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-rw-r--r--src/object/sp-radial-gradient.cpp252
1 files changed, 252 insertions, 0 deletions
diff --git a/src/object/sp-radial-gradient.cpp b/src/object/sp-radial-gradient.cpp
new file mode 100644
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--- /dev/null
+++ b/src/object/sp-radial-gradient.cpp
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#include <cairo.h>
+
+#include "sp-radial-gradient.h"
+
+#include "attributes.h"
+#include "style.h"
+#include "xml/repr.h"
+
+#include <2geom/transforms.h>
+
+/*
+ * Radial Gradient
+ */
+SPRadialGradient::SPRadialGradient() : SPGradient() {
+ this->cx.unset(SVGLength::PERCENT, 0.5, 0.5);
+ this->cy.unset(SVGLength::PERCENT, 0.5, 0.5);
+ this->r.unset(SVGLength::PERCENT, 0.5, 0.5);
+ this->fx.unset(SVGLength::PERCENT, 0.5, 0.5);
+ this->fy.unset(SVGLength::PERCENT, 0.5, 0.5);
+ this->fr.unset(SVGLength::PERCENT, 0.5, 0.5);
+}
+
+SPRadialGradient::~SPRadialGradient() = default;
+
+/**
+ * Set radial gradient attributes from associated repr.
+ */
+void SPRadialGradient::build(SPDocument *document, Inkscape::XML::Node *repr) {
+ SPGradient::build(document, repr);
+
+ this->readAttr(SPAttr::CX);
+ this->readAttr(SPAttr::CY);
+ this->readAttr(SPAttr::R);
+ this->readAttr(SPAttr::FX);
+ this->readAttr(SPAttr::FY);
+ this->readAttr(SPAttr::FR);
+}
+
+/**
+ * Set radial gradient attribute.
+ */
+void SPRadialGradient::set(SPAttr key, gchar const *value) {
+
+ switch (key) {
+ case SPAttr::CX:
+ if (!this->cx.read(value)) {
+ this->cx.unset(SVGLength::PERCENT, 0.5, 0.5);
+ }
+
+ if (!this->fx._set) {
+ this->fx.value = this->cx.value;
+ this->fx.computed = this->cx.computed;
+ }
+
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ break;
+
+ case SPAttr::CY:
+ if (!this->cy.read(value)) {
+ this->cy.unset(SVGLength::PERCENT, 0.5, 0.5);
+ }
+
+ if (!this->fy._set) {
+ this->fy.value = this->cy.value;
+ this->fy.computed = this->cy.computed;
+ }
+
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ break;
+
+ case SPAttr::R:
+ if (!this->r.read(value)) {
+ this->r.unset(SVGLength::PERCENT, 0.5, 0.5);
+ }
+
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ break;
+
+ case SPAttr::FX:
+ if (!this->fx.read(value)) {
+ this->fx.unset(this->cx.unit, this->cx.value, this->cx.computed);
+ }
+
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ break;
+
+ case SPAttr::FY:
+ if (!this->fy.read(value)) {
+ this->fy.unset(this->cy.unit, this->cy.value, this->cy.computed);
+ }
+
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ break;
+
+ case SPAttr::FR:
+ if (!this->fr.read(value)) {
+ this->fr.unset(SVGLength::PERCENT, 0.0, 0.0);
+ }
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ break;
+
+ default:
+ SPGradient::set(key, value);
+ break;
+ }
+}
+
+void
+SPRadialGradient::update(SPCtx *ctx, guint flags)
+{
+ // To do: Verify flags.
+ if (flags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG | SP_OBJECT_VIEWPORT_MODIFIED_FLAG)) {
+
+ SPItemCtx const *ictx = reinterpret_cast<SPItemCtx const *>(ctx);
+
+ if (getUnits() == SP_GRADIENT_UNITS_USERSPACEONUSE) {
+ double w = ictx->viewport.width();
+ double h = ictx->viewport.height();
+ double d = sqrt ((w*w + h*h)/2.0);
+ double const em = style->font_size.computed;
+ double const ex = 0.5 * em; // fixme: get x height from pango or libnrtype.
+
+ this->cx.update(em, ex, w);
+ this->cy.update(em, ex, h);
+ this->r.update(em, ex, d);
+ this->fx.update(em, ex, w);
+ this->fy.update(em, ex, h);
+ this->fr.update(em, ex, d);
+ }
+ }
+}
+
+/**
+ * Write radial gradient attributes to associated repr.
