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Diffstat (limited to 'eel/eel-canvas-util.c')
| -rw-r--r-- | eel/eel-canvas-util.c | 426 |
1 files changed, 0 insertions, 426 deletions
diff --git a/eel/eel-canvas-util.c b/eel/eel-canvas-util.c deleted file mode 100644 index 26e2b29e..00000000 --- a/eel/eel-canvas-util.c +++ /dev/null @@ -1,426 +0,0 @@ -/* - * Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation - * All rights reserved. - * - * This file is part of the Mate Library. - * - * The Mate 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. - * - * The Mate 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 the Mate Library; see the file COPYING.LIB. If not, - * write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, - * Boston, MA 02110-1301, USA. - */ -/* - @NOTATION@ - */ -/* Miscellaneous utility functions for the EelCanvas widget - * - * EelCanvas is basically a port of the Tk toolkit's most excellent canvas widget. Tk is - * copyrighted by the Regents of the University of California, Sun Microsystems, and other parties. - * - * - * Author: Federico Mena <[email protected]> - */ - -#include <config.h> - -#include <sys/types.h> -#include <glib.h> -#include <math.h> - -#include "eel-canvas.h" -#include "eel-canvas-util.h" - -/* - * Ok, so some systems require magic incantations for M_PI to be defined. - * It's not important enough to worry about. - */ -#ifndef M_PI -#define M_PI 3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117 -#endif - -/** - * eel_canvas_points_new: - * @num_points: The number of points to allocate space for in the array. - * - * Creates a structure that should be used to pass an array of points to - * items. - * - * Return value: A newly-created array of points. It should be filled in - * by the user. - **/ -EelCanvasPoints * -eel_canvas_points_new (int num_points) -{ - EelCanvasPoints *points; - - g_return_val_if_fail (num_points > 1, NULL); - - points = g_new (EelCanvasPoints, 1); - points->num_points = num_points; - points->coords = g_new (double, 2 * num_points); - points->ref_count = 1; - - return points; -} - -/** - * eel_canvas_points_ref: - * @points: A canvas points structure. - * - * Increases the reference count of the specified points structure. - * - * Return value: The canvas points structure itself. - **/ -EelCanvasPoints * -eel_canvas_points_ref (EelCanvasPoints *points) -{ - g_return_val_if_fail (points != NULL, NULL); - - points->ref_count += 1; - return points; -} - -/** - * eel_canvas_points_free: - * @points: A canvas points structure. - * - * Decreases the reference count of the specified points structure. If it - * reaches zero, then the structure is freed. - **/ -void -eel_canvas_points_free (EelCanvasPoints *points) -{ - g_return_if_fail (points != NULL); - - points->ref_count -= 1; - if (points->ref_count == 0) - { - g_free (points->coords); - g_free (points); - } -} - -/** - * eel_canvas_get_miter_points: - * @x1: X coordinate of the first point - * @y1: Y coordinate of the first point - * @x2: X coordinate of the second (angle) point - * @y2: Y coordinate of the second (angle) point - * @x3: X coordinate of the third point - * @y3: Y coordinate of the third point - * @width: Width of the line - * @mx1: The X coordinate of the first miter point is returned here. - * @my1: The Y coordinate of the first miter point is returned here. - * @mx2: The X coordinate of the second miter point is returned here. - * @my2: The Y coordinate of the second miter point is returned here. - * - * Given three points forming an angle, computes the coordinates of the inside - * and outside points of the mitered corner formed by a line of a given width at - * that angle. - * - * Return value: FALSE if the angle is less than 11 degrees (this is the same - * threshold as X uses. If this occurs, the return points are not modified. - * Otherwise, returns TRUE. - **/ -int -eel_canvas_get_miter_points (double x1, double y1, double x2, double y2, double x3, double y3, - double width, - double *mx1, double *my1, double *mx2, double *my2) -{ - double theta1; /* angle of segment p2-p1 */ - double theta2; /* angle of segment p2-p3 */ - double theta; /* angle between line segments */ - double theta3; /* angle that bisects theta1 and theta2 and points to p1 */ - double dist; /* distance of miter points from p2 */ - double dx, dy; /* x and y offsets corresponding to dist */ - - double ELEVEN_DEGREES = 11.0 * M_PI / 180.0; - - /* Degenerate cases. */ - if ((x1 == x2 && y1 == y2) || (x2 == x3 && y2 == y3)) - return FALSE; - - theta1 = atan2 (y1 - y2, x1 - x2); - theta2 = atan2 (y3 - y2, x3 - x2); - theta = theta1 - theta2; - - /* Normalize to (-pi; pi]. */ - if (theta > M_PI) - theta -= 2.0 * M_PI; - else if (theta <= -M_PI) - theta += 2.0 * M_PI; - - if (fabs (theta) < ELEVEN_DEGREES) - return FALSE; - - dist = fabs (0.5 * width / sin (0.5 * theta)); - - theta3 = (theta1 + theta2) / 2.0; - if (sin (theta3 - theta1) > 0.0) - theta3 += M_PI; - - dx = dist * cos (theta3); - dy = dist * sin (theta3); - - *mx1 = x2 + dx; - *mx2 = x2 - dx; - *my1 = y2 + dy; - *my2 = y2 - dy; - - return