diff options
Diffstat (limited to 'src/measure-context.cpp')
| -rw-r--r-- | src/measure-context.cpp | 140 |
1 files changed, 106 insertions, 34 deletions
diff --git a/src/measure-context.cpp b/src/measure-context.cpp index 563d8e5e9..b3ea82e3b 100644 --- a/src/measure-context.cpp +++ b/src/measure-context.cpp @@ -153,6 +153,105 @@ void repositionOverlappingLabels(std::vector<LabelPlacement> &placements, SPDesk } } +/** + * Calculates where to place the anchor for the display text and arc. + * + * @param desktop the desktop that is being used. + * @param angle the angle to be displaying. + * @param startPoint the point that is the vertex of the selected angle. + * @param endPoint the point that is the end the user is manipulating for measurement. + * @param fontsize the size to display the text label at. + */ +Geom::Point calcAngleDisplayAnchor(SPDesktop *desktop, double angle, + Geom::Point const &startPoint, Geom::Point const &endPoint, + double fontsize) +{ + // Time for the trick work of figuring out where things should go, and how. + Geom::Point where = endPoint; + Geom::Affine adjust = Geom::Affine(Geom::Translate(-startPoint)) + * Geom::Affine(Geom::Rotate(-angle / 2)) + * Geom::Affine(Geom::Translate(startPoint)); + where *= adjust; + // We now have the ideal position, but need to see if it will fit/work. + + Geom::Rect visibleArea = desktop->get_display_area(); + // Bring it in to "title safe" for the anchor point + Geom::Point textBox = desktop->w2d(Geom::Point(fontsize * 3, fontsize / 2)); + textBox[Geom::Y] = std::abs(textBox[Geom::Y]); + + visibleArea = Geom::Rect(visibleArea.min()[Geom::X] + textBox[Geom::X], + visibleArea.min()[Geom::Y] + textBox[Geom::Y], + visibleArea.max()[Geom::X] - textBox[Geom::X], + visibleArea.max()[Geom::Y] - textBox[Geom::Y]); + std::vector<Geom::LineSegment> edges; + edges.push_back(Geom::LineSegment(Geom::Point(visibleArea.max()[Geom::X], visibleArea.min()[Geom::Y]), + visibleArea.max())); // right + edges.push_back(Geom::LineSegment(Geom::Point(visibleArea.min()[Geom::X], visibleArea.max()[Geom::Y]), + visibleArea.max())); // bottom + edges.push_back(Geom::LineSegment(visibleArea.min(), + Geom::Point(visibleArea.max()[Geom::X], visibleArea.min()[Geom::Y]))); // top + edges.push_back(Geom::LineSegment(visibleArea.min(), + Geom::Point(visibleArea.min()[Geom::X], visibleArea.max()[Geom::Y]))); // left + + Geom::LineSegment dispLine(start_point, where); + + for (std::vector<Geom::LineSegment>::iterator it = edges.begin(); it != edges.end(); ++it) { + try { + Geom::OptCrossing inters = Geom::intersection(dispLine, *it); + if (inters) { + where = dispLine.pointAt(inters->ta); + break; + } + } catch (Geom::InfiniteSolutions const & /*e*/) { + // don't fail. + } + } + + return where; +} + +/** + * Given an angle, the arc center and edge point, draw an arc segment centered around that edge point. + * + * @param desktop the desktop that is being used. + * @param center the center point for the arc. + * @param end the point that ends in the center of the arc segment. + * @param angle the angle of the arc segment to draw. + */ +void createAngleDisplayCurve(SPDesktop *desktop, Geom::Point const ¢er, Geom::Point const &end, double angle) +{ + // Given that we have a point on the arc's center and the angle of the arc, we need to get the two endpoints. + + // arc start + Geom::Point p1 = end * (Geom::Affine(Geom::Translate(-center)) + * Geom::Affine(Geom::Rotate(-angle / 