Refactor

2026-05-06 09:28:46 +10:00
parent 437199f3f0
commit 0bfffa6552
41 changed files with 1592 additions and 1368 deletions
--- a/apps/LoopThroughWithOpenGLCompositing/gl/TextRasterizer.cpp
+++ b/apps/LoopThroughWithOpenGLCompositing/gl/TextRasterizer.cpp
@@ -0,0 +1,316 @@
+#include "TextRasterizer.h"
+
+#include <windows.h>
+
+#include <algorithm>
+#include <cmath>
+#include <cstring>
+#include <fstream>
+#include <gdiplus.h>
+#include <memory>
+#include <sstream>
+
+namespace
+{
+constexpr int kTextSdfSpread = 20;
+constexpr unsigned kTextSdfBlurPasses = 1;
+constexpr float kTextFontPixelSize = 144.0f;
+constexpr float kTextLayoutPadding = 48.0f;
+
+class GdiplusSession
+{
+public:
+	GdiplusSession()
+	{
+		Gdiplus::GdiplusStartupInput startupInput;
+		mStarted = Gdiplus::GdiplusStartup(&mToken, &startupInput, NULL) == Gdiplus::Ok;
+	}
+
+	~GdiplusSession()
+	{
+		if (mStarted)
+			Gdiplus::GdiplusShutdown(mToken);
+	}
+
+	GdiplusSession(const GdiplusSession&) = delete;
+	GdiplusSession& operator=(const GdiplusSession&) = delete;
+
+	bool started() const { return mStarted; }
+
+private:
+	ULONG_PTR mToken = 0;
+	bool mStarted = false;
+};
+
+std::wstring Utf8ToWide(const std::string& text)
+{
+	if (text.empty())
+		return std::wstring();
+	const int required = MultiByteToWideChar(CP_UTF8, 0, text.c_str(), -1, NULL, 0);
+	if (required <= 1)
+		return std::wstring();
+	std::wstring wide(static_cast<std::size_t>(required - 1), L'\0');
+	MultiByteToWideChar(CP_UTF8, 0, text.c_str(), -1, wide.data(), required);
+	return wide;
+}
+
+std::vector<unsigned char> BuildLocalSdf(const std::vector<unsigned char>& alpha, unsigned width, unsigned height)
+{
+	std::vector<unsigned char> sdf(static_cast<std::size_t>(width) * height * 4, 0);
+	for (unsigned y = 0; y < height; ++y)
+	{
+		for (unsigned x = 0; x < width; ++x)
+		{
+			const bool inside = alpha[static_cast<std::size_t>(y) * width + x] > 127;
+			int bestDistanceSq = kTextSdfSpread * kTextSdfSpread;
+			for (int oy = -kTextSdfSpread; oy <= kTextSdfSpread; ++oy)
+			{
+				const int sy = static_cast<int>(y) + oy;
+				if (sy < 0 || sy >= static_cast<int>(height))
+					continue;
+				for (int ox = -kTextSdfSpread; ox <= kTextSdfSpread; ++ox)
+				{
+					const int sx = static_cast<int>(x) + ox;
+					if (sx < 0 || sx >= static_cast<int>(width))
+						continue;
+					const bool sampleInside = alpha[static_cast<std::size_t>(sy) * width + sx] > 127;
+					if (sampleInside == inside)
+						continue;
+					const int distanceSq = ox * ox + oy * oy;
+					if (distanceSq < bestDistanceSq)
+						bestDistanceSq = distanceSq;
+				}
+			}
+
+			const float distance = std::sqrt(static_cast<float>(bestDistanceSq));
+			const float signedDistance = (inside ? 1.0f : -1.0f) * distance;
+			float normalized = 0.5f + signedDistance / static_cast<float>(kTextSdfSpread * 2);
+			const unsigned char sourceAlpha = alpha[static_cast<std::size_t>(y) * width + x];
+			if (sourceAlpha > 0 && sourceAlpha < 255)
+				normalized = static_cast<float>(sourceAlpha) / 255.0f;
+			if (normalized < 0.0f)
+				normalized = 0.0f;
+			if (normalized > 1.0f)
+				normalized = 1.0f;
+			const unsigned char value = static_cast<unsigned char>(normalized * 255.0f + 0.5f);
+			const std::size_t out = (static_cast<std::size_t>(y) * width + x) * 4;
+			sdf[out + 0] = value;
+			sdf[out + 1] = value;
+			sdf[out + 2] = value;
+			sdf[out + 3] = value;
+		}
+	}
+	return sdf;
+}
+
+std::vector<unsigned char> BuildTextCoverageTexture(const std::vector<unsigned char>& alpha, unsigned width, unsigned height)
+{
+	std::vector<unsigned char> coverage(static_cast<std::size_t>(width) * height * 4, 0);
+	for (unsigned y = 0; y < height; ++y)
+	{
+		for (unsigned x = 0; x < width; ++x)
+		{
+			const unsigned char value = alpha[static_cast<std::size_t>(y) * width + x];
+			const std::size_t out = (static_cast<std::size_t>(y) * width + x) * 4;
