From baea14611e37dfdeaa239b5567914f49dc298514 Mon Sep 17 00:00:00 2001
From: 23rd <23rd@vivaldi.net>
Date: Mon, 30 Nov 2020 09:17:12 +0300
Subject: [PATCH] Added class for radial gradient color animation.

---
 ui/effects/animation_value.h | 50 ++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/ui/effects/animation_value.h b/ui/effects/animation_value.h
index 93110ce..93db8f2 100644
--- a/ui/effects/animation_value.h
+++ b/ui/effects/animation_value.h
@@ -12,6 +12,7 @@
 
 #include <QtGui/QPainterPath>
 #include <QtGui/QLinearGradient>
+#include <QtGui/QRadialGradient>
 
 namespace anim {
 
@@ -404,6 +405,55 @@ private:
 
 };
 
+class radial_gradient {
+public:
+	radial_gradient(
+		std::vector<QColor> colors_from,
+		std::vector<QColor> colors_to,
+		QPointF center,
+		float radius)
+	: _colors_from(colors_from)
+	, _colors_to(colors_to)
+	, _center(center)
+	, _radius(radius)
+	, _gradient_from(gradient(colors_from))
+	, _gradient_to(gradient(colors_to)) {
+		Expects(colors_from.size() == colors_to.size());
+	}
+
+	QRadialGradient gradient(float64 b_ratio) const {
+		if (b_ratio == 0.) {
+			return _gradient_from;
+		} else if (b_ratio == 1.) {
+			return _gradient_to;
+		}
+		auto colors = std::vector<QColor>(_colors_to.size());
+		for (auto i = 0; i < colors.size(); i++) {
+			colors[i] = color(_colors_from[i], _colors_to[i], b_ratio);
+		}
+		return gradient(colors);
+	}
+
+private:
+	QRadialGradient gradient(const std::vector<QColor> &colors) const {
+		auto gradient = QRadialGradient(_center, _radius);
+		const auto size = colors.size();
+		for (auto i = 0; i < size; i++) {
+			gradient.setColorAt(i / (size - 1), colors[i]);
+		}
+		return gradient;
+	}
+
+	std::vector<QColor> _colors_from;
+	std::vector<QColor> _colors_to;
+	QPointF _center;
+	float _radius;
+
+	QRadialGradient _gradient_from;
+	QRadialGradient _gradient_to;
+
+};
+
 class continuous_value {
 public:
 	continuous_value() = default;