1 files changed, 214 insertions, 0 deletions
diff --git a/Runtime/GUI/Font.cpp b/Runtime/GUI/Font.cpp
index e69de29..f00f33d 100644
--- a/Runtime/GUI/Font.cpp
+++ b/Runtime/GUI/Font.cpp
@@ -0,0 +1,214 @@
+#include "freetype.h"
+#include "Font.h"
+#include "../Math/Math.h"
+#include "Runtime/Debug/Log.h"
+#include "Runtime/Utilities/Assert.h"
+#include "Runtime/Graphics/ImageData.h"
+
+using namespace character;
+
+//https://unicode-table.com/en/#cjk-unified-ideographs-extension-a
+//https://learnopengl.com/In-Practice/Text-Rendering
+//https://www.zhihu.com/question/294660079
+//https://baike.baidu.com/item/%E5%9F%BA%E6%9C%AC%E5%A4%9A%E6%96%87%E7%A7%8D%E5%B9%B3%E9%9D%A2/10788078
+//https://stackoverflow.com/questions/27331819/whats-the-difference-between-a-character-a-code-point-a-glyph-and-a-grapheme
+
+void Font::Setup(TextGeneratingSettings settings)
+{
+	m_AtlasMargin = settings.margin;
+	m_GlyphPadding = settings.padding;
+	m_AtlasSize = settings.atlasSize;
+
+	if (FT_Init_FreeType(&m_FTLibrary))
+	{
+		return;
+	}
+
+	if (FT_New_Face(m_FTLibrary, "Resources/Font/Deng.ttf", 0, &m_FTFace))
+	{
+		return;
+	}
+}
+
+character::Hash Font::GetHash(Codepoint codepoint, int pixelSize)
+{
+	character::Hash hash;
+	hash.codepoint = codepoint;
+	hash.size = pixelSize;
+	return hash;
+}
+
+const Character* Font::GetCharacter(character::Codepoint codepoint, int pixelSize)
+{
+	character::Hash hash = GetHash(codepoint, pixelSize);
+	auto iter = m_Characters.find(hash);
+	if (iter == m_Characters.end())
+	{
+		RenderCharacter(codepoint, pixelSize);
+		iter = m_Characters.find(hash);
+	}
+	Assert(iter != m_Characters.end());
+	return &iter->second;
+}
+
+void Font::RenderCharacters(character::Codepoint* codepoint, int n, int pixelSize)
+{
+	for (int i = 0; i < n; ++i)
+	{
+		RenderCharacter(codepoint[i], pixelSize);
+	}
+}
+
+void Font::RenderCharacter(character::Codepoint codepoint, int pixelSize)
+{
+	character::Hash hash = GetHash(codepoint, pixelSize);
+	if (m_Characters.count(hash) != 0)
+		return; 
+	FT_Set_Pixel_Sizes(m_FTFace, 0, pixelSize);
+	if (FT_Load_Char(m_FTFace, codepoint, FT_LOAD_RENDER))
+	{
+		return;
+	}
+
+	int w = m_FTFace->glyph->bitmap.width;
+	int h = m_FTFace->glyph->bitmap.rows;
+
+	//TextHelper::print_glyph(m_FTFace->glyph->bitmap.buffer, w, h);
+
+	GlyphAtals* atlas = RequestAtlas(pixelSize, Internal::Vector2(w, h));
+	Assert(atlas);
+
+	Internal::Rect rect = GetRenderChartAndMove(atlas, Internal::Vector2(w, h));
+
+	try
+	{
+		atlas->altas->UpdateSubImage(rect, EPixelFormat::PixelFormat_R, EPixelElementType::PixelType_UNSIGNED_BYTE, m_FTFace->glyph->bitmap.buffer);
+	}
+	catch (TextureException& e)
+	{
+		std::string error = e.what();
+		error = "Render Character Error: " + error;
+		log_error(e.what());
+		return;
+	}
+
+	Character character;
+	character.atlas = atlas->index;
+	character.position = rect;
+	character.bearing = Internal::Vector2(m_FTFace->glyph->bitmap_left, m_FTFace->glyph->bitmap_top);
+	character.advance = m_FTFace->glyph->advance.x * 1/64.f;
+
+	m_Characters.insert(std::pair<character::Hash, Character>(hash, character));
+}
+