+			coverage[out + 0] = value;
+			coverage[out + 1] = value;
+			coverage[out + 2] = value;
+			coverage[out + 3] = value;
+		}
+	}
+	return coverage;
+}
+
+std::vector<unsigned char> FlipTextTextureForShaderUv(const std::vector<unsigned char>& pixels, unsigned width, unsigned height)
+{
+	std::vector<unsigned char> flipped(pixels.size(), 0);
+	const std::size_t stride = static_cast<std::size_t>(width) * 4;
+	for (unsigned y = 0; y < height; ++y)
+	{
+		const std::size_t srcOffset = static_cast<std::size_t>(y) * stride;
+		const std::size_t dstOffset = static_cast<std::size_t>(height - 1 - y) * stride;
+		std::memcpy(flipped.data() + dstOffset, pixels.data() + srcOffset, stride);
+	}
+	return flipped;
+}
+
+std::vector<unsigned char> BlurTextSdf(const std::vector<unsigned char>& pixels, unsigned width, unsigned height, unsigned passes)
+{
+	std::vector<unsigned char> current = pixels;
+	std::vector<unsigned char> next(pixels.size(), 0);
+	for (unsigned pass = 0; pass < passes; ++pass)
+	{
+		for (unsigned y = 0; y < height; ++y)
+		{
+			for (unsigned x = 0; x < width; ++x)
+			{
+				unsigned weightedTotal = 0;
+				unsigned weightSum = 0;
+				for (int oy = -1; oy <= 1; ++oy)
+				{
+					const int sy = static_cast<int>(y) + oy;
+					if (sy < 0 || sy >= static_cast<int>(height))
+						continue;
+					for (int ox = -1; ox <= 1; ++ox)
+					{
+						const int sx = static_cast<int>(x) + ox;
+						if (sx < 0 || sx >= static_cast<int>(width))
+							continue;
+						const unsigned weight = (ox == 0 && oy == 0) ? 4u : ((ox == 0 || oy == 0) ? 2u : 1u);
+						const std::size_t sample = (static_cast<std::size_t>(sy) * width + sx) * 4;
+						weightedTotal += static_cast<unsigned>(current[sample]) * weight;
+						weightSum += weight;
+					}
+				}
+
+				const unsigned char value = static_cast<unsigned char>((weightedTotal + weightSum / 2) / weightSum);
+				const std::size_t out = (static_cast<std::size_t>(y) * width + x) * 4;
+				next[out + 0] = value;
+				next[out + 1] = value;
+				next[out + 2] = value;
+				next[out + 3] = value;
+			}
+		}
+		current.swap(next);
+	}
+	return current;
+}
+
+void WriteTextMaskDebugDump(const std::string& text, const std::vector<unsigned char>& alpha, const std::vector<unsigned char>& sdf, unsigned width, unsigned height)
+{
+	try
+	{
+		std::filesystem::path debugDir = std::filesystem::current_path() / "runtime";
+		std::filesystem::create_directories(debugDir);
+
+		auto writePgm = [width, height](const std::filesystem::path& path, const std::vector<unsigned char>& gray, std::size_t stride)
+		{
+			std::ofstream out(path, std::ios::binary);
+			if (!out)
+				return;
+			out << "P5\n" << width << " " << height << "\n255\n";
+			for (unsigned y = 0; y < height; ++y)
+			{
+				for (unsigned x = 0; x < width; ++x)
+					out.put(static_cast<char>(gray[(static_cast<std::size_t>(y) * width + x) * stride]));
+			}
+		};
+
+		writePgm(debugDir / "text-mask-alpha-debug.pgm", alpha, 1);
+		writePgm(debugDir / "text-mask-sdf-debug.pgm", sdf, 4);
+
+		unsigned alphaMin = 255;
+		unsigned alphaMax = 0;
+		unsigned sdfMin = 255;
+		unsigned sdfMax = 0;
+		std::size_t alphaLit = 0;
+		std::size_t sdfLit = 0;
+		for (unsigned char value : alpha)
+		{
+			alphaMin = std::min<unsigned>(alphaMin, value);
+			alphaMax = std::max<unsigned>(alphaMax, value);
+			if (value > 0)
+				++alphaLit;
+		}
+		for (std::size_t index = 0; index < sdf.size(); index += 4)
+		{
+			const unsigned char value = sdf[index];
+			sdfMin = std::min<unsigned>(sdfMin, value);
+			sdfMax = std::max<unsigned>(sdfMax, value);
+			if (value > 127)
+				++sdfLit;
+		}
+
+		std::ostringstream message;
+		message << "Text mask debug for '" << text << "': alpha min/max/lit=" << alphaMin << "/" << alphaMax << "/" << alphaLit
+			<< ", sdf min/max/gt127=" << sdfMin << "/" << sdfMax << "/" << sdfLit << "\n";
+		OutputDebugStringA(message.str().c_str());
+	}
+	catch (...)
