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ladybird/Userland/Libraries/LibWeb/SVG/SVGPathElement.cpp
Andreas Kling 5d180d1f99 Everywhere: Rename ASSERT => VERIFY 
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)

Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.

We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
2021-02-23 20:56:54 +01:00

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/*
* Copyright (c) 2020, Matthew Olsson <matthewcolsson@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Debug.h>
#include <AK/StringBuilder.h>
#include <LibGfx/Painter.h>
#include <LibGfx/Path.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/DOM/Event.h>
#include <LibWeb/Layout/SVGPathBox.h>
#include <LibWeb/SVG/SVGPathElement.h>
#include <ctype.h>
namespace Web::SVG {
static void print_instruction(const PathInstruction& instruction)
{
VERIFY(PATH_DEBUG);
auto& data = instruction.data;
switch (instruction.type) {
case PathInstructionType::Move:
dbgln("Move (absolute={})", instruction.absolute);
for (size_t i = 0; i < data.size(); i += 2)
dbgln(" x={}, y={}", data[i], data[i + 1]);
break;
case PathInstructionType::ClosePath:
dbgln("ClosePath (absolute={})", instruction.absolute);
break;
case PathInstructionType::Line:
dbgln("Line (absolute={})", instruction.absolute);
for (size_t i = 0; i < data.size(); i += 2)
dbgln(" x={}, y={}", data[i], data[i + 1]);
break;
case PathInstructionType::HorizontalLine:
dbgln("HorizontalLine (absolute={})", instruction.absolute);
for (size_t i = 0; i < data.size(); ++i)
dbgln(" x={}", data[i]);
break;
case PathInstructionType::VerticalLine:
dbgln("VerticalLine (absolute={})", instruction.absolute);
for (size_t i = 0; i < data.size(); ++i)
dbgln(" y={}", data[i]);
break;
case PathInstructionType::Curve:
dbgln("Curve (absolute={})", instruction.absolute);
for (size_t i = 0; i < data.size(); i += 6)
dbgln(" (x1={}, y1={}, x2={}, y2={}), (x={}, y={})", data[i], data[i + 1], data[i + 2], data[i + 3], data[i + 4], data[i + 5]);
break;
case PathInstructionType::SmoothCurve:
dbgln("SmoothCurve (absolute={})", instruction.absolute);
for (size_t i = 0; i < data.size(); i += 4)
dbgln(" (x2={}, y2={}), (x={}, y={})", data[i], data[i + 1], data[i + 2], data[i + 3]);
break;
case PathInstructionType::QuadraticBezierCurve:
dbgln("QuadraticBezierCurve (absolute={})", instruction.absolute);
for (size_t i = 0; i < data.size(); i += 4)
dbgln(" (x1={}, y1={}), (x={}, y={})", data[i], data[i + 1], data[i + 2], data[i + 3]);
break;
case PathInstructionType::SmoothQuadraticBezierCurve:
dbgln("SmoothQuadraticBezierCurve (absolute={})", instruction.absolute);
for (size_t i = 0; i < data.size(); i += 2)
dbgln(" x={}, y={}", data[i], data[i + 1]);
break;
case PathInstructionType::EllipticalArc:
dbgln("EllipticalArc (absolute={})", instruction.absolute);
for (size_t i = 0; i < data.size(); i += 7)
dbgln(" (rx={}, ry={}) x-axis-rotation={}, large-arc-flag={}, sweep-flag={}, (x={}, y={})",
data[i],
data[i + 1],
data[i + 2],
data[i + 3],
data[i + 4],
data[i + 5],
data[i + 6]);
break;
case PathInstructionType::Invalid:
dbgln("Invalid");
break;
}
}
PathDataParser::PathDataParser(const String& source)
: m_source(source)
{
}
Vector<PathInstruction> PathDataParser::parse()
{
parse_whitespace();
while (!done())
parse_drawto();
if (!m_instructions.is_empty() && m_instructions[0].type != PathInstructionType::Move)
VERIFY_NOT_REACHED();
return m_instructions;
}
void PathDataParser::parse_drawto()
{
if (match('M') || match('m')) {
parse_moveto();
} else if (match('Z') || match('z')) {
parse_closepath();
} else if (match('L') || match('l')) {
parse_lineto();
} else if (match('H') || match('h')) {
parse_horizontal_lineto();
} else if (match('V') || match('v')) {
parse_vertical_lineto();
} else if (match('C') || match('c')) {
parse_curveto();
} else if (match('S') || match('s')) {
parse_smooth_curveto();
} else if (match('Q') || match('q')) {
parse_quadratic_bezier_curveto();
} else if (match('T') || match('t')) {
parse_smooth_quadratic_bezier_curveto();
} else if (match('A') || match('a')) {
parse_elliptical_arc();
} else {
dbgln("PathDataParser::parse_drawto failed to match: '{}'", ch());
