Engine: Fix font spacing in TextAreaComponent

src/inferno/component/textareacomponent.cpp

@@ -27,7 +27,7 @@ void fromJson(const ruc::Json& json, TextAreaComponent& value)
 		json.at("width").getTo(value.width);
 	}
 	if (json.exists("lines") && json.at("lines").type() == ruc::Json::Type::Number) {
-		json.at("lines").getTo(value.width);
+		json.at("lines").getTo(value.lines);
 	}
 }
 

src/inferno/render/font.cpp

@@ -4,13 +4,18 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <array>    // std::array
+#include <charconv> // std;:from_chars
+#include <cstdint>  // int32_t, uint32_t
 #include <limits>   // std::numeric_limits
-#include <string>  // std::getline, std::stoi
+#include <ranges>   // std::views::split
+#include <string>   // std::getline
 #include <utility>  // std::move
 
 #include "ruc/file.h"
 #include "ruc/format/log.h"
 #include "ruc/meta/assert.h"
+#include "ruc/meta/concepts.h"
 
 #include "inferno/render/font.h"
 #include "inferno/render/texture.h"
@@ -30,43 +35,96 @@ Font::Font(const std::string& name)
 	m_texture = std::make_shared<Texture>(image);
 }
 
+// TODO: Move this to ruc
+template<Integral T>
+static T convert(std::string_view value)
+{
+	T tmp;
+	std::from_chars(value.data(), value.data() + value.size(), tmp);
+	return tmp;
+}
+
 void Font::parseFont(const std::string& font)
 {
 	std::istringstream iss(font);
 	for (std::string line; std::getline(iss, line);) {
+		std::string action = findAction(line);
+		const std::vector<std::string> columns = findColumns(line);
+
+		// Info
+		// ---------------------------------
 
-		if (findAction(line).compare("info") != 0 && findAction(line).compare("char") != 0) {
+		if (action.compare("info") == 0) {
+			m_size = convert<uint32_t>(findValue("size", columns));
+			auto paddings = findValue("padding", columns) | std::views::split(',');
+			size_t i = 0;
+			for (const auto& padding : paddings) {
+				// top, right, bottom, left
+				m_padding[i++] = convert<uint32_t>(padding.data()) - PADDING;
+			}
 			continue;
 		}
 
-		const std::vector<std::string> columns = findColumns(line);
-
-		// Info
+		// Common
+		// ---------------------------------
 
-		if (findAction(line).compare("info") == 0) {
-			m_size = std::stou(findValue("size", columns));
+		if (action.compare("common") == 0) {
+			m_lineSpacing = convert<uint32_t>(findValue("lineHeight", columns)) - m_padding[Padding::Top] - m_padding[Padding::Bottom];
 			continue;
 		}
 
 		// Character
+		// ---------------------------------
 
-		unsigned char id = std::stoi(findValue("id", columns));
+		if (action.compare("char") == 0) {
+			unsigned char id = convert<unsigned char>(findValue("id", columns));
+			uint32_t width = convert<uint32_t>(findValue("width", columns));
+			uint32_t height = convert<uint32_t>(findValue("height", columns));
 			Character character = {
-			{ std::stou(findValue("x", columns)), std::stou(findValue("y", columns)) },
-			{ std::stou(findValue("width", columns)), std::stou(findValue("height", columns)) },
-			{ std::stoi(findValue("xoffset", columns)), std::stoi(findValue("yoffset", columns)) },
-			std::stou(findValue("xadvance", columns))
+				.position = {
+					convert<uint32_t>(findValue("x", columns)) + m_padding[Padding::Left],
+					convert<uint32_t>(findValue("y", columns)) + m_padding[Padding::Top],
+				},
+				.size = {
+					width == 0 ? 0 : width - m_padding[Padding::Left] - m_padding[Padding::Right],
+					height == 0 ? 0 : height - m_padding[Padding::Top] - m_padding[Padding::Bottom],
+				},
+				.offset = {
+					convert<int32_t>(findValue("xoffset", columns)) + m_padding[Padding::Left],
+					convert<int32_t>(findValue("yoffset", columns)) + m_padding[Padding::Top],
+				},
+				.advance = convert<uint32_t>(findValue("xadvance", columns)) - m_padding[Padding::Left] - m_padding[Padding::Right]
 			};
+
 			m_characterList.emplace(id, std::make_shared<Character>(character));
+			continue;
+		}
+
+		// Kerning
+		// ---------------------------------
+
+		if (action.compare("kerning") == 0) {
+			unsigned char first = convert<unsigned char>(findValue("first", columns));
+			unsigned char second = convert<unsigned char>(findValue("second", columns));
+			char amount = convert<char>(findValue("amount", columns));
+
+			// Add the kerning of the previous character to this character
+			if (m_characterList.find(second) != m_characterList.end()) {
+				auto character = m_characterList.at(second);
+				character->kernings.emplace(first, amount);
+			}
+
+			continue;
+		}
 	}
 }
 