+const GlyphAtals* Font::GetGlyphAtlas(int index)
+{
+	if (index >= m_Atlases.size())
+		return NULL;
+	return &m_Atlases[index];
+}
+
+Internal::Rect Font::GetRenderChartAndMove(GlyphAtals* atlas, Internal::Vector2 preferSize)
+{
+	Internal::Rect rect;
+	Internal::Vector2 space;
+	space.x = atlas->width - atlas->cursor.x - m_AtlasMargin;
+	space.y = atlas->height - atlas->cursor.y - m_AtlasMargin;
+	if (space.x > preferSize.x && space.y > preferSize.y)
+	{
+		rect.x = atlas->cursor.x;
+		rect.y = atlas->cursor.y;
+		rect.width = preferSize.x;
+		rect.height = preferSize.y;
+		atlas->cursor.x += rect.width + m_GlyphPadding;
+		atlas->rowHeight = max(atlas->rowHeight, preferSize.y);
+	}
+	else if (space.y - atlas->rowHeight - m_GlyphPadding - m_AtlasMargin > preferSize.y)
+	{
+		rect.x = m_AtlasMargin;
+		rect.y = atlas->cursor.y + m_GlyphPadding + atlas->rowHeight;
+		rect.width = preferSize.x;
+		rect.height = preferSize.y;
+		atlas->cursor.x = m_AtlasMargin;
+		atlas->cursor.y += atlas->rowHeight + m_GlyphPadding;
+		atlas->rowHeight = rect.height;
+	}
+	else
+	{
+		Assert(false);
+	}
+	return rect;
+}
+
+GlyphAtals* Font::RequestAtlas(int pixelSize, Internal::Vector2 preferSize)
+{
+	GlyphAtals* atlas = NULL;
+	auto iter = m_AtlasCache.find(pixelSize);
+	if (iter == m_AtlasCache.end() || !HasEnoughSpace(iter->second, preferSize))
+	{
+		Texture* tex = CreateAtlas();
+		GlyphAtals newAtlas = GlyphAtals();
+		newAtlas.altas = tex;
+		newAtlas.width = m_AtlasSize.x;
+		newAtlas.height = m_AtlasSize.y;
+		newAtlas.index = m_Atlases.size();
+		newAtlas.cursor = Internal::Vector2(m_AtlasMargin, m_AtlasMargin);
+
+		m_Atlases.push_back(newAtlas);
+		atlas = &m_Atlases[m_Atlases.size() - 1];
+
+		if (iter != m_AtlasCache.end())
+			m_AtlasCache.erase(pixelSize);
+		m_AtlasCache.insert(std::pair<int, GlyphAtals*>(pixelSize, atlas));
+	}
+	else 
+	{
+		atlas = iter->second;
+	}
+	Assert(atlas);
+	return atlas;
+}
+
+Texture* Font::CreateAtlas()
+{
+	TextureSetting setting; 
+	setting.filterMode = ETextureFilterMode::Linear;
+	setting.wrapMode = ETextureWrapMode::Clamp;
+	setting.format = ETextureFormat::R8;
+	setting.type = ETextureType::TEX_2D;
+	setting.keepImageData = false;
+	Texture* tex = new Texture(setting, m_AtlasSize.x, m_AtlasSize.y);
+	return tex;
+}
+
+bool Font::HasEnoughSpace(GlyphAtals* atlas, Internal::Vector2 preferSize)
+{
+	if (atlas == NULL)
+		return false;
+	Internal::Vector2 space;
+	space.x = atlas->width - atlas->cursor.x - m_AtlasMargin;
+	space.y = atlas->height - atlas->cursor.y - m_AtlasMargin;
+	if (space.x > preferSize.x && space.y > preferSize.y)
+		return true;
+	if (space.y - atlas->rowHeight - m_GlyphPadding - m_AtlasMargin > preferSize.y)
+		return true;
+	return false;
+}
+
+Character GetCharacter(character::Codepoint Codepoint, int pixelSize)
+{
+	return Character();
+}
+
+void TextHelper::print_glyph(unsigned char* glyph, int width, int height)
+{
+	for (int r = 0; r < height; ++r)
+	{
+		for (int c = 0; c < width; ++c)
+		{
+			unsigned char ch = glyph[c + r * width];
+			printf("%c", ch == 0 ? ' ' : '+');
+		}
+		printf("\n");
+	}
+}