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// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "pdf/draw_utils.h"
#include <math.h>
#include <stddef.h>
#include <stdint.h>
#include <algorithm>
#include <vector>
#include "base/logging.h"
#include "base/numerics/safe_math.h"
namespace chrome_pdf {
inline uint8_t GetBlue(const uint32_t& pixel) {
return static_cast<uint8_t>(pixel & 0xFF);
}
inline uint8_t GetGreen(const uint32_t& pixel) {
return static_cast<uint8_t>((pixel >> 8) & 0xFF);
}
inline uint8_t GetRed(const uint32_t& pixel) {
return static_cast<uint8_t>((pixel >> 16) & 0xFF);
}
inline uint8_t GetAlpha(const uint32_t& pixel) {
return static_cast<uint8_t>((pixel >> 24) & 0xFF);
}
inline uint32_t MakePixel(uint8_t red,
uint8_t green,
uint8_t blue,
uint8_t alpha) {
return (static_cast<uint32_t>(alpha) << 24) |
(static_cast<uint32_t>(red) << 16) |
(static_cast<uint32_t>(green) << 8) |
static_cast<uint32_t>(blue);
}
inline uint8_t GradientChannel(uint8_t start, uint8_t end, double ratio) {
double new_channel = start - (static_cast<double>(start) - end) * ratio;
if (new_channel < 0)
return 0;
if (new_channel > 255)
return 255;
return static_cast<uint8_t>(new_channel + 0.5);
}
inline uint8_t ProcessColor(uint8_t src_color,
uint8_t dest_color,
uint8_t alpha) {
uint32_t processed = static_cast<uint32_t>(src_color) * alpha +
static_cast<uint32_t>(dest_color) * (0xFF - alpha);
return static_cast<uint8_t>((processed / 0xFF) & 0xFF);
}
inline bool ImageDataContainsRect(const pp::ImageData& image_data,
const pp::Rect& rect) {
return rect.width() >= 0 && rect.height() >= 0 &&
pp::Rect(image_data.size()).Contains(rect);
}
void AlphaBlend(const pp::ImageData& src,
const pp::Rect& src_rc,
pp::ImageData* dest,
const pp::Point& dest_origin,
uint8_t alpha_adjustment) {
if (src_rc.IsEmpty() || !ImageDataContainsRect(src, src_rc))
return;
pp::Rect dest_rc(dest_origin, src_rc.size());
if (dest_rc.IsEmpty() || !ImageDataContainsRect(*dest, dest_rc))
return;
const uint32_t* src_origin_pixel = src.GetAddr32(src_rc.point());
uint32_t* dest_origin_pixel = dest->GetAddr32(dest_origin);
int height = src_rc.height();
int width = src_rc.width();
for (int y = 0; y < height; y++) {
const uint32_t* src_pixel = src_origin_pixel;
uint32_t* dest_pixel = dest_origin_pixel;
for (int x = 0; x < width; x++) {
uint8_t alpha =
static_cast<uint8_t>(static_cast<uint32_t>(alpha_adjustment) *
GetAlpha(*src_pixel) / 0xFF);
uint8_t red =
ProcessColor(GetRed(*src_pixel), GetRed(*dest_pixel), alpha);
uint8_t green =
ProcessColor(GetGreen(*src_pixel), GetGreen(*dest_pixel), alpha);
uint8_t blue =
ProcessColor(GetBlue(*src_pixel), GetBlue(*dest_pixel), alpha);
*dest_pixel = MakePixel(red, green, blue, GetAlpha(*dest_pixel));
src_pixel++;
dest_pixel++;
}
src_origin_pixel = reinterpret_cast<const uint32_t*>(
reinterpret_cast<const char*>(src_origin_pixel) + src.stride());
dest_origin_pixel = reinterpret_cast<uint32_t*>(
reinterpret_cast<char*>(dest_origin_pixel) + dest->stride());
}
}
void GradientFill(pp::ImageData* image,
const pp::Rect& rc,
uint32_t start_color,
uint32_t end_color,
bool horizontal) {
std::vector<uint32_t> colors;
colors.resize(horizontal ? rc.width() : rc.height());
for (size_t i = 0; i < colors.size(); ++i) {
double ratio = static_cast<double>(i) / colors.size();
colors[i] = MakePixel(
GradientChannel(GetRed(start_color), GetRed(end_color), ratio),
GradientChannel(GetGreen(start_color), GetGreen(end_color), ratio),
GradientChannel(GetBlue(start_color), GetBlue(end_color), ratio),
GradientChannel(GetAlpha(start_color), GetAlpha(end_color), ratio));
}
if (horizontal) {
const void* data = &(colors[0]);
size_t size = colors.size() * 4;
