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SVG rendering improvements:

Browse source 
* process `font-size` attributes and use them to scale `em` units
* fix default `color-stop` value
* store `viewBox` and use it to calculate `%` values correctly
* add more absolute/relative values
* default `DPI`:96
* default `font-size`: 10
* process style attributes on `<svg>` element
* use viewBox `width`, `height` and `normalized_diagonal` for relevant length values
* apply scale factor to gradient transforms
This commit is contained in:
Artem Pavlenko 2021-04-13 09:19:33 +01:00
parent 9c2132f895
commit f293371a9d
2 changed files with 167 additions and 90 deletions
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14
include/mapnik/svg/svg_parser.hpp
View file

@ -34,6 +34,9 @@
// stl
#include <map>
#include <algorithm>
#include <deque>
// boost
#include <boost/optional.hpp>
namespace boost { namespace property_tree { namespace detail { namespace rapidxml {
template <typename T> class xml_node;
@ -41,6 +44,14 @@ template <typename T> class xml_node;
namespace mapnik { namespace svg {
struct viewbox
{
double x0;
double y0;
double width;
double height;
};
class svg_parser_error_handler
{
using error_message_container = std::vector<std::string> ;
@ -88,7 +99,10 @@ public:
std::map<std::string, gradient> gradient_map_;
std::map<std::string, boost::property_tree::detail::rapidxml::xml_node<char> const*> node_cache_;
mapnik::css_data css_data_;
boost::optional<viewbox> vbox_{};
double normalized_diagonal_ = 0.0;
agg::trans_affine viewbox_tr_{};
std::deque<double> font_sizes_{};
error_handler err_handler_;
};

243
src/svg/svg_parser.cpp
View file

@ -39,10 +39,6 @@ MAPNIK_DISABLE_WARNING_PUSH
#include "agg_rounded_rect.h"
#include "agg_span_gradient.h"
#include "agg_color_rgba.h"
MAPNIK_DISABLE_WARNING_POP
#include <mapnik/warning.hpp>
MAPNIK_DISABLE_WARNING_PUSH
#include <mapnik/warning_ignore.hpp>
#include <boost/spirit/home/x3.hpp>
#include <boost/fusion/adapted/struct.hpp>
@ -62,14 +58,6 @@ namespace mapnik { namespace svg {
using util::name_to_int;
using util::operator"" _case;
struct viewbox
{
double x0;
double y0;
double width;
double height;
};
}}
BOOST_FUSION_ADAPT_STRUCT (
@ -118,7 +106,7 @@ static std::array<unsigned, 9> const unsupported_elements
"pattern"_case}
};
static std::array<unsigned, 43> const unsupported_attributes
static std::array<unsigned, 42> const unsupported_attributes
{ {"alignment-baseline"_case,
"baseline-shift"_case,
"clip"_case,
@ -136,7 +124,6 @@ static std::array<unsigned, 43> const unsupported_attributes
"flood-color"_case,
"flood-opacity"_case,
"font-family"_case,
"font-size"_case,
"font-size-adjust"_case,
"font-stretch"_case,
"font-style"_case,
@ -257,31 +244,70 @@ double parse_double(T & err_handler, const char* str)
}
// https://www.w3.org/TR/SVG/coords.html#Units
template <typename T, int DPI = 90>
double parse_svg_value(T & err_handler, const char* str, bool & is_percent)
template <typename T>
double parse_svg_value(T & parser, char const* str, bool & is_percent)
{
namespace x3 = boost::spirit::x3;
double val = 0.0;
css_unit_value units;
const char* cur = str; // phrase_parse mutates the first iterator
const char* end = str + std::strlen(str);
double font_size = parser.font_sizes_.back();
auto apply_value = [&](auto const& ctx) { val = _attr(ctx); is_percent = false; };
auto apply_units = [&](auto const& ctx) { val *= _attr(ctx); };
