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author | Matthew Barnes <mbarnes@redhat.com> | 2010-06-14 06:37:27 +0800 |
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committer | Matthew Barnes <mbarnes@redhat.com> | 2010-06-14 09:31:58 +0800 |
commit | e6972011f01eab9f8d0a4584f32ee1e2a00f3231 (patch) | |
tree | 69e2a5e846965c3b369724b825f5b35c6d88056a /libgnomecanvas/gnome-canvas-util.c | |
parent | 7f3377c78a560aa762e04d596b79f847c4acd870 (diff) | |
download | gsoc2013-evolution-e6972011f01eab9f8d0a4584f32ee1e2a00f3231.tar.gz gsoc2013-evolution-e6972011f01eab9f8d0a4584f32ee1e2a00f3231.tar.zst gsoc2013-evolution-e6972011f01eab9f8d0a4584f32ee1e2a00f3231.zip |
Embed libart_lgpl and libgnomecanvas.
Both of these modules are deprecated and going away in GNOME 3 but we
still rely heavily on them for GnomeCalendar and ETable. So, welcome
to the island of unwanted libraries...
Diffstat (limited to 'libgnomecanvas/gnome-canvas-util.c')
-rw-r--r-- | libgnomecanvas/gnome-canvas-util.c | 700 |
1 files changed, 700 insertions, 0 deletions
diff --git a/libgnomecanvas/gnome-canvas-util.c b/libgnomecanvas/gnome-canvas-util.c new file mode 100644 index 0000000000..d306292144 --- /dev/null +++ b/libgnomecanvas/gnome-canvas-util.c @@ -0,0 +1,700 @@ +/* + * Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation + * All rights reserved. + * + * This file is part of the Gnome Library. + * + * The Gnome 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 Gnome 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 Gnome Library; see the file COPYING.LIB. If not, + * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ +/* + @NOTATION@ + */ +/* Miscellaneous utility functions for the GnomeCanvas widget + * + * GnomeCanvas 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 <federico@nuclecu.unam.mx> + */ + +#include <config.h> + +/* needed for M_PI_2 under 'gcc -ansi -predantic' on GNU/Linux */ +#ifndef _BSD_SOURCE +# define _BSD_SOURCE 1 +#endif +#include <sys/types.h> + +#include <glib.h> +#include <math.h> +#include "gnome-canvas.h" +#include "gnome-canvas-util.h" +#include <libart_lgpl/art_uta.h> +#include <libart_lgpl/art_svp.h> +#include <libart_lgpl/art_svp_ops.h> +#include <libart_lgpl/art_rgb.h> +#include <libart_lgpl/art_rgb_svp.h> +#include <libart_lgpl/art_uta_svp.h> +#include <libart_lgpl/art_rect_svp.h> + +/** + * gnome_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. + **/ +GnomeCanvasPoints * +gnome_canvas_points_new (int num_points) +{ + GnomeCanvasPoints *points; + + g_return_val_if_fail (num_points > 1, NULL); + + points = g_new (GnomeCanvasPoints, 1); + points->num_points = num_points; + points->coords = g_new (double, 2 * num_points); + points->ref_count = 1; + + return points; +} + +/** + * gnome_canvas_points_ref: + * @points: A canvas points structure. + * + * Increases the reference count of the specified points structure. + * + * Return value: The canvas points structure itself. + **/ +GnomeCanvasPoints * +gnome_canvas_points_ref (GnomeCanvasPoints *points) +{ + g_return_val_if_fail (points != NULL, NULL); + + points->ref_count += 1; + return points; +} + +/** + * gnome_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 +gnome_canvas_points_free (GnomeCanvasPoints *points) +{ + g_return_if_fail (points != NULL); + + points->ref_count -= 1; + if (points->ref_count == 0) { + g_free (points->coords); + g_free (points); + } +} + +/** + * gnome_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 +gnome_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 */ + +#define ELEVEN_DEGREES (11.0 * G_PI / 180.0) + + if (y2 == y1) + theta1 = (x2 < x1) ? 