| #ifndef OT_GLYF_PATH_BUILDER_HH |
| #define OT_GLYF_PATH_BUILDER_HH |
| |
| |
| #include "../../hb.hh" |
| |
| |
| namespace OT { |
| namespace glyf_impl { |
| |
| |
| struct path_builder_t |
| { |
| hb_font_t *font; |
| hb_draw_session_t *draw_session; |
| |
| struct optional_point_t |
| { |
| optional_point_t () {} |
| optional_point_t (float x_, float y_) : has_data (true), x (x_), y (y_) {} |
| operator bool () const { return has_data; } |
| |
| bool has_data = false; |
| float x = 0.; |
| float y = 0.; |
| |
| optional_point_t lerp (optional_point_t p, float t) |
| { return optional_point_t (x + t * (p.x - x), y + t * (p.y - y)); } |
| } first_oncurve, first_offcurve, last_offcurve; |
| |
| path_builder_t (hb_font_t *font_, hb_draw_session_t &draw_session_) |
| { |
| font = font_; |
| draw_session = &draw_session_; |
| first_oncurve = first_offcurve = last_offcurve = optional_point_t (); |
| } |
| |
| /* based on https://github.com/RazrFalcon/ttf-parser/blob/4f32821/src/glyf.rs#L287 |
| See also: |
| * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM01/Chap1.html |
| * https://stackoverflow.com/a/20772557 */ |
| void consume_point (const contour_point_t &point) |
| { |
| bool is_on_curve = point.flag & glyf_impl::SimpleGlyph::FLAG_ON_CURVE; |
| optional_point_t p (font->em_fscalef_x (point.x), font->em_fscalef_y (point.y)); |
| if (!first_oncurve) |
| { |
| if (is_on_curve) |
| { |
| first_oncurve = p; |
| draw_session->move_to (p.x, p.y); |
| } |
| else |
| { |
| if (first_offcurve) |
| { |
| optional_point_t mid = first_offcurve.lerp (p, .5f); |
| first_oncurve = mid; |
| last_offcurve = p; |
| draw_session->move_to (mid.x, mid.y); |
| } |
| else |
| first_offcurve = p; |
| } |
| } |
| else |
| { |
| if (last_offcurve) |
| { |
| if (is_on_curve) |
| { |
| draw_session->quadratic_to (last_offcurve.x, last_offcurve.y, |
| p.x, p.y); |
| last_offcurve = optional_point_t (); |
| } |
| else |
| { |
| optional_point_t mid = last_offcurve.lerp (p, .5f); |
| draw_session->quadratic_to (last_offcurve.x, last_offcurve.y, |
| mid.x, mid.y); |
| last_offcurve = p; |
| } |
| } |
| else |
| { |
| if (is_on_curve) |
| draw_session->line_to (p.x, p.y); |
| else |
| last_offcurve = p; |
| } |
| } |
| |
| if (point.is_end_point) |
| { |
| if (first_offcurve && last_offcurve) |
| { |
| optional_point_t mid = last_offcurve.lerp (first_offcurve, .5f); |
| draw_session->quadratic_to (last_offcurve.x, last_offcurve.y, |
| mid.x, mid.y); |
| last_offcurve = optional_point_t (); |
| /* now check the rest */ |
| } |
| |
| if (first_offcurve && first_oncurve) |
| draw_session->quadratic_to (first_offcurve.x, first_offcurve.y, |
| first_oncurve.x, first_oncurve.y); |
| else if (last_offcurve && first_oncurve) |
| draw_session->quadratic_to (last_offcurve.x, last_offcurve.y, |
| first_oncurve.x, first_oncurve.y); |
| else if (first_oncurve) |
| draw_session->line_to (first_oncurve.x, first_oncurve.y); |
| else if (first_offcurve) |
| { |
| float x = first_offcurve.x, y = first_offcurve.y; |
| draw_session->move_to (x, y); |
| draw_session->quadratic_to (x, y, x, y); |
| } |
| |
| /* Getting ready for the next contour */ |
| first_oncurve = first_offcurve = last_offcurve = optional_point_t (); |
| draw_session->close_path (); |
| } |
| } |
| void points_end () {} |
| |
| bool is_consuming_contour_points () { return true; } |
| contour_point_t *get_phantoms_sink () { return nullptr; } |
| }; |
| |
| |
| } /* namespace glyf_impl */ |
| } /* namespace OT */ |
| |
| |
| #endif /* OT_GLYF_PATH_BUILDER_HH */ |