auto apply_em = [&](auto const& ctx) { val *= font_size;};
auto apply_percent = [&](auto const& ctx) { val *= 0.01; is_percent = true; };
if (!x3::phrase_parse(cur, end,
x3::double_[apply_value]
> - (units[apply_units]
|
x3::lit("em")[apply_em]
|
x3::lit('%')[apply_percent]),
x3::space) || (cur != end))
{
err_handler.on_error("SVG parse error: failed to parse <number> with value \"" + std::string(str) + "\"");
parser.err_handler().on_error("SVG parse error: failed to parse <number> with value \"" + std::string(str) + "\"");
}
return val;
}
template <typename T>
double parse_font_size(T & parser, char const* str)
{
namespace x3 = boost::spirit::x3;
double val;
css_unit_value units;
css_absolute_size absolute;
css_relative_size relative;
std::size_t size = parser.font_sizes_.size();
double parent_font_size = size > 1 ? parser.font_sizes_[size - 2] : 10.0 ;
const char* cur = str; // phrase_parse mutates the first iterator
const char* end = str + std::strlen(str);
auto apply_value = [&](auto const& ctx) { val = _attr(ctx);};
auto apply_relative =[&](auto const& ctx) { val = parent_font_size * _attr(ctx);};
auto apply_units = [&](auto const& ctx) { val *= _attr(ctx); };
auto apply_percent = [&](auto const& ctx) { val = val * parent_font_size / 100.0;};
auto apply_em = [&](auto const& ctx) { val = val * parent_font_size;};
if (!x3::phrase_parse(cur, end,
absolute[apply_value]
|
relative[apply_relative]
|
x3::double_[apply_value]
> -(units[apply_units]
| x3::lit("em")[apply_em]
| x3::lit('%')[apply_percent]),
x3::space) || (cur != end))
{
parser.err_handler().on_error("SVG parse error: failed to parse <font-size> with value \"" + std::string(str) + "\"");
}
parser.font_sizes_.back() = val;
return val;
}
template <typename T, typename V>
bool parse_viewbox(T & err_handler, char const* str, V & viewbox)
{
@ -371,7 +397,6 @@ void process_css(svg_parser & parser, rapidxml::xml_node<char> const* node)
auto itr = css.find(element_name);
if (itr != css.end())
{
//std::cerr << "-> element key:" << element_name << std::endl;
for (auto const& def : std::get<1>(*itr))
{
style[std::get<0>(def)] = std::get<1>(def);
@ -396,8 +421,6 @@ void process_css(svg_parser & parser, rapidxml::xml_node<char> const* node)
auto range = css.equal_range(solitary_class_key);
for (auto itr = range.first; itr != range.second; ++itr)
{
//std::cerr << "<" << element_name << ">";
//std::cerr << "--> solitary class key:" << solitary_class_key << std::endl;
for (auto const& def : std::get<1>(*itr))
{
style[std::get<0>(def)] = std::get<1>(def);
@ -407,8 +430,6 @@ void process_css(svg_parser & parser, rapidxml::xml_node<char> const* node)
range = css.equal_range(class_key);
for (auto itr = range.first; itr != range.second; ++itr)
{
//std::cerr << "<" << element_name << ">";
//std::cerr << "---> class key:" << class_key << std::endl;
for (auto const& def : std::get<1>(*itr))
{
style[std::get<0>(def)] = std::get<1>(def);
@ -416,10 +437,6 @@ void process_css(svg_parser & parser, rapidxml::xml_node<char> const* node)
}
}
}
//else
//{
// std::cerr << "Failed to parse styles..." << std::endl;
//}
}
}
auto const* id_attr = node->first_attribute("id");
@ -432,8 +449,6 @@ void process_css(svg_parser & parser, rapidxml::xml_node<char> const* node)
itr = css.find(id_key);
if (itr != css.end())
{
//std::cerr << "<" << element_name << ">";
//std::cerr << "----> ID key:" << id_key << std::endl;
