Just-DataInspector/Components/Shared/Src/PaintUtil.cpp

#include "PaintUtil.hpp"

#include <algorithm>
#include <cmath>
#include <cstddef>
#include <functional>
#include <mutex>
#include <unordered_map>
#include <utility>
#include <string>

namespace jdi
{

	namespace
	{
		/**
		 * @brief 矩形面积超过该阈值（逻辑像素²）且为不透明色时，改用 GDI 填充。
		 *
		 * GDI+ 的 FillRectangle 约 2.2ns/像素；面积过小时 GDI 的 GetHDC/ReleaseHDC
		 * 固定开销反而不划算，因此在阈值以下仍走 GDI+。
		 */
		const float kGdiFillAreaThreshold = 20000.0f;
	}

	// 圆角矩形路径是公开的几何构建器：`UiFillRoundRect` / `UiDrawRoundRect` / 需要把位图或渐变
	// **裁剪进同一个圆角形状**的调用方共用它，保证"填充的形状"与"描边的形状"逐点一致。
	void UiBuildRoundRectPath(gd::GraphicsPath& path, const gd::RectF& rect, float radius)
	{
		if (rect.Width <= 0.0f || rect.Height <= 0.0f)
		{
			return;
		}

		float diameter = radius * 2.0f;
		if (diameter > rect.Width)
		{
			diameter = rect.Width;
		}
		if (diameter > rect.Height)
		{
			diameter = rect.Height;
		}
		if (diameter < 1.0f)
		{
			path.AddRectangle(rect);
			return;
		}

		const float right = rect.X + rect.Width;
		const float bottom = rect.Y + rect.Height;

		path.AddArc(rect.X, rect.Y, diameter, diameter, 180.0f, 90.0f);
		path.AddArc(right - diameter, rect.Y, diameter, diameter, 270.0f, 90.0f);
		path.AddArc(right - diameter, bottom - diameter, diameter, diameter, 0.0f, 90.0f);
		path.AddArc(rect.X, bottom - diameter, diameter, diameter, 90.0f, 90.0f);
		path.CloseFigure();
	}

	namespace
	{
		/**
		 * @brief 创建指定字号的界面字体。
		 * @param [IN] face 字体名称。
		 * @param [IN] pixelHeight 字符高度（像素）。
		 * @param [IN] bold 是否加粗。
		 * @return 字体句柄，失败返回 nullptr。
		 */
		HFONT CreateUiFont(const wchar_t* face, int pixelHeight, bool bold)
		{
			LOGFONTW logFont = {};
			logFont.lfHeight = -pixelHeight;
			logFont.lfWeight = bold ? FW_SEMIBOLD : FW_NORMAL;
			logFont.lfCharSet = DEFAULT_CHARSET;
			logFont.lfOutPrecision = OUT_TT_PRECIS;
			logFont.lfClipPrecision = CLIP_DEFAULT_PRECIS;
			logFont.lfQuality = CLEARTYPE_QUALITY;
			logFont.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;
			wcsncpy(logFont.lfFaceName, face, LF_FACESIZE - 1);
			logFont.lfFaceName[LF_FACESIZE - 1] = L'\0';

			HFONT font = CreateFontIndirectW(&logFont);
			if (font == nullptr)
			{
				font = static_cast<HFONT>(GetStockObject(DEFAULT_GUI_FONT));
			}
			return font;
		}
	} // namespace

	namespace
	{
		/**
		 * @brief 文本宽度测量的缓存键（字体句柄 + 文本）。
		 */
		struct MeasureKey
		{
			HFONT font = nullptr;
			std::wstring text;
			bool operator==(const MeasureKey& other) const
			{
				return font == other.font && text == other.text;
			}
		};
		struct MeasureKeyHash
		{
			std::size_t operator()(const MeasureKey& key) const
			{
				std::size_t hash = std::hash<const void*>()(key.font);
				for (const wchar_t character : key.text)
				{
					hash = hash * 131u + static_cast<std::size_t>(character);
				}
				return hash;
			}
		};
		/** 上限保护：超过时整体清空（缓存只是加速手段，清空后重新填充即可）。 */
		constexpr std::size_t kMeasureCacheLimit = 4096;

		/** 文本的像素宽度与字符单元高度（后者与 `DT_VCENTER` 的居中口径一致）。 */
		struct TextExtent
		{
			float width = 0.0f;		/**< 像素宽度。 */
			float height = 0.0f;	/**< 字符单元高度。 */
		};

		std::unordered_map<MeasureKey, TextExtent, MeasureKeyHash> g_measureCache;
		std::mutex g_measureMutex;