+	{
+		OutputDebugStringA("Failed to write text mask debug dump.\n");
+	}
+}
+}
+
+bool RasterizeTextSdf(const std::string& text, const std::filesystem::path& fontPath, std::vector<unsigned char>& sdf, std::string& error)
+{
+	GdiplusSession gdiplus;
+	if (!gdiplus.started())
+	{
+		error = "Could not start GDI+ for text rendering.";
+		return false;
+	}
+
+	Gdiplus::PrivateFontCollection fontCollection;
+	Gdiplus::FontFamily fallbackFamily(L"Arial");
+	Gdiplus::FontFamily* fontFamily = &fallbackFamily;
+	std::unique_ptr<Gdiplus::FontFamily[]> families;
+	const std::wstring wideFontPath = fontPath.empty() ? std::wstring() : fontPath.wstring();
+	if (!wideFontPath.empty())
+	{
+		if (fontCollection.AddFontFile(wideFontPath.c_str()) != Gdiplus::Ok)
+		{
+			error = "Could not load packaged font file for text rendering: " + fontPath.string();
+			return false;
+		}
+
+		const INT familyCount = fontCollection.GetFamilyCount();
+		if (familyCount <= 0)
+		{
+			error = "Packaged font did not contain a usable font family: " + fontPath.string();
+			return false;
+		}
+
+		families.reset(new Gdiplus::FontFamily[familyCount]);
+		INT found = 0;
+		if (fontCollection.GetFamilies(familyCount, families.get(), &found) != Gdiplus::Ok || found <= 0)
+		{
+			error = "Could not read the packaged font family: " + fontPath.string();
+			return false;
+		}
+		fontFamily = &families[0];
+	}
+
+	Gdiplus::Bitmap bitmap(kTextTextureWidth, kTextTextureHeight, PixelFormat32bppARGB);
+	Gdiplus::Graphics graphics(&bitmap);
+	graphics.SetCompositingMode(Gdiplus::CompositingModeSourceCopy);
+	graphics.Clear(Gdiplus::Color(255, 0, 0, 0));
+	graphics.SetCompositingMode(Gdiplus::CompositingModeSourceOver);
+	graphics.SetTextRenderingHint(Gdiplus::TextRenderingHintAntiAlias);
+	graphics.SetSmoothingMode(Gdiplus::SmoothingModeHighQuality);
+	Gdiplus::Font font(fontFamily, kTextFontPixelSize, Gdiplus::FontStyleRegular, Gdiplus::UnitPixel);
+	Gdiplus::SolidBrush brush(Gdiplus::Color(255, 255, 255, 255));
+	Gdiplus::StringFormat format;
+	format.SetAlignment(Gdiplus::StringAlignmentNear);
+	format.SetLineAlignment(Gdiplus::StringAlignmentCenter);
+	format.SetFormatFlags(Gdiplus::StringFormatFlagsNoWrap | Gdiplus::StringFormatFlagsMeasureTrailingSpaces);
+	const Gdiplus::RectF layout(
+		kTextLayoutPadding,
+		0.0f,
+		static_cast<Gdiplus::REAL>(kTextTextureWidth) - (kTextLayoutPadding * 2.0f),
+		static_cast<Gdiplus::REAL>(kTextTextureHeight));
+	const std::wstring wideText = Utf8ToWide(text);
+	graphics.DrawString(wideText.c_str(), -1, &font, layout, &format, &brush);
+
+	std::vector<unsigned char> alpha(static_cast<std::size_t>(kTextTextureWidth) * kTextTextureHeight, 0);
+	for (unsigned y = 0; y < kTextTextureHeight; ++y)
+	{
+		for (unsigned x = 0; x < kTextTextureWidth; ++x)
+		{
+			Gdiplus::Color pixel;
+			bitmap.GetPixel(x, y, &pixel);
+			BYTE luminance = pixel.GetRed();
+			if (pixel.GetGreen() > luminance)
+				luminance = pixel.GetGreen();
+			if (pixel.GetBlue() > luminance)
+				luminance = pixel.GetBlue();
+			alpha[static_cast<std::size_t>(y) * kTextTextureWidth + x] = static_cast<unsigned char>(luminance);
+		}
+	}
+	sdf = BuildTextCoverageTexture(alpha, kTextTextureWidth, kTextTextureHeight);
+	sdf = BlurTextSdf(sdf, kTextTextureWidth, kTextTextureHeight, kTextSdfBlurPasses);
+	sdf = FlipTextTextureForShaderUv(sdf, kTextTextureWidth, kTextTextureHeight);
+	WriteTextMaskDebugDump(text, alpha, sdf, kTextTextureWidth, kTextTextureHeight);
+	return true;
+}