backport of
https://github.com/bulletphysics/bullet3/commit/4f0673810cab0eee67ea314a3243952afd150cb4

Index: src/BulletSoftBody/btSoftBodyHelpers.cpp
--- src/BulletSoftBody/btSoftBodyHelpers.cpp.orig
+++ src/BulletSoftBody/btSoftBodyHelpers.cpp
@@ -1488,30 +1488,6 @@ void btSoftBodyHelpers::writeObj(const char* filename,
 	fs.close();
 }
 
-static inline bool isSpace(const char c)
-{
-	return (c == ' ') || (c == '\t');
-}
-static inline bool isNewLine(const char c)
-{
-	return (c == '\r') || (c == '\n') || (c == '\0');
-}
-static inline float parseFloat(const char*& token)
-{
-	token += strspn(token, " \t");
-	float f = (float)atof(token);
-	token += strcspn(token, " \t\r");
-	return f;
-}
-static inline void parseFloat3(
-	float& x, float& y, float& z,
-	const char*& token)
-{
-	x = parseFloat(token);
-	y = parseFloat(token);
-	z = parseFloat(token);
-}
-
 void btSoftBodyHelpers::writeState(const char* file, const btSoftBody* psb)
 {
 	std::ofstream fs;
@@ -1540,114 +1516,6 @@ void btSoftBodyHelpers::writeState(const char* file, c
 		fs << "\n";
 	}
 	fs.close();
-}
-
-std::string btSoftBodyHelpers::loadDeformableState(btAlignedObjectArray<btVector3>& qs, btAlignedObjectArray<btVector3>& vs, const char* filename, CommonFileIOInterface* fileIO)
-{
-	{
-		qs.clear();
-		vs.clear();
-		std::string tmp = filename;
-		std::stringstream err;
-#ifdef USE_STREAM
-		std::ifstream ifs(filename);
-		if (!ifs)
-		{
-			err << "Cannot open file [" << filename << "]" << std::endl;
-			return err.str();
-		}
-#else
-		int fileHandle = fileIO->fileOpen(filename, "r");
-		if (fileHandle < 0)
-		{
-			err << "Cannot open file [" << filename << "]" << std::endl;
-			return err.str();
-		}
-#endif
-
-		std::string name;
-
-		int maxchars = 8192;              // Alloc enough size.
-		std::vector<char> buf(maxchars);  // Alloc enough size.
-		std::string linebuf;
-		linebuf.reserve(maxchars);
-
-#ifdef USE_STREAM
-		while (ifs.peek() != -1)
-#else
-		char* line = 0;
-		do
-#endif
-		{
-			linebuf.resize(0);
-#ifdef USE_STREAM
-			safeGetline(ifs, linebuf);
-#else
-			char tmpBuf[1024];
-			line = fileIO->readLine(fileHandle, tmpBuf, 1024);
-			if (line)
-			{
-				linebuf = line;
-			}
-#endif
-			// Trim newline '\r\n' or '\r'
-			if (linebuf.size() > 0)
-			{
-				if (linebuf[linebuf.size() - 1] == '\n') linebuf.erase(linebuf.size() - 1);
-			}
-			if (linebuf.size() > 0)
-			{
-				if (linebuf[linebuf.size() - 1] == '\n') linebuf.erase(linebuf.size() - 1);
-			}
-
-			// Skip if empty line.
-			if (linebuf.empty())
-			{
-				continue;
-			}
-
-			// Skip leading space.
-			const char* token = linebuf.c_str();
-			token += strspn(token, " \t");
-
-			btAssert(token);
-			if (token[0] == '\0') continue;  // empty line
-
-			if (token[0] == '#') continue;  // comment line
-
-			// q
-			if (token[0] == 'q' && isSpace((token[1])))
-			{
-				token += 2;
-				float x, y, z;
-				parseFloat3(x, y, z, token);
-				qs.push_back(btVector3(x, y, z));
-				continue;
-			}
-
-			// v
-			if (token[0] == 'v' && isSpace((token[1])))
-			{
-				token += 3;
-				float x, y, z;
-				parseFloat3(x, y, z, token);
-				vs.push_back(btVector3(x, y, z));
-				continue;
-			}
-
-			// Ignore unknown command.
-		}
-#ifndef USE_STREAM
-		while (line)
-			;
-#endif
-
-		if (fileHandle >= 0)
-		{
-			fileIO->fileClose(fileHandle);
-		}
-		return err.str();
-	}
 }
 
 void btSoftBodyHelpers::duplicateFaces(const char* filename, const btSoftBody* psb)