/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */

/* cairo - a vector graphics library with display and print output

 *

 * Copyright © 2002 University of Southern California

 * Copyright © 2013 Intel Corporation

 *

 * This library is free software; you can redistribute it and/or

 * modify it either under the terms of the GNU Lesser General Public

 * License version 2.1 as published by the Free Software Foundation

 * (the "LGPL") or, at your option, under the terms of the Mozilla

 * Public License Version 1.1 (the "MPL"). If you do not alter this

 * notice, a recipient may use your version of this file under either

 * the MPL or the LGPL.

 *

 * You should have received a copy of the LGPL along with this library

 * in the file COPYING-LGPL-2.1; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

 * You should have received a copy of the MPL along with this library

 * in the file COPYING-MPL-1.1

 *

 * The contents of this file are subject to the Mozilla Public License

 * Version 1.1 (the "License"); you may not use this file except in

 * compliance with the License. You may obtain a copy of the License at

 * http://www.mozilla.org/MPL/

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY

 * OF ANY KIND, either express or implied. See the LGPL or the MPL for

 * the specific language governing rights and limitations.

 *

 * The Original Code is the cairo graphics library.

 *

 * The Initial Developer of the Original Code is University of Southern

 * California.

 *

 * Contributor(s):

 *	Carl D. Worth <cworth@cworth.org>

 *	Chris Wilson <chris@chris-wilson.co.uk>

 */

#include "cairoint.h"

#include "cairo-box-inline.h"

#include "cairo-path-fixed-private.h"

#include "cairo-slope-private.h"

#include "cairo-stroke-dash-private.h"

#include "cairo-traps-private.h"

#include <float.h>

struct stroker {

    const cairo_stroke_style_t	*style;

    const cairo_matrix_t *ctm;

    const cairo_matrix_t *ctm_inverse;

    double spline_cusp_tolerance;

    double half_line_width;

    double tolerance;

    double ctm_determinant;

    cairo_bool_t ctm_det_positive;

    cairo_line_join_t line_join;

    cairo_traps_t *traps;

    cairo_pen_t pen;

    cairo_point_t first_point;

    cairo_bool_t has_initial_sub_path;

    cairo_bool_t has_current_face;

    cairo_stroke_face_t current_face;

    cairo_bool_t has_first_face;

    cairo_stroke_face_t first_face;

    cairo_stroker_dash_t dash;

    cairo_bool_t has_bounds;

    cairo_box_t tight_bounds;

    cairo_box_t line_bounds;

    cairo_box_t join_bounds;

};

static cairo_status_t

	      const cairo_path_fixed_t	*path,

	      const cairo_stroke_style_t	*style,

	      const cairo_matrix_t	*ctm,

	      const cairo_matrix_t	*ctm_inverse,

	      double			 tolerance,

	      cairo_traps_t		*traps)

{

    cairo_status_t status;

    /* If `CAIRO_LINE_JOIN_ROUND` is selected and a joint's `arc height`

     * is greater than `tolerance` then two segments are joined with

     * round-join, otherwise bevel-join is used.

     *

     * `Arc height` is the difference of the "half of a line width" and

     * the "half of a line width" times `cos(half the angle between segment vectors)`.

     *

     * See detailed description in the `_cairo_path_fixed_stroke_to_polygon()`

     * function in the `cairo-path-stroke-polygon.c` file or follow the

     * https://gitlab.freedesktop.org/cairo/cairo/-/merge_requests/372#note_1698225

     * link to see the detailed description with an illustration.

     */

    } else {

    }

		              stroker->half_line_width,

			      tolerance, ctm);

	/* Extend the bounds in each direction to account for the maximum area

	 * we might generate trapezoids, to capture line segments that are outside

	 * of the bounds but which might generate rendering that's within bounds.

	 */

	double dx, dy;

	cairo_fixed_t fdx, fdy;

						    stroker->ctm, &dx, &dy);

							 stroker->ctm, &dx, &dy);

							 stroker->ctm, &dx, &dy);

    }

}

static void

{

static void

{

static int

		   const cairo_stroke_face_t *out)

{

}

static int

{

}

static cairo_bool_t

			 const cairo_point_t *in,

			 const cairo_point_t *out)

{

    cairo_line_t segment;

}

static void

      cairo_stroke_face_t *in,

      cairo_stroke_face_t *out)

{

    cairo_point_t *inpt, *outpt;

    {

    }

    } else {

    }

	/* construct a fan around the common midpoint */

	{

	    int start, stop;

	    cairo_point_t tri[3], edges[4];

						     &start, &stop);

								 tri, edges);

