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/*
* Helper functions to use cairo with inkscape
*
* Copyright (C) 2007 bulia byak
*
* Released under GNU GPL
*
*/
#include <cairo.h>
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <libnr/n-art-bpath.h>
#include <libnr/nr-matrix-ops.h>
#include <libnr/nr-matrix-fns.h>
#include <libnr/nr-pixblock.h>
#include "../style.h"
#include "nr-arena.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)
{
if (!nr_rect_l_test_intersect (&pb->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);
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)),
width,
height,
pb->rs);
cairo_t *ct = cairo_create (cst);
return ct;
}
/** 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 const *bpath, NR::Matrix trans, NR::Maybe<NR::Rect> area, bool optimize_stroke, double stroke_width)
{
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) {
// 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:
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: {
NR::Point tm1, tm2, tm3;
tm1[0]=bpath[i].x1;
tm1[1]=bpath[i].y1;
tm2[0]=bpath[i].x2;
tm2[1]=bpath[i].y2;
tm3[0]=bpath[i].x3;
tm3[1]=bpath[i].y3;
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;
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;
}
default:
break;
}
}
}
/*
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:encoding=utf-8:textwidth=99 :
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