		/**
		 * @brief 取文本的宽 / 高（带缓存）。
		 *
		 * ⚠️ 必须走 GDI（`GetDC` + `GetTextExtentPoint32W` + `ReleaseDC`），单次约 10µs；
		 * 而布局与绘制每帧会把同一批字符串**重复测量成百上千次**，因此按 (字体, 文本) 缓存。
		 * 高度也一并缓存：`DrawUiText` 的快速路径要用它做垂直居中（见那里的说明）。
		 */
		TextExtent MeasureText(HFONT font, const std::wstring& text)
		{
			if (text.empty() || font == nullptr)
			{
				return TextExtent();
			}
			const MeasureKey key{font, text};
			{
				std::lock_guard<std::mutex> lock(g_measureMutex);
				const auto found = g_measureCache.find(key);
				if (found != g_measureCache.end())
				{
					return found->second;
				}
			}

			HDC hdc = GetDC(nullptr);
			if (hdc == nullptr)
			{
				return TextExtent();
			}
			HGDIOBJ oldFont = SelectObject(hdc, font);
			SIZE size = {};
			GetTextExtentPoint32W(hdc, text.c_str(), static_cast<int>(text.size()), &size);
			SelectObject(hdc, oldFont);
			ReleaseDC(nullptr, hdc);

			TextExtent extent;
			extent.width = static_cast<float>(size.cx);
			extent.height = static_cast<float>(size.cy);
			{
				std::lock_guard<std::mutex> lock(g_measureMutex);
				if (g_measureCache.size() >= kMeasureCacheLimit)
				{
					g_measureCache.clear();
				}
				g_measureCache.emplace(key, extent);
			}
			return extent;
		}
	} // namespace

	void UiClearMeasureCache()
	{
		std::lock_guard<std::mutex> lock(g_measureMutex);
		g_measureCache.clear();
	}

	bool UiFonts::Create(UINT targetDpi)
	{
		Destroy();
		// 字体句柄会被重新创建，旧句柄可能被系统复用：必须作废按句柄缓存的文本宽度，
		// 否则复用同一句柄值的新字体会命中旧宽度（布局错位）。
		UiClearMeasureCache();
		dpi = (targetDpi == 0) ? 96u : targetDpi;

		const double scale = static_cast<double>(dpi) / 96.0;
		const int uiHeight = static_cast<int>(std::lround(14.0 * scale));
		const int smallHeight = static_cast<int>(std::lround(12.0 * scale));
		const int tinyHeight = static_cast<int>(std::lround(10.0 * scale));
		const int titleHeight = static_cast<int>(std::lround(15.0 * scale));
		const int monoHeight = static_cast<int>(std::lround(13.0 * scale));

		ui = CreateUiFont(L"Segoe UI", uiHeight, false);
		uiBold = CreateUiFont(L"Segoe UI Semibold", uiHeight, true);
		uiSmall = CreateUiFont(L"Segoe UI", smallHeight, false);
		uiSmallBold = CreateUiFont(L"Segoe UI Semibold", smallHeight, true);
		uiTiny = CreateUiFont(L"Segoe UI", tinyHeight, false);
		title = CreateUiFont(L"Segoe UI Semibold", titleHeight, true);
		mono = CreateUiFont(L"Consolas", monoHeight, false);
		monoSmall = CreateUiFont(L"Consolas", smallHeight, false);

		return ui != nullptr && uiBold != nullptr && uiSmall != nullptr && uiTiny != nullptr &&
		       title != nullptr && mono != nullptr;
	}

	void UiFonts::Destroy()
	{
		const HFONT resources[] = {ui, uiBold, uiSmall, uiSmallBold, uiTiny, title, mono, monoSmall};
		for (const HFONT font : resources)
		{
			if (font != nullptr)
			{
				DeleteObject(font);
			}
		}
		ui = nullptr;
		uiBold = nullptr;
		uiSmall = nullptr;
		uiSmallBold = nullptr;
		uiTiny = nullptr;
		title = nullptr;
		mono = nullptr;
		monoSmall = nullptr;
	}

	void UiFillRect(gd::Graphics& g, const gd::RectF& rect, std::uint32_t argb)
	{
		if (rect.Width <= 0.0f || rect.Height <= 0.0f)
		{
			return;
		}

