+++ /dev/null
-/*
- * Copyright (c) 1987, 1988, 1989 Stanford University
- *
- * Permission to use, copy, modify, distribute, and sell this software and its
- * documentation for any purpose is hereby granted without fee, provided
- * that the above copyright notice appear in all copies and that both that
- * copyright notice and this permission notice appear in supporting
- * documentation, and that the name of Stanford not be used in advertising or
- * publicity pertaining to distribution of the software without specific,
- * written prior permission. Stanford makes no representations about
- * the suitability of this software for any purpose. It is provided "as is"
- * without express or implied warranty.
- *
- * STANFORD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
- * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
- * IN NO EVENT SHALL STANFORD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
- * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
- * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
- * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
- * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-/* This code came with the InterViews distribution, and was translated
- from C++ to C by Matthieu Devin <devin@lucid.com> some time in 1992.
- */
-
-#include <stdio.h>
-#include "spline.h"
-#if __STDC__
-#include <stdlib.h>
-#endif
-#include <math.h>
-
-/* Lifted from InterViews */
-#define SMOOTHNESS 1.0
-
-#if __STDC__
-static void no_more_memory (void);
-static void grow_spline_points (spline* s);
-static void mid_point (double x0, double y0, double x1, double y1,
- double *mx, double *my);
-static int can_approx_with_line (double x0, double y0, double x2,
- double y2, double x3, double y3);
-static void add_line (spline* s, double x0, double y0, double x1, double y1);
-static void add_bezier_arc (spline* s,
- double x0, double y0, double x1, double y1,
- double x2, double y2, double x3, double y3);
-static void third_point (double x0, double y0, double x1, double y1,
- double *tx, double *ty);
-static void calc_section (spline* s, double cminus1x, double cminus1y,
- double cx, double cy, double cplus1x, double cplus1y,
- double cplus2x, double cplus2y);
-
-#endif
-
-static void
-no_more_memory ()
-{
- fprintf (stderr, "No more memory\n");
- exit (1);
-}
-
-spline*
-make_spline (size)
- u_int size;
-{
- spline* s = (spline*)calloc (1, sizeof (spline));
- if (!s)
- no_more_memory ();
- s->n_controls = size;
- s->control_x = (double*)calloc (s->n_controls, sizeof (double));
- s->control_y = (double*)calloc (s->n_controls, sizeof (double));
-
- s->n_points = 0;
- s->allocated_points = s->n_controls;
- s->points = (XPoint*)calloc (s->allocated_points, sizeof (XPoint));
-
- if (!s->control_x || !s->control_y || !s->points)
- no_more_memory ();
-
- return s;
-}
-
-static void
-grow_spline_points (s)
- spline* s;
-{
- s->allocated_points *= 2;
- s->points =
- (XPoint*)realloc (s->points, s->allocated_points * sizeof (XPoint));
-
- if (!s->points)
- no_more_memory ();
-}
-
-static void
-mid_point (x0, y0, x1, y1, mx, my)
- double x0, y0, x1, y1, *mx, *my;
-{
- *mx = (x0 + x1) / 2.0;
- *my = (y0 + y1) / 2.0;
