* TextGenerator -> Font

1 files changed, 110 insertions, 0 deletions

diff --git a/Runtime/GUI/Font.h b/Runtime/GUI/Font.h
index e69de29..da9ef55 100644
--- a/Runtime/GUI/Font.h
+++ b/Runtime/GUI/Font.h
@@ -0,0 +1,110 @@
+#pragma once 
+
+#include "Runtime/Utilities/Singleton.h"
+#include "Runtime/Graphics/Texture.h"
+#include "freetype.h"
+#include "Runtime/Lua/LuaHelper.h"
+
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+//https://learnopengl.com/In-Practice/Text-Rendering
+
+struct Character {
+	unsigned int      atlas;    // atlas索引
+	Internal::Rect    position; // 在altas里的位置
+	Internal::Vector2 bearing;  // 左上角相对于原点的偏移
+	unsigned int      advance;  // 总宽，算上了间隔
+};
+
+namespace character
+{
+	typedef unsigned short Codepoint; // unicode Codepoint（BMP，U+0000至U+FFFF)
+
+	union Hash {
+		unsigned int hashCode;
+		struct {
+			Codepoint codepoint;
+			unsigned short size;//字体大小
+		};
+		bool operator==(const Hash &other) const
+		{
+			return codepoint == other.codepoint && size == other.size;
+		}
+	};
+}
+
+namespace std
+{
+	template <>
+	struct hash<character::Hash>
+	{
+		std::size_t operator()(const character::Hash& k) const
+		{
+			return k.hashCode;
+		}
+	};
+}
+
+struct GlyphAtals
+{
+	int index;
+	Texture* altas;           // 贴图
+	int width, height;        // 尺寸
+
+	Internal::Vector2 cursor; // 游标，从左上角（0,0）开始
+	int rowHeight;            // 当前行的高度
+};
+
+struct TextGeneratingSettings
+{
+	Internal::Vector2 atlasSize; // atlas的尺寸
+	int margin;  // atlas的边界
+	int padding; // glyph相互之间的间距，防止采样的时候越界
+};
+
+class Font : public Singleton<Font>
+{
+public:
+	void Setup(TextGeneratingSettings settings);
+
+	const Character* GetCharacter(character::Codepoint codepoint, int pixelSize);
+	const GlyphAtals* GetGlyphAtlas(int index);
+
+	// pre-bake
+	void RenderCharacter(character::Codepoint codepoint, int pixelSize);
+	void RenderCharacters(character::Codepoint* codepoint, int n, int pixelSize);
+
+private: 
+
+	Texture* CreateAtlas();
+	GlyphAtals* RequestAtlas(int pixelSize, Internal::Vector2 preferSize);
+
+	Internal::Rect GetRenderChartAndMove(GlyphAtals* atlas, Internal::Vector2 preferSize);
+	bool HasEnoughSpace(GlyphAtals* atlas, Internal::Vector2 preferSize);
+
+	character::Hash GetHash(character::Codepoint Codepoint, int pixelSize);
+
+	std::unordered_map<character::Hash, Character> m_Characters; // 渲染完的文字
+
+	std::vector<GlyphAtals> m_Atlases; // 当前所有的atlas
+	std::unordered_map<int, GlyphAtals*> m_AtlasCache;  // 快速找到可用的atlas
+
+	int m_AtlasMargin;
+	int m_GlyphPadding;
+	Internal::Vector2 m_AtlasSize;
+
+	FT_Library m_FTLibrary;
+	FT_Face m_FTFace;
+
+};
+
+#define g_TextGenerator (*Font::Instance())
+
+namespace TextHelper
+{
+
+	void print_glyph(unsigned char* glyph, int width, int height);
+
+}