for (auto const& def : std::get<1>(*itr))
{
style[std::get<0>(def)] = std::get<1>(def);
@ -449,7 +464,6 @@ void process_css(svg_parser & parser, rapidxml::xml_node<char> const* node)
{
auto const& r = std::get<1>(def);
std::string val{r.begin(), r.end()};
//std::cerr << "PARSE ATTR:" << std::get<0>(def) << ":" << val << std::endl;
parse_attr(parser, std::get<0>(def).c_str(), val.c_str());
}
}
@ -459,10 +473,12 @@ void traverse_tree(svg_parser & parser, rapidxml::xml_node<char> const* node)
{
if (parser.ignore_) return;
auto name = name_to_int(node->name());
switch (node->type())
{
case rapidxml::node_element:
{
parser.font_sizes_.push_back(parser.font_sizes_.back());
switch(name)
{
case "defs"_case:
@ -574,6 +590,7 @@ void traverse_tree(svg_parser & parser, rapidxml::xml_node<char> const* node)
void end_element(svg_parser & parser, rapidxml::xml_node<char> const* node)
{
parser.font_sizes_.pop_back();
auto name = name_to_int(node->name());
if (!parser.is_defs_ && (name == "g"_case))
{
@ -582,6 +599,13 @@ void end_element(svg_parser & parser, rapidxml::xml_node<char> const* node)
parser.path_.pop_attr();
}
}
else if (name == "svg"_case)
{
if (node->first_node() != nullptr)
{
parser.path_.pop_attr();
}
}
else if (name == "defs"_case)
{
if (node->first_node() != nullptr)
@ -629,7 +653,9 @@ void parse_element(svg_parser & parser, char const* name, rapidxml::xml_node<cha
parse_ellipse(parser, node);
break;
case "svg"_case:
parser.path_.push_attr();
parse_dimensions(parser, node);
parse_attr(parser, node);
break;
default:
handle_unsupported(parser, unsupported_elements, name, "element");
@ -762,9 +788,13 @@ void parse_attr(svg_parser & parser, char const* name, char const* value )
parse_stroke(parser, value);
break;
case "stroke-width"_case:
bool percent;
parser.path_.stroke_width(parse_svg_value(parser.err_handler(), value, percent));
{
bool percent = false;
double stroke_width = parse_svg_value(parser, value, percent);
if (percent && parser.vbox_) stroke_width *= parser.normalized_diagonal_;
parser.path_.stroke_width(stroke_width);
break;
}
case "stroke-opacity"_case:
parser.path_.stroke_opacity(parse_double(parser.err_handler(), value));
break;
@ -805,6 +835,11 @@ void parse_attr(svg_parser & parser, char const* name, char const* value )
parser.path_.display(false);
}
break;
case "font-size"_case:
{
double font_size = parse_font_size(parser, value);
break;
}
default:
handle_unsupported(parser, unsupported_attributes, name, "attribute");
break;
@ -847,22 +882,24 @@ void parse_dimensions(svg_parser & parser, rapidxml::xml_node<char> const* node)
auto const* width_attr = node->first_attribute("width");
if (width_attr)
{
width = parse_svg_value(parser.err_handler(), width_attr->value(), has_percent_width);
width = parse_svg_value(parser, width_attr->value(), has_percent_width);
}
auto const* height_attr = node->first_attribute("height");
if (height_attr)
{
height = parse_svg_value(parser.err_handler(), height_attr->value(), has_percent_height);
height = parse_svg_value(parser, height_attr->value(), has_percent_height);
}
parser.vbox_ = viewbox{0, 0, width, height} ;
auto const* viewbox_attr = node->first_attribute("viewBox");
if (viewbox_attr && parse_viewbox(parser.err_handler(), viewbox_attr->value(), vbox))
{
agg::trans_affine t{};
parser.vbox_ = vbox;
parser.normalized_diagonal_ = std::sqrt(vbox.width * vbox.width + vbox.height * vbox.height)/std::sqrt(2.0);
