// SPDX-License-Identifier: GPL-2.0-or-later /* * Horizontal/vertical but can also be angled line * * Authors: * Lauris Kaplinski * Johan Engelen * Maximilian Albert * Jon A. Cruz * * Copyright (C) 2000-2002 Lauris Kaplinski * Copyright (C) 2007 Johan Engelen * Copyright (C) 2009 Maximilian Albert * Copyright (C) 2017 Tavmjong Bah * * Released under GNU GPL v2+, read the file 'COPYING' for more information. */ #include <2geom/coord.h> #include <2geom/transforms.h> #include <2geom/line.h> #include "sp-canvas-util.h" #include "inkscape.h" #include "guideline.h" #include "display/cairo-utils.h" #include "display/sp-canvas.h" #include "display/sodipodi-ctrl.h" #include "object/sp-namedview.h" static void sp_guideline_destroy(SPCanvasItem *object); static void sp_guideline_update(SPCanvasItem *item, Geom::Affine const &affine, unsigned int flags); static void sp_guideline_render(SPCanvasItem *item, SPCanvasBuf *buf); static double sp_guideline_point(SPCanvasItem *item, Geom::Point p, SPCanvasItem **actual_item); G_DEFINE_TYPE(SPGuideLine, sp_guideline, SP_TYPE_CANVAS_ITEM); static void sp_guideline_class_init(SPGuideLineClass *c) { SPCanvasItemClass *item_class = SP_CANVAS_ITEM_CLASS(c); item_class->destroy = sp_guideline_destroy; item_class->update = sp_guideline_update; item_class->render = sp_guideline_render; item_class->point = sp_guideline_point; } static void sp_guideline_init(SPGuideLine *gl) { gl->rgba = 0x0000ff7f; gl->locked = false; gl->normal_to_line = Geom::Point(0,1); gl->angle = M_PI_2; gl->point_on_line = Geom::Point(0,0); gl->sensitive = 0; gl->origin = nullptr; gl->label = nullptr; } static void sp_guideline_destroy(SPCanvasItem *object) { g_return_if_fail (object != nullptr); g_return_if_fail (SP_IS_GUIDELINE (object)); SPGuideLine *gl = SP_GUIDELINE(object); if (gl->origin) { sp_canvas_item_destroy(SP_CANVAS_ITEM(gl->origin)); } if (gl->label) { g_free(gl->label); } SP_CANVAS_ITEM_CLASS(sp_guideline_parent_class)->destroy(object); } static void sp_guideline_render(SPCanvasItem *item, SPCanvasBuf *buf) { SPGuideLine const *gl = SP_GUIDELINE (item); cairo_save(buf->ct); cairo_translate(buf->ct, -buf->rect.left(), -buf->rect.top()); Inkscape::Preferences *prefs = Inkscape::Preferences::get(); bool xrayactive = prefs->getBool("/desktop/xrayactive", false); SPDesktop * desktop = SP_ACTIVE_DESKTOP; if (xrayactive && desktop) { guint32 bg = desktop->getNamedView()->pagecolor; guint32 _color = SP_RGBA32_F_COMPOSE( CLAMP(((1 - SP_RGBA32_A_F(gl->rgba)) * SP_RGBA32_R_F(bg)) + (SP_RGBA32_A_F(gl->rgba) * SP_RGBA32_R_F(gl->rgba)), 0.0, 1.0), CLAMP(((1 - SP_RGBA32_A_F(gl->rgba)) * SP_RGBA32_G_F(bg)) + (SP_RGBA32_A_F(gl->rgba) * SP_RGBA32_G_F(gl->rgba)), 0.0, 1.0), CLAMP(((1 - SP_RGBA32_A_F(gl->rgba)) * SP_RGBA32_B_F(bg)) + (SP_RGBA32_A_F(gl->rgba) * SP_RGBA32_B_F(gl->rgba)), 0.0, 1.0), 1.0); ink_cairo_set_source_rgba32(buf->ct, _color); } else { ink_cairo_set_source_rgba32(buf->ct, gl->rgba); } cairo_set_line_width(buf->ct, 1); cairo_set_line_cap(buf->ct, CAIRO_LINE_CAP_SQUARE); cairo_set_font_size(buf->ct, 10); // normal_dt does not have unit length Geom::Point normal_dt = gl->normal_to_line * gl->affine.withoutTranslation(); Geom::Point point_on_line_dt = gl->point_on_line * gl->affine; if (gl->label) { int px = round(point_on_line_dt[Geom::X]); int py = round(point_on_line_dt[Geom::Y]); cairo_save(buf->ct); cairo_translate(buf->ct, px, py); cairo_rotate(buf->ct, atan2(normal_dt.cw()) + M_PI * (desktop && desktop->is_yaxisdown() ? 1 : 0)); cairo_translate(buf->ct, 0, -5); cairo_move_to(buf->ct, 0, 0); cairo_show_text(buf->ct, gl->label); cairo_restore(buf->ct); } // Draw guide. // Special case horizontal and vertical lines so they accurately align to the to pixels. // Need to use floor()+0.5 such that Cairo will draw us lines with a width of a single pixel, without any aliasing. // For this we need to position the lines at exactly half pixels, see https://www.cairographics.org/FAQ/#sharp_lines // Must be consistent with the pixel alignment of the grid lines, see CanvasXYGrid::Render(), and the drawing of the rulers // Don't use isHorizontal()/isVertical() as they test only exact matches. if ( Geom::are_near(normal_dt[Geom::Y], 0.0) ) { // Vertical? double position = floor(point_on_line_dt[Geom::X]) + 0.5; cairo_move_to(buf->ct, position, buf->rect.top() + 0.5); cairo_line_to(buf->ct, position, buf->rect.bottom() - 0.5); cairo_stroke(buf->ct); } else if ( Geom::are_near(normal_dt[Geom::X], 0.0) ) { // Horizontal? double position = floor(point_on_line_dt[Geom::Y]) + 0.5; cairo_move_to(buf->ct, buf->rect.left() + 0.5, position); cairo_line_to(buf->ct, buf->rect.right() - 0.5, position); cairo_stroke(buf->ct); } else { Geom::Line guide = Geom::Line::from_origin_and_vector( point_on_line_dt, Geom::rot90(normal_dt) ); // Find intersections of guide with buf rectangle. There should be zero or two. std::vector intersections; for (unsigned i = 0; i < 4; ++i) { Geom::LineSegment side( buf->rect.corner(i), buf->rect.corner((i+1)%4) ); try { Geom::OptCrossing oc = Geom::intersection(guide, side); if (oc) { intersections.push_back( guide.pointAt((*oc).ta)); } } catch (Geom::InfiniteSolutions) { // Shouldn't happen as we have already taken care of horizontal/vertical guides. std::cerr << "sp_guideline_render: Error: Infinite intersections." << std::endl; } } if (intersections.size() == 2) { double x0 = intersections[0][Geom::X]; double x1 = intersections[1][Geom::X]; double y0 = intersections[0][Geom::Y]; double y1 = intersections[1][Geom::Y]; cairo_move_to(buf->ct, x0, y0); cairo_line_to(buf->ct, x1, y1); cairo_stroke(buf->ct); } } cairo_restore(buf->ct); } static void sp_guideline_update(SPCanvasItem *item, Geom::Affine const &affine, unsigned int flags) { SPGuideLine *gl = SP_GUIDELINE(item); if ((SP_CANVAS_ITEM_CLASS(sp_guideline_parent_class))->update) { (SP_CANVAS_ITEM_CLASS(sp_guideline_parent_class))->update(item, affine, flags); } if (item->visible) { if (gl->locked) { g_object_set(G_OBJECT(gl->origin), "stroke_color", 0x0000ff88, "shape", SP_CTRL_SHAPE_CROSS, "size", 7, NULL); } else { g_object_set(G_OBJECT(gl->origin), "stroke_color", 0xff000088, "shape", SP_CTRL_SHAPE_CIRCLE, "size", 5, NULL); } gl->origin->moveto(gl->point_on_line); sp_canvas_item_request_update(SP_CANVAS_ITEM(gl->origin)); } gl->affine = affine; // Rotated canvas requires large bbox for all guides. sp_canvas_update_bbox (item, -1000000, -1000000, 1000000, 1000000); } // Returns 0.0 if point is on the guideline static double sp_guideline_point(SPCanvasItem *item, Geom::Point p, SPCanvasItem **actual_item) { SPGuideLine *gl = SP_GUIDELINE (item); if (!gl->sensitive) { return Geom::infinity(); } *actual_item = item; Geom::Point vec = gl->normal_to_line * gl->affine.withoutTranslation(); double distance = Geom::dot((p - gl->point_on_line * gl->affine), unit_vector(vec)); return MAX(fabs(distance)-1, 0); } SPCanvasItem *sp_guideline_new(SPCanvasGroup *parent, char* label, Geom::Point point_on_line, Geom::Point normal) { SPCanvasItem *item = sp_canvas_item_new(parent, SP_TYPE_GUIDELINE, nullptr); SPGuideLine *gl = SP_GUIDELINE(item); normal.normalize(); gl->label = label; gl->locked = false; gl->normal_to_line = normal; gl->angle = tan( -gl->normal_to_line[Geom::X] / gl->normal_to_line[Geom::Y]); sp_guideline_set_position(gl, point_on_line); gl->origin = (SPCtrl *) sp_canvas_item_new(parent, SP_TYPE_CTRL, "anchor", SP_ANCHOR_CENTER, "mode", SP_CTRL_MODE_COLOR, "filled", FALSE, "stroked", TRUE, "stroke_color", 0x01000000, NULL); gl->origin->pickable = false; return item; } void sp_guideline_set_label(SPGuideLine *gl, const char* label) { if (gl->label) { g_free(gl->label); } gl->label = g_strdup(label); sp_canvas_item_request_update(SP_CANVAS_ITEM (gl)); } void sp_guideline_set_locked(SPGuideLine *gl, const bool locked) { gl->locked = locked; sp_canvas_item_request_update(SP_CANVAS_ITEM (gl)); } void sp_guideline_set_position(SPGuideLine *gl, Geom::Point point_on_line) { gl->point_on_line = point_on_line; sp_canvas_item_request_update(SP_CANVAS_ITEM (gl)); } void sp_guideline_set_normal(SPGuideLine *gl, Geom::Point normal_to_line) { gl->normal_to_line = normal_to_line; gl->angle = tan( -normal_to_line[Geom::X] / normal_to_line[Geom::Y]); sp_canvas_item_request_update(SP_CANVAS_ITEM (gl)); } void sp_guideline_set_color(SPGuideLine *gl, unsigned int rgba) { gl->rgba = rgba; g_object_set(G_OBJECT(gl->origin), "stroke_color", rgba, NULL); sp_canvas_item_request_update(SP_CANVAS_ITEM(gl)); } void sp_guideline_set_sensitive(SPGuideLine *gl, int sensitive) { gl->sensitive = sensitive; } void sp_guideline_delete(SPGuideLine *gl) { sp_canvas_item_destroy(SP_CANVAS_ITEM(gl)); } /* Local Variables: mode:c++ c-file-style:"stroustrup" c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) indent-tabs-mode:nil fill-column:99 End: */ // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :