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index 817bc1b44e6f7cef4c1784ce0c75c77a44948f5f..93c3f5b7b410a15c83204283d93b9907cb34f57f 100644 (file)
return NR::translate(-m[0], -m[1]);
}
-void
+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);
+ NR::Point center = item->getCenter();
+ NR::translate const s(item->getCenter());
+ NR::Matrix affine = NR::Matrix(inverse(s)) * NR::Matrix(rotation) * NR::Matrix(s);
+
+ // Rotate item.
+ sp_item_set_i2d_affine(item, sp_item_i2d_affine(item) * affine);
+ // Use each item's own transform writer, consistent with sp_selection_apply_affine()
+ sp_item_write_transform(item, SP_OBJECT_REPR(item), item->transform);
+
+ // Restore the center position (it's changed because the bbox center changed)
+ if (item->isCenterSet()) {
+ item->setCenter(center * affine);
+ }
}
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);
-}
+ NR::Maybe<NR::Rect> bbox = sp_item_bbox_desktop(item);
+ if (bbox) {
+ NR::translate const s(bbox->midpoint()); // use getCenter?
+ 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::Point center = item->getCenter();
+ NR::translate const s(item->getCenter());
- NR::translate const s(bbox.midpoint());
+ NR::Matrix const skew(1, skewY, skewX, 1, 0, 0);
+ NR::Matrix affine = NR::Matrix(inverse(s)) * skew * NR::Matrix(s);
- NR::Matrix const skew(1, skewY, skewX, 1, 0, 0);
+ sp_item_set_i2d_affine(item, sp_item_i2d_affine(item) * affine);
+ sp_item_write_transform(item, SP_OBJECT_REPR(item), item->transform);
- 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);
-}
+ // Restore the center position (it's changed because the bbox center changed)
+ if (item->isCenterSet()) {
+ item->setCenter(center * affine);
+ }
+}
void sp_item_move_rel(SPItem *item, NR::translate const &tr)
{
the goal is met exactly and the stroke scaling is obeyed.
*/
-NR::Matrix
+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);
@@ -87,40 +97,59 @@ get_scale_transform_with_stroke (NR::Rect &bbox_param, gdouble strokewidth, bool
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 w0 = bbox.extent(NR::X); // will return a value >= 0, as required further down the road
gdouble h0 = bbox.extent(NR::Y);
- gdouble w1 = x1 - x0;
+ gdouble w1 = x1 - x0; // can have any sign
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))
- ) {
+ if (bbox.isEmpty()) {
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
+ return (move); // cannot scale from empty boxes at all, so only translate
}
NR::Matrix direct = NR::Matrix (NR::scale(w1 / w0, h1 / h0));
+
+ if (fabs(w0 - r0) < 1e-6 || fabs(h0 - r0) < 1e-6 || (!transform_stroke && (fabs(w1 - r0) < 1e-6 || fabs(h1 - r0) < 1e-6))) {
+ return (p2o * direct * o2n); // can't solve the equation: one of the dimensions is equal to stroke width, so return the straightforward scaler
+ }
+
+ int flip_x = (w1 > 0) ? 1 : -1;
+ int flip_y = (h1 > 0) ? 1 : -1;
+
+ // w1 and h1 will be negative when mirroring, but if so then e.g. w1-r0 won't make sense
+ // Therefore we will use the absolute values from this point on
+ w1 = fabs(w1);
+ h1 = fabs(h1);
+ r0 = fabs(r0);
+ // w0 and h0 will always be positive due to the definition extent()
+
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));
+
+ NR::Matrix direct_constant_r = NR::Matrix (NR::scale(flip_x * ratio_x, flip_y * 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);
+ // matrix. We're trying to solve this equation:
+ // r1 = r0 * sqrt (((w1-r0)/(w0-r0))*((h1-r1)/(h0-r0)))
+ // The operant of the sqrt() must be positive, which is ensured by the fabs() a few lines above
+ 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 r1 = fabs((-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";
+ //
+ // If w1 < 0 then the scale will be wrong if we just do
+ // gdouble scale_x = (w1 - r1)/(w0 - r0);
+ // Here we also need the absolute values of w0, w1, h0, h1, and r1
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));
+ scale *= NR::scale(flip_x * scale_x, flip_y * scale_y);
+ unbudge *= NR::translate (-flip_x * 0.5 * (r0 * scale_x - r1), -flip_y * 0.5 * (r0 * scale_y - r1));
} else {
scale *= direct;
}
@@ -129,7 +158,7 @@ get_scale_transform_with_stroke (NR::Rect &bbox_param, gdouble strokewidth, bool
scale *= direct;
} else {// nonscaling strokewidth
scale *= direct_constant_r;
- unbudge *= NR::translate (0.5 * r0 * (1 - ratio_x), 0.5 * r0 * (1 - ratio_y));
+ unbudge *= NR::translate (flip_x * 0.5 * r0 * (1 - ratio_x), flip_y * 0.5 * r0 * (1 - ratio_y));
}
}