		}

	    } else {

						    &start, &stop);

								 tri, edges);

		}

	    }

							 tri, edges);

	} else {

	}

    default: {

	/* dot product of incoming slope vector with outgoing slope vector */

	/* Check the miter limit -- lines meeting at an acute angle

	 * can generate long miters, the limit converts them to bevel

	 *

	 * Consider the miter join formed when two line segments

	 * meet at an angle psi:

	 *

	 *	   /.\

	 *	  /. .\

	 *	 /./ \.\

	 *	/./psi\.\

	 *

	 * We can zoom in on the right half of that to see:

	 *

	 *	    |\

	 *	    | \ psi/2

	 *	    |  \

	 *	    |   \

	 *	    |    \

	 *	    |     \

	 *	  miter    \

	 *	 length     \

	 *	    |        \

	 *	    |        .\

	 *	    |    .     \

	 *	    |.   line   \

	 *	     \    width  \

	 *	      \           \

	 *

	 *

	 * The right triangle in that figure, (the line-width side is

	 * shown faintly with three '.' characters), gives us the

	 * following expression relating miter length, angle and line

	 * width:

	 *

	 *	1 /sin (psi/2) = miter_length / line_width

	 *

	 * The right-hand side of this relationship is the same ratio

	 * in which the miter limit (ml) is expressed. We want to know

	 * when the miter length is within the miter limit. That is

	 * when the following condition holds:

	 *

	 *	1/sin(psi/2) <= ml

	 *	1 <= ml sin(psi/2)

	 *	1 <= ml² sin²(psi/2)

	 *	2 <= ml² 2 sin²(psi/2)

	 *				2·sin²(psi/2) = 1-cos(psi)

	 *	2 <= ml² (1-cos(psi))

	 *

	 *				in · out = |in| |out| cos (psi)

	 *

	 * in and out are both unit vectors, so:

	 *

	 *				in · out = cos (psi)

	 *

	 *	2 <= ml² (1 - in · out)

	 *

	 */

	    double		x1, y1, x2, y2;

	    double		mx, my;

	    double		dx1, dx2, dy1, dy2;

	    cairo_point_t	outer;

	    cairo_point_t	quad[4];

	    double		ix, iy;

	    double		fdx1, fdy1, fdx2, fdy2;

	    double		mdx, mdy;

	    /*

	     * we've got the points already transformed to device

	     * space, but need to do some computation with them and

	     * also need to transform the slope from user space to

	     * device space

	     */

	    /* outer point of incoming line face */

	    /* outer point of outgoing line face */

	    /*

	     * Compute the location of the outer corner of the miter.

	     * That's pretty easy -- just the intersection of the two

	     * outer edges.  We've got slopes and points on each

	     * of those edges.  Compute my directly, then compute

	     * mx by using the edge with the larger dy; that avoids

	     * dividing by values close to zero.

	     */

	    else

	    /*

	     * When the two outer edges are nearly parallel, slight

	     * perturbations in the position of the outer points of the lines

	     * caused by representing them in fixed point form can cause the

	     * intersection point of the miter to move a large amount. If

	     * that moves the miter intersection from between the two faces,

	     * then draw a bevel instead.

	     */

	    /* slope of one face */

	    /* slope of the other face */

	    /* slope from the intersection to the miter point */

	    /*

	     * Make sure the miter point line lies between the two

	     * faces by comparing the slopes

	     */

	    {

		/*

		 * Draw the quadrilateral

		 */

	    }

	}

    }

    /* fall through ... */

    case CAIRO_LINE_JOIN_BEVEL: {

    }

    }

}

static void

{

	int start, stop;

	cairo_slope_t in_slope, out_slope;

	cairo_point_t tri[3], edges[4];

					    &start, &stop);

							 tri, edges);

	}

						     tri, edges);

    }

	double dx, dy;

	cairo_slope_t fvector;

	cairo_point_t quad[4];

    }

    default:

    }

static void

		 cairo_stroke_face_t *face)

{

    cairo_stroke_face_t reversed;

    cairo_point_t t;

    /* The initial cap needs an outward facing vector. Reverse everything */

static void

{

static inline double

{

	} else {

	}

	} else {

	}

    } else {

    }

}

static void

	      const cairo_slope_t *dev_slope,

	      struct stroker *stroker,

	      cairo_stroke_face_t *face)

{

    double face_dx, face_dy;

    cairo_point_t offset_ccw, offset_cw;

    double slope_dx, slope_dy;

    /*

     * rotate to get a line_width/2 vector along the face, note that

     * the vector must be rotated the right direction in device space,

     * but by 90° in user space. So, the rotation depends on

     * whether the ctm reflects or not, and that can be determined

     * by looking at the determinant of the matrix.