if (!has_percent_width && !has_percent_height)
{
if (width > 0 && height > 0 && vbox.width > 0 && vbox.height > 0)
{
agg::trans_affine t{};
std::pair<unsigned,bool> preserve_aspect_ratio {xMidYMid, true};
auto const* aspect_ratio_attr = node->first_attribute("preserveAspectRatio");
if (aspect_ratio_attr)
@ -918,9 +955,6 @@ void parse_dimensions(svg_parser & parser, rapidxml::xml_node<char> const* node)
-1.0 * (vbox.height - height / scale)) * t;
break;
};
t = agg::trans_affine_translation(-vbox.x0, -vbox.y0) * t;
parser.viewbox_tr_ = t;
}
}
if (has_percent_width && !has_percent_height)
@ -938,6 +972,8 @@ void parse_dimensions(svg_parser & parser, rapidxml::xml_node<char> const* node)
width = vbox.width;
height = vbox.height;
}
t = agg::trans_affine_translation(-vbox.x0, -vbox.y0) * t;
parser.viewbox_tr_ = t;
}
parser.path_.set_dimensions(width, height);
}
@ -990,25 +1026,25 @@ void parse_use(svg_parser & parser, rapidxml::xml_node<char> const* node)
attr = node->first_attribute("x");
if (attr != nullptr)
{
x = parse_svg_value(parser.err_handler(), attr->value(), percent);
x = parse_svg_value(parser, attr->value(), percent);
}
attr = node->first_attribute("y");
if (attr != nullptr)
{
y = parse_svg_value(parser.err_handler(), attr->value(), percent);
y = parse_svg_value(parser, attr->value(), percent);
}
attr = node->first_attribute("width");
if (attr != nullptr)
{
w = parse_svg_value(parser.err_handler(), attr->value(), percent);
w = parse_svg_value(parser, attr->value(), percent);
if (percent) w *= parser.path_.width();
}
attr = node->first_attribute("height");
if (attr)
{
h = parse_svg_value(parser.err_handler(), attr->value(), percent);
h = parse_svg_value(parser, attr->value(), percent);
if (percent) h *= parser.path_.height();
}
if (w < 0.0)
@ -1073,19 +1109,32 @@ void parse_line(svg_parser & parser, rapidxml::xml_node<char> const* node)
double y1 = 0.0;
double x2 = 0.0;
double y2 = 0.0;
bool percent;
bool percent = false;
auto const* x1_attr = node->first_attribute("x1");
if (x1_attr) x1 = parse_svg_value(parser.err_handler(), x1_attr->value(), percent);
if (x1_attr)
{
x1 = parse_svg_value(parser, x1_attr->value(), percent);
if (percent && parser.vbox_) x1 *= parser.vbox_->width;
}
auto const* y1_attr = node->first_attribute("y1");
if (y1_attr) y1 = parse_svg_value(parser.err_handler(), y1_attr->value(), percent);
if (y1_attr)
{
y1 = parse_svg_value(parser, y1_attr->value(), percent);
if (percent && parser.vbox_) y1 *= parser.vbox_->height;
}
auto const* x2_attr = node->first_attribute("x2");
if (x2_attr) x2 = parse_svg_value(parser.err_handler(), x2_attr->value(), percent);
if (x2_attr)
{
x2 = parse_svg_value(parser, x2_attr->value(), percent);
if (percent && parser.vbox_) x2 *= parser.vbox_->width;
}
auto const* y2_attr = node->first_attribute("y2");
if (y2_attr) y2 = parse_svg_value(parser.err_handler(), y2_attr->value(), percent);
if (y2_attr)
{
y2 = parse_svg_value(parser, y2_attr->value(), percent);
if (percent && parser.vbox_) y2 *= parser.vbox_->height;
}
parser.path_.begin_path();
parser.path_.move_to(x1, y1);
parser.path_.line_to(x2, y2);
@ -1097,23 +1146,26 @@ void parse_circle(svg_parser & parser, rapidxml::xml_node<char> const* node)
double cx = 0.0;
double cy = 0.0;
double r = 0.0;
bool percent;
bool percent = false;
auto * attr = node->first_attribute("cx");
if (attr != nullptr)
{
cx = parse_svg_value(parser.err_handler(), attr->value(), percent);