+ */
+Inkscape::XML::Node* SPRadialGradient::write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, guint flags) {
+ if ((flags & SP_OBJECT_WRITE_BUILD) && !repr) {
+ repr = xml_doc->createElement("svg:radialGradient");
+ }
+
+ if ((flags & SP_OBJECT_WRITE_ALL) || this->cx._set) {
+ repr->setAttributeSvgDouble("cx", this->cx.computed);
+ }
+
+ if ((flags & SP_OBJECT_WRITE_ALL) || this->cy._set) {
+ repr->setAttributeSvgDouble("cy", this->cy.computed);
+ }
+
+ if ((flags & SP_OBJECT_WRITE_ALL) || this->r._set) {
+ repr->setAttributeSvgDouble("r", this->r.computed);
+ }
+
+ if ((flags & SP_OBJECT_WRITE_ALL) || this->fx._set) {
+ repr->setAttributeSvgDouble("fx", this->fx.computed);
+ }
+
+ if ((flags & SP_OBJECT_WRITE_ALL) || this->fy._set) {
+ repr->setAttributeSvgDouble("fy", this->fy.computed);
+ }
+
+ if ((flags & SP_OBJECT_WRITE_ALL) || this->fr._set) {
+ repr->setAttributeSvgDouble("fr", this->fr.computed);
+ }
+
+ SPGradient::write(xml_doc, repr, flags);
+
+ return repr;
+}
+
+cairo_pattern_t* SPRadialGradient::pattern_new(cairo_t *ct, Geom::OptRect const &bbox, double opacity) {
+ this->ensureVector();
+
+ Geom::Point focus(this->fx.computed, this->fy.computed);
+ Geom::Point center(this->cx.computed, this->cy.computed);
+
+ double radius = this->r.computed;
+ double focusr = this->fr.computed;
+ double scale = 1.0;
+ double tolerance = cairo_get_tolerance(ct);
+
+ // NOTE: SVG2 will allow the use of a focus circle which can
+ // have its center outside the first circle.
+
+ // code below suggested by Cairo devs to overcome tolerance problems
+ // more: https://bugs.freedesktop.org/show_bug.cgi?id=40918
+
+ // Corrected for
+ // https://bugs.launchpad.net/inkscape/+bug/970355
+
+ Geom::Affine gs2user = this->gradientTransform;
+
+ if (this->getUnits() == SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX && bbox) {
+ Geom::Affine bbox2user(bbox->width(), 0, 0, bbox->height(), bbox->left(), bbox->top());
+ gs2user *= bbox2user;
+ }
+
+ // we need to use vectors with the same direction to represent the transformed
+ // radius and the focus-center delta, because gs2user might contain non-uniform scaling
+ Geom::Point d(focus - center);
+ Geom::Point d_user(d.length(), 0);
+ Geom::Point r_user(radius, 0);
+ Geom::Point fr_user(focusr, 0);
+ d_user *= gs2user.withoutTranslation();
+ r_user *= gs2user.withoutTranslation();
+ fr_user *= gs2user.withoutTranslation();
+
+ double dx = d_user.x(), dy = d_user.y();
+ cairo_user_to_device_distance(ct, &dx, &dy);
+
+ // compute the tolerance distance in user space
+ // create a vector with the same direction as the transformed d,
+ // with the length equal to tolerance
+ double dl = hypot(dx, dy);
+ double tx = tolerance * dx / dl, ty = tolerance * dy / dl;
+ cairo_device_to_user_distance(ct, &tx, &ty);
+ double tolerance_user = hypot(tx, ty);
+
+ if (d_user.length() + tolerance_user > r_user.length()) {
+ scale = r_user.length() / d_user.length();
+
+ // nudge the focus slightly inside
+ scale *= 1.0 - 2.0 * tolerance / dl;
+ }
+
+ cairo_pattern_t *cp = cairo_pattern_create_radial(
+ scale * d.x() + center.x(), scale * d.y() + center.y(), focusr,
+ center.x(), center.y(), radius);
+
+ sp_gradient_pattern_common_setup(cp, this, bbox, opacity);
+
+ return cp;
+}
+
+/*
+ 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 :
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