-}
-
-static void
-third_point (x0, y0, x1, y1, tx, ty)
- double x0, y0, x1, y1, *tx, *ty;
-{
- *tx = (2 * x0 + x1) / 3.0;
- *ty = (2 * y0 + y1) / 3.0;
-}
-
-static int
-can_approx_with_line (x0, y0, x2, y2, x3, y3)
- double x0, y0, x2, y2, x3, y3;
-{
- double triangle_area, side_squared, dx, dy;
-
- triangle_area = x0 * y2 - x2 * y0 + x2 * y3 - x3 * y2 + x3 * y0 - x0 * y3;
- /* actually 4 times the area. */
- triangle_area *= triangle_area;
- dx = x3 - x0;
- dy = y3 - y0;
- side_squared = dx * dx + dy * dy;
- return triangle_area <= SMOOTHNESS * side_squared;
-}
-
-static void
-add_line (s, x0, y0, x1, y1)
- spline* s;
- double x0, y0, x1, y1;
-{
- if (s->n_points >= s->allocated_points)
- grow_spline_points (s);
-
- if (s->n_points == 0)
- {
- s->points [s->n_points].x = x0;
- s->points [s->n_points].y = y0;
- s->n_points += 1;
- }
- s->points [s->n_points].x = x1;
- s->points [s->n_points].y = y1;
- s->n_points += 1;
-}
-
-static void
-add_bezier_arc (s, x0, y0, x1, y1, x2, y2, x3, y3)
- spline* s;
- double x0, y0, x1, y1, x2, y2, x3, y3;
-{
- double midx01, midx12, midx23, midlsegx, midrsegx, cx,
- midy01, midy12, midy23, midlsegy, midrsegy, cy;
-
- mid_point (x0, y0, x1, y1, &midx01, &midy01);
- mid_point (x1, y1, x2, y2, &midx12, &midy12);
- mid_point (x2, y2, x3, y3, &midx23, &midy23);
- mid_point (midx01, midy01, midx12, midy12, &midlsegx, &midlsegy);
- mid_point (midx12, midy12, midx23, midy23, &midrsegx, &midrsegy);
- mid_point (midlsegx, midlsegy, midrsegx, midrsegy, &cx, &cy);
-
- if (can_approx_with_line (x0, y0, midlsegx, midlsegy, cx, cy))
- add_line (s, x0, y0, cx, cy);
- else if ((midx01 != x1) || (midy01 != y1) || (midlsegx != x2)
- || (midlsegy != y2) || (cx != x3) || (cy != y3))
- add_bezier_arc (s, x0, y0, midx01, midy01, midlsegx, midlsegy, cx, cy);
-
- if (can_approx_with_line (cx, cy, midx23, midy23, x3, y3))
- add_line (s, cx, cy, x3, y3);
- else if ((cx != x0) || (cy != y0) || (midrsegx != x1) || (midrsegy != y1)
- || (midx23 != x2) || (midy23 != y2))
- add_bezier_arc (s, cx, cy, midrsegx, midrsegy, midx23, midy23, x3, y3);
-}
-
-static void
-calc_section (s, cminus1x, cminus1y, cx, cy, cplus1x, cplus1y,
- cplus2x, cplus2y)
- spline* s;
- double cminus1x, cminus1y, cx, cy, cplus1x, cplus1y, cplus2x, cplus2y;
-{
- double p0x, p1x, p2x, p3x, tempx,
- p0y, p1y, p2y, p3y, tempy;
-
- third_point (cx, cy, cplus1x, cplus1y, &p1x, &p1y);
- third_point (cplus1x, cplus1y, cx, cy, &p2x, &p2y);
- third_point (cx, cy, cminus1x, cminus1y, &tempx, &tempy);
- mid_point (tempx, tempy, p1x, p1y, &p0x, &p0y);
- third_point (cplus1x, cplus1y, cplus2x, cplus2y, &tempx, &tempy);
- mid_point (tempx, tempy, p2x, p2y, &p3x, &p3y);
- add_bezier_arc (s, p0x, p0y, p1x, p1y, p2x, p2y, p3x, p3y);
-}
-
-void
-compute_spline (s)
- spline* s;
-{
- int i;
- s->n_points = 0;
-
- if (s->n_controls < 3)
- return;
-
- calc_section (s, s->control_x [0], s->control_y [0], s->control_x [0],
- s->control_y [0], s->control_x [0], s->control_y [0],
- s->control_x [1], s->control_y [1]);
- calc_section (s, s->control_x [0], s->control_y [0], s->control_x [0],
- s->control_y [0], s->control_x [1], s->control_y [1],
- s->control_x [2], s->control_y [2]);