		// 大面积且**不透明**的填充走 GDI 路线：GDI+ 的 FillRectangle 实测约 2.2ns/像素
		// （整个窗口背景 1.7M 像素约 0.9ms，信号面板背景约 1.9ms），
		// 而 GDI 的 FillRect 快一个数量级。半透明填充必须留在 GDI+（GDI 不做 alpha 混色）。
		// 顺序安全：GetHDC() 会先把已排队的 GDI+ 内容刷入 DC，本次填充之后再发生的 GDI+ 绘制
		// 会在 ReleaseHDC() 之后刷出、正确地覆盖在上面。
		const float area = rect.Width * rect.Height;
		if ((argb & 0xFF000000u) == 0xFF000000u && area >= kGdiFillAreaThreshold)
		{
			HDC hdc = g.GetHDC();
			if (hdc != nullptr)
			{
				RECT rc;
				rc.left = static_cast<LONG>(std::floor(rect.X));
				rc.top = static_cast<LONG>(std::floor(rect.Y));
				rc.right = static_cast<LONG>(std::ceil(rect.X + rect.Width));
				rc.bottom = static_cast<LONG>(std::ceil(rect.Y + rect.Height));
				HBRUSH brush = CreateSolidBrush(ToColorRef(argb));
				if (brush != nullptr)
				{
					FillRect(hdc, &rc, brush);
					DeleteObject(brush);
				}
				g.ReleaseHDC(hdc);
				return;
			}
		}

		gd::SolidBrush brush(ToGdiColor(argb));
		g.FillRectangle(&brush, rect);
	}

	void UiFillRoundRect(gd::Graphics& g, const gd::RectF& rect, float radius, std::uint32_t argb)
	{
		if (rect.Width <= 0.0f || rect.Height <= 0.0f)
		{
			return;
		}
		gd::GraphicsPath path;
		UiBuildRoundRectPath(path, rect, radius);
		gd::SolidBrush brush(ToGdiColor(argb));
		g.FillPath(&brush, &path);
	}

	void UiDrawRoundRect(gd::Graphics& g, const gd::RectF& rect, float radius, std::uint32_t argb, float width)
	{
		if (rect.Width <= 0.0f || rect.Height <= 0.0f)
		{
			return;
		}
		gd::GraphicsPath path;
		UiBuildRoundRectPath(path, rect, radius);
		gd::Pen pen(ToGdiColor(argb), width);
		g.DrawPath(&pen, &path);
	}

	void UiFillRoundRects(gd::Graphics& g, const std::vector<gd::RectF>& rects, float radius,
	                      std::uint32_t argb)
	{
		if (rects.empty())
		{
			return;
		}
		gd::GraphicsPath path;
		for (const gd::RectF& rect : rects)
		{
			if (rect.Width <= 0.0f || rect.Height <= 0.0f)
			{
				continue;
			}
			UiBuildRoundRectPath(path, rect, radius);
		}
		if (path.GetPointCount() > 0)
		{
			gd::SolidBrush brush(ToGdiColor(argb));
			g.FillPath(&brush, &path);
		}
	}

	std::uint32_t UiBlendOver(std::uint32_t background, std::uint32_t argb)
	{
		const unsigned int alpha = (argb >> 24) & 0xFFu;
		if (alpha >= 0xFFu)
		{
			return argb | 0xFF000000u;
		}
		if (alpha == 0u)
		{
			return background | 0xFF000000u;
		}
		const double ratio = static_cast<double>(alpha) / 255.0;
		std::uint32_t result = 0xFF000000u;
		for (int shift = 0; shift <= 16; shift += 8)
		{
			const double top = static_cast<double>((argb >> shift) & 0xFFu);
			const double bottom = static_cast<double>((background >> shift) & 0xFFu);
			const double mixed = bottom + (top - bottom) * ratio;
			result |= (static_cast<std::uint32_t>(mixed + 0.5) & 0xFFu) << shift;
		}
		return result;
	}

	void UiDrawSolidLines(gd::Graphics& g, const gd::RectF& clip, const float* segments,
	                      std::size_t segmentCount, std::uint32_t argb, int width)
	{
		if (segments == nullptr || segmentCount == 0 || (argb & 0xFF000000u) != 0xFF000000u)
		{
			return;
		}
		if (width < 1)
		{
			width = 1;
		}

		const int clipLeft = static_cast<int>(std::floor(clip.X));
		const int clipTop = static_cast<int>(std::floor(clip.Y));
		const int clipRight = static_cast<int>(std::ceil(clip.X + clip.Width));
		const int clipBottom = static_cast<int>(std::ceil(clip.Y + clip.Height));
		if (clipRight <= clipLeft || clipBottom <= clipTop)
		{
			return;
		}

