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vguimatsurface/FontTextureCache.h

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+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//=============================================================================//
+
+#ifndef FONTTEXTURECACHE_H
+#define FONTTEXTURECACHE_H
+#ifdef _WIN32
+#pragma once
+#endif
+
+#include "vgui_surfacelib/FontManager.h"
+#include "utlrbtree.h"
+#include <vgui/ISurface.h>
+#include "utlmap.h"
+
+class ITexture;
+
+//-----------------------------------------------------------------------------
+// Purpose: manages texture memory for unicode fonts in vgui
+//-----------------------------------------------------------------------------
+class CFontTextureCache
+{
+public:
+	CFontTextureCache();
+	~CFontTextureCache();
+
+	// returns a texture ID and a pointer to an array of 4 texture coords for the given character & font
+	// generates+uploads more texture if necessary
+	bool GetTextureForChar( vgui::HFont font, vgui::FontDrawType_t type, wchar_t wch, int *textureID, float **texCoords );
+
+	// for each character in an array (not assumed to be a NULL-terminated string), returns a
+	// texture ID and a pointer to an array of 4 texture coords for the given character & font
+	// generates+uploads more texture if necessary
+	bool GetTextureForChars( vgui::HFont font, vgui::FontDrawType_t type, const wchar_t *wch, int *textureID, float **texCoords, int numChars = 1 );
+
+	// clears the cache
+	void Clear();
+
+private:
+	// NOTE: If you change this, change s_pFontPageSize
+	enum
+	{
+		FONT_PAGE_SIZE_16,
+		FONT_PAGE_SIZE_32,
+		FONT_PAGE_SIZE_64,
+		FONT_PAGE_SIZE_128,
+		FONT_PAGE_SIZE_256,
+		FONT_PAGE_SIZE_COUNT,
+	};
+
+	// a single character in the cache
+	typedef unsigned short HCacheEntry;
+	struct CacheEntry_t
+	{
+		vgui::HFont		font;
+		wchar_t			wch;
+		unsigned char	page;
+		float			texCoords[4];
+
+		// doubly-linked list for use in the LRU
+		HCacheEntry		nextEntry;
+		HCacheEntry		prevEntry;
+	};
+	
+	// a single texture page
+	struct Page_t
+	{
+		short textureID[vgui::FONT_DRAW_TYPE_COUNT];
+		short maxFontHeight;
+		short tallestCharOnLine;
+		short wide, tall;	// total size of the page
+		short nextX, nextY;	// position to draw any new character positions
+	};
+
+	// allocates a new page for a given character
+	bool AllocatePageForChar(int charWide, int charTall, int &pageIndex, int &drawX, int &drawY, int &twide, int &ttall);
+
+	// Creates font materials
+	void CreateFontMaterials( Page_t &page, ITexture *pFontTexture, bool bitmapFont = false );
+
+	// Computes the page size given a character height
+	int ComputePageType( int charTall ) const;
+
+	static bool CacheEntryLessFunc(const CacheEntry_t &lhs, const CacheEntry_t &rhs);
+
+	CUtlRBTree<CacheEntry_t, HCacheEntry>	m_CharCache;
+
+	// cache
+	typedef CUtlVector<Page_t>	FontPageList_t;
+	FontPageList_t				m_PageList;
+	
+	int			m_pCurrPage[FONT_PAGE_SIZE_COUNT];
+	HCacheEntry	m_LRUListHeadIndex;
+	static int	s_pFontPageSize[FONT_PAGE_SIZE_COUNT];
+	CUtlMap< vgui::HFont, Page_t >	m_FontPages;
+};
+
+
+#endif // FONTTEXTURECACHE_H