TODO();
}
}
void PathDataParser::parse_moveto()
{
bool absolute = consume() == 'M';
parse_whitespace();
for (auto& pair : parse_coordinate_pair_sequence())
m_instructions.append({ PathInstructionType::Move, absolute, pair });
}
void PathDataParser::parse_closepath()
{
bool absolute = consume() == 'Z';
parse_whitespace();
m_instructions.append({ PathInstructionType::ClosePath, absolute, {} });
}
void PathDataParser::parse_lineto()
{
bool absolute = consume() == 'L';
parse_whitespace();
for (auto& pair : parse_coordinate_pair_sequence())
m_instructions.append({ PathInstructionType::Line, absolute, pair });
}
void PathDataParser::parse_horizontal_lineto()
{
bool absolute = consume() == 'H';
parse_whitespace();
m_instructions.append({ PathInstructionType::HorizontalLine, absolute, parse_coordinate_sequence() });
}
void PathDataParser::parse_vertical_lineto()
{
bool absolute = consume() == 'V';
parse_whitespace();
m_instructions.append({ PathInstructionType::VerticalLine, absolute, parse_coordinate_sequence() });
}
void PathDataParser::parse_curveto()
{
bool absolute = consume() == 'C';
parse_whitespace();
while (true) {
m_instructions.append({ PathInstructionType::Curve, absolute, parse_coordinate_pair_triplet() });
if (match_comma_whitespace())
parse_comma_whitespace();
if (!match_coordinate())
break;
}
}
void PathDataParser::parse_smooth_curveto()
{
bool absolute = consume() == 'S';
parse_whitespace();
while (true) {
m_instructions.append({ PathInstructionType::SmoothCurve, absolute, parse_coordinate_pair_double() });
if (match_comma_whitespace())
parse_comma_whitespace();
if (!match_coordinate())
break;
}
}
void PathDataParser::parse_quadratic_bezier_curveto()
{
bool absolute = consume() == 'Q';
parse_whitespace();
while (true) {
m_instructions.append({ PathInstructionType::QuadraticBezierCurve, absolute, parse_coordinate_pair_double() });
if (match_comma_whitespace())
parse_comma_whitespace();
if (!match_coordinate())
break;
}
}
void PathDataParser::parse_smooth_quadratic_bezier_curveto()
{
bool absolute = consume() == 'T';
parse_whitespace();
while (true) {
m_instructions.append({ PathInstructionType::SmoothQuadraticBezierCurve, absolute, parse_coordinate_pair() });
if (match_comma_whitespace())
parse_comma_whitespace();
if (!match_coordinate())
break;
}
}
void PathDataParser::parse_elliptical_arc()
{
bool absolute = consume() == 'A';
parse_whitespace();
while (true) {
m_instructions.append({ PathInstructionType::EllipticalArc, absolute, parse_elliptical_arg_argument() });
if (match_comma_whitespace())
parse_comma_whitespace();
if (!match_coordinate())
break;
}
}
float PathDataParser::parse_coordinate()
{
return parse_sign() * parse_number();
}
Vector<float> PathDataParser::parse_coordinate_pair()
{
Vector<float> coordinates;
coordinates.append(parse_coordinate());
if (match_comma_whitespace())
parse_comma_whitespace();
coordinates.append(parse_coordinate());
return coordinates;
}
Vector<float> PathDataParser::parse_coordinate_sequence()
{
Vector<float> sequence;
while (true) {
sequence.append(parse_coordinate());
if (match_comma_whitespace())
parse_comma_whitespace();
if (!match_comma_whitespace() && !match_coordinate())
break;
}
return sequence;
}
Vector<Vector<float>> PathDataParser::parse_coordinate_pair_sequence()
{
Vector<Vector<float>> sequence;
while (true) {
sequence.append(parse_coordinate_pair());
if (match_comma_whitespace())
parse_comma_whitespace();
if (!match_comma_whitespace() && !match_coordinate())
break;
}
return sequence;
}
Vector<float> PathDataParser::parse_coordinate_pair_double()
{
Vector<float> coordinates;
coordinates.append(parse_coordinate_pair());
if (match_comma_whitespace())
parse_comma_whitespace();
coordinates.append(parse_coordinate_pair());
return coordinates;
}
Vector<float> PathDataParser::parse_coordinate_pair_triplet()
{
Vector<float> coordinates;
coordinates.append(parse_coordinate_pair());
if (match_comma_whitespace())
parse_comma_whitespace();
coordinates.append(parse_coordinate_pair());
if (match_comma_whitespace())
parse_comma_whitespace();
coordinates.append(parse_coordinate_pair());
return coordinates;
}