cx = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) cx *= parser.vbox_->width;
}
attr = node->first_attribute("cy");
if (attr != nullptr)
{
cy = parse_svg_value(parser.err_handler(), attr->value(), percent);
cy = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) cy *= parser.vbox_->height;
}
attr = node->first_attribute("r");
if (attr != nullptr)
{
r = parse_svg_value(parser.err_handler(), attr->value(), percent);
r = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) r *= parser.normalized_diagonal_;
}
parser.path_.begin_path();
@ -1140,29 +1192,33 @@ void parse_ellipse(svg_parser & parser, rapidxml::xml_node<char> const * node)
double cy = 0.0;
double rx = 0.0;
double ry = 0.0;
bool percent;
bool percent = false;
auto * attr = node->first_attribute("cx");
if (attr != nullptr)
{
cx = parse_svg_value(parser.err_handler(), attr->value(), percent);
cx = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) cx *= parser.vbox_->width;
}
attr = node->first_attribute("cy");
if (attr)
{
cy = parse_svg_value(parser.err_handler(), attr->value(), percent);
cy = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) cy *= parser.vbox_->height;
}
attr = node->first_attribute("rx");
if (attr != nullptr)
{
rx = parse_svg_value(parser.err_handler(), attr->value(), percent);
rx = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) rx *= parser.normalized_diagonal_;
}
attr = node->first_attribute("ry");
if (attr != nullptr)
{
ry = parse_svg_value(parser.err_handler(), attr->value(), percent);
ry = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) ry *= parser.normalized_diagonal_;
}
if (rx != 0.0 && ry != 0.0)
@ -1198,35 +1254,40 @@ void parse_rect(svg_parser & parser, rapidxml::xml_node<char> const* node)
double h = 0.0;
double rx = 0.0;
double ry = 0.0;
bool percent;
bool percent = false;
auto * attr = node->first_attribute("x");
if (attr != nullptr)
{
x = parse_svg_value(parser.err_handler(), attr->value(), percent);
x = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) x *= parser.vbox_->width;
}
attr = node->first_attribute("y");
if (attr != nullptr)
{
y = parse_svg_value(parser.err_handler(), attr->value(), percent);
y = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) y *= parser.vbox_->height;
}
attr = node->first_attribute("width");
if (attr != nullptr)
{
w = parse_svg_value(parser.err_handler(), attr->value(), percent);
w = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) w *= parser.vbox_->width;
}
attr = node->first_attribute("height");
if (attr)
{
h = parse_svg_value(parser.err_handler(), attr->value(), percent);
h = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) h *= parser.vbox_->height;
}
bool rounded = true;
attr = node->first_attribute("rx");
if (attr != nullptr)
{
rx = parse_svg_value(parser.err_handler(), attr->value(), percent);
rx = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) rx *= parser.vbox_->width;
if ( rx > 0.5 * w ) rx = 0.5 * w;
}
else rounded = false;
@ -1234,7 +1295,8 @@ void parse_rect(svg_parser & parser, rapidxml::xml_node<char> const* node)
attr = node->first_attribute("ry");
if (attr != nullptr)
{
ry = parse_svg_value(parser.err_handler(), attr->value(), percent);
ry = parse_svg_value(parser, attr->value(), percent);
if (percent && parser.vbox_) ry *= parser.vbox_->height;
if ( ry > 0.5 * h ) ry = 0.5 * h;
if (!rounded)
{
@ -1300,14 +1362,14 @@ void parse_rect(svg_parser & parser, rapidxml::xml_node<char> const* node)