0.0 : G_PI; + else if (x2 == x1) + theta1 = (y2 < y1) ? G_PI_2 : -G_PI_2; + else + theta1 = atan2 (y1 - y2, x1 - x2); + + if (y3 == y2) + theta2 = (x3 > x2) ? 0 : G_PI; + else if (x3 == x2) + theta2 = (y3 > y2) ? G_PI_2 : -G_PI_2; + else + theta2 = atan2 (y3 - y2, x3 - x2); + + theta = theta1 - theta2; + + if (theta > G_PI) + theta -= 2.0 * G_PI; + else if (theta < -G_PI) + theta += 2.0 * G_PI; + + if ((theta < ELEVEN_DEGREES) && (theta > -ELEVEN_DEGREES)) + return FALSE; + + dist = 0.5 * width / sin (0.5 * theta); + if (dist < 0.0) + dist = -dist; + + theta3 = (theta1 + theta2) / 2.0; + if (sin (theta3 - (theta1 + G_PI)) < 0.0) + theta3 += G_PI; + + dx = dist * cos (theta3); + dy = dist * sin (theta3); + + *mx1 = x2 + dx; + *mx2 = x2 - dx; + *my1 = y2 + dy; + *my2 = y2 - dy; + + return TRUE; +} + +/** + * gnome_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 +gnome_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 < GNOME_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; + } + } +} + +/** + * gnome_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 +gnome_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; + 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; +} + +/* Here are some helper functions for aa rendering: */ + +/** + * gnome_canvas_render_svp: + * @buf: the canvas buffer to render over + * @svp: the vector path to render + * @rgba: the rgba color to render + * + * Render the svp over the buf. + **/ +void +gnome_canvas_render_svp (GnomeCanvasBuf *buf, ArtSVP *svp, guint32 rgba) +{ + guint32 fg_color, bg_color; + int alpha; + + if (buf->is_bg) { + bg_color = buf->bg_color; + alpha = rgba & 0xff; + if (alpha == 0xff) + fg_color = rgba >> 8; + else { + /* composite over background color */ + int bg_r, bg_g, bg_b; + int fg_r, fg_g, fg_b; + int tmp; + + bg_r = (bg_color >> 16) & 0xff; + fg_r = (rgba >> 24) & 0xff; + tmp = (fg_r - bg_r) * alpha; + fg_r = bg_r + ((tmp + (tmp >> 8) + 0x80) >> 8); + + bg_g = (bg_color >> 8) & 0xff; + fg_g = (rgba >> 16) & 0xff; + tmp = (fg_g - bg_g) * alpha; + fg_g = bg_g + ((tmp + (tmp >> 8) + 0x80) >> 8); + + bg_b = bg_color & 0xff; + fg_b = (rgba >> 8) & 0xff; + tmp = (fg_b - bg_b) * alpha; + fg_b = bg_b + ((tmp + (tmp >> 8) + 0x80) >> 8); + + fg_color = (fg_r << 16) | (fg_g << 8) | fg_b; + } + art_rgb_svp_aa (svp, + buf->rect.x0, buf->rect.y0, buf->rect.x1, buf->rect.y1, + fg_color, bg_color, + buf->buf, buf->buf_rowstride, + NULL); + buf->is_bg = 0; + buf->is_buf = 1; + } else { + art_rgb_svp_alpha (svp, + buf->rect.x0, buf->rect.y0, buf->rect.x1, buf->rect.y1, + rgba, + buf->buf, buf->buf_rowstride, + NULL); + } +} + +/** + * gnome_canvas_update_svp: + * @canvas: the canvas containing the svp that needs updating. + * @p_svp: a pointer to the existing svp + * @new_svp: the new svp + * + * Sets the svp to the new