232 lines
6.4 KiB
C++
232 lines
6.4 KiB
C++
/*
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* Copyright © 2020 Ebrahim Byagowi
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*
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* This is part of HarfBuzz, a text shaping library.
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*
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* Permission is hereby granted, without written agreement and without
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* license or royalty fees, to use, copy, modify, and distribute this
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* software and its documentation for any purpose, provided that the
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* above copyright notice and the following two paragraphs appear in
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* all copies of this software.
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*
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* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
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* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*/
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#ifndef HB_DRAW_HH
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#define HB_DRAW_HH
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#include "hb.hh"
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/*
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* hb_draw_funcs_t
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*/
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#define HB_DRAW_FUNCS_IMPLEMENT_CALLBACKS \
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HB_DRAW_FUNC_IMPLEMENT (move_to) \
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HB_DRAW_FUNC_IMPLEMENT (line_to) \
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HB_DRAW_FUNC_IMPLEMENT (quadratic_to) \
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HB_DRAW_FUNC_IMPLEMENT (cubic_to) \
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HB_DRAW_FUNC_IMPLEMENT (close_path) \
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/* ^--- Add new callbacks here */
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struct hb_draw_funcs_t
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{
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hb_object_header_t header;
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struct {
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#define HB_DRAW_FUNC_IMPLEMENT(name) hb_draw_##name##_func_t name;
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HB_DRAW_FUNCS_IMPLEMENT_CALLBACKS
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#undef HB_DRAW_FUNC_IMPLEMENT
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} func;
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struct {
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#define HB_DRAW_FUNC_IMPLEMENT(name) void *name;
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HB_DRAW_FUNCS_IMPLEMENT_CALLBACKS
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#undef HB_DRAW_FUNC_IMPLEMENT
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} user_data;
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struct {
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#define HB_DRAW_FUNC_IMPLEMENT(name) hb_destroy_func_t name;
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HB_DRAW_FUNCS_IMPLEMENT_CALLBACKS
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#undef HB_DRAW_FUNC_IMPLEMENT
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} destroy;
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void emit_move_to (void *draw_data, hb_draw_state_t &st,
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float to_x, float to_y)
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{ func.move_to (this, draw_data, &st,
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to_x, to_y,
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user_data.move_to); }
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void emit_line_to (void *draw_data, hb_draw_state_t &st,
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float to_x, float to_y)
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{ func.line_to (this, draw_data, &st,
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to_x, to_y,
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user_data.line_to); }
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void emit_quadratic_to (void *draw_data, hb_draw_state_t &st,
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float control_x, float control_y,
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float to_x, float to_y)
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{ func.quadratic_to (this, draw_data, &st,
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control_x, control_y,
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to_x, to_y,
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user_data.quadratic_to); }
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void emit_cubic_to (void *draw_data, hb_draw_state_t &st,
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float control1_x, float control1_y,
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float control2_x, float control2_y,
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float to_x, float to_y)
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{ func.cubic_to (this, draw_data, &st,
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control1_x, control1_y,
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control2_x, control2_y,
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to_x, to_y,
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user_data.cubic_to); }
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void emit_close_path (void *draw_data, hb_draw_state_t &st)
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{ func.close_path (this, draw_data, &st,
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user_data.close_path); }
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void move_to (void *draw_data, hb_draw_state_t &st,
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float to_x, float to_y)
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{
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if (st.path_open) close_path (draw_data, st);
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st.current_x = to_x;
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st.current_y = to_y;
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}
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void line_to (void *draw_data, hb_draw_state_t &st,
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float to_x, float to_y)
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{
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if (!st.path_open) start_path (draw_data, st);
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emit_line_to (draw_data, st, to_x, to_y);
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st.current_x = to_x;
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st.current_y = to_y;
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}
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void
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quadratic_to (void *draw_data, hb_draw_state_t &st,
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float control_x, float control_y,
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float to_x, float to_y)
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{
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if (!st.path_open) start_path (draw_data, st);
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emit_quadratic_to (draw_data, st, control_x, control_y, to_x, to_y);
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st.current_x = to_x;
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st.current_y = to_y;
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}
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void
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cubic_to (void *draw_data, hb_draw_state_t &st,
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float control1_x, float control1_y,
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float control2_x, float control2_y,
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float to_x, float to_y)
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{
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if (!st.path_open) start_path (draw_data, st);
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emit_cubic_to (draw_data, st, control1_x, control1_y, control2_x, control2_y, to_x, to_y);
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st.current_x = to_x;
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st.current_y = to_y;
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}
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void
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close_path (void *draw_data, hb_draw_state_t &st)
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{
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if (st.path_open)
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{
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if ((st.path_start_x != st.current_x) || (st.path_start_y != st.current_y))
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emit_line_to (draw_data, st, st.path_start_x, st.path_start_y);
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emit_close_path (draw_data, st);
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}
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st.path_open = false;
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st.path_start_x = st.current_x = st.path_start_y = st.current_y = 0;
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}
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protected:
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void start_path (void *draw_data, hb_draw_state_t &st)
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{
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assert (!st.path_open);
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emit_move_to (draw_data, st, st.current_x, st.current_y);
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st.path_open = true;
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st.path_start_x = st.current_x;
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st.path_start_y = st.current_y;
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}
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};
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DECLARE_NULL_INSTANCE (hb_draw_funcs_t);
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struct hb_draw_session_t
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{
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hb_draw_session_t (hb_draw_funcs_t *funcs_, void *draw_data_, float slant_ = 0.f)
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: slant {slant_}, not_slanted {slant == 0.f},
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funcs {funcs_}, draw_data {draw_data_}, st HB_DRAW_STATE_DEFAULT
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{}
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~hb_draw_session_t () { close_path (); }
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void move_to (float to_x, float to_y)
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{
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if (likely (not_slanted))
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funcs->move_to (draw_data, st,
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to_x, to_y);
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else
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funcs->move_to (draw_data, st,
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to_x + to_y * slant, to_y);
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}
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void line_to (float to_x, float to_y)
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{
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if (likely (not_slanted))
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funcs->line_to (draw_data, st,
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to_x, to_y);
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else
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funcs->line_to (draw_data, st,
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to_x + to_y * slant, to_y);
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}
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void
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quadratic_to (float control_x, float control_y,
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float to_x, float to_y)
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{
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if (likely (not_slanted))
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funcs->quadratic_to (draw_data, st,
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control_x, control_y,
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to_x, to_y);
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else
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funcs->quadratic_to (draw_data, st,
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control_x + control_y * slant, control_y,
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to_x + to_y * slant, to_y);
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}
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void
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cubic_to (float control1_x, float control1_y,
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float control2_x, float control2_y,
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float to_x, float to_y)
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{
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if (likely (not_slanted))
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funcs->cubic_to (draw_data, st,
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control1_x, control1_y,
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control2_x, control2_y,
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to_x, to_y);
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else
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funcs->cubic_to (draw_data, st,
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control1_x + control1_y * slant, control1_y,
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control2_x + control2_y * slant, control2_y,
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to_x + to_y * slant, to_y);
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}
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void close_path ()
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{
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funcs->close_path (draw_data, st);
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}
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protected:
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float slant;
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bool not_slanted;
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hb_draw_funcs_t *funcs;
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void *draw_data;
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hb_draw_state_t st;
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};
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#endif /* HB_DRAW_HH */
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