Draw emoji in colour in the clip list

CP_Main.vcxproj

@@ -548,6 +548,7 @@
     <ClCompile Include="src\ClipFormatQListCtrl.cpp" />
     <ClCompile Include="src\ClipIds.cpp" />
     <ClCompile Include="src\Clip_ImportExport.cpp" />
+    <ClCompile Include="src\ColorEmojiText.cpp" />
     <ClCompile Include="src\ConvertRTFToText.cpp" />
     <ClCompile Include="src\CopyProperties.cpp" />
     <ClCompile Include="src\CopyThread.cpp" />
@@ -816,6 +817,7 @@
     <ClInclude Include="src\ClipFormatQListCtrl.h" />
     <ClInclude Include="src\ClipIds.h" />
     <ClInclude Include="src\Clip_ImportExport.h" />
+    <ClInclude Include="src\ColorEmojiText.h" />
     <ClInclude Include="src\ConvertRTFToText.h" />
     <ClInclude Include="src\CopyProperties.h" />
     <ClInclude Include="src\CopyThread.h" />

CP_Main.vcxproj.filters

@@ -55,6 +55,9 @@
     <ClCompile Include="src\ClipboardViewer.cpp">
       <Filter>src</Filter>
     </ClCompile>
+    <ClCompile Include="src\ColorEmojiText.cpp">
+      <Filter>src</Filter>
+    </ClCompile>
     <ClCompile Include="src\ClipCompare.cpp">
       <Filter>src</Filter>
     </ClCompile>
@@ -550,6 +553,9 @@
     <ClInclude Include="src\ClipboardViewer.h">
       <Filter>src</Filter>
     </ClInclude>
+    <ClInclude Include="src\ColorEmojiText.h">
+      <Filter>src</Filter>
+    </ClInclude>
     <ClInclude Include="src\ClipCompare.h">
       <Filter>src</Filter>
     </ClInclude>

