working version of text rendering

2024-08-02 09:52:26 +03:00
parent 9b58ba5f55
commit e69a553b18
13 changed files with 491 additions and 102 deletions
--- a/openVulkanoCpp/Scene/FontAtlasGenerator.cpp
+++ b/openVulkanoCpp/Scene/FontAtlasGenerator.cpp
@@ -0,0 +1,95 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include "FontAtlasGenerator.hpp"
+#include "Base/Logger.hpp"
+
+namespace OpenVulkano::Scene
+{
+	using namespace msdfgen;
+	using namespace msdf_atlas;
+
+	void FontAtlasGenerator::GenerateAtlas(const std::string& fontFile, const std::string& outputFile, const Charset& chset)
+	{
+		if (chset.empty())
+		{
+			return;
+		}
+		// TODO: dynamic atlas and add only those symbols which are not present yet in current atlas
+		Charset absentSymbols;
+		for (auto c : chset)
+		{
+			if (!m_symbols.contains(c))
+			{
+				absentSymbols.add(c);
+			}
+		}
+		if (m_loadedFont == fontFile && absentSymbols.empty())
+		{
+			return;
+		}
+		m_symbols.clear();
+		m_loadedFont = fontFile;
+
+		std::vector<GlyphGeometry> glyphsGeometry;
+		std::pair<FreetypeHandle*, FontHandle*> handlers = GetHandlers(fontFile);
+		FreetypeHandle* ft = handlers.first;
+		FontHandle* font = handlers.second;
+
+		// FontGeometry is a helper class that loads a set of glyphs from a single font.
+		FontGeometry fontGeometry(&glyphsGeometry);
+		fontGeometry.loadCharset(font, 1, absentSymbols);
+
+		TightAtlasPacker packer;
+		packer.setDimensionsConstraint(DimensionsConstraint::SQUARE);
+		int width = 1024, height = 1024;
+		packer.setDimensions(width, height);
+		// more value - more sdf impact
+		packer.setPixelRange(26.0);
+		packer.setMiterLimit(1.0);
+		packer.pack(glyphsGeometry.data(), glyphsGeometry.size());
+
+		m_generator.resize(width, height);
+		GeneratorAttributes attributes;
+		m_generator.setAttributes(attributes);
+		m_generator.setThreadCount(4);
+		m_generator.generate(glyphsGeometry.data(), glyphsGeometry.size());
+
+		int idx = 0;
+		BitmapConstRef<byte, 1> storage = m_generator.atlasStorage();
+		for (const auto& glyph: glyphsGeometry)
+		{
+			unicode_t c = static_cast<char8_t>(glyph.getCodepoint());
+			GlyphInfo info;
+			info.texture.resolution = Math::Vector3ui(storage.width, storage.height, 1);
+			info.texture.textureBuffer = (msdfgen::byte*)storage.pixels;
+			info.texture.format = OpenVulkano::DataFormat::R8_UNORM;
+			info.texture.size = storage.width * storage.height * 1; // 1 channel
+			info.geometry = glyph;
+			info.glyphBox = m_generator.getLayout()[idx++];
+			m_symbols[c] = std::move(info);
+		}
+		savePng(m_generator.atlasStorage(), outputFile.c_str());
+		destroyFont(font);
+		deinitializeFreetype(ft);
+	}
+
+	std::pair<FreetypeHandle*, FontHandle*> FontAtlasGenerator::GetHandlers(const std::string& fontFile)
+	{
+		FreetypeHandle* ft = initializeFreetype();
+		if (!ft)
+		{
+			throw std::runtime_error("Failed to initialize freetype");
+		}
+		FontHandle* font = loadFont(ft, fontFile.data());
+		if (!font)
+		{
+			deinitializeFreetype(ft);
+			throw std::runtime_error(fmt::format("Failed to load font from file {0}", fontFile.data()));
+		}
+		return { ft, font };
+	}
+}