value, requesting repaint on what's changed. This + * function takes responsibility for freeing new_svp. + **/ +void +gnome_canvas_update_svp (GnomeCanvas *canvas, ArtSVP **p_svp, ArtSVP *new_svp) +{ + ArtSVP *old_svp; + ArtSVP *diff G_GNUC_UNUSED; + ArtUta *repaint_uta; + + old_svp = *p_svp; + + if (old_svp != NULL) { + ArtDRect bb; + art_drect_svp (&bb, old_svp); + if ((bb.x1 - bb.x0) * (bb.y1 - bb.y0) > (64 * 64)) { + repaint_uta = art_uta_from_svp (old_svp); + gnome_canvas_request_redraw_uta (canvas, repaint_uta); + } else { + ArtIRect ib; + art_drect_to_irect (&ib, &bb); + gnome_canvas_request_redraw (canvas, ib.x0, ib.y0, ib.x1, ib.y1); + } + art_svp_free (old_svp); + } + + if (new_svp != NULL) { + ArtDRect bb; + art_drect_svp (&bb, new_svp); + if ((bb.x1 - bb.x0) * (bb.y1 - bb.y0) > (64 * 64)) { + repaint_uta = art_uta_from_svp (new_svp); + gnome_canvas_request_redraw_uta (canvas, repaint_uta); + } else { + ArtIRect ib; + art_drect_to_irect (&ib, &bb); + gnome_canvas_request_redraw (canvas, ib.x0, ib.y0, ib.x1, ib.y1); + } + } + + *p_svp = new_svp; +} + +/** + * gnome_canvas_update_svp_clip: + * @canvas: the canvas containing the svp that needs updating. + * @p_svp: a pointer to the existing svp + * @new_svp: the new svp + * @clip_svp: a clip path, if non-null + * + * Sets the svp to the new value, clipping if necessary, and requesting repaint + * on what's changed. This function takes responsibility for freeing new_svp. + **/ +void +gnome_canvas_update_svp_clip (GnomeCanvas *canvas, ArtSVP **p_svp, ArtSVP *new_svp, ArtSVP *clip_svp) +{ + ArtSVP *clipped_svp; + + if (clip_svp != NULL) { + clipped_svp = art_svp_intersect (new_svp, clip_svp); + art_svp_free (new_svp); + } else { + clipped_svp = new_svp; + } + gnome_canvas_update_svp (canvas, p_svp, clipped_svp); +} + +/** + * gnome_canvas_item_reset_bounds: + * @item: A canvas item + * + * Resets the bounding box of a canvas item to an empty rectangle. + **/ +void +gnome_canvas_item_reset_bounds (GnomeCanvasItem *item) +{ + item->x1 = 0.0; + item->y1 = 0.0; + item->x2 = 0.0; + item->y2 = 0.0; +} + +/** + * gnome_canvas_item_update_svp: + * @item: the canvas item containing the svp that needs updating. + * @p_svp: a pointer to the existing svp + * @new_svp: the new svp + * + * Sets the svp to the new value, requesting repaint on what's changed. This + * function takes responsibility for freeing new_svp. This routine also adds the + * svp's bbox to the item's. + **/ +void +gnome_canvas_item_update_svp (GnomeCanvasItem *item, ArtSVP **p_svp, ArtSVP *new_svp) +{ + ArtDRect bbox; + + gnome_canvas_update_svp (item->canvas, p_svp, new_svp); + if (new_svp) { + bbox.x0 = item->x1; + bbox.y0 = item->y1; + bbox.x1 = item->x2; + bbox.y1 = item->y2; + art_drect_svp_union (&bbox, new_svp); + item->x1 = bbox.x0; + item->y1 = bbox.y0; + item->x2 = bbox.x1; + item->y2 = bbox.y1; + } +} + +/** + * gnome_canvas_item_update_svp_clip: + * @item: the canvas item containing the svp that needs updating. + * @p_svp: a pointer to the existing svp + * @new_svp: the new svp + * @clip_svp: a clip path, if non-null + * + * Sets the svp to the new value, clipping if necessary, and requesting repaint + * on what's changed. This function takes responsibility