From be0fb7e9eb6d47f0c8a7ada18e1b5951b3fb320e Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Fri, 26 Feb 2021 12:19:35 +0300
Subject: [PATCH] Fonts are guaranteed to preserve space symbols when shaping

---
 libs/ui/include/psemek/ui/monospace_font.hpp |  2 +-
 libs/ui/source/monospace_font.cpp            | 20 ++++++++++++++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/libs/ui/include/psemek/ui/monospace_font.hpp b/libs/ui/include/psemek/ui/monospace_font.hpp
index 30a01e87..ca251967 100644
--- a/libs/ui/include/psemek/ui/monospace_font.hpp
+++ b/libs/ui/include/psemek/ui/monospace_font.hpp
@@ -16,7 +16,7 @@ namespace psemek::ui
 
 		geom::vector<int, 2> size() const override { return size_; }
 
-		bool supports_character(char32_t c) const override { return c >= range_.begin && c < range_.end; }
+		bool supports_character(char32_t c) const override;
 		std::vector<character_range> supported_characters() const override { return {range_}; }
 
 		std::vector<glyph> shape(std::string_view str, shape_options const & options) const override;
diff --git a/libs/ui/source/monospace_font.cpp b/libs/ui/source/monospace_font.cpp
index 791a1954..dbbab4aa 100644
--- a/libs/ui/source/monospace_font.cpp
+++ b/libs/ui/source/monospace_font.cpp
@@ -32,6 +32,11 @@ namespace psemek::ui
 		return {1.f, 0.f};
 	}
 
+	bool monospace_font::supports_character(char32_t c) const
+	{
+		return std::isspace(c) || (c >= range_.begin && c < range_.end);
+	}
+
 	std::vector<glyph> monospace_font::shape(std::string_view str, shape_options const & options) const
 	{
 		char32_t const unknown = supports_character(options.unknown_character) ? options.unknown_character : '?';
@@ -44,8 +49,16 @@ namespace psemek::ui
 		for (char32_t c : util::utf8_range(str))
 		{
 			glyph g;
-			g.character = supports_character(c) ? c : unknown;
-			g.position = {{{pos[0], pos[0] + size[0]}, {pos[1], pos[1] + size[1]}}};
+			if (std::isspace(c))
+			{
+				g.character = c;
+				g.position = {{{pos[0], pos[0]}, {pos[1], pos[1]}}};
+			}
+			else
+			{
+				g.character = supports_character(c) ? c : unknown;
+				g.position = {{{pos[0], pos[0] + size[0]}, {pos[1], pos[1] + size[1]}}};
+			}
 			result.push_back(g);
 			pos += advance;
 		}
@@ -57,6 +70,9 @@ namespace psemek::ui
 	{
 		if (!supports_character(c)) return std::nullopt;
 
+		if (std::isspace(c))
+			return texcoords_[' ' - range_.begin];
+
 		return texcoords_[c - range_.begin];
 	}