diff options
Diffstat (limited to 'src/platform/graphics/Geometry.cpp')
| -rw-r--r-- | src/platform/graphics/Geometry.cpp | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/src/platform/graphics/Geometry.cpp b/src/platform/graphics/Geometry.cpp index a9a93bf4..d4d36eb4 100644 --- a/src/platform/graphics/Geometry.cpp +++ b/src/platform/graphics/Geometry.cpp @@ -1,6 +1,8 @@ #include "cru/platform/graphics/Geometry.h" #include <cmath> +#include <unordered_set> +#include "cru/common/Exception.h" namespace cru::platform::graphics { constexpr float PI = 3.14159265358979323846f; @@ -153,4 +155,214 @@ void IGeometryBuilder::ArcTo(const Point& radius, float angle, end_point.x, end_point.y, current_position.x, current_position.y); } +namespace { +const std::unordered_set<char16_t> kSvgPathDataCommands = { + 'M', 'm', 'L', 'l', 'H', 'h', 'V', 'v', 'C', 'c', + 'S', 's', 'Q', 'q', 'T', 't', 'A', 'a', 'Z', 'z'}; +} + +void IGeometryBuilder::ParseAndApplySvgPathData(StringView path_d) { + Index position = 0; + const auto size = path_d.size(); + + char16_t last_command = 0; + bool last_is_cubic = false; + bool last_is_quad = false; + Point last_end_point; + Point last_control_point; + + auto read_spaces = [&] { + while (position < size && + (path_d[position] == ' ' || path_d[position] == '\n')) { + ++position; + } + return position == size; + }; + + auto read_number = [&] { + if (read_spaces()) { + throw Exception(u"Unexpected eof of svg path data command."); + } + + if (path_d[position] == ',') { + ++position; + } + + Index processed_count = 0; + + auto result = path_d.substr(position).ParseToFloat(&processed_count); + + if (std::isnan(result)) throw Exception(u"Invalid svg path data number."); + + position += processed_count; + + return result; + }; + + auto read_point = [&] { + auto x = read_number(); + auto y = read_number(); + return Point(x, y); + }; + + auto do_command = [&, this](char16_t command) { + last_command = command; + last_is_cubic = false; + last_is_quad = false; + + switch (command) { + case 'M': + MoveTo(read_point()); + break; + case 'm': + RelativeMoveTo(read_point()); + break; + case 'L': + LineTo(read_point()); + break; + case 'l': + RelativeLineTo(read_point()); + break; + case 'H': + LineTo(read_number(), this->GetCurrentPosition().y); + break; + case 'h': + RelativeLineTo(read_number(), 0); + break; + case 'V': + LineTo(GetCurrentPosition().x, read_number()); + break; + case 'v': + RelativeLineTo(0, read_number()); + break; + case 'C': { + auto start_control_point = read_point(), + end_control_point = read_point(), end_point = read_point(); + CubicBezierTo(start_control_point, end_control_point, end_point); + last_is_cubic = true; + last_control_point = end_control_point; + last_end_point = end_point; + break; + } + case 'c': { + auto current_position = GetCurrentPosition(); + auto start_control_point = current_position + read_point(), + end_control_point = current_position + read_point(), + end_point = current_position + read_point(); + CubicBezierTo(start_control_point, end_control_point, end_point); + last_is_cubic = true; + last_control_point = end_control_point; + last_end_point = end_point; + break; + } + case 'S': { + auto current_position = GetCurrentPosition(); + auto start_control_point = last_is_cubic ? Point{last_end_point.x * 2, + last_end_point.y * 2} - + last_control_point + : current_position, + end_control_point = read_point(), end_point = read_point(); + CubicBezierTo(start_control_point, end_control_point, end_point); + last_is_cubic = true; + last_control_point = end_control_point; + last_end_point = end_point; + break; + } + case 's': { + auto current_position = GetCurrentPosition(); + auto start_control_point = last_is_cubic ? Point{last_end_point.x * 2, + last_end_point.y * 2} - + last_control_point + : current_position, + end_control_point = current_position + read_point(), + end_point = current_position + read_point(); + CubicBezierTo(start_control_point, end_control_point, end_point); + last_is_cubic = true; + last_control_point = end_control_point; + last_end_point = end_point; + break; + } + case 'Q': { + auto control_point = read_point(), end_point = read_point(); + QuadraticBezierTo(control_point, end_point); + last_is_quad = true; + last_control_point = control_point; + last_end_point = end_point; + break; + } + case 'q': { + auto current_position = GetCurrentPosition(); + auto control_point = current_position + read_point(), + end_point = current_position + read_point(); + QuadraticBezierTo(control_point, end_point); + last_is_quad = true; + last_control_point = control_point; + last_end_point = end_point; + break; + } + case 'T': { + auto current_position = GetCurrentPosition(); + auto control_point = last_is_quad ? Point{last_end_point.x * 2, + last_end_point.y * 2} - + last_control_point + : current_position, + end_point = read_point(); + QuadraticBezierTo(control_point, end_point); + last_is_quad = true; + last_control_point = control_point; + last_end_point = end_point; + break; + } + case 't': { + auto current_position = GetCurrentPosition(); + auto control_point = last_is_quad ? Point{last_end_point.x * 2, + last_end_point.y * 2} - + last_control_point + : current_position, + end_point = current_position + read_point(); + QuadraticBezierTo(control_point, end_point); + last_is_quad = true; + last_control_point = control_point; + last_end_point = end_point; + break; + } + case 'A': + ArcTo({read_number(), read_number()}, read_number(), read_number(), + read_number(), read_point()); + break; + case 'a': + RelativeArcTo({read_number(), read_number()}, read_number(), + read_number(), read_number(), read_point()); + break; + case 'Z': + case 'z': + CloseFigure(true); + break; + default: + throw Exception(u"Invalid svg path command."); + } + return true; + }; + + auto read_command = [&] { + if (read_spaces()) { + return false; + } + auto command = path_d[position]; + + if (kSvgPathDataCommands.contains(command)) { + position++; + do_command(command); + } else { + do_command(last_command); + } + + return true; + }; + + while (true) { + if (!read_command()) break; + } +} + } // namespace cru::platform::graphics |