fix: reduce shader usage

Plugins/ZShell/Components/roundedclip.cpp

@@ -0,0 +1,131 @@
+#include "roundedclip.hpp"
+
+#include <private/qquickclipnode_p.h>
+#include <private/qquickitem_p.h>
+
+#include <qsggeometry.h>
+
+#include <algorithm>
+#include <cmath>
+
+namespace ZShell::components {
+
+RoundedClip::RoundedClip(QQuickItem* parent) : QQuickItem(parent) {
+	setFlag(ItemHasContents);
+	setClip(true);
+}
+
+bool RoundedClip::updateRadius(qreal& member, qreal radius) {
+	if (qFuzzyCompare(member + 1.0, radius + 1.0)) return false;
+
+	member = radius;
+	update();
+	return true;
+}
+
+void RoundedClip::geometryChange(
+	const QRectF& newGeometry, const QRectF& oldGeometry) {
+	QQuickItem::geometryChange(newGeometry, oldGeometry);
+	if (newGeometry.size() != oldGeometry.size()) update();
+}
+
+QSGNode* RoundedClip::updatePaintNode(
+	QSGNode* oldNode, UpdatePaintNodeData* data) {
+	Q_UNUSED(oldNode)
+	Q_UNUSED(data)
+
+	QQuickItemPrivate* priv = QQuickItemPrivate::get(this);
+	QQuickDefaultClipNode* clip = priv->clipNode();
+
+	if (!clip) return nullptr;
+
+	// Clip node geometry is in item-local coordinates. The clip node is a
+	// child of the item's transform node, so the clip rect is
+	// QRectF(0, 0, width, height), i.e. boundingRect()/clipRect().
+	const QRectF r(0, 0, width(), height());
+
+	// Per-corner radii fall back to the shared `radius` shorthand.
+	const qreal tl = m_topLeftRadius > 0 ? m_topLeftRadius : m_radius;
+	const qreal tr = m_topRightRadius > 0 ? m_topRightRadius : m_radius;
+	const qreal br = m_bottomRightRadius > 0 ? m_bottomRightRadius : m_radius;
+	const qreal bl = m_bottomLeftRadius > 0 ? m_bottomLeftRadius : m_radius;
+
+	// Nothing rounded: plain rectangular clip.
+	if (tl <= 0 && tr <= 0 && br <= 0 && bl <= 0) {
+		clip->setRect(r);
+		clip->update();
+		return nullptr;
+	}
+
+	// All corners equal: let QQuickDefaultClipNode build its own known-correct
+	// scanline geometry. This is the working path.
+	if (qFuzzyCompare(tl, tr) && qFuzzyCompare(tr, br) &&
+		qFuzzyCompare(br, bl)) {
+		clip->setRect(r);
+		clip->setRadius(tl);
+		clip->update();
+		return nullptr;
+	}
+
+	// Per-corner radii. setRadius() supports only a single value, so we
+	// must supply the geometry ourselves. Build it as a triangle fan from an
+	// interior point so the polygon interior fills for the stencil clip.
+	const qreal half = std::min(r.width() / 2, r.height() / 2);
+	const qreal rtl = std::min(tl, half);
+	const qreal rtr = std::min(tr, half);
+	const qreal rbr = std::min(br, half);
+	const qreal rbl = std::min(bl, half);
+
+	auto segments = [](qreal radius) {
+		return qMin(30, int(std::ceil(radius)));
+	};
+
+	const int s_tl = segments(rtl);
+	const int s_tr = segments(rtr);
+	const int s_br = segments(rbr);
+	const int s_bl = segments(rbl);
+
+	clip->setRect(r);
+	clip->setIsRectangular(false);
+
+	QSGGeometry* g = clip->geometry();
+	g->setDrawingMode(QSGGeometry::DrawTriangleFan);
+
+	// One apex + one point per arc step + one point per zero-radius corner,
+	// plus a closing apex to complete the fan.
+	g->allocate(1 + s_tl + s_tr + s_br + s_bl + 5);
+
+	QSGGeometry::Point2D* vertices = g->vertexDataAsPoint2D();
+	int vi = 0;
+
+	// Apex at an interior point.
+	vertices[vi++] =
+		QSGGeometry::Point2D(float(r.center().x()), float(r.center().y()));
+
+	// Each corner contributes its arc points (i = 0..segments) from its
+	// edge-entry tangent to its edge-exit tangent. Consecutive corners are
+	// joined by the implicit straight edges, forming the rounded rectangle.
+	auto addArc =
+		[&](int segs, qreal cx, qreal cy, qreal rad, qreal a0, qreal a1) {
+			for (int i = 0; i <= segs; ++i) {
+				const qreal angle = a0 + (a1 - a0) * qreal(i) / qreal(segs);
+				vertices[vi++] = QSGGeometry::Point2D(
+					float(cx + rad * std::cos(angle)),
+					float(cy + rad * std::sin(angle)));
+			}
+		};
+
+	addArc(s_tl, rtl, rtl, rtl, M_PI, 3.0 * M_PI / 2.0);
+	addArc(s_tr, r.width() - rtr, rtr, rtr, -M_PI / 2.0, 0.0);
+	addArc(s_br, r.width() - rbr, r.height() - rbr, rbr, 0.0, M_PI / 2.0);
+	addArc(s_bl, rbl, r.height() - rbl, rbl, M_PI / 2.0, M_PI);
+
+	// Close the fan back to the first perimeter vertex.
+	vertices[vi] = vertices[1];
+
+	clip->markDirty(QSGNode::DirtyGeometry);
+
+	return nullptr;
+}
+
+} // namespace ZShell::components