void parse_gradient_stop(svg_parser & parser, mapnik::gradient& gr, rapidxml::xml_node<char> const* node)
{
double offset = 0.0;
mapnik::color stop_color;
mapnik::color stop_color{0,0,0,255};
double opacity = 1.0;
auto * attr = node->first_attribute("offset");
if (attr != nullptr)
{
bool percent = false;
offset = parse_svg_value(parser.err_handler(),attr->value(), percent);
offset = parse_svg_value(parser,attr->value(), percent);
}
attr = node->first_attribute("style");
@ -1406,39 +1468,38 @@ void parse_radial_gradient(svg_parser & parser, rapidxml::xml_node<char> const*
double fx = 0.0;
double fy = 0.0;
double r = 0.5;
bool has_percent=true;
bool has_percent = false;
attr = node->first_attribute("cx");
if (attr != nullptr)
{
cx = parse_svg_value(parser.err_handler(), attr->value(), has_percent);
cx = parse_svg_value(parser, attr->value(), has_percent);
}
attr = node->first_attribute("cy");
if (attr != nullptr)
{
cy = parse_svg_value(parser.err_handler(), attr->value(), has_percent);
cy = parse_svg_value(parser, attr->value(), has_percent);
}
attr = node->first_attribute("fx");
if (attr != nullptr)
{
fx = parse_svg_value(parser.err_handler(),attr->value(), has_percent);
fx = parse_svg_value(parser,attr->value(), has_percent);
}
else
fx = cx;
else fx = cx;
attr = node->first_attribute("fy");
if (attr != nullptr)
{
fy = parse_svg_value(parser.err_handler(), attr->value(), has_percent);
fy = parse_svg_value(parser, attr->value(), has_percent);
}
else fy = cy;
attr = node->first_attribute("r");
if (attr != nullptr)
{
r = parse_svg_value(parser.err_handler(), attr->value(), has_percent);
r = parse_svg_value(parser, attr->value(), has_percent);
}
// this logic for detecting %'s will not support mixed coordinates.
if (has_percent && gr.get_units() == USER_SPACE_ON_USE)
@ -1471,40 +1532,39 @@ void parse_linear_gradient(svg_parser & parser, rapidxml::xml_node<char> const*
if (!parse_common_gradient(parser, id, gr, node)) return;
double x1 = 0.0;
double x2 = 1.0;
double y1 = 0.0;
double x2 = 1.0;
double y2 = 0.0;
bool has_percent=true;
bool has_percent = true;
attr = node->first_attribute("x1");
if (attr != nullptr)
{
x1 = parse_svg_value(parser.err_handler(), attr->value(), has_percent);
}
attr = node->first_attribute("x2");
if (attr != nullptr)
{
x2 = parse_svg_value(parser.err_handler(), attr->value(), has_percent);
x1 = parse_svg_value(parser, attr->value(), has_percent);
}
attr = node->first_attribute("y1");
if (attr != nullptr)
{
y1 = parse_svg_value(parser.err_handler(), attr->value(), has_percent);
y1 = parse_svg_value(parser, attr->value(), has_percent);
}
attr = node->first_attribute("x2");
if (attr != nullptr)
{
x2 = parse_svg_value(parser, attr->value(), has_percent);
}
attr = node->first_attribute("y2");
if (attr != nullptr)
{
y2 = parse_svg_value(parser.err_handler(), attr->value(), has_percent);
y2 = parse_svg_value(parser, attr->value(), has_percent);
}
// this logic for detecting %'s will not support mixed coordinates.
if (has_percent && gr.get_units() == USER_SPACE_ON_USE)
{
gr.set_units(USER_SPACE_ON_USE_BOUNDING_BOX);
}
gr.set_gradient_type(LINEAR);
gr.set_control_points(x1, y1, x2, y2);
@ -1526,7 +1586,10 @@ svg_parser::svg_parser(svg_converter_type & path, bool strict)
is_defs_(false),
ignore_(false),
css_style_(false),
err_handler_(strict) {}
err_handler_(strict)
{
font_sizes_.push_back(10.0);
}
svg_parser::~svg_parser() {}