diff options
Diffstat (limited to 'src/display/sp-ctrlcurve.cpp')
| -rw-r--r-- | src/display/sp-ctrlcurve.cpp | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/src/display/sp-ctrlcurve.cpp b/src/display/sp-ctrlcurve.cpp new file mode 100644 index 0000000..41572cd --- /dev/null +++ b/src/display/sp-ctrlcurve.cpp @@ -0,0 +1,192 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Simple bezier curve used for Mesh Gradients + * + * Author: + * Tavmjong Bah <tavmjong@free.fr> + * + * Copyright (C) 2011 Tavmjong Bah + * Copyright (C) 2007 Johan Engelen + * Copyright (C) 1999-2002 Lauris Kaplinski + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#include "display/sp-ctrlcurve.h" +#include "display/sp-canvas-util.h" +#include "display/cairo-utils.h" +#include "color.h" +#include "display/sp-canvas.h" + +namespace { + +static void sp_ctrlcurve_destroy(SPCanvasItem *object); + +static void sp_ctrlcurve_update(SPCanvasItem *item, Geom::Affine const &affine, unsigned int flags); +static void sp_ctrlcurve_render(SPCanvasItem *item, SPCanvasBuf *buf); + +} // namespace + +G_DEFINE_TYPE(SPCtrlCurve, sp_ctrlcurve, SP_TYPE_CANVAS_ITEM); + +static void +sp_ctrlcurve_class_init(SPCtrlCurveClass *klass) +{ + klass->destroy = sp_ctrlcurve_destroy; + + klass->update = sp_ctrlcurve_update; + klass->render = sp_ctrlcurve_render; +} + +static void +sp_ctrlcurve_init(SPCtrlCurve *ctrlcurve) +{ + // Points are initialized to 0,0 + ctrlcurve->rgba = 0x0000ff7f; + ctrlcurve->item=nullptr; + ctrlcurve->corner0 = -1; + ctrlcurve->corner1 = -1; +} + +namespace { +static void +sp_ctrlcurve_destroy(SPCanvasItem *object) +{ + g_return_if_fail (object != nullptr); + g_return_if_fail (SP_IS_CTRLCURVE (object)); + + SPCtrlCurve *ctrlcurve = SP_CTRLCURVE (object); + + ctrlcurve->item=nullptr; + + if (SP_CANVAS_ITEM_CLASS(sp_ctrlcurve_parent_class)->destroy) + SP_CANVAS_ITEM_CLASS(sp_ctrlcurve_parent_class)->destroy(object); +} + +static void +sp_ctrlcurve_render(SPCanvasItem *item, SPCanvasBuf *buf) +{ + SPCtrlCurve *cl = SP_CTRLCURVE (item); + + if (!buf->ct) + return; + + if ( cl->p0 == cl->p1 && + cl->p1 == cl->p2 && + cl->p2 == cl->p3 ) + return; + + ink_cairo_set_source_rgba32(buf->ct, cl->rgba); + cairo_set_line_width(buf->ct, 1); + cairo_new_path(buf->ct); + + Geom::Point p0 = cl->p0 * cl->affine; + Geom::Point p1 = cl->p1 * cl->affine; + Geom::Point p2 = cl->p2 * cl->affine; + Geom::Point p3 = cl->p3 * cl->affine; + + cairo_move_to (buf->ct, p0[Geom::X] - buf->rect.left(), p0[Geom::Y] - buf->rect.top()); + cairo_curve_to (buf->ct, + p1[Geom::X] - buf->rect.left(), p1[Geom::Y] - buf->rect.top(), + p2[Geom::X] - buf->rect.left(), p2[Geom::Y] - buf->rect.top(), + p3[Geom::X] - buf->rect.left(), p3[Geom::Y] - buf->rect.top() ); + + cairo_stroke(buf->ct); +} + +static void +sp_ctrlcurve_update(SPCanvasItem *item, Geom::Affine const &affine, unsigned int flags) +{ + SPCtrlCurve *cl = SP_CTRLCURVE (item); + + item->canvas->requestRedraw(item->x1, item->y1, item->x2, item->y2); + + if (SP_CANVAS_ITEM_CLASS(sp_ctrlcurve_parent_class)->update) + SP_CANVAS_ITEM_CLASS(sp_ctrlcurve_parent_class)->update(item, affine, flags); + + sp_canvas_item_reset_bounds (item); + + cl->affine = affine; + + if (cl->p0 == cl->p1 && cl->p1 == cl->p2 && cl->p2 == cl->p3 ) { + item->x1 = item->x2 = item->y1 = item->y2 = 0; + } else { + + Geom::Point p0 = cl->p0 * affine; + Geom::Point p1 = cl->p1 * affine; + Geom::Point p2 = cl->p2 * affine; + Geom::Point p3 = cl->p3 * affine; + + double min_x = p0[Geom::X]; + double min_y = p0[Geom::Y]; + double max_x = p0[Geom::X]; + double max_y = p0[Geom::Y]; + + min_x = MIN( min_x, p1[Geom::X] ); + min_y = MIN( min_y, p1[Geom::Y] ); + max_x = MAX( max_x, p1[Geom::X] ); + max_y = MAX( max_y, p1[Geom::Y] ); + + min_x = MIN( min_x, p2[Geom::X] ); + min_y = MIN( min_y, p2[Geom::Y] ); + max_x = MAX( max_x, p2[Geom::X] ); + max_y = MAX( max_y, p2[Geom::Y] ); + + min_x = MIN( min_x, p3[Geom::X] ); + min_y = MIN( min_y, p3[Geom::Y] ); + max_x = MAX( max_x, p3[Geom::X] ); + max_y = MAX( max_y, p3[Geom::Y] ); + + item->x1 = round( min_x - 1 ); + item->y1 = round( min_y - 1 ); + item->x2 = round( max_x + 1 ); + item->y2 = round( max_y + 1 ); + + item->canvas->requestRedraw(item->x1, item->y1, item->x2, item->y2); + + } +} + +} // namespace + +#define EPSILON 1e-6 +#define DIFFER(a,b) (fabs ((a) - (b)) > EPSILON) + +void SPCtrlCurve::setCoords( gdouble x0, gdouble y0, gdouble x1, gdouble y1, + gdouble x2, gdouble y2, gdouble x3, gdouble y3 ) +{ + + Geom::Point q0( x0, y0 ); + Geom::Point q1( x1, y1 ); + Geom::Point q2( x2, y2 ); + Geom::Point q3( x3, y3 ); + + setCoords( q0, q1, q2, q3 ); + +} + +void SPCtrlCurve::setCoords( Geom::Point const &q0, Geom::Point const &q1, + Geom::Point const &q2, Geom::Point const &q3) +{ + if (DIFFER(p0[Geom::X], q0[Geom::X]) || DIFFER(p0[Geom::Y], q0[Geom::Y]) || + DIFFER(p1[Geom::X], q1[Geom::X]) || DIFFER(p1[Geom::Y], q1[Geom::Y]) || + DIFFER(p2[Geom::X], q2[Geom::X]) || DIFFER(p2[Geom::Y], q2[Geom::Y]) || + DIFFER(p3[Geom::X], q3[Geom::X]) || DIFFER(p3[Geom::Y], q3[Geom::Y]) ) { + p0 = q0; + p1 = q1; + p2 = q2; + p3 = q3; + sp_canvas_item_request_update( this ); + } +} + +/* + 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 : |