src/ColorEmojiText.cpp

@@ -0,0 +1,200 @@
+#include "stdafx.h"
+#include "ColorEmojiText.h"
+#include <atlbase.h>
+#include <d2d1.h>
+#include <dwrite.h>
+#include <string>
+
+#pragma comment(lib, "d2d1.lib")
+#pragma comment(lib, "dwrite.lib")
+
+namespace
+{
+	CComPtr<ID2D1Factory> g_d2dFactory;
+	CComPtr<IDWriteFactory> g_writeFactory;
+	CComPtr<IDWriteGdiInterop> g_gdiInterop;
+	CComPtr<ID2D1DCRenderTarget> g_target;
+	bool g_factoriesFailed = false;
+
+	// text format for the last used GDI font, the list draws every row with the same one
+	CComPtr<IDWriteTextFormat> g_format;
+	LOGFONT g_formatLogFont = {};
+	TEXTMETRIC g_formatMetrics = {};
+
+	// Rows without these characters keep the plain GDI path, so ordinary text looks exactly as before.
+	bool HasEmoji(const CString& text)
+	{
+		for (int i = 0; i < text.GetLength(); i++)
+		{
+			wchar_t c = text[i];
+			if (IS_HIGH_SURROGATE(c) ||           // U+1F000 and up: most emoji
+				c == 0xFE0F ||                     // emoji presentation selector
+				c == 0x200D ||                     // zero width joiner in emoji sequences
+				(c >= 0x231A && c <= 0x231B) ||    // watch, hourglass
+				(c >= 0x23E9 && c <= 0x23FA) ||    // media buttons, alarm clock, pause
+				(c >= 0x25FD && c <= 0x25FE) ||    // small squares
+				(c >= 0x2600 && c <= 0x27BF) ||    // misc symbols, dingbats
+				(c >= 0x2B00 && c <= 0x2BFF))      // arrows and stars like U+2B50
+			{
+				return true;
+			}
+		}
+		return false;
+	}
+
+	bool CreateResources()
+	{
+		if (g_target)
+			return true;
+		if (g_factoriesFailed)
+			return false;
+
+		HRESULT hr = S_OK;
+		if (!g_d2dFactory)
+		{
+			hr = D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, &g_d2dFactory.p);
+			if (SUCCEEDED(hr))
+				hr = DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED, __uuidof(IDWriteFactory), reinterpret_cast<IUnknown**>(&g_writeFactory.p));
+			if (SUCCEEDED(hr))
+				hr = g_writeFactory->GetGdiInterop(&g_gdiInterop);
+			if (FAILED(hr))
+			{
+				g_factoriesFailed = true;
+				return false;
+			}
+		}
+
+		// software target: the rows are small and GDI owns the DC, a GPU round trip per row costs more than it gives.
+		// 96 dpi makes one DIP equal one pixel, so GDI rects and font sizes are used as is.
+		D2D1_RENDER_TARGET_PROPERTIES props = D2D1::RenderTargetProperties(
+			D2D1_RENDER_TARGET_TYPE_SOFTWARE,
+			D2D1::PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_IGNORE),
+			96.0f, 96.0f);
+
+		hr = g_d2dFactory->CreateDCRenderTarget(&props, &g_target);
+		if (FAILED(hr))
+		{
+			g_factoriesFailed = true;
+			return false;
+		}
+
+		// GDI classic rendering, so letters in an emoji row look like the GDI rows next to it
+		CComPtr<IDWriteRenderingParams> defaults;
+		CComPtr<IDWriteRenderingParams> gdiClassic;
+		if (SUCCEEDED(g_writeFactory->CreateRenderingParams(&defaults)) &&
+			SUCCEEDED(g_writeFactory->CreateCustomRenderingParams(defaults->GetGamma(), defaults->GetEnhancedContrast(),
+				defaults->GetClearTypeLevel(), defaults->GetPixelGeometry(), DWRITE_RENDERING_MODE_GDI_CLASSIC, &gdiClassic)))
+		{
+			g_target->SetTextRenderingParams(gdiClassic);
+		}
+		return true;
+	}
+
+	IDWriteTextFormat* GetTextFormat(CDC* pDC)
+	{
+		LOGFONT lf = {};
+		CFont* font = pDC->GetCurrentFont();
+		if (font == NULL || font->GetLogFont(&lf) == 0)
+			return NULL;
+
+		TEXTMETRIC tm = {};
+		if (pDC->GetTextMetrics(&tm) == FALSE)
+			return NULL;
+
+		if (g_format &&
+			memcmp(&lf, &g_formatLogFont, sizeof(lf)) == 0 &&
+			memcmp(&tm, &g_formatMetrics, sizeof(tm)) == 0)
+		{
+			return g_format;
+		}
+
+		g_format.Release();
+
+		// the GDI face name ("Segoe UI Semibold") is not always a DirectWrite family name, ask GDI interop for the real one
+		CComPtr<IDWriteFont> writeFont;
+		if (FAILED(g_gdiInterop->CreateFontFromLOGFONT(&lf, &writeFont)))
+			return NULL;
+
+		CComPtr<IDWriteFontFamily> family;
+		CComPtr<IDWriteLocalizedStrings> names;
+		if (FAILED(writeFont->GetFontFamily(&family)) ||
+			FAILED(family->GetFamilyNames(&names)))
+		{
+			return NULL;
+		}
+
+		UINT32 index = 0;
+		BOOL exists = FALSE;
+		if (FAILED(names->FindLocaleName(L"en-us", &index, &exists)) || exists == FALSE)
+			index = 0;
+
+		UINT32 length = 0;
+		if (FAILED(names->GetStringLength(index, &length)))
+			return NULL;
+
+		std::wstring familyName(length + 1, L'\0');
+		if (FAILED(names->GetString(index, &familyName[0], length + 1)))
+			return NULL;
+
+		// em size the way GDI sees it: cell height without internal leading
+		float emSize = static_cast<float>(tm.tmHeight - tm.tmInternalLeading);
+		if (emSize <= 0)
+			return NULL;
+
+		CComPtr<IDWriteTextFormat> format;
+		if (FAILED(g_writeFactory->CreateTextFormat(familyName.c_str(), NULL,
+			writeFont->GetWeight(), writeFont->GetStyle(), writeFont->GetStretch(),
+			emSize, L"", &format)))
+		{
+			return NULL;
+		}
+
+		// same geometry as GDI DrawText: no wrapping, line height = tmHeight, tab = 8 average chars
+		format->SetWordWrapping(DWRITE_WORD_WRAPPING_NO_WRAP);
+		format->SetLineSpacing(DWRITE_LINE_SPACING_METHOD_UNIFORM, static_cast<float>(tm.tmHeight), static_cast<float>(tm.tmAscent));
+		format->SetIncrementalTabStop(static_cast<float>(8 * tm.tmAveCharWidth));
+
+		g_format = format;
+		g_formatLogFont = lf;
+		g_formatMetrics = tm;
+		return g_format;
+	}
+}
+
+bool ColorEmojiText::DrawColorText(CDC* pDC, const CString& text, const CRect& rc)
+{
+	if (rc.IsRectEmpty() || HasEmoji(text) == false || CreateResources() == false)
+		return false;
+
+	IDWriteTextFormat* format = GetTextFormat(pDC);
+	if (format == NULL)
+		return false;
+
+	// GDI-compatible layout: whole-pixel advances, same text widths as GDI DrawText
+	CComPtr<IDWriteTextLayout> layout;
+	if (FAILED(g_writeFactory->CreateGdiCompatibleTextLayout(text, text.GetLength(), format,
+		static_cast<float>(rc.Width()), static_cast<float>(rc.Height()), 1.0f, NULL, FALSE, &layout)))
+	{
+		return false;
+	}
+
+	RECT bindRect = rc;
+	if (FAILED(g_target->BindDC(pDC->GetSafeHdc(), &bindRect)))
+		return false;
+
+	COLORREF color = pDC->GetTextColor();
+	CComPtr<ID2D1SolidColorBrush> brush;
+	if (FAILED(g_target->CreateSolidColorBrush(D2D1::ColorF(GetRValue(color) / 255.0f, GetGValue(color) / 255.0f, GetBValue(color) / 255.0f), &brush)))
+		return false;
+
+	g_target->BeginDraw();
+	g_target->SetTransform(D2D1::Matrix3x2F::Identity());
+	g_target->DrawTextLayout(D2D1::Point2F(0, 0), layout, brush,
+		D2D1_DRAW_TEXT_OPTIONS_ENABLE_COLOR_FONT | D2D1_DRAW_TEXT_OPTIONS_CLIP);
+	HRESULT hr = g_target->EndDraw();
+
+	if (hr == D2DERR_RECREATE_TARGET)
+		g_target.Release();
+
+	return SUCCEEDED(hr);
+}