-const std::string Font::findAction(const std::string& line)
+std::string Font::findAction(const std::string& line) const
 {
 	return line.substr(0, line.find(" "));
 }
 
-const std::vector<std::string> Font::findColumns(const std::string& line)
+std::vector<std::string> Font::findColumns(const std::string& line) const
 {
 	std::vector<std::string> elements;
 
@@ -93,7 +151,7 @@ const std::vector<std::string> Font::findColumns(const std::string& line)
 	return elements;
 }
 
-const std::string Font::findValue(const std::string& key, const std::vector<std::string>& columns)
+std::string Font::findValue(const std::string& key, const std::vector<std::string>& columns) const
 {
 	size_t find = 0;
 	// Loop over columns

src/inferno/render/font.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <array>         // std::array
 #include <cstdint>       // int32_t, uint32_t
 #include <memory>        // std::shared_ptr
 #include <string>        // std::string
@@ -17,6 +18,8 @@
 #include "ruc/format/format.h"
 #include "ruc/singleton.h"
 
+#define PADDING 3
+
 namespace Inferno {
 
 class Texture;
@@ -26,6 +29,7 @@ struct Character {
 	glm::uvec2 size;                                  // Width/height
 	glm::ivec2 offset;                                // Offset from baseline to left / top of glyph
 	uint32_t advance;                                 // Amount to advance to next glyph
+	std::unordered_map<unsigned char, char> kernings; // Kernings for characters that come before this one
 };
 
 // -------------------------------------
@@ -35,8 +39,16 @@ public:
 	Font(const std::string& name);
 	virtual ~Font() {}
 
+	enum Padding {
+		Top = 0,
+		Right,
+		Bottom,
+		Left,
+	};
+
 	inline std::string name() const { return m_name; }
 	inline uint32_t size() const { return m_size; }
+	inline uint32_t lineSpacing() const { return m_lineSpacing; }
 	inline std::shared_ptr<Texture> texture() const { return m_texture; }
 
 	inline std::shared_ptr<Character> get(unsigned char c) const { return m_characterList.at(c); }
@@ -44,12 +56,14 @@ public:
 
 private:
 	void parseFont(const std::string& font);
-	const std::string findAction(const std::string& line);
-	const std::vector<std::string> findColumns(const std::string& line);
-	const std::string findValue(const std::string& key, const std::vector<std::string>& columns);
+	std::string findAction(const std::string& line) const;
+	std::vector<std::string> findColumns(const std::string& line) const;
+	std::string findValue(const std::string& key, const std::vector<std::string>& columns) const;
 
 	std::string m_name;
-	uint32_t m_size;
+	uint32_t m_size = { 0 };
+	uint32_t m_lineSpacing = { 0 };
+	std::array<uint32_t, 4> m_padding = { 0 };
 	std::shared_ptr<Texture> m_texture;
 	std::unordered_map<unsigned char, std::shared_ptr<Character>> m_characterList;
 };

src/inferno/system/textareasystem.cpp

@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <algorithm> // std::max
+
 #include "ruc/format/log.h"
 #include "ruc/meta/assert.h"
 
@@ -46,9 +48,12 @@ void TextAreaSystem::render()
 		std::shared_ptr<Font> font = FontManager::the().load(textarea.font);
 		// glm::mat4 translate = transform.translate;
 
-		float advance = 0.0f;
+		unsigned char previous = 0;
+		float advanceX = 0.0f;
+		float advanceY = 0.0f;
 		for (auto character : textarea.content) {
-			std::optional<CharacterQuad> quad = calculateCharacterQuad(character, font, advance);
+			std::optional<CharacterQuad> quad = calculateCharacterQuad(character, previous, font, advanceX, advanceY);
+			previous = character;
 
 			if (quad) {
 				RendererCharacter::the().drawCharacter(quad.value(), font->texture());
@@ -57,53 +62,65 @@ void TextAreaSystem::render()
 	}
 }
 
