From de95db5c9397cec28749a2c0217a240dd33e036e Mon Sep 17 00:00:00 2001
From: Benau <Benau@users.noreply.github.com>
Date: Sun, 20 Nov 2016 10:08:59 +0800
Subject: [PATCH] Avoid creating new glyph page too many times

---
 lib/irrlicht/include/IGUIFont.h               |  2 +-
 .../source/Irrlicht/CTextSceneNode.cpp        |  6 ++---
 src/guiengine/scalable_font.cpp               | 23 ++++++++++++++++---
 src/guiengine/scalable_font.hpp               |  2 +-
 4 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/lib/irrlicht/include/IGUIFont.h b/lib/irrlicht/include/IGUIFont.h
index 99d7670ab..b8ef7a070 100644
--- a/lib/irrlicht/include/IGUIFont.h
+++ b/lib/irrlicht/include/IGUIFont.h
@@ -96,7 +96,7 @@ public:
 	*/
 	virtual void setInvisibleCharacters( const wchar_t *s ) = 0;
 
-	virtual void addLazyLoadCharacters(const wchar_t *s) {}
+	virtual u32 addLazyLoadCharacters(const wchar_t *s) { return 0; }
 };
 
 } // end namespace gui
diff --git a/lib/irrlicht/source/Irrlicht/CTextSceneNode.cpp b/lib/irrlicht/source/Irrlicht/CTextSceneNode.cpp
index ddccaacab..88ff8cb05 100644
--- a/lib/irrlicht/source/Irrlicht/CTextSceneNode.cpp
+++ b/lib/irrlicht/source/Irrlicht/CTextSceneNode.cpp
@@ -114,12 +114,12 @@ CBillboardTextSceneNode::CBillboardTextSceneNode(ISceneNode* parent, ISceneManag
 		{
 			Font = (gui::IGUIFontBitmap*)font;
 			Font->grab();
-			u32 old_texture_count = Font->getSpriteBank()->getTextureCount();
-			Font->addLazyLoadCharacters(text);
+			u32 texture_count = Font->addLazyLoadCharacters(text);
+			_IRR_DEBUG_BREAK_IF(texture_count==0);
 
 			// mesh with one buffer per texture
 			Mesh = new SMesh();
-			for (u32 i=0; i<old_texture_count; ++i)
+			for (u32 i=0; i<texture_count; ++i)
 			{
 				SMeshBuffer *mb = new SMeshBuffer();
 				mb->Material = Material;
diff --git a/src/guiengine/scalable_font.cpp b/src/guiengine/scalable_font.cpp
index 12784a31c..331cc6ed8 100644
--- a/src/guiengine/scalable_font.cpp
+++ b/src/guiengine/scalable_font.cpp
@@ -126,13 +126,30 @@ u32 ScalableFont::getSpriteNoFromChar(const wchar_t *c) const
 }   // getSpriteNoFromChar
 
 // ------------------------------------------------------------------------
-void ScalableFont::addLazyLoadCharacters(const wchar_t *c)
+u32 ScalableFont::addLazyLoadCharacters(const wchar_t *c)
 {
-    if (!m_face->supportLazyLoadChar()) return;
+    IGUISpriteBank* sp = m_face->getSpriteBank();
+    u32 tex_count = sp->getTextureCount();
+    if (!m_face->supportLazyLoadChar()) return tex_count;
 
     m_face->insertCharacters(c);
     m_face->updateCharactersList();
-    m_face->createNewGlyphPage();
+
+    // Make sure text of billboard wasn't located in the last texture
+    for (const wchar_t p = *c; *c; c++)
+    {
+        const core::array<SGUISprite>& s = sp->getSprites();
+        const FontWithFace::FontArea& area =
+            m_face->getAreaFromCharacter(p, NULL/*fallback_font*/);
+        u32 cur_tex_no = s[area.spriteno].Frames[0].textureNumber;
+        if (cur_tex_no == (tex_count -1))
+        {
+            m_face->createNewGlyphPage();
+            return tex_count;
+        }
+    }
+
+    return tex_count -1;
 
 }   // addLazyLoadCharacters
 
diff --git a/src/guiengine/scalable_font.hpp b/src/guiengine/scalable_font.hpp
index 7ef1b3faf..dae0b9728 100644
--- a/src/guiengine/scalable_font.hpp
+++ b/src/guiengine/scalable_font.hpp
@@ -86,7 +86,7 @@ public:
     /** returns the sprite number from a given character */
     virtual u32 getSpriteNoFromChar(const wchar_t *c) const;
     // ------------------------------------------------------------------------
-    virtual void addLazyLoadCharacters(const wchar_t *s);
+    virtual u32 addLazyLoadCharacters(const wchar_t *s);
     // ------------------------------------------------------------------------
     // Below is not used:
     /** set an Pixel Offset on Drawing ( scale position on width ) */