
|
*/
|
|
// Create the white blurred background
|
|
// Use box blur, it's enough for our purposes
|
|
|
|
// PI / 4 (45 degrees): sin = cos = 1/sqrt(2)
|
|
const double sin = 0.707106781186547524;
|
|
const double cos = sin;
|
|
|
|
const double x0 = width / 2.0;
|
|
const double y0 = height / 2.0;
|
|
|
|
std::vector<unsigned char> _rotatedText(pixel_count);
|
|
|
|
const int r = 2;
|
|
const double weight = (r+1) * (r+1);
|
|
for (int y = 0; y < height; ++y)
|
|
{
|
|
for (int x = 0; x < width; ++x)
|
|
{
|
|
// move origin to the center
|
|
const double fx = x - x0;
|
|
const double fy = y - y0;
|
|
const int rX = (fx * cos) - (fy * sin) + x0;
|
|
const int rY = (fx * sin) + (fy * cos) + y0;
|
|
const unsigned int pPos = 4 * (rY * width + rX);
|
|
if (rX >= 0 && rX <= width && rY >= 0 && rY <= height && pPos < text.size())
|
|
{
|
|
unsigned char* p = text.data() + 4 * (rY * width + rX);
|
|
_rotatedText[4 * (y * width + x) + 0] = p[0];
|
|
_rotatedText[4 * (y * width + x) + 1] = p[1];
|
|
_rotatedText[4 * (y * width + x) + 2] = p[2];
|
|
_rotatedText[4 * (y * width + x) + 3] = p[3];
|
|
}
|
|
else
|
|
{
|
|
_rotatedText[4 * (y * width + x) + 0] = 0.0;
|
|
_rotatedText[4 * (y * width + x) + 1] = 0.0;
|
|
_rotatedText[4 * (y * width + x) + 2] = 0.0;
|
|
_rotatedText[4 * (y * width + x) + 3] = 0.0;
|
|
}
|
|
|
|
double t = 0;
|
|
for (int ky = std::max(rY - r, 0); ky <= std::min(rY + r, height - 1); ++ky)
|
|
{
|
|
for (int kx = std::max(rX - r, 0); kx <= std::min(rX + r, width - 1); ++kx)
|
|
{
|
|
// Pre-multiplied alpha; the text is black, so all the
|
|
// information is only in the alpha channel
|
|
t += text[4 * (ky * width + kx) + 3];
|
|
}
|
|
}
|
|
|
|
// Clamp the result.
|
|
double avg = t / weight;
|
|
if (avg > 255.0)
|
|
avg = 255.0;
|
|
|
|
// Pre-multiplied alpha, but use white for the resulting color
|
|
const double alpha = avg / 255.0;
|
|
_pixmap[4 * (y * width + x) + 0] = 0xff * alpha;
|
|
_pixmap[4 * (y * width + x) + 1] = 0xff * alpha;
|
|
_pixmap[4 * (y * width + x) + 2] = 0xff * alpha;
|
|
_pixmap[4 * (y * width + x) + 3] = avg;
|
|
}
|
|
}
|
|
|
|
// Now copy the (black) text over the (white) blur
|
|
alphaBlend(_rotatedText, width, height, 0, 0, _pixmap.data(), width, height, true);
|
|
|
|
// Make the resulting pixmap semi-transparent
|
|
for (unsigned char* p = _pixmap.data(); p < _pixmap.data() + pixel_count; p++)
|
|
{
|
|
*p = static_cast<unsigned char>(*p * _alphaLevel);
|
|
}
|
|
|
|
return &_pixmap;
|
|
}
|
|
|
|
private:
|
|
const std::shared_ptr<lok::Document> _loKitDoc;
|
|
const std::string _text;
|
|
const std::string _font;
|
|
const double _alphaLevel;
|
|
std::unordered_map<size_t, std::vector<unsigned char>> _pixmaps;
|
|
};
|
|
|
|
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|