Vector<float> PathDataParser::parse_elliptical_arg_argument()
{
Vector<float> numbers;
numbers.append(parse_number());
if (match_comma_whitespace())
parse_comma_whitespace();
numbers.append(parse_number());
if (match_comma_whitespace())
parse_comma_whitespace();
numbers.append(parse_number());
parse_comma_whitespace();
numbers.append(parse_flag());
if (match_comma_whitespace())
parse_comma_whitespace();
numbers.append(parse_flag());
if (match_comma_whitespace())
parse_comma_whitespace();
numbers.append(parse_coordinate_pair());
return numbers;
}
void PathDataParser::parse_whitespace(bool must_match_once)
{
bool matched = false;
while (!done() && match_whitespace()) {
consume();
matched = true;
}
VERIFY(!must_match_once || matched);
}
void PathDataParser::parse_comma_whitespace()
{
if (match(',')) {
consume();
parse_whitespace();
} else {
parse_whitespace(1);
if (match(','))
consume();
parse_whitespace();
}
}
float PathDataParser::parse_fractional_constant()
{
StringBuilder builder;
bool floating_point = false;
while (!done() && isdigit(ch()))
builder.append(consume());
if (match('.')) {
floating_point = true;
builder.append('.');
consume();
while (!done() && isdigit(ch()))
builder.append(consume());
} else {
VERIFY(builder.length() > 0);
}
if (floating_point)
return strtof(builder.to_string().characters(), nullptr);
return builder.to_string().to_int().value();
}
float PathDataParser::parse_number()
{
auto number = parse_fractional_constant();
if (match('e') || match('E'))
TODO();
return number;
}
float PathDataParser::parse_flag()
{
if (!match('0') && !match('1'))
VERIFY_NOT_REACHED();
return consume() - '0';
}
int PathDataParser::parse_sign()
{
if (match('-')) {
consume();
return -1;
}
if (match('+'))
consume();
return 1;
}
bool PathDataParser::match_whitespace() const
{
if (done())
return false;
char c = ch();
return c == 0x9 || c == 0x20 || c == 0xa || c == 0xc || c == 0xd;
}
bool PathDataParser::match_comma_whitespace() const
{
return match_whitespace() || match(',');
}
bool PathDataParser::match_coordinate() const
{
return !done() && (isdigit(ch()) || ch() == '-' || ch() == '+' || ch() == '.');
}
SVGPathElement::SVGPathElement(DOM::Document& document, QualifiedName qualified_name)
: SVGGeometryElement(document, move(qualified_name))
{
}
RefPtr<Layout::Node> SVGPathElement::create_layout_node()
{
auto style = document().style_resolver().resolve_style(*this);
if (style->display() == CSS::Display::None)
return nullptr;
return adopt(*new Layout::SVGPathBox(document(), *this, move(style)));
}
void SVGPathElement::parse_attribute(const FlyString& name, const String& value)
{
SVGGeometryElement::parse_attribute(name, value);
if (name == "d")
m_instructions = PathDataParser(value).parse();
}
Gfx::Path& SVGPathElement::get_path()
{
if (m_path.has_value())
return m_path.value();
Gfx::Path path;
for (auto& instruction : m_instructions) {
auto& absolute = instruction.absolute;
auto& data = instruction.data;
if constexpr (PATH_DEBUG) {
print_instruction(instruction);
}
bool clear_last_control_point = true;
switch (instruction.type) {
case PathInstructionType::Move: {
Gfx::FloatPoint point = { data[0], data[1] };
if (absolute) {
path.move_to(point);
} else {
VERIFY(!path.segments().is_empty());
path.move_to(point + path.segments().last().point());
}
break;
}
case PathInstructionType::ClosePath:
path.close();
break;
case PathInstructionType::Line: {
Gfx::FloatPoint point = { data[0], data[1] };
if (absolute) {
path.line_to(point);
} else {
VERIFY(!path.segments().is_empty());
path.line_to(point + path.segments().last().point());
}
break;
}
case PathInstructionType::HorizontalLine: {
VERIFY(!path.segments().is_empty());
auto last_point = path.segments().last().point();
if (absolute) {
path.line_to(Gfx::FloatPoint { data[0], last_point.y() });
} else {
path.line_to(Gfx::FloatPoint { data[0] + last_point.x(), last_point.y() });
}
break;
}
case PathInstructionType::VerticalLine: {
VERIFY(!path.segments().is_empty());
auto last_point = path.segments().last().point();
if (absolute) {
path.line_to(Gfx::FloatPoint { last_point.x(), data[0] });
} else {
path.line_to(Gfx::FloatPoint { last_point.x(), data[0] + last_point.y() });
