Engine: Allow configuration of font size and line spacing

assets/scene/scene1.json

@@ -42,9 +42,9 @@
 			"name": "Text",
 			"content": "Hello World!",
 			"font": "assets/fnt/open-sans",
-			"font-size": 10,
-			"width": 150,
-			"lines": 3
+			"font-size": 24,
+			"line-spacing": 1.0,
+			"width": 150
 		}
 	]
 }

src/inferno/component/textareacomponent.cpp

@@ -23,12 +23,12 @@ void fromJson(const ruc::Json& json, TextAreaComponent& value)
 	if (json.exists("font-size") && json.at("font-size").type() == ruc::Json::Type::Number) {
 		json.at("font-size").getTo(value.fontSize);
 	}
+	if (json.exists("line-spacing") && json.at("line-spacing").type() == ruc::Json::Type::Number) {
+		json.at("line-spacing").getTo(value.lineSpacing);
+	}
 	if (json.exists("width") && json.at("width").type() == ruc::Json::Type::Number) {
 		json.at("width").getTo(value.width);
 	}
-	if (json.exists("lines") && json.at("lines").type() == ruc::Json::Type::Number) {
-		json.at("lines").getTo(value.lines);
-	}
 }
 
 } // namespace Inferno

src/inferno/component/textareacomponent.h

@@ -18,9 +18,9 @@ namespace Inferno {
 struct TextAreaComponent {
 	std::string content;
 	std::string font;
-	uint32_t fontSize { 0 };
+	unsigned char fontSize { 0 };
+	float lineSpacing { 1.0f };
 	uint32_t width { 0 };
-	uint32_t lines { 0 };
 
 #if 0
 	TextAreaComponent() {}

src/inferno/render/font.cpp

@@ -55,7 +55,7 @@ void Font::parseFont(const std::string& font)
 		// ---------------------------------
 
 		if (action.compare("info") == 0) {
-			m_size = convert<uint32_t>(findValue("size", columns));
+			m_size = convert<unsigned char>(findValue("size", columns));
 			auto paddings = findValue("padding", columns) | std::views::split(',');
 			size_t i = 0;
 			for (const auto& padding : paddings) {
@@ -81,6 +81,7 @@ void Font::parseFont(const std::string& font)
 			uint32_t width = convert<uint32_t>(findValue("width", columns));
 			uint32_t height = convert<uint32_t>(findValue("height", columns));
 			Character character = {
+				.id = id,
 				.position = {
 					convert<uint32_t>(findValue("x", columns)) + m_padding[Padding::Left],
 					convert<uint32_t>(findValue("y", columns)) + m_padding[Padding::Top],

src/inferno/render/font.h

@@ -25,6 +25,7 @@ namespace Inferno {
 class Texture;
 
 struct Character {
+	char id;                                          // Character
 	glm::uvec2 position;                              // Position
 	glm::uvec2 size;                                  // Width/height
 	glm::ivec2 offset;                                // Offset from baseline to left / top of glyph
@@ -61,7 +62,7 @@ private:
 	std::string findValue(const std::string& key, const std::vector<std::string>& columns) const;
 
 	std::string m_name;
-	uint32_t m_size = { 0 };
+	unsigned char m_size = { 0 };
 	uint32_t m_lineSpacing = { 0 };
 	std::array<uint32_t, 4> m_padding = { 0 };
 	std::shared_ptr<Texture> m_texture;

src/inferno/system/textareasystem.cpp

@@ -48,25 +48,86 @@ void TextAreaSystem::render()
 		std::shared_ptr<Font> font = FontManager::the().load(textarea.font);
 		// glm::mat4 translate = transform.translate;
 
-		unsigned char previous = 0;
-		float advanceX = 0.0f;
-		float advanceY = 0.0f;
-		for (auto character : textarea.content) {
-			std::optional<CharacterQuad> quad = calculateCharacterQuad(character, previous, font, advanceX, advanceY);
-			previous = character;
-
-			if (quad) {
-				RendererCharacter::the().drawCharacter(quad.value(), font->texture());
-			}
+		m_characters.clear();
+		createLines(font, textarea);
+		createQuads(font, textarea);
+	}
+}
+
+using Characters = std::vector<std::shared_ptr<Character>>;
+
+void TextAreaSystem::createLines(std::shared_ptr<Font> font, const TextAreaComponent& textarea)
+{
+	float fontScale = textarea.fontSize / (float)font->size();
+
+	// 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");
+
+	// -------------------------------------
+
+	char previous = 0;
+	size_t spaceIndex = 0;
+	float lineWidth = 0.0f;
+	float lineWidthSinceLastSpace = 0.0f;
+	for (char character : textarea.content) {
+		auto c = font->get(character);
+		m_characters.push_back(c);
+
+		// Kerning
+		char kerning = 0;
+		if (c->kernings.find(previous) != c->kernings.end()) {
+			kerning = c->kernings.at(previous);
+		}
+
+		lineWidth += (c->advance + c->offset.x + kerning) * fontScale;
+		lineWidthSinceLastSpace += (c->advance + c->offset.x + kerning) * fontScale;
+
+		if (character == ' ') {
+			spaceIndex = m_characters.size() - 1;
+			lineWidthSinceLastSpace = 0;
+		}
+
+		if (lineWidth > textureWidth) {
+			m_characters[spaceIndex] = nullptr;
+			lineWidth = 0;
+			lineWidth = lineWidthSinceLastSpace;
 		}
+
+		previous = character;
 	}
 }
 
