Make svg geometry builder a mixin. Record a lot of notes for geometry.

1 files changed, 68 insertions, 0 deletions

diff --git a/include/cru/platform/graphics/SvgGeometryBuilderMixin.h b/include/cru/platform/graphics/SvgGeometryBuilderMixin.h
new file mode 100644
index 00000000..d516ce6c
--- /dev/null
+++ b/include/cru/platform/graphics/SvgGeometryBuilderMixin.h
@@ -0,0 +1,68 @@
+#pragma once
+
+#include "Geometry.h"
+#include "cru/common/Format.h"
+
+#include <utility>
+
+namespace cru::platform::graphics {
+/**
+ * \remarks This class is a helper mixin for some platforms, especially web
+ * canvas. It constructs a svg data by recording commands. Use GetPathData to
+ * get svg path data and use it to build real geometry.
+ */
+class CRU_PLATFORM_GRAPHICS_API SvgGeometryBuilderMixin
+    : public virtual IGeometryBuilder {
+ public:
+  SvgGeometryBuilderMixin();
+
+  ~SvgGeometryBuilderMixin() override;
+
+  Point GetCurrentPosition() override;
+
+  void MoveTo(const Point& point) override;
+  void RelativeMoveTo(const Point& offset) override;
+
+  void LineTo(const Point& point) override;
+  void RelativeLineTo(const Point& offset) override;
+
+  void CubicBezierTo(const Point& start_control_point,
+                     const Point& end_control_point,
+                     const Point& end_point) override;
+  void RelativeCubicBezierTo(const Point& start_control_offset,
+                             const Point& end_control_offset,
+                             const Point& end_offset) override;
+
+  void QuadraticBezierTo(const Point& control_point,
+                         const Point& end_point) override;
+  void RelativeQuadraticBezierTo(const Point& control_offset,
+                                 const Point& end_offset) override;
+
+  void ArcTo(const Point& radius, float angle, bool is_large_arc,
+             bool is_clockwise, const Point& end_point) override;
+  void RelativeArcTo(const Point& radius, float angle, bool is_large_arc,
+                     bool is_clockwise, const Point& end_offset) override;
+
+  void CloseFigure(bool close) override;
+
+  void ParseAndApplySvgPathData(StringView path_d) override;
+
+ protected:
+  String GetPathData() const { return current_; }
+
+ private:
+  template <typename... Args>
+  void Append(StringView format, Args&&... args) {
+    current_ += Format(format, std::forward<Args>(args)...);
+    current_ += u' ';
+  }
+
+  void AppendCommand(StringView command);
+  void Append(bool flag);
+  void Append(float number);
+  void Append(const Point& point);
+
+ private:
+  String current_;
+};
+}  // namespace cru::platform::graphics