}
break;
}
case PathInstructionType::EllipticalArc: {
double rx = data[0];
double ry = data[1];
double x_axis_rotation = data[2] * M_DEG2RAD;
double large_arc_flag = data[3];
double sweep_flag = data[4];
double x_axis_rotation_c = cos(x_axis_rotation);
double x_axis_rotation_s = sin(x_axis_rotation);
auto& last_point = path.segments().last().point();
Gfx::FloatPoint next_point;
if (absolute) {
next_point = { data[5], data[6] };
} else {
next_point = { data[5] + last_point.x(), data[6] + last_point.y() };
}
// Step 1 of out-of-range radii correction
if (rx == 0.0 || ry == 0.0) {
path.line_to(next_point);
break;
}
// Step 2 of out-of-range radii correction
if (rx < 0)
rx *= -1.0;
if (ry < 0)
ry *= -1.0;
// Find (cx, cy), theta_1, theta_delta
// Step 1: Compute (x1', y1')
auto x_avg = (last_point.x() - next_point.x()) / 2.0f;
auto y_avg = (last_point.y() - next_point.y()) / 2.0f;
auto x1p = x_axis_rotation_c * x_avg + x_axis_rotation_s * y_avg;
auto y1p = -x_axis_rotation_s * x_avg + x_axis_rotation_c * y_avg;
// Step 2: Compute (cx', cy')
double x1p_sq = pow(x1p, 2.0);
double y1p_sq = pow(y1p, 2.0);
double rx_sq = pow(rx, 2.0);
double ry_sq = pow(ry, 2.0);
// Step 3 of out-of-range radii correction
double lambda = x1p_sq / rx_sq + y1p_sq / ry_sq;
double multiplier;
if (lambda > 1.0) {
auto lambda_sqrt = sqrt(lambda);
rx *= lambda_sqrt;
ry *= lambda_sqrt;
multiplier = 0.0;
} else {
double numerator = rx_sq * ry_sq - rx_sq * y1p_sq - ry_sq * x1p_sq;
double denominator = rx_sq * y1p_sq + ry_sq * x1p_sq;
multiplier = sqrt(numerator / denominator);
}
if (large_arc_flag == sweep_flag)
multiplier *= -1.0;
double cxp = multiplier * rx * y1p / ry;
double cyp = multiplier * -ry * x1p / rx;
// Step 3: Compute (cx, cy) from (cx', cy')
x_avg = (last_point.x() + next_point.x()) / 2.0f;
y_avg = (last_point.y() + next_point.y()) / 2.0f;
double cx = x_axis_rotation_c * cxp - x_axis_rotation_s * cyp + x_avg;
double cy = x_axis_rotation_s * cxp + x_axis_rotation_c * cyp + y_avg;
double theta_1 = atan2((y1p - cyp) / ry, (x1p - cxp) / rx);
double theta_2 = atan2((-y1p - cyp) / ry, (-x1p - cxp) / rx);
auto theta_delta = theta_2 - theta_1;
if (sweep_flag == 0 && theta_delta > 0.0f) {
theta_delta -= M_TAU;
} else if (sweep_flag != 0 && theta_delta < 0) {
theta_delta += M_TAU;
}
path.elliptical_arc_to(next_point, { cx, cy }, { rx, ry }, x_axis_rotation, theta_1, theta_delta);
break;
}
case PathInstructionType::QuadraticBezierCurve: {
clear_last_control_point = false;
Gfx::FloatPoint through = { data[0], data[1] };
Gfx::FloatPoint point = { data[2], data[3] };
if (absolute) {
path.quadratic_bezier_curve_to(through, point);
m_previous_control_point = through;
} else {
VERIFY(!path.segments().is_empty());
auto last_point = path.segments().last().point();
auto control_point = through + last_point;
path.quadratic_bezier_curve_to(control_point, point + last_point);
m_previous_control_point = control_point;
}
break;
}
case PathInstructionType::SmoothQuadraticBezierCurve: {
clear_last_control_point = false;
VERIFY(!path.segments().is_empty());
auto last_point = path.segments().last().point();
if (m_previous_control_point.is_null()) {
m_previous_control_point = last_point;
}
auto dx_end_control = last_point.dx_relative_to(m_previous_control_point);
auto dy_end_control = last_point.dy_relative_to(m_previous_control_point);
auto control_point = Gfx::FloatPoint { last_point.x() + dx_end_control, last_point.y() + dy_end_control };
Gfx::FloatPoint end_point = { data[0], data[1] };
if (absolute) {
path.quadratic_bezier_curve_to(control_point, end_point);
} else {
path.quadratic_bezier_curve_to(control_point, end_point + last_point);
}
m_previous_control_point = control_point;
break;
}
case PathInstructionType::Curve:
case PathInstructionType::SmoothCurve:
// Instead of crashing the browser every time we come across an SVG
// with these path instructions, let's just skip them
continue;
case PathInstructionType::Invalid:
VERIFY_NOT_REACHED();
}
if (clear_last_control_point) {
m_previous_control_point = Gfx::FloatPoint {};
}
}
m_path = path;
return m_path.value();
}
}
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