		HDC hdc = g.GetHDC();
		if (hdc == nullptr)
		{
			return;
		}

		// GDI 绘制不受 GDI+ 裁剪约束，这里显式设置并随后完整还原 DC 状态。
		const int saved = SaveDC(hdc);
		if (saved != 0)
		{
			IntersectClipRect(hdc, clipLeft, clipTop, clipRight, clipBottom);
		}

		HPEN pen = CreatePen(PS_SOLID, width, ToColorRef(argb));
		if (pen != nullptr)
		{
			HGDIOBJ oldPen = SelectObject(hdc, pen);
			for (std::size_t index = 0; index < segmentCount; ++index)
			{
				const float* segment = segments + index * 4;
				MoveToEx(hdc, static_cast<int>(std::lround(segment[0])),
				         static_cast<int>(std::lround(segment[1])), nullptr);
				LineTo(hdc, static_cast<int>(std::lround(segment[2])),
				       static_cast<int>(std::lround(segment[3])));
			}
			SelectObject(hdc, oldPen);
			DeleteObject(pen);
		}

		if (saved != 0)
		{
			RestoreDC(hdc, saved);
		}
		g.ReleaseHDC(hdc);
	}

	void UiDrawLine(gd::Graphics& g, float x1, float y1, float x2, float y2, std::uint32_t argb, float width)
	{
		gd::Pen pen(ToGdiColor(argb), width);
		pen.SetStartCap(gd::LineCapFlat);
		pen.SetEndCap(gd::LineCapFlat);
		g.DrawLine(&pen, x1, y1, x2, y2);
	}

	namespace
	{
		/**
		 * @brief `UiText` 与 `UiTextClipped` 的公共实现。
		 *
		 * ⚠️ `clip == nullptr` 时**不加任何 GDI 裁剪**（与历史行为完全一致）；
		 * 提供裁剪时在同一个 HDC 上 `SaveDC`/`IntersectClipRect` 并完整还原 ——
		 * 这是唯一能让 `DrawTextW` 受限于指定范围的办法（GDI+ 的 `SetClip` 对 GDI 文本无效）。
		 *
		 * @param [IN,OUT] g 绘图上下文。
		 * @param [IN] text 文本内容。
		 * @param [IN] font 字体句柄。
		 * @param [IN] rect 文本布局矩形。
		 * @param [IN] argb 文本颜色。
		 * @param [IN] align 水平对齐方式。
		 * @param [IN] clip 裁剪矩形（nullptr = 不裁剪）。
		 */
		void DrawUiText(gd::Graphics& g, const std::wstring& text, HFONT font, const gd::RectF& rect,
		                std::uint32_t argb, TextAlign align, const gd::RectF* clip)
		{
			if (text.empty() || font == nullptr || rect.Width <= 0.0f || rect.Height <= 0.0f)
			{
				return;
			}
			if (clip != nullptr && (clip->Width <= 0.0f || clip->Height <= 0.0f))
			{
				return;		// 裁剪区为空：任何文字都落在界外
			}

			HDC hdc = g.GetHDC();
			if (hdc == nullptr)
			{
				return;
			}

			// GDI 文本不受 GDI+ 裁剪区约束：需要限制范围时显式裁剪，结束前完整还原 DC 状态。
			int saved = 0;
			if (clip != nullptr)
			{
				saved = SaveDC(hdc);
				if (saved != 0)
				{
					IntersectClipRect(hdc, static_cast<int>(std::floor(clip->X)),
					                  static_cast<int>(std::floor(clip->Y)),
					                  static_cast<int>(std::ceil(clip->X + clip->Width)),
					                  static_cast<int>(std::ceil(clip->Y + clip->Height)));
				}
			}

			HGDIOBJ oldFont = SelectObject(hdc, font);
			const int oldMode = SetBkMode(hdc, TRANSPARENT);
			const COLORREF oldColor = SetTextColor(hdc, ToColorRef(argb));

			RECT rc;
			rc.left = static_cast<LONG>(std::floor(rect.X));
			rc.top = static_cast<LONG>(std::floor(rect.Y));
			rc.right = static_cast<LONG>(std::ceil(rect.X + rect.Width));
			rc.bottom = static_cast<LONG>(std::ceil(rect.Y + rect.Height));