-std::optional<CharacterQuad> TextAreaSystem::calculateCharacterQuad(unsigned char character, unsigned char previous, std::shared_ptr<Font> font, float& advanceX, float& advanceY)
+void TextAreaSystem::createQuads(std::shared_ptr<Font> font, const TextAreaComponent& textarea)
 {
-	CharacterQuad characterQuad;
+	float fontScale = textarea.fontSize / (float)font->size();
+
+	char previous = 0;
+	float advanceX = 0.0f;
+	float advanceY = 0.0f;
+	for (const auto& character : m_characters) {
+		// Go to the next line on "\n"
+		if (character == nullptr) {
+			advanceX = 0;
+			advanceY -= (font->lineSpacing() * textarea.lineSpacing) * fontScale;
+			continue;
+		}
+
+		std::optional<CharacterQuad> quad = calculateCharacterQuad(character, previous, font, fontScale, advanceX, advanceY);
+		if (quad) {
+			RendererCharacter::the().drawCharacter(quad.value(), font->texture());
+		}
+
+		previous = character->id;
+	}
+}
 
-	auto c = font->get(character);
+std::optional<CharacterQuad> TextAreaSystem::calculateCharacterQuad(std::shared_ptr<Character> c, char previous, std::shared_ptr<Font> font, float fontScale, float& advanceX, float& advanceY)
+{
+	CharacterQuad characterQuad;
 
 	// Texture
 	// -------------------------------------
@@ -78,7 +139,7 @@ std::optional<CharacterQuad> TextAreaSystem::calculateCharacterQuad(unsigned cha
 	// Skip empty characters (like space)
 	if (c->size.x == 0 || c->size.y == 0) {
 		// Jump to the next glyph
-		advanceX += c->advance;
+		advanceX += c->advance * fontScale;
 		return {};
 	}
 
@@ -87,19 +148,13 @@ std::optional<CharacterQuad> TextAreaSystem::calculateCharacterQuad(unsigned cha
 
 	// Kerning
 	if (c->kernings.find(previous) != c->kernings.end()) {
-		advanceX += c->kernings.at(previous);
-	}
-
-	// Line wrapping
-	if (advanceX + c->offset.x + c->size.x > textureWidth) {
-		advanceX = 0;
-		advanceY -= font->lineSpacing();
+		advanceX += c->kernings.at(previous) * fontScale;
 	}
 
-	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 };
+	glm::vec2 cursor = { advanceX + (c->offset.x * fontScale),
+		                 advanceY - (c->offset.y * fontScale) };
+	glm::vec2 cursorMax = { cursor.x + (c->size.x * fontScale),
+		                    cursor.y - (c->size.y * fontScale) };
 
 	// Scale the values from 0:512 (texture size) to -1:1 (screen space)
 	glm::vec2 cursorScreen = {
@@ -117,7 +172,7 @@ std::optional<CharacterQuad> TextAreaSystem::calculateCharacterQuad(unsigned cha
 	characterQuad.at(3).quad.position = { cursorScreen.x, cursorScreen.y, 0.0f };       // top left
 
 	// Jump to the next glyph
-	advanceX += c->advance;
+	advanceX += c->advance * fontScale;
 
 	// Texture coordinates
 	// -------------------------------------

src/inferno/system/textareasystem.h

@@ -14,10 +14,13 @@
 #include "glm/ext/vector_float3.hpp" // glm::vec3
 #include "ruc/singleton.h"
 
+#include "inferno/component/textareacomponent.h"
+#include "inferno/render/font.h"
 #include "inferno/render/renderer.h"
 
 namespace Inferno {
 
+using Characters = std::vector<std::shared_ptr<Character>>;
 using CharacterQuad = std::array<CharacterVertex, Renderer::vertexPerQuad>;
 
 class Font;
@@ -33,8 +36,12 @@ public:
 	void setScene(Scene* scene) { m_scene = scene; }
 
 private:
-	std::optional<CharacterQuad> calculateCharacterQuad(unsigned char character, unsigned char previous, std::shared_ptr<Font> font, float& advanceX, float& advanceY);
+	void createLines(std::shared_ptr<Font> font, const TextAreaComponent& textarea);
+	void createQuads(std::shared_ptr<Font> font, const TextAreaComponent& textarea);
 
+	std::optional<CharacterQuad> calculateCharacterQuad(std::shared_ptr<Character> c, char previous, std::shared_ptr<Font> font, float fontSize, float& advanceX, float& advanceY);
+
+	Characters m_characters;
 	Scene* m_scene { nullptr };
 };