feat: graphs now properly sized + port static graphs to c++

Plugins/ZShell/Components/sparklinecontent.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <qcolor.h>
+#include <qelapsedtimer.h>
 #include <qpainterpath.h>
 #include <qquickpainteditem.h>
 
@@ -30,6 +31,15 @@ class SparklineContent : public QQuickPaintedItem {
 
 	void setViewportSize(qreal viewportWidth, qreal viewportHeight);
 
+	// How often a new sample arrives, in milliseconds. With this set the slide
+	// phase is read from the sample clock rather than from `progress`, which
+	// makes the wrap exact; without it the phase is the value QML supplies.
+	void setSlideInterval(qreal intervalMs);
+
+	// Offsets the item for the slide. Kept here rather than in SparklineItem
+	// because the quantization needs both stepX() and the window's dpr.
+	void setSlideProgress(qreal progress);
+
 	[[nodiscard]] qreal stepX() const;
 
 	protected:
@@ -44,12 +54,15 @@ class SparklineContent : public QQuickPaintedItem {
 		bool hasData = false;
 	};
 
+	[[nodiscard]] qreal slidePhase(qreal progress) const;
+
 	void invalidate();
 	void rebuildIfNeeded();
 	[[nodiscard]] LineGeometry buildGeometry(
 		internal::CircularBuffer* buffer) const;
 	void connectBuffer(internal::CircularBuffer* buffer);
 	void applyGeometry();
+	void onSampleArrived();
 
 	internal::CircularBuffer* m_line1 = nullptr;
 	internal::CircularBuffer* m_line2 = nullptr;
@@ -65,7 +78,14 @@ class SparklineContent : public QQuickPaintedItem {
 
 	qreal m_viewportW = 0.0;
 	qreal m_viewportH = 0.0;
+	// The height actually painted, snapped so the texture maps 1:1 onto device
+	// rows. The plot bounds are built from this, not from the slot's height.
+	qreal m_paintedH = 0.0;
 	qreal m_dpr = 1.0;
+	qreal m_slideIntervalMs = 0.0;
+	// Restarted whenever a sample arrives, so the slide phase follows the sample
+	// cadence instead of the animation's timeline.
+	QElapsedTimer m_sampleClock;
 
 	LineGeometry m_geom1;
 	LineGeometry m_geom2;