From 934512f7622428db7574e20b61a2171990ddfc34 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Sat, 17 Jul 2021 17:42:30 +0300
Subject: [PATCH] Support scaling ui styles

---
 libs/ui/include/psemek/ui/style.hpp |  2 ++
 libs/ui/source/style.cpp            | 47 ++++++++++++++++++++++++-----
 2 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/libs/ui/include/psemek/ui/style.hpp b/libs/ui/include/psemek/ui/style.hpp
index f70881de..f86edecb 100644
--- a/libs/ui/include/psemek/ui/style.hpp
+++ b/libs/ui/include/psemek/ui/style.hpp
@@ -39,6 +39,8 @@ namespace psemek::ui
 
 	void merge(style & dst, style const & src);
 
+	style scale(style const & s, float factor);
+
 	style default_style();
 
 }
diff --git a/libs/ui/source/style.cpp b/libs/ui/source/style.cpp
index 8f3e96e8..50444d82 100644
--- a/libs/ui/source/style.cpp
+++ b/libs/ui/source/style.cpp
@@ -3,16 +3,33 @@
 namespace psemek::ui
 {
 
-	template <typename T>
-	void merge(std::optional<T> & dst, std::optional<T> const & src)
+	namespace
 	{
-		if (!dst) dst = src;
-	}
 
-	template <typename T>
-	void merge(std::shared_ptr<T> & dst, std::shared_ptr<T> const & src)
-	{
-		if (!dst) dst = src;
+		template <typename T>
+		void merge(std::optional<T> & dst, std::optional<T> const & src)
+		{
+			if (!dst) dst = src;
+		}
+
+		template <typename T>
+		void merge(std::shared_ptr<T> & dst, std::shared_ptr<T> const & src)
+		{
+			if (!dst) dst = src;
+		}
+
+		template <typename T>
+		void scale(T & dst, float factor)
+		{
+			if (dst) dst = static_cast<T>((*dst) * factor);
+		}
+
+		template <typename T, std::size_t N>
+		void scale(std::optional<geom::vector<T, N>> & dst, float factor)
+		{
+			if (dst) dst = geom::cast<T>(geom::cast<float>(*dst) * factor);
+		}
+
 	}
 
 	void merge(style & dst, style const & src)
@@ -36,6 +53,20 @@ namespace psemek::ui
 		merge(dst.font, src.font);
 	}
 
+	style scale(style const & s, float factor)
+	{
+		style result = s;
+		scale(result.action_offset, factor);
+		scale(result.border_width, factor);
+		scale(result.ref_height, factor);
+		scale(result.shadow_offset, factor);
+		scale(result.inner_margin, factor);
+		scale(result.outer_margin, factor);
+		scale(result.text_scale, factor);
+		scale(result.text_shadow_offset, factor);
+		return result;
+	}
+
 	style default_style()
 	{
 		style s;