index 39cd90ed61d7ccce2e25b9ad7e0f9ce22c25de5e..b67ac1311cb703d229ff472e768a30cb5c738872 100644 (file)
* Helper functions to use cairo with inkscape
*
* Copyright (C) 2007 bulia byak
+ * Copyright (C) 2008 Johan Engelen
*
* Released under GNU GPL
*
#include <libnr/nr-matrix-ops.h>
#include <libnr/nr-matrix-fns.h>
#include <libnr/nr-pixblock.h>
+#include <libnr/nr-convert2geom.h>
#include "../style.h"
#include "nr-arena.h"
-
+#include "sp-canvas.h"
+#include <2geom/pathvector.h>
+#include <2geom/matrix.h>
+#include <2geom/point.h>
+#include <2geom/path.h>
+#include <2geom/transforms.h>
+#include <2geom/sbasis-to-bezier.h>
/** Creates a cairo context to render to the given pixblock on the given area */
cairo_t *
-nr_create_cairo_context (NRRectL *area, NRPixBlock *pb)
+nr_create_cairo_context_for_data (NRRectL *area, NRRectL *buf_area, unsigned char *px, unsigned int rowstride)
{
- if (!nr_rect_l_test_intersect (&pb->area, area))
+ if (!nr_rect_l_test_intersect (buf_area, area))
return NULL;
NRRectL clip;
- nr_rect_l_intersect (&clip, &pb->area, area);
- unsigned char *dpx = NR_PIXBLOCK_PX (pb) + (clip.y0 - pb->area.y0) * pb->rs + NR_PIXBLOCK_BPP (pb) * (clip.x0 - pb->area.x0);
+ nr_rect_l_intersect (&clip, buf_area, area);
+ unsigned char *dpx = px + (clip.y0 - buf_area->y0) * rowstride + 4 * (clip.x0 - buf_area->x0);
int width = area->x1 - area->x0;
int height = area->y1 - area->y0;
// even though cairo cannot draw in nonpremul mode, select ARGB32 for R8G8B8A8N as the closest; later eliminate R8G8B8A8N everywhere
cairo_surface_t* cst = cairo_image_surface_create_for_data
(dpx,
- ((pb->mode == NR_PIXBLOCK_MODE_R8G8B8A8P || pb->mode == NR_PIXBLOCK_MODE_R8G8B8A8N) ? CAIRO_FORMAT_ARGB32 : (pb->mode == NR_PIXBLOCK_MODE_R8G8B8? CAIRO_FORMAT_RGB24 : CAIRO_FORMAT_A8)),
+ CAIRO_FORMAT_ARGB32,
width,
height,
- pb->rs);
+ rowstride);
cairo_t *ct = cairo_create (cst);
return ct;
}
+/** Creates a cairo context to render to the given SPCanvasBuf on the given area */
+cairo_t *
+nr_create_cairo_context_canvasbuf (NRRectL */*area*/, SPCanvasBuf *b)
+{
+ return nr_create_cairo_context_for_data (&(b->rect), &(b->rect), b->buf, b->buf_rowstride);
+}
+
+
+/** Creates a cairo context to render to the given NRPixBlock on the given area */
+cairo_t *
+nr_create_cairo_context (NRRectL *area, NRPixBlock *pb)
+{
+ return nr_create_cairo_context_for_data (area, &(pb->area), NR_PIXBLOCK_PX (pb), pb->rs);
+}
+
/** Feeds path-creating calls to the cairo context translating them from the SPCurve, with the given transform and shift */
void
-feed_curve_to_cairo (cairo_t *ct, NArtBpath *bpath, NR::Matrix trans, NR::Point shift)
+feed_curve_to_cairo (cairo_t *ct, NArtBpath const *bpath, NR::Matrix trans, NR::Maybe<NR::Rect> area, bool optimize_stroke, double stroke_width)
{
- NR::Point lastX(0,0);
+ NR::Point next(0,0), last(0,0);
+ if (!area || area->isEmpty())
+ return;
+ NR::Point shift = area->min();
+ NR::Rect view = *area;
+ view.growBy (stroke_width);
+ NR::Rect swept;
bool closed = false;
+ NR::Point startpath(0,0);
for (int i = 0; bpath[i].code != NR_END; i++) {
switch (bpath[i].code) {
case NR_MOVETO_OPEN:
case NR_MOVETO:
- if (closed) cairo_close_path(ct);
- closed = (bpath[i].code == NR_MOVETO);
- lastX[NR::X] = bpath[i].x3;
- lastX[NR::Y] = bpath[i].y3;
- lastX *= trans;
- lastX -= shift;
- cairo_move_to(ct, lastX[NR::X], lastX[NR::Y]);