-std::optional<CharacterQuad> TextAreaSystem::calculateCharacterQuad(unsigned char character, std::shared_ptr<Font> font, float& advance)
+std::optional<CharacterQuad> TextAreaSystem::calculateCharacterQuad(unsigned char character, unsigned char previous, std::shared_ptr<Font> font, float& advanceX, float& advanceY)
 {
 	CharacterQuad characterQuad;
 
 	auto c = font->get(character);
 
 	// Texture
-	// ---------------------------------
+	// -------------------------------------
 
 	float textureWidth = static_cast<float>(font->texture()->width());
 	float textureHeight = static_cast<float>(font->texture()->height());
 	VERIFY(textureWidth == textureHeight, "TextAreaSystem read invalid font texture");
 
-	// Skip empty characters
+	// Skip empty characters (like space)
 	if (c->size.x == 0 || c->size.y == 0) {
 		// Jump to the next glyph
-		advance += c->advance / textureWidth;
+		advanceX += c->advance;
 		return {};
 	}
 
 	// Position
-	// ---------------------------------
+	// -------------------------------------
 
-	float quadWidth = c->size.x / textureWidth;
-	float quadHeight = c->size.y / textureHeight;
-	characterQuad.at(0).quad.position = { -quadWidth, -quadHeight, 0.0f }; // bottom left
-	characterQuad.at(1).quad.position = { quadWidth, -quadHeight, 0.0f };  // bottom right
-	characterQuad.at(2).quad.position = { quadWidth, quadHeight, 0.0f };   // top right
-	characterQuad.at(3).quad.position = { -quadWidth, quadHeight, 0.0f };  // top left
+	// Kerning
+	if (c->kernings.find(previous) != c->kernings.end()) {
+		advanceX += c->kernings.at(previous);
+	}
 
-	for (auto& quad : characterQuad) {
-		quad.quad.position.x -= 0.5f;
+	// Line wrapping
+	if (advanceX + c->offset.x + c->size.x > textureWidth) {
+		advanceX = 0;
+		advanceY -= font->lineSpacing();
+	}
 
-		quad.quad.position.x += c->offset.x / (float)textureWidth;
-		quad.quad.position.y -= c->offset.y / (float)textureHeight;
+	glm::vec2 cursor = { std::max(advanceX + c->offset.x, 0.0f),
+		                 advanceY - c->offset.y };
+	glm::vec2 cursorMax = { cursor.x + c->size.x,
+		                    cursor.y - c->size.y };
 
-		quad.quad.position.x += advance;
-	}
+	// Scale the values from 0:512 (texture size) to -1:1 (screen space)
+	glm::vec2 cursorScreen = {
+		(cursor.x / textureWidth * 2) - 1,
+		(cursor.y / textureHeight * 2) + 1,
+	};
+	glm::vec2 cursorScreenMax = {
+		(cursorMax.x / textureWidth * 2) - 1,
+		(cursorMax.y / textureHeight * 2) + 1,
+	};
 
-	// ruc::debug("character: {} ({}) width: {} height: {} advance: {} x: {}",
-	//       character, (int)character, quadWidth, quadHeight, advance, characterQuad.at(0).quad.position.x);
+	characterQuad.at(0).quad.position = { cursorScreen.x, cursorScreenMax.y, 0.0f };    // bottom left
+	characterQuad.at(1).quad.position = { cursorScreenMax.x, cursorScreenMax.y, 0.0f }; // bottom right
+	characterQuad.at(2).quad.position = { cursorScreenMax.x, cursorScreen.y, 0.0f };    // top right
+	characterQuad.at(3).quad.position = { cursorScreen.x, cursorScreen.y, 0.0f };       // top left
 
 	// Jump to the next glyph
-	advance += c->advance / textureWidth;
+	advanceX += c->advance;
 
 	// Texture coordinates
-	// ---------------------------------
+	// -------------------------------------
 
 	glm::vec2 x {
 		1 - (textureWidth - c->position.x) / textureWidth,

src/inferno/system/textareasystem.h

@@ -33,7 +33,7 @@ public:
 	void setScene(Scene* scene) { m_scene = scene; }
 
 private:
-	std::optional<CharacterQuad> calculateCharacterQuad(unsigned char character, std::shared_ptr<Font> font, float& advance);
+	std::optional<CharacterQuad> calculateCharacterQuad(unsigned char character, unsigned char previous, std::shared_ptr<Font> font, float& advanceX, float& advanceY);
 
 	Scene* m_scene { nullptr };
 };