for freeing new_svp. + **/ +void +gnome_canvas_item_update_svp_clip (GnomeCanvasItem *item, ArtSVP **p_svp, ArtSVP *new_svp, + ArtSVP *clip_svp) +{ + ArtSVP *clipped_svp; + + if (clip_svp != NULL) { + clipped_svp = art_svp_intersect (new_svp, clip_svp); + art_svp_free (new_svp); + } else { + clipped_svp = new_svp; + } + + gnome_canvas_item_update_svp (item, p_svp, clipped_svp); +} + +/** + * gnome_canvas_item_request_redraw_svp + * @item: the item containing the svp + * @svp: the svp that needs to be redrawn + * + * Request redraw of the svp if in aa mode, or the entire item in in xlib mode. + **/ +void +gnome_canvas_item_request_redraw_svp (GnomeCanvasItem *item, const ArtSVP *svp) +{ + GnomeCanvas *canvas; + ArtUta *uta; + + canvas = item->canvas; + if (canvas->aa) { + if (svp != NULL) { + uta = art_uta_from_svp (svp); + gnome_canvas_request_redraw_uta (canvas, uta); + } + } else { + gnome_canvas_request_redraw (canvas, item->x1, item->y1, item->x2, item->y2); + } +} + +/** + * gnome_canvas_update_bbox: + * @item: the canvas item 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 +gnome_canvas_update_bbox (GnomeCanvasItem *item, int x1, int y1, int x2, int y2) +{ + gnome_canvas_request_redraw (item->canvas, item->x1, item->y1, item->x2, item->y2); + item->x1 = x1; + item->y1 = y1; + item->x2 = x2; + item->y2 = y2; + gnome_canvas_request_redraw (item->canvas, item->x1, item->y1, item->x2, item->y2); +} + +/** + * gnome_canvas_buf_ensure_buf: + * @buf: the buf that needs to be represened in RGB format + * + * Ensure that the buffer is in RGB format, suitable for compositing. + **/ +void +gnome_canvas_buf_ensure_buf (GnomeCanvasBuf *buf) +{ + guchar *bufptr; + int y; + + if (!buf->is_buf) { + bufptr = buf->buf; + for (y = buf->rect.y0; y < buf->rect.y1; y++) { + art_rgb_fill_run (bufptr, + buf->bg_color >> 16, + (buf->bg_color >> 8) & 0xff, + buf->bg_color & 0xff, + buf->rect.x1 - buf->rect.x0); + bufptr += buf->buf_rowstride; + } + buf->is_buf = 1; + } +} + +/** + * gnome_canvas_join_gdk_to_art + * @gdk_join: a join type, represented in GDK format + * + * Convert from GDK line join specifier to libart. + * + * Return value: The line join specifier in libart format. + **/ +ArtPathStrokeJoinType +gnome_canvas_join_gdk_to_art (GdkJoinStyle gdk_join) +{ + switch (gdk_join) { + case GDK_JOIN_MITER: + return ART_PATH_STROKE_JOIN_MITER; + + case GDK_JOIN_ROUND: + return ART_PATH_STROKE_JOIN_ROUND; + + case GDK_JOIN_BEVEL: + return ART_PATH_STROKE_JOIN_BEVEL; + + default: + g_assert_not_reached (); + return ART_PATH_STROKE_JOIN_MITER; /* shut up the compiler */ + } +} + +/** + * gnome_canvas_cap_gdk_to_art + * @gdk_cap: a cap type, represented in GDK format + * + * Convert from GDK line cap specifier to libart. + * + * Return value: The line cap specifier in libart format. + **/ +ArtPathStrokeCapType +gnome_canvas_cap_gdk_to_art (GdkCapStyle gdk_cap) +{ + switch (gdk_cap) { + case GDK_CAP_BUTT: + case GDK_CAP_NOT_LAST: + return ART_PATH_STROKE_CAP_BUTT; + + case GDK_CAP_ROUND: + return ART_PATH_STROKE_CAP_ROUND; + + case GDK_CAP_PROJECTING: + return ART_PATH_STROKE_CAP_SQUARE; + + default: + g_assert_not_reached (); + return ART_PATH_STROKE_CAP_BUTT; /* shut up the compiler */ + } +} |