+ if (closed) {
+ // we cannot use close_path because some of the curves/lines may have been optimized out
+ cairo_line_to(ct, startpath[NR::X], startpath[NR::Y]);
+ }
+ next[NR::X] = bpath[i].x3;
+ next[NR::Y] = bpath[i].y3;
+ next *= trans;
+ last = next;
+ next -= shift;
+ if (bpath[i].code == NR_MOVETO) {
+ // remember the start point of the subpath, for closing it later
+ closed = true;
+ startpath = next;
+ } else {
+ closed = false;
+ }
+ cairo_move_to(ct, next[NR::X], next[NR::Y]);
break;
case NR_LINETO:
- lastX[NR::X] = bpath[i].x3;
- lastX[NR::Y] = bpath[i].y3;
- lastX *= trans;
- lastX -= shift;
- cairo_line_to(ct, lastX[NR::X], lastX[NR::Y]);
+ next[NR::X] = bpath[i].x3;
+ next[NR::Y] = bpath[i].y3;
+ next *= trans;
+ if (optimize_stroke) {
+ swept = NR::Rect(last, next);
+ //std::cout << "swept: " << swept;
+ //std::cout << "view: " << view;
+ //std::cout << "intersects? " << (swept.intersects(view)? "YES" : "NO") << "\n";
+ }
+ last = next;
+ next -= shift;
+ if (!optimize_stroke || swept.intersects(view))
+ cairo_line_to(ct, next[NR::X], next[NR::Y]);
+ else
+ cairo_move_to(ct, next[NR::X], next[NR::Y]);
break;
case NR_CURVETO: {
@@ -82,10 +132,20 @@ feed_curve_to_cairo (cairo_t *ct, NArtBpath *bpath, NR::Matrix trans, NR::Point
tm1 *= trans;
tm2 *= trans;
tm3 *= trans;
+ if (optimize_stroke) {
+ swept = NR::Rect(last, last);
+ swept.expandTo(tm1);
+ swept.expandTo(tm2);
+ swept.expandTo(tm3);
+ }
+ last = tm3;
tm1 -= shift;
tm2 -= shift;
tm3 -= shift;
- cairo_curve_to (ct, tm1[NR::X], tm1[NR::Y], tm2[NR::X], tm2[NR::Y], tm3[NR::X], tm3[NR::Y]);
+ if (!optimize_stroke || swept.intersects(view))
+ cairo_curve_to (ct, tm1[NR::X], tm1[NR::Y], tm2[NR::X], tm2[NR::Y], tm3[NR::X], tm3[NR::Y]);
+ else
+ cairo_move_to(ct, tm3[NR::X], tm3[NR::Y]);
break;
}
@@ -96,6 +156,128 @@ feed_curve_to_cairo (cairo_t *ct, NArtBpath *bpath, NR::Matrix trans, NR::Point
}
+static void
+feed_curve_to_cairo(cairo_t *cr, Geom::Curve const &c, Geom::Matrix & trans, Geom::Rect view, bool optimize_stroke)
+{
+ if( dynamic_cast<Geom::LineSegment const*>(&c) ||
+ dynamic_cast<Geom::HLineSegment const*>(&c) ||
+ dynamic_cast<Geom::VLineSegment const*>(&c) )
+ {
+ Geom::Point end_tr = c.finalPoint() * trans;
+ if (!optimize_stroke) {
+ cairo_line_to(cr, end_tr[0], end_tr[1]);
+ } else {
+ Geom::Rect swept(c.initialPoint()*trans, end_tr);
+ if (swept.intersects(view)) {
+ cairo_line_to(cr, end_tr[0], end_tr[1]);
+ } else {
+ cairo_move_to(cr, end_tr[0], end_tr[1]);
+ }
+ }
+ }
+ else if(Geom::QuadraticBezier const *quadratic_bezier = dynamic_cast<Geom::QuadraticBezier const*>(&c)) {
+ std::vector<Geom::Point> points = quadratic_bezier->points();
+ points[0] *= trans;
+ points[1] *= trans;
+ points[2] *= trans;
+ Geom::Point b1 = points[0] + (2./3) * (points[1] - points[0]);
+ Geom::Point b2 = b1 + (1./3) * (points[2] - points[0]);
+ if (!optimize_stroke) {
+ cairo_curve_to(cr, b1[0], b1[1], b2[0], b2[1], points[2][0], points[2][1]);
+ } else {
+ Geom::Rect swept(points[0], points[2]);
+ swept.expandTo(points[1]);
+ if (swept.intersects(view)) {
+ cairo_curve_to(cr, b1[0], b1[1], b2[0], b2[1], points[2][0], points[2][1]);
+ } else {
+ cairo_move_to(cr, points[2][0], points[2][1]);
+ }
+ }
+ }
+ else if(Geom::CubicBezier const *cubic_bezier = dynamic_cast<Geom::CubicBezier const*>(&c)) {