uint32_t* origin_pixel = image->GetAddr32(rc.point());
for (int y = 0; y < rc.height(); y++) {
memcpy(origin_pixel, data, size);
origin_pixel = reinterpret_cast<uint32_t*>(
reinterpret_cast<char*>(origin_pixel) + image->stride());
}
} else {
uint32_t* origin_pixel = image->GetAddr32(rc.point());
for (int y = 0; y < rc.height(); y++) {
uint32_t* pixel = origin_pixel;
for (int x = 0; x < rc.width(); x++) {
*pixel = colors[y];
pixel++;
}
origin_pixel = reinterpret_cast<uint32_t*>(
reinterpret_cast<char*>(origin_pixel) + image->stride());
}
}
}
void GradientFill(pp::Instance* instance,
pp::ImageData* image,
const pp::Rect& dirty_rc,
const pp::Rect& gradient_rc,
uint32_t start_color,
uint32_t end_color,
bool horizontal,
uint8_t transparency) {
pp::Rect draw_rc = gradient_rc.Intersect(dirty_rc);
if (draw_rc.IsEmpty())
return;
pp::ImageData gradient(instance, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
gradient_rc.size(), false);
GradientFill(&gradient, pp::Rect(pp::Point(), gradient_rc.size()),
start_color, end_color, horizontal);
pp::Rect copy_rc(draw_rc);
copy_rc.Offset(-gradient_rc.x(), -gradient_rc.y());
AlphaBlend(gradient, copy_rc, image, draw_rc.point(), transparency);
}
void CopyImage(const pp::ImageData& src, const pp::Rect& src_rc,
pp::ImageData* dest, const pp::Rect& dest_rc,
bool stretch) {
if (src_rc.IsEmpty() || !ImageDataContainsRect(src, src_rc))
return;
pp::Rect stretched_rc(dest_rc.point(),
stretch ? dest_rc.size() : src_rc.size());
if (stretched_rc.IsEmpty() || !ImageDataContainsRect(*dest, stretched_rc))
return;
const uint32_t* src_origin_pixel = src.GetAddr32(src_rc.point());
uint32_t* dest_origin_pixel = dest->GetAddr32(dest_rc.point());
if (stretch) {
double x_ratio = static_cast<double>(src_rc.width()) / dest_rc.width();
double y_ratio = static_cast<double>(src_rc.height()) / dest_rc.height();
int32_t height = dest_rc.height();
int32_t width = dest_rc.width();
for (int32_t y = 0; y < height; ++y) {
uint32_t* dest_pixel = dest_origin_pixel;
for (int32_t x = 0; x < width; ++x) {
uint32_t src_x = static_cast<uint32_t>(x * x_ratio);
uint32_t src_y = static_cast<uint32_t>(y * y_ratio);
const uint32_t* src_pixel = src.GetAddr32(
pp::Point(src_rc.x() + src_x, src_rc.y() + src_y));
*dest_pixel = *src_pixel;
dest_pixel++;
}
dest_origin_pixel = reinterpret_cast<uint32_t*>(
reinterpret_cast<char*>(dest_origin_pixel) + dest->stride());
}
} else {
int32_t height = src_rc.height();
base::CheckedNumeric<int32_t> width_bytes = src_rc.width();
width_bytes *= 4;
for (int32_t y = 0; y < height; ++y) {
memcpy(dest_origin_pixel, src_origin_pixel, width_bytes.ValueOrDie());
src_origin_pixel = reinterpret_cast<const uint32_t*>(
reinterpret_cast<const char*>(src_origin_pixel) + src.stride());
dest_origin_pixel = reinterpret_cast<uint32_t*>(
reinterpret_cast<char*>(dest_origin_pixel) + dest->stride());
}
}
}
void FillRect(pp::ImageData* image, const pp::Rect& rc, uint32_t color) {
int height = rc.height();
if (height == 0)
return;
// Fill in first row.
uint32_t* top_line = image->GetAddr32(rc.point());
int width = rc.width();
for (int x = 0; x < width; x++)
top_line[x] = color;
// Fill in the rest of the rectangle.
int byte_width = width * 4;
uint32_t* cur_line = reinterpret_cast<uint32_t*>(
reinterpret_cast<char*>(top_line) + image->stride());
for (int y = 1; y < height; y++) {
memcpy(cur_line, top_line, byte_width);
cur_line = reinterpret_cast<uint32_t*>(
reinterpret_cast<char*>(cur_line) + image->stride());
}
}
ShadowMatrix::ShadowMatrix(uint32_t depth, double factor, uint32_t background)
: depth_(depth), factor_(factor), background_(background) {
DCHECK(depth_ > 0);
matrix_.resize(depth_ * depth_);
// pv - is a rounding power factor for smoothing corners.
