render text in outline mode via cairo (still no endian-safe); factor out helper functions

(bzr r2470)

1 files changed, 108 insertions, 0 deletions

diff --git a/src/display/inkscape-cairo.cpp b/src/display/inkscape-cairo.cpp
new file mode 100644
index 000000000..39cd90ed6
--- /dev/null
+++ b/src/display/inkscape-cairo.cpp
@@ -0,0 +1,108 @@
+/*
+ * 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 *bpath, NR::Matrix trans, NR::Point shift)
+{
+    NR::Point lastX(0,0);
+    bool  closed = false;
+    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]);
+                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]);
+                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;
+                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]);
+                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 :