+ std::vector<Geom::Point> points = cubic_bezier->points();
+ //points[0] *= trans; // don't do this one here for fun: it is only needed for optimized strokes
+ points[1] *= trans;
+ points[2] *= trans;
+ points[3] *= trans;
+ if (!optimize_stroke) {
+ cairo_curve_to(cr, points[1][0], points[1][1], points[2][0], points[2][1], points[3][0], points[3][1]);
+ } else {
+ points[0] *= trans; // didn't transform this point yet
+ Geom::Rect swept(points[0], points[3]);
+ swept.expandTo(points[1]);
+ swept.expandTo(points[2]);
+ if (swept.intersects(view)) {
+ cairo_curve_to(cr, points[1][0], points[1][1], points[2][0], points[2][1], points[3][0], points[3][1]);
+ } else {
+ cairo_move_to(cr, points[3][0], points[3][1]);
+ }
+ }
+ }
+// else if(Geom::EllipticalArc const *svg_elliptical_arc = dynamic_cast<Geom::EllipticalArc *>(c)) {
+// //TODO: get at the innards and spit them out to cairo
+// }
+ else {
+ //this case handles sbasis as well as all other curve types
+ Geom::Path sbasis_path = path_from_sbasis(c.toSBasis(), 0.1);
+
+ //recurse to convert the new path resulting from the sbasis to svgd
+ for(Geom::Path::iterator iter = sbasis_path.begin(); iter != sbasis_path.end(); ++iter) {
+ feed_curve_to_cairo(cr, *iter, trans, view, optimize_stroke);
+ }
+ }
+}
+
+
+/** Feeds path-creating calls to the cairo context translating them from the SPCurve, with the given transform and shift */
+void
+feed_path_to_cairo (cairo_t *ct, Geom::Path const &path, Geom::Matrix trans, NR::Maybe<NR::Rect> area, bool optimize_stroke, double stroke_width)
+{
+ if (!area || area->isEmpty())
+ return;
+ if (path.empty())
+ return;
+
+ // Transform all coordinates to coords within "area"
+ Geom::Point shift = to_2geom(area->min());
+ NR::Rect view = *area;
+ view.growBy (stroke_width);
+ view = view * from_2geom(Geom::Translate(-shift));
+ // Pass transformation to feed_curve, so that we don't need to create a whole new path.
+ Geom::Matrix transshift(trans * Geom::Translate(-shift));
+
+ Geom::Point initial = path.initialPoint() * transshift;
+ cairo_move_to(ct, initial[0], initial[1] );
+
+ for(Geom::Path::const_iterator cit = path.begin(); cit != path.end_open(); ++cit) {
+ feed_curve_to_cairo(ct, *cit, transshift, to_2geom(view), optimize_stroke);
+ }
+
+ if (path.closed()) {
+ cairo_line_to(ct, initial[0], initial[1]);
+ // I think we should use cairo_close_path(ct) here but it doesn't work. (the closing line is not rendered completely)
+ /* according to cairo documentation:
+ The behavior of cairo_close_path() is distinct from simply calling cairo_line_to() with the equivalent coordinate
+ in the case of stroking. When a closed sub-path is stroked, there are no caps on the ends of the sub-path. Instead,
+ there is a line join connecting the final and initial segments of the sub-path.
+ */
+ }
+}
+
+/** Feeds path-creating calls to the cairo context translating them from the SPCurve, with the given transform and shift */
+void
+feed_pathvector_to_cairo (cairo_t *ct, Geom::PathVector const &pathv, Geom::Matrix trans, NR::Maybe<NR::Rect> area, bool optimize_stroke, double stroke_width)
+{
+ if (!area || area->isEmpty())
+ return;
+ if (pathv.empty())
+ return;
+
+ for(Geom::PathVector::const_iterator it = pathv.begin(); it != pathv.end(); ++it) {
+ feed_path_to_cairo(ct, *it, trans, area, optimize_stroke, stroke_width);
+ }
+}
+
/*
Local Variables:
mode:c++