TRUE; -} - -/** - * eel_canvas_get_butt_points: - * @x1: X coordinate of first point in the line - * @y1: Y cooordinate of first point in the line - * @x2: X coordinate of second point (endpoint) of the line - * @y2: Y coordinate of second point (endpoint) of the line - * @width: Width of the line - * @project: Whether the butt points should project out by width/2 distance - * @bx1: X coordinate of first butt point is returned here - * @by1: Y coordinate of first butt point is returned here - * @bx2: X coordinate of second butt point is returned here - * @by2: Y coordinate of second butt point is returned here - * - * Computes the butt points of a line segment. - **/ -void -eel_canvas_get_butt_points (double x1, double y1, double x2, double y2, - double width, int project, - double *bx1, double *by1, double *bx2, double *by2) -{ - double length; - double dx, dy; - - width *= 0.5; - dx = x2 - x1; - dy = y2 - y1; - length = sqrt (dx * dx + dy * dy); - - if (length < EEL_CANVAS_EPSILON) - { - *bx1 = *bx2 = x2; - *by1 = *by2 = y2; - } - else - { - dx = -width * (y2 - y1) / length; - dy = width * (x2 - x1) / length; - - *bx1 = x2 + dx; - *bx2 = x2 - dx; - *by1 = y2 + dy; - *by2 = y2 - dy; - - if (project) - { - *bx1 += dy; - *bx2 += dy; - *by1 -= dx; - *by2 -= dx; - } - } -} - -/** - * eel_canvas_polygon_to_point: - * @poly: Vertices of the polygon. X coordinates are in the even indices, and Y - * coordinates are in the odd indices - * @num_points: Number of points in the polygon - * @x: X coordinate of the point - * @y: Y coordinate of the point - * - * Computes the distance between a point and a polygon. - * - * Return value: The distance from the point to the polygon, or zero if the - * point is inside the polygon. - **/ -double -eel_canvas_polygon_to_point (double *poly, int num_points, double x, double y) -{ - double best; - int intersections; - int i; - double *p; - double dx, dy; - - /* Iterate through all the edges in the polygon, updating best and intersections. - * - * When computing intersections, include left X coordinate of line within its range, but not - * Y coordinate. Otherwise if the point lies exactly below a vertex we'll count it as two - * intersections. - */ - - best = 1.0e36; - if (poly == NULL) - return best; - - intersections = 0; - - for (i = num_points, p = poly; i > 1; i--, p += 2) - { - double px, py, dist; - - /* Compute the point on the current edge closest to the point and update the - * intersection count. This must be done separately for vertical edges, horizontal - * edges, and others. - */ - - if (p[2] == p[0]) - { - /* Vertical edge */ - - px = p[0]; - - if (p[1] >= p[3]) - { - py = MIN (p[1], y); - py = MAX (py, p[3]); - } - else - { - py = MIN (p[3], y); - py = MAX (py, p[1]); - } - } - else if (p[3] == p[1]) - { - /* Horizontal edge */ - - py = p[1]; - - if (p[0] >= p[2]) - { - px = MIN (p[0], x); - px = MAX (px, p[2]); - - if ((y < py) && (x < p[0]) && (x >= p[2])) - intersections++; - } - else - { - px = MIN (p[2], x); - px = MAX (px, p[0]); - - if ((y < py) && (x < p[2]) && (x >= p[0])) - intersections++; - } - } - else - { - double m1, b1, m2, b2; - int lower; - - /* Diagonal edge. Convert the edge to a line equation (y = m1*x + b1), then - * compute a line perpendicular to this edge but passing through the point, - * (y = m2*x + b2). - */ - - m1 = (p[3] - p[1]) / (p[2] - p[0]); - b1 = p[1] - m1 * p[0]; - - m2 = -1.0 / m1; - b2 = y - m2 * x; - - px = (b2 - b1) / (m1 - m2); - py = m1 * px + b1; - - if (p[0] > p[2]) - { - if (px > p[0]) - { - px = p[0]; - py = p[1]; - } - else if (px < p[2]) - { - px = p[2]; - py = p[3]; - } - } - else - { - if (px > p[2]) - { - px = p[2]; - py = p[3]; - } - else if (px < p[0]) - { - px = p[0]; - py = p[1]; - } - } - - lower = (m1 * x + b1) > y; - - if (lower && (x >= MIN (p[0], p[2])) && (x < MAX (p[0], p[2]))) - intersections++; - } - - /* Compute the distance to the closest point, and see if that is the best so far */ - - dx = x - px; - dy = y - py; - dist = sqrt (dx * dx + dy * dy); - if (dist < best) - best = dist; - } - - /* We've processed all the points. If the number of intersections is odd, the point is - * inside the polygon. - */ - - if (intersections & 0x1) - return 0.0; - else - return best; -} - -/** - * eel_canvas_item_reset_bounds: - * @item: A canvas item - * - * Resets the bounding box of a canvas item to an empty rectangle. - **/ -void -eel_canvas_item_reset_bounds (EelCanvasItem *item) -{ - item->x1 = 0.0; - item->y1 = 0.0; - item->x2 = 0.0; - item->y2 = 0.0; -} - -/** - * eel_canvas_update_bbox: - * @canvas: the canvas needing update - * @x1: Left coordinate of the new bounding box - * @y1: Top coordinate of the new bounding box - * @x2: Right coordinate of the new bounding box - * @y2: Bottom coordinate of the new bounding box - * - * Sets the bbox to the new value, requesting full repaint. - **/ -void -eel_canvas_update_bbox (EelCanvasItem *item, int x1, int y1, int x2, int y2) -{ - eel_canvas_item_request_redraw (item); - item->x1 = x1; - item->y1 = y1; - item->x2 = x2; - item->y2 = y2; - eel_canvas_item_request_redraw (item); -} - |