// pv = 2.0 will make corners completely round.
const double pv = 4.0;
// pow_pv - cache to avoid recalculating pow(x, pv) every time.
std::vector<double> pow_pv(depth_, 0.0);
double r = static_cast<double>(depth_);
double coef = 256.0 / pow(r, factor);
for (uint32_t y = 0; y < depth_; y++) {
// Since matrix is symmetrical, we can reduce the number of calculations
// by mirroring results.
for (uint32_t x = 0; x <= y; x++) {
// Fill cache if needed.
if (pow_pv[x] == 0.0)
pow_pv[x] = pow(x, pv);
if (pow_pv[y] == 0.0)
pow_pv[y] = pow(y, pv);
// v - is a value for the smoothing function.
// If x == 0 simplify calculations.
double v = (x == 0) ? y : pow(pow_pv[x] + pow_pv[y], 1 / pv);
// Smoothing function.
// If factor == 1, smoothing will be linear from 0 to the end,
// if 0 < factor < 1, smoothing will drop faster near 0.
// if factor > 1, smoothing will drop faster near the end (depth).
double f = 256.0 - coef * pow(v, factor);
uint8_t alpha = 0;
if (f > kOpaqueAlpha)
alpha = kOpaqueAlpha;
else if (f < kTransparentAlpha)
alpha = kTransparentAlpha;
else
alpha = static_cast<uint8_t>(f);
uint8_t red = ProcessColor(0, GetRed(background), alpha);
uint8_t green = ProcessColor(0, GetGreen(background), alpha);
uint8_t blue = ProcessColor(0, GetBlue(background), alpha);
uint32_t pixel = MakePixel(red, green, blue, GetAlpha(background));
// Mirror matrix.
matrix_[y * depth_ + x] = pixel;
matrix_[x * depth_ + y] = pixel;
}
}
}
ShadowMatrix::~ShadowMatrix() {
}
void PaintShadow(pp::ImageData* image,
const pp::Rect& clip_rc,
const pp::Rect& shadow_rc,
const ShadowMatrix& matrix) {
pp::Rect draw_rc = shadow_rc.Intersect(clip_rc);
if (draw_rc.IsEmpty())
return;
int32_t depth = static_cast<int32_t>(matrix.depth());
for (int32_t y = draw_rc.y(); y < draw_rc.bottom(); y++) {
for (int32_t x = draw_rc.x(); x < draw_rc.right(); x++) {
int32_t matrix_x = std::max(depth + shadow_rc.x() - x - 1,
depth - shadow_rc.right() + x);
int32_t matrix_y = std::max(depth + shadow_rc.y() - y - 1,
depth - shadow_rc.bottom() + y);
uint32_t* pixel = image->GetAddr32(pp::Point(x, y));
if (matrix_x < 0)
matrix_x = 0;
else if (matrix_x >= static_cast<int32_t>(depth))
matrix_x = depth - 1;
if (matrix_y < 0)
matrix_y = 0;
else if (matrix_y >= static_cast<int32_t>(depth))
matrix_y = depth - 1;
*pixel = matrix.GetValue(matrix_x, matrix_y);
}
}
}
void DrawShadow(pp::ImageData* image,
const pp::Rect& shadow_rc,
const pp::Rect& object_rc,
const pp::Rect& clip_rc,
const ShadowMatrix& matrix) {
if (shadow_rc == object_rc)
return; // Nothing to paint.
// Fill top part.
pp::Rect rc(shadow_rc.point(),
pp::Size(shadow_rc.width(), object_rc.y() - shadow_rc.y()));
PaintShadow(image, rc.Intersect(clip_rc), shadow_rc, matrix);
// Fill bottom part.
rc = pp::Rect(shadow_rc.x(), object_rc.bottom(),
shadow_rc.width(), shadow_rc.bottom() - object_rc.bottom());
PaintShadow(image, rc.Intersect(clip_rc), shadow_rc, matrix);
// Fill left part.
rc = pp::Rect(shadow_rc.x(), object_rc.y(),
object_rc.x() - shadow_rc.x(), object_rc.height());
PaintShadow(image, rc.Intersect(clip_rc), shadow_rc, matrix);
// Fill right part.
rc = pp::Rect(object_rc.right(), object_rc.y(),
shadow_rc.right() - object_rc.right(), object_rc.height());
PaintShadow(image, rc.Intersect(clip_rc), shadow_rc, matrix);
}
} // namespace chrome_pdf