2)) + * Geom::Affine(Geom::Translate(center))); + // arc end + Geom::Point p4 = end * (Geom::Affine(Geom::Translate(-center)) + * Geom::Affine(Geom::Rotate(angle / 2)) + * Geom::Affine(Geom::Translate(center))); + + // from Riskus + double xc = center[Geom::X]; + double yc = center[Geom::Y]; + double ax = p1[Geom::X] - xc; + double ay = p1[Geom::Y] - yc; + double bx = p4[Geom::X] - xc; + double by = p4[Geom::Y] - yc; + double q1 = (ax * ax) + (ay * ay); + double q2 = q1 + (ax * bx) + (ay * by); + + double k2 = (4.0 / 3.0) * (std::sqrt(2 * q1 * q2) - q2) / ((ax * by) - (ay * bx)); + + Geom::Point p2(xc + ax - (k2 * ay), + yc + ay + (k2 * ax)); + Geom::Point p3(xc + bx + (k2 * by), + yc + by - (k2 * bx)); + SPCtrlCurve *curve = ControlManager::getManager().createControlCurve(sp_desktop_tempgroup(desktop), p1, p2, p3, p4, CTLINE_SECONDARY); + + measure_tmp_items.push_back(desktop->add_temporary_canvasitem(SP_CANVAS_ITEM(curve), 0, true)); +} + } // namespace static void sp_measure_context_class_init(SPMeasureContextClass *klass) @@ -459,32 +558,24 @@ static gint sp_measure_context_root_handler(SPEventContext *event_context, GdkEv g_free(measure_str); } + Geom::Point angleDisplayPt = calcAngleDisplayAnchor(desktop, angle, + start_point, end_point, + fontsize); + { // TODO cleanup memory, Glib::ustring, etc.: gchar *angle_str = g_strdup_printf("%.2f °", angle * 180/M_PI); - CanvasTextAnchorPositionEnum anchor = TEXT_ANCHOR_LEFT; - Geom::Point where = end_point; - if (desktop->d2w(end_point - start_point).length() > 30) { - Geom::Affine adjust = Geom::Affine(Geom::Translate(-start_point)) - * Geom::Affine(Geom::Rotate(-angle / 2)) - * Geom::Affine(Geom::Translate(start_point)); - where *= adjust; - anchor = TEXT_ANCHOR_CENTER; - } else { - where += desktop->w2d(Geom::Point(3*fontsize, fontsize)); - } - SPCanvasText *canvas_tooltip = sp_canvastext_new(sp_desktop_tempgroup(desktop), desktop, - where, + angleDisplayPt, angle_str); sp_canvastext_set_fontsize(canvas_tooltip, fontsize); canvas_tooltip->rgba = 0xffffffff; canvas_tooltip->rgba_background = 0x337f337f; canvas_tooltip->outline = false; canvas_tooltip->background = true; - canvas_tooltip->anchor_position = anchor; + canvas_tooltip->anchor_position = TEXT_ANCHOR_CENTER; measure_tmp_items.push_back(desktop->add_temporary_canvasitem(canvas_tooltip, 0)); g_free(angle_str); @@ -570,26 +661,7 @@ static gint sp_measure_context_root_handler(SPEventContext *event_context, GdkEv CTLINE_SECONDARY); measure_tmp_items.push_back(desktop->add_temporary_canvasitem(control_line, 0)); - // from Riskus - double xc = start_point[Geom::X]; - double yc = start_point[Geom::Y]; - double ax = anchorEnd[Geom::X] - xc; - double ay = anchorEnd[Geom::Y] - yc; - double bx = end_point[Geom::X] - xc; - double by = end_point[Geom::Y] - yc; - double q1 = (ax * ax) + (ay * ay); - double q2 = q1 + (ax * bx) + (ay * by); - - double k2 = (4.0 / 3.0) * (std::sqrt(2 * q1 * q2) - q2) / ((ax * by) - (ay * bx)); - - Geom::Point p0 = anchorEnd; - Geom::Point p1(xc + ax - (k2 * ay), - yc + ay + (k2 * ax)); - Geom::Point p2(xc + bx + (k2 * by), - yc + by - (k2 * bx)); - Geom::Point p3 = end_point; - SPCtrlCurve *curve = ControlManager::getManager().createControlCurve(sp_desktop_tempgroup(desktop), p0, p1, p2, p3, CTLINE_SECONDARY); - measure_tmp_items.push_back(desktop->add_temporary_canvasitem(SP_CANVAS_ITEM(curve), 0, true)); + createAngleDisplayCurve(desktop, start_point, angleDisplayPt, angle); } } |