moving trunk for module inkscape

(bzr r1)

1 files changed, 148 insertions, 0 deletions

diff --git a/src/sp-item-transform.cpp b/src/sp-item-transform.cpp
new file mode 100644
index 000000000..817bc1b44
--- /dev/null
+++ b/src/sp-item-transform.cpp
@@ -0,0 +1,148 @@
+#define __SP_ITEM_TRANSFORM_C__
+
+/*
+ * Transforming single items
+ *
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *   Frank Felfe <innerspace@iname.com>
+ *   bulia byak <buliabyak@gmail.com>
+ *
+ * Copyright (C) 1999-2005 authors
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include <libnr/nr-matrix-ops.h>
+#include "libnr/nr-matrix-rotate-ops.h"
+#include "libnr/nr-matrix-scale-ops.h"
+#include "libnr/nr-matrix-translate-ops.h"
+#include "sp-item.h"
+
+static NR::translate inverse(NR::translate const m)
+{
+	/* TODO: Move this to nr-matrix-fns.h or the like. */
+	return NR::translate(-m[0], -m[1]);
+}
+
+void 
+sp_item_rotate_rel(SPItem *item, NR::rotate const &rotation)
+{
+	NR::translate const s(sp_item_bbox_desktop(item).midpoint());
+
+	// Rotate item.
+	sp_item_set_i2d_affine(item,
+			       sp_item_i2d_affine(item) * inverse(s) * rotation * s);
+
+	// Use each item's own transform writer, consistent with sp_selection_apply_affine()
+	sp_item_write_transform(item, SP_OBJECT_REPR(item), item->transform);
+}
+
+void
+sp_item_scale_rel (SPItem *item, NR::scale const &scale)
+{
+	NR::translate const s(sp_item_bbox_desktop(item).midpoint());
+
+	sp_item_set_i2d_affine(item,
+			       sp_item_i2d_affine(item) * inverse(s) * scale * s);
+	sp_item_write_transform(item, SP_OBJECT_REPR(item), item->transform);
+} 
+
+void
+sp_item_skew_rel (SPItem *item, double skewX, double skewY)
+{
+	NR::Rect bbox(sp_item_bbox_desktop(item));
+
+	NR::translate const s(bbox.midpoint());
+
+	NR::Matrix const skew(1, skewY, skewX, 1, 0, 0);
+
+	sp_item_set_i2d_affine(item,
+			       sp_item_i2d_affine(item) * inverse(s) * skew * s);
+	sp_item_write_transform(item, SP_OBJECT_REPR(item), item->transform);
+} 
+
+void sp_item_move_rel(SPItem *item, NR::translate const &tr)
+{
+	sp_item_set_i2d_affine(item, sp_item_i2d_affine(item) * tr);
+
+	sp_item_write_transform(item, SP_OBJECT_REPR(item), item->transform);
+}
+
+/*
+** Returns the matrix you need to apply to an object with given bbox and strokewidth to
+scale/move it to the new box x0/y0/x1/y1. Takes into account the "scale stroke"
+preference value passed to it. Has to solve a quadratic equation to make sure
+the goal is met exactly and the stroke scaling is obeyed.
+*/
+
+NR::Matrix 
+get_scale_transform_with_stroke (NR::Rect &bbox_param, gdouble strokewidth, bool transform_stroke, gdouble x0, gdouble y0, gdouble x1, gdouble y1)
+{
+    NR::Rect bbox (bbox_param);
+
+    NR::Matrix p2o = NR::Matrix (NR::translate (-bbox.min()));
+    NR::Matrix o2n = NR::Matrix (NR::translate (x0, y0));
+
+    NR::Matrix scale = NR::Matrix (NR::scale (1, 1)); // scale component
+    NR::Matrix unbudge = NR::Matrix (NR::translate (0, 0)); // move component to compensate for the drift caused by stroke width change
+
+    gdouble w0 = bbox.extent(NR::X);
+    gdouble h0 = bbox.extent(NR::Y);
+    gdouble w1 = x1 - x0;
+    gdouble h1 = y1 - y0;
+    gdouble r0 = strokewidth;
+
+    if (bbox.isEmpty() || bbox.extent(NR::X) < 1e-06 || bbox.extent(NR::Y) < 1e-06 || 
+        fabs(w0 - r0) < 1e-6 || fabs(h0 - r0) < 1e-6 ||
+        (!transform_stroke && (fabs(w1 - r0) < 1e-6 || fabs(h1 - r0) < 1e-6)) 
+        ) {
+        NR::Matrix move = NR::Matrix(NR::translate(x0 - bbox.min()[NR::X], y0 - bbox.min()[NR::Y]));
+        return (move); // sorry, cannot scale from or to empty boxes, so only translate
+    }
+
+    NR::Matrix direct = NR::Matrix (NR::scale(w1 / w0,   h1 / h0));
+    gdouble ratio_x = (w1 - r0) / (w0 - r0);
+    gdouble ratio_y = (h1 - r0) / (h0 - r0);
+    NR::Matrix direct_constant_r = NR::Matrix (NR::scale(ratio_x, ratio_y));
+
+    if (transform_stroke && r0 != 0 && r0 != NR_HUGE) { // there's stroke, and we need to scale it
+        // These coefficients are obtained from the assumption that scaling applies to the
+        // non-stroked "shape proper" and that stroke scale is scaled by the expansion of that
+        // matrix
+        gdouble A = -(w0 *h0) + r0*(w0 + h0);
+        gdouble B = -(w1 + h1) * r0*r0;
+        gdouble C = w1 * h1 * r0*r0;
+        if (B*B - 4*A*C > 0) {
+            gdouble r1 = (-B - sqrt (B*B - 4*A*C))/(2*A);
+            //gdouble r2 = (-B + sqrt (B*B - 4*A*C))/(2*A);
+            //std::cout << "r0" << r0 << " r1" << r1 << " r2" << r2 << "\n";
+            gdouble scale_x = (w1 - r1)/(w0 - r0);
+            gdouble scale_y = (h1 - r1)/(h0 - r0);
+            scale *= NR::scale(scale_x, scale_y);
+            unbudge *= NR::translate (-0.5 * (r0 * scale_x - r1), -0.5 * (r0 * scale_y - r1));
+        } else {
+            scale *= direct;
+        }
+    } else {
+        if (r0 == 0 || r0 == NR_HUGE) { // no stroke to scale
+            scale *= direct;
+        } else {// nonscaling strokewidth
+            scale *= direct_constant_r;
+            unbudge *= NR::translate (0.5 * r0 * (1 - ratio_x), 0.5 * r0 * (1 - ratio_y));
+        }
+    }
+
+    return (p2o * scale * unbudge * o2n);
+}
+
+/*
+  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 :