+++ /dev/null
-/* Libart_LGPL - library of basic graphic primitives
- * Copyright (C) 1998-2000 Raph Levien
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
- */
-
-/* Basic constructors and operations for vector paths */
-
-#include <math.h>
-#include <stdlib.h>
-
-#include "art_misc.h"
-
-#include "art_rect.h"
-#include "art_vpath.h"
-
-/**
- * art_vpath_add_point: Add point to vpath.
- * @p_vpath: Where the pointer to the #ArtVpath structure is stored.
- * @pn_points: Pointer to the number of points in *@p_vpath.
- * @pn_points_max: Pointer to the number of points allocated.
- * @code: The pathcode for the new point.
- * @x: The X coordinate of the new point.
- * @y: The Y coordinate of the new point.
- *
- * Adds a new point to *@p_vpath, reallocating and updating *@p_vpath
- * and *@pn_points_max as necessary. *@pn_points is incremented.
- *
- * This routine always adds the point after all points already in the
- * vpath. Thus, it should be called in the order the points are
- * desired.
- **/
-void
-art_vpath_add_point (ArtVpath **p_vpath, int *pn_points, int *pn_points_max,
- ArtPathcode code, double x, double y)
-{
- int i;
-
- i = (*pn_points)++;
- if (i == *pn_points_max)
- art_expand (*p_vpath, ArtVpath, *pn_points_max);
- (*p_vpath)[i].code = code;
- (*p_vpath)[i].x = x;
- (*p_vpath)[i].y = y;
-}
-
-/* number of steps should really depend on radius. */
-#define CIRCLE_STEPS 128
-
-/**
- * art_vpath_new_circle: Create a new circle.
- * @x: X coordinate of center.
- * @y: Y coordinate of center.
- * @r: radius.
- *
- * Creates a new polygon closely approximating a circle with center
- * (@x, @y) and radius @r. Currently, the number of points used in the
- * approximation is fixed, but that will probably change.
- *
- * Return value: The newly created #ArtVpath.
- **/
-ArtVpath *
-art_vpath_new_circle (double x, double y, double r)
-{
- int i;
- ArtVpath *vec;
- double theta;
-
- vec = art_new (ArtVpath, CIRCLE_STEPS + 2);
-
- for (i = 0; i < CIRCLE_STEPS + 1; i++)
- {
- vec[i].code = i ? ART_LINETO : ART_MOVETO;
- theta = (i & (CIRCLE_STEPS - 1)) * (M_PI * 2.0 / CIRCLE_STEPS);
- vec[i].x = x + r * cos (theta);
- vec[i].y = y - r * sin (theta);
- }
- vec[i].code = ART_END;
-
- return vec;
-}
-
-/**
- * art_vpath_affine_transform: Affine transform a vpath.
- * @src: Source vpath to transform.
- * @matrix: Affine transform.
- *
- * Computes the affine transform of the vpath, using @matrix as the
- * transform. @matrix is stored in the same format as PostScript, ie.
- * x' = @matrix[0] * x + @matrix[2] * y + @matrix[4]
- * y' = @matrix[1] * x + @matrix[3] * y + @matrix[5]
- *
- * Return value: the newly allocated vpath resulting from the transform.
-**/
-ArtVpath *
-art_vpath_affine_transform (const ArtVpath *src, const double matrix[6])
-{
- int i;
- int size;
- ArtVpath *new;
- double x, y;
-
- for (i = 0; src[i].code != ART_END; i++);
- size = i;
-
- new = art_new (ArtVpath, size + 1);
-
- for (i = 0; i < size; i++)
- {
- new[i].code = src[i].code;
- x = src[i].x;
- y = src[i].y;
- new[i].x = matrix[0] * x + matrix[2] * y + matrix[4];
- new[i].y = matrix[1] * x + matrix[3] * y + matrix[5];
- }
- new[i].code = ART_END;
-
- return new;
-}
-
-/**
- * art_vpath_bbox_drect: Determine bounding box of vpath.
- * @vec: Source vpath.
- * @drect: Where to store bounding box.
- *
- * Determines bounding box of @vec, and stores it in @drect.
- **/
-void
-art_vpath_bbox_drect (const ArtVpath *vec, ArtDRect *drect)
-{
- int i;
- double x0, y0, x1, y1;
-
- if (vec[0].code == ART_END)
- {
- x0 = y0 = x1 = y1 = 0;
- }
- else
- {
- x0 = x1 = vec[0].x;
- y0 = y1 = vec[0].y;
- for (i = 1; vec[i].code != ART_END; i++)
- {
- if (vec[i].x < x0) x0 = vec[i].x;
- if (vec[i].x > x1) x1 = vec[i].x;
- if (vec[i].y < y0) y0 = vec[i].y;
- if (vec[i].y > y1) y1 = vec[i].y;
- }
- }
- drect->x0 = x0;
- drect->y0 = y0;
- drect->x1 = x1;
- drect->y1 = y1;
-}
-
-/**
- * art_vpath_bbox_irect: Determine integer bounding box of vpath.
- * @vec: Source vpath.
- * idrect: Where to store bounding box.
- *
- * Determines integer bounding box of @vec, and stores it in @irect.
- **/
-void
-art_vpath_bbox_irect (const ArtVpath *vec, ArtIRect *irect)
-{
- ArtDRect drect;
-
- art_vpath_bbox_drect (vec, &drect);
- art_drect_to_irect (irect, &drect);
-}
-
-#define PERTURBATION 2e-3
-
-/**
- * art_vpath_perturb: Perturb each point in vpath by small random amount.
- * @src: Source vpath.
- *
- * Perturbs each of the points by a small random amount. This is
- * helpful for cheating in cases when algorithms haven't attained
- * numerical stability yet.
- *
- * Return value: Newly allocated vpath containing perturbed @src.
- **/
-ArtVpath *
-art_vpath_perturb (ArtVpath *src)
-{
- int i;
- int size;
- ArtVpath *new;
- double x, y;
- double x_start, y_start;
- int open;
-
- for (i = 0; src[i].code != ART_END; i++);
- size = i;
-
- new = art_new (ArtVpath, size + 1);
-
- x_start = 0;
- y_start = 0;
- open = 0;
- for (i = 0; i < size; i++)
- {
- new[i].code = src[i].code;
- x = src[i].x + (PERTURBATION * rand ()) / RAND_MAX - PERTURBATION * 0.5;
- y = src[i].y + (PERTURBATION * rand ()) / RAND_MAX - PERTURBATION * 0.5;
- if (src[i].code == ART_MOVETO)
- {
- x_start = x;
- y_start = y;
- open = 0;
- }
- else if (src[i].code == ART_MOVETO_OPEN)
- open = 1;
- if (!open && (i + 1 == size || src[i + 1].code != ART_LINETO))
- {
- x = x_start;
- y = y_start;
- }
- new[i].x = x;
- new[i].y = y;
- }
- new[i].code = ART_END;
-
- return new;
-}
projects / rrdtool.git / blobdiff