src/ColorEmojiText.h

@@ -0,0 +1,13 @@
+#pragma once
+
+// Colour emoji in the clip list (issue #251).
+// GDI DrawText renders colour fonts (Segoe UI Emoji) black and white, so rows
+// that contain emoji are drawn through Direct2D/DirectWrite instead.
+namespace ColorEmojiText
+{
+	// Draws text the way CDC::DrawText(text, rc, DT_EXPANDTABS | DT_NOPREFIX) does,
+	// with the font and text colour currently selected into pDC, but keeps colour glyphs.
+	// Returns false without drawing anything when the text has no emoji-like characters
+	// or DirectWrite failed - the caller then draws with GDI as before.
+	bool DrawColorText(CDC* pDC, const CString& text, const CRect& rc);
+}

src/QListCtrl.cpp

@@ -10,6 +10,7 @@
 #include "DittoCopyBuffer.h"
 #include <atlbase.h>
 #include "DrawHTML.h"
+#include "ColorEmojiText.h"
 #include "..\Shared\TextConvert.h"
 #include <cmath>
 #include <vector>
@@ -599,7 +600,11 @@ void CQListCtrl::OnCustomdrawList(NMHDR* pNMHDR, LRESULT* pResult)
 			}
 			else
 			{
-				pDC->DrawText(csText, rcText, DT_VCENTER | DT_EXPANDTABS | DT_NOPREFIX);
+				// rows with emoji go through DirectWrite, GDI draws them black and white
+				if (ColorEmojiText::DrawColorText(pDC, csText, rcText) == false)
+				{
+					pDC->DrawText(csText, rcText, DT_VCENTER | DT_EXPANDTABS | DT_NOPREFIX);
+				}
 			}
 		}