-
- for (i = 1; i < s->n_controls - 2; i++)
- calc_section (s, s->control_x [i - 1], s->control_y [i - 1],
- s->control_x [i], s->control_y [i],
- s->control_x [i + 1], s->control_y [i + 1],
- s->control_x [i + 2], s->control_y [i + 2]);
-
- calc_section (s, s->control_x [i - 1], s->control_y [i - 1],
- s->control_x [i], s->control_y [i],
- s->control_x [i + 1], s->control_y [i + 1],
- s->control_x [i + 1], s->control_y [i + 1]);
- calc_section (s, s->control_x [i], s->control_y [i],
- s->control_x [i + 1], s->control_y [i + 1],
- s->control_x [i + 1], s->control_y [i + 1],
- s->control_x [i + 1], s->control_y [i + 1]);
-}
-
-void
-compute_closed_spline (s)
- spline *s;
-{
- int i;
- s->n_points = 0;
-
- if (s->n_controls < 3)
- return;
-
- calc_section (s,
- s->control_x [s->n_controls - 1],
- s->control_y [s->n_controls - 1],
- s->control_x [0], s->control_y [0],
- s->control_x [1], s->control_y [1],
- s->control_x [2], s->control_y [2]);
-
- for (i = 1; i < s->n_controls - 2; i++)
- calc_section (s, s->control_x [i - 1], s->control_y [i - 1],
- s->control_x [i], s->control_y [i],
- s->control_x [i + 1], s->control_y [i + 1],
- s->control_x [i + 2], s->control_y [i + 2]);
-
- calc_section (s, s->control_x [i - 1], s->control_y [i - 1],
- s->control_x [i], s->control_y [i],
- s->control_x [i + 1], s->control_y [i + 1],
- s->control_x [0], s->control_y [0]);
- calc_section (s, s->control_x [i], s->control_y [i],
- s->control_x [i + 1], s->control_y [i + 1],
- s->control_x [0], s->control_y [0],
- s->control_x [1], s->control_y [1]);
-}
-
-void
-just_fill_spline (s)
- spline *s;
-{
- int i;
-
- while (s->allocated_points < s->n_controls + 1)
- grow_spline_points (s);
-
- for (i = 0; i < s->n_controls; i++)
- {
- s->points [i].x = s->control_x [i];
- s->points [i].y = s->control_y [i];
- }
- s->points [s->n_controls].x = s->control_x [0];
- s->points [s->n_controls].y = s->control_y [0];
- s->n_points = s->n_controls + 1;
-}
-
-void
-append_spline_points (s1, s2)
- spline *s1, *s2;
-{
- int i;
- while (s1->allocated_points < s1->n_points + s2->n_points)
- grow_spline_points (s1);
- for (i = s1->n_points; i < s1->n_points + s2->n_points; i++)
- {
- s1->points [i].x = s2->points [i - s1->n_points].x;
- s1->points [i].y = s2->points [i - s1->n_points].y;
- }
- s1->n_points = s1->n_points + s2->n_points;
-}
-
-void
-spline_bounding_box (s, rectangle_out)
- spline* s;
- XRectangle* rectangle_out;
-{
- int min_x;
- int max_x;
- int min_y;
- int max_y;
- int i;
-
- if (s->n_points == 0)
- {
- rectangle_out->x = 0;
- rectangle_out->y = 0;
- rectangle_out->width = 0;
- rectangle_out->height = 0;
- }
-
- min_x = s->points [0].x;
- max_x = min_x;
- min_y = s->points [0].y;
- max_y = min_y;
-
- for (i = 1; i < s->n_points; i++)
- {
- if (s->points [i].x < min_x)
- min_x = s->points [i].x;
- if (s->points [i].x > max_x)
- max_x = s->points [i].x;
- if (s->points [i].y < min_y)
- min_y = s->points [i].y;
- if (s->points [i].y > max_y)
- max_y = s->points [i].y;
- }
- rectangle_out->x = min_x;
- rectangle_out->y = min_y;
- rectangle_out->width = max_x - min_x;
- rectangle_out->height = max_y - min_y;
-}
projects / xscreensaver / blobdiff