     */

	} else {

	}

	/* back to device space */

    } else {

    }

static void

{

    /* check for a degenerative sub_path */

    {

	/* pick an arbitrary slope to use */

	cairo_stroke_face_t face;

	/* arbitrarily choose first_point

	 * first_point and current_point should be the same */

    }

static cairo_bool_t

			 const cairo_stroke_face_t *start,

			 const cairo_stroke_face_t *end)

{

    cairo_box_t box;

}

static void

	      const cairo_point_t *p1, const cairo_point_t *p2,

	      const cairo_slope_t *dev_slope,

	      cairo_stroke_face_t *start, cairo_stroke_face_t *end)

{

    cairo_point_t rectangle[4];

}

static cairo_status_t

{

    /* Cap the start and end of the previous sub path as needed */

}

static cairo_status_t

{

    /* reset the dash pattern for new sub paths */

}

static cairo_status_t

{

    cairo_stroke_face_t start, end;

    cairo_slope_t dev_slope;

	/* Join with final face from previous segment */

	/* Save sub path's first face in case needed for closing join */

    }

}

/*

 * Dashed lines.  Cap each dash end, join around turns when on

 */

static cairo_status_t

{

    double slope_dx, slope_dy;

    double dx2, dy2;

    cairo_stroke_face_t sub_start, sub_end;

    cairo_slope_t dev_slope;

    cairo_line_t segment;

    cairo_bool_t fully_in_bounds;

    {

    }

	{

			  &segment.p1, &segment.p2,

			  &dev_slope,

			  &sub_start, &sub_end);

		/* Join with final face from previous segment */

		/* Save sub path's first face in case needed for closing join */

	    } else {

		/* Cap dash start if not connecting to a previous segment */

	    }

		/* Cap dash end if not at end of segment */

	    } else {

	    }

	} else {

		/* Cap final face from previous segment */

	    }

	}

    }

	/* This segment ends on a transition to dash_on, compute a new face

	 * and add cap for the beginning of the next dash_on step.

	 *

	 * Note: this will create a degenerate cap if this is not the last line

	 * in the path. Whether this behaviour is desirable or not is debatable.

	 * On one side these degenerate caps can not be reproduced with regular

	 * path stroking.

	 * On the other hand, Acroread 7 also produces the degenerate caps.

	 */

    } else

}

static cairo_status_t

	   const cairo_point_t *point,

	   const cairo_slope_t *tangent)

{

};

static cairo_status_t

	   const cairo_point_t *point,

	   const cairo_slope_t *tangent)

{

    cairo_stroke_face_t face;

	cairo_point_t t;

    } else {

	cairo_point_t rectangle[4];

    }

}

static cairo_status_t

	  const cairo_point_t *b,

	  const cairo_point_t *c,

	  const cairo_point_t *d)

{

    cairo_line_join_t line_join_save;

    cairo_spline_t spline;

    cairo_stroke_face_t face;

    cairo_status_t status;

		  stroker, &face);

	/* Join with final face from previous segment */

    } else {

	    /* Save sub path's first face in case needed for closing join */

	}

    }

    /* Temporarily modify the stroker to use round joins to guarantee

     * smooth stroked curves. */

}

static cairo_status_t

		 const cairo_point_t *b,

		 const cairo_point_t *c,

		 const cairo_point_t *d)

{

    cairo_spline_t spline;

    cairo_line_join_t line_join_save;

    cairo_spline_add_point_func_t func;

    cairo_status_t status;

    /* Temporarily modify the stroker to use round joins to guarantee

     * smooth stroked curves. */

}

static cairo_status_t

{

	/* Join first and final faces of sub path */

    } else {

	/* Cap the start and end of the sub path as needed */

    }

}

static cairo_status_t

{

    cairo_status_t status;

}

static cairo_status_t

{

    cairo_status_t status;

}

cairo_int_status_t

				   const cairo_stroke_style_t	*style,

				   const cairo_matrix_t		*ctm,

				   const cairo_matrix_t		*ctm_inverse,

				   double			 tolerance,

				   cairo_traps_t		*traps)

{

    struct stroker stroker;

    cairo_status_t status;

			   ctm, ctm_inverse, tolerance,

			   traps);

					      move_to_dashed,

					      line_to_dashed,

					      curve_to_dashed,

					      close_path_dashed,

					      &stroker);

    else

					      move_to,

					      line_to,

					      curve_to,

					      close_path,

					      &stroker);

}