			// ⚠️ 这里必须继续用 `DrawTextW`：试过改用 `ExtTextOutW` 的"快速路径"（约快 2~4 倍），
			// 但同一段文字的**光栅化结果并不相同**（实测面板区域 10% 的像素有差异，
			// 亚像素边缘与基线差 1px）—— 全体界面文字观感都会变，因此放弃。
			// 列表卡顿改由"行位图缓存 + 动画期间不预热网格图层"解决（见 `SignalPanel::PaintRowCached`）。
			UINT flags = DT_SINGLELINE | DT_VCENTER | DT_NOPREFIX | DT_END_ELLIPSIS;
			switch (align)
			{
			case TextAlign::CENTER:
				flags |= DT_CENTER;
				break;
			case TextAlign::RIGHT:
				flags |= DT_RIGHT;
				break;
			case TextAlign::LEFT:
			default:
				flags |= DT_LEFT;
				break;
			}

			DrawTextW(hdc, text.c_str(), static_cast<int>(text.size()), &rc, flags);

			SetTextColor(hdc, oldColor);
			SetBkMode(hdc, oldMode);
			SelectObject(hdc, oldFont);
			if (saved != 0)
			{
				RestoreDC(hdc, saved);
			}
			g.ReleaseHDC(hdc);
		}
	} // namespace

	void UiText(gd::Graphics& g, const std::wstring& text, HFONT font, const gd::RectF& rect, std::uint32_t argb,
	            TextAlign align)
	{
		DrawUiText(g, text, font, rect, argb, align, nullptr);
	}

	void UiTextClipped(gd::Graphics& g, const std::wstring& text, HFONT font, const gd::RectF& rect,
	                   std::uint32_t argb, TextAlign align, const gd::RectF& clipRect)
	{
		DrawUiText(g, text, font, rect, argb, align, &clipRect);
	}

	float UiMeasureTextWidth(HFONT font, const std::wstring& text)
	{
		// 记忆化（键 = 字体 + 文本，值 = 宽 / 高）：布局代码每帧会把同一批字符串
		// **重复测量成百上千次**，而 `GetTextExtentPoint32W` 单次约 10µs。
		return MeasureText(font, text).width;
	}

	std::wstring UiEllipsize(const std::wstring& text, HFONT font, float maxWidth)
	{
		if (text.empty() || font == nullptr || maxWidth <= 0.0f)
		{
			return std::wstring();
		}
		if (UiMeasureTextWidth(font, text) <= maxWidth)
		{
			return text;
		}

		const std::wstring ellipsis = L"…";
		const float ellipsisWidth = UiMeasureTextWidth(font, ellipsis);
		if (ellipsisWidth > maxWidth)
		{
			return std::wstring();
		}

		std::wstring result = text;
		while (!result.empty())
		{
			result.pop_back();
			if (UiMeasureTextWidth(font, result) + ellipsisWidth <= maxWidth)
			{
				return result + ellipsis;
			}
		}
		return ellipsis;
	}

	void UiTextAtClipped(gd::Graphics& g, const std::wstring& text, HFONT font, float x, const gd::RectF& rect,
	                     std::uint32_t argb, const gd::RectF& clipRect)
	{
		if (text.empty() || font == nullptr || clipRect.Width <= 0.0f || clipRect.Height <= 0.0f)
		{
			return;
		}

		HDC hdc = g.GetHDC();
		if (hdc == nullptr)
		{
			return;
		}

		HGDIOBJ oldFont = SelectObject(hdc, font);
		const int oldMode = SetBkMode(hdc, TRANSPARENT);
		const COLORREF oldColor = SetTextColor(hdc, ToColorRef(argb));

		TEXTMETRICW metrics = {};
		GetTextMetricsW(hdc, &metrics);
		const int baselineY = static_cast<int>(
		    std::floor(rect.Y + (rect.Height - static_cast<float>(metrics.tmHeight)) * 0.5f));

		RECT clip = {};
		clip.left = static_cast<LONG>(std::floor(clipRect.X));
		clip.top = static_cast<LONG>(std::floor(clipRect.Y));
		clip.right = static_cast<LONG>(std::ceil(clipRect.X + clipRect.Width));
		clip.bottom = static_cast<LONG>(std::ceil(clipRect.Y + clipRect.Height));

		// ETO_CLIPPED 让 GDI 在指定矩形内裁剪，长文本不会再画到输入框之外。
		ExtTextOutW(hdc, static_cast<int>(std::floor(x)), baselineY, ETO_CLIPPED, &clip, text.c_str(),
		            static_cast<UINT>(text.size()), nullptr);

		SetTextColor(hdc, oldColor);
		SetBkMode(hdc, oldMode);
		SelectObject(hdc, oldFont);
		g.ReleaseHDC(hdc);
	}

} // namespace jdi