Initiual commit: AssetImporter source moved from ZFXCE repository to its own repository. PLease do not use the ZFXCE repo any more.

git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@1 67173fc5-114c-0410-ac8e-9d2fd5bffc1f

code/fast_atof.h

@@ -0,0 +1,114 @@
+// Copyright (C) 2002-2007 Nikolaus Gebhardt
+// This file is part of the "Irrlicht Engine" and the "irrXML" project.
+// For conditions of distribution and use, see copyright notice in irrlicht.h and irrXML.h
+// Adapted to the ASSIMP library because the builtin atof indeed takes AGES to parse a
+// float inside a large string. Before parsing, it does a strlen on the given point.
+
+#ifndef __FAST_A_TO_F_H_INCLUDED__
+#define __FAST_A_TO_F_H_INCLUDED__
+
+#include <math.h>
+
+namespace Assimp
+{
+
+const float fast_atof_table[16] =	{  // we write [16] here instead of [] to work around a swig bug
+	0.f,
+	0.1f,
+	0.01f,
+	0.001f,
+	0.0001f,
+	0.00001f,
+	0.000001f,
+	0.0000001f,
+	0.00000001f,
+	0.000000001f,
+	0.0000000001f,
+	0.00000000001f,
+	0.000000000001f,
+	0.0000000000001f,
+	0.00000000000001f,
+	0.000000000000001f
+};
+
+inline unsigned int strtol10( const char* in, const char** out=0)
+{
+	unsigned int value = 0;
+
+	while ( 1 )
+	{
+		if ( *in < '0' || *in > '9' )
+			break;
+
+		value = ( value * 10 ) + ( *in - '0' );
+		++in;
+	}
+	if (out)
+		*out = in;
+	return value;
+}
+
+//! Provides a fast function for converting a string into a float,
+//! about 6 times faster than atof in win32.
+// If you find any bugs, please send them to me, niko (at) irrlicht3d.org.
+inline const char* fast_atof_move( const char* c, float& out)
+{
+	bool inv = false;
+	const char *t;
+	float f;
+
+	if (*c=='-')
+	{
+		++c;
+		inv = true;
+	}
+
+	//f = (float)strtol(c, &t, 10);
+	f = (float) strtol10 ( c, &c );
+
+	if (*c == '.')
+	{
+		++c;
+
+		//float pl = (float)strtol(c, &t, 10);
+		float pl = (float) strtol10 ( c, &t );
+		pl *= fast_atof_table[t-c];
+
+		f += pl;
+
+		c = t;
+
+		if (*c == 'e')
+		{
+			++c;
+			//float exp = (float)strtol(c, &t, 10);
+			bool einv = (*c=='-');
+			if (einv)
+				++c;
+
+			float exp = (float)strtol10(c, &c);
+			if (einv)
+				exp *= -1.0f;
+
+			f *= pow(10.0f, exp);
+		}
+	}
+
+	if (inv)
+		f *= -1.0f;
+	
+	out = f;
+	return c;
+}
+
+inline float fast_atof(const char* c)
+{
+	float ret;
+	fast_atof_move(c, ret);
+	return ret;
+}
+
+} // end of namespace Assimp
+
+#endif
+