From 893d0c8915203ce4d25766872fbe508fea024706 Mon Sep 17 00:00:00 2001
From: "alexey.lysiuk" <alexey.lysiuk@gmail.com>
Date: Sat, 30 Apr 2016 13:33:54 +0300
Subject: [PATCH] Added old method to collect extensions

This required manual changes in generated file gl_load.c
---
 src/gl/system/gl_interface.cpp | 31 +++++++++++++++++++---
 src/gl/system/gl_load.c        | 48 +++++++++++++++++++++++++++++++---
 2 files changed, 73 insertions(+), 6 deletions(-)

diff --git a/src/gl/system/gl_interface.cpp b/src/gl/system/gl_interface.cpp
index c09038bf8f..a5dbf0533e 100644
--- a/src/gl/system/gl_interface.cpp
+++ b/src/gl/system/gl_interface.cpp
@@ -66,10 +66,35 @@ static void CollectExtensions()
 	int max = 0;
 	glGetIntegerv(GL_NUM_EXTENSIONS, &max);
 
-	for(int i = 0; i < max; i++)
+	if (0 == max)
 	{
-		extension = (const char*)glGetStringi(GL_EXTENSIONS, i);
-		m_Extensions.Push(FString(extension));
+		// Try old method to collect extensions
+		const char *supported = (char *)glGetString(GL_EXTENSIONS);
+
+		if (nullptr != supported)
+		{
+			char *extensions = new char[strlen(supported) + 1];
+			strcpy(extensions, supported);
+
+			char *extension = strtok(extensions, " ");
+
+			while (extension)
+			{
+				m_Extensions.Push(FString(extension));
+				extension = strtok(nullptr, " ");
+			}
+
+			delete [] extensions;
+		}
+	}
+	else
+	{
+		// Use modern method to collect extensions
+		for (int i = 0; i < max; i++)
+		{
+			extension = (const char*)glGetStringi(GL_EXTENSIONS, i);
+			m_Extensions.Push(FString(extension));
+		}
 	}
 }
 
diff --git a/src/gl/system/gl_load.c b/src/gl/system/gl_load.c
index a6b7df013e..d3de767c3d 100644
--- a/src/gl/system/gl_load.c
+++ b/src/gl/system/gl_load.c
@@ -2375,8 +2375,41 @@ static void LoadExtByName(const char *extensionName)
 	}
 }
 
+static void ProcExtsFromExtString(const char *strExtList)
+{
+	size_t iExtListLen = strlen(strExtList);
+	const char *strExtListEnd = strExtList + iExtListLen;
+	const char *strCurrPos = strExtList;
+	char strWorkBuff[256];
 
-static void ProcExtsFromExtList(void)
+	while(*strCurrPos)
+	{
+		/*Get the extension at our position.*/
+		int iStrLen = 0;
+		const char *strEndStr = strchr(strCurrPos, ' ');
+		int iStop = 0;
+		if(strEndStr == NULL)
+		{
+			strEndStr = strExtListEnd;
+			iStop = 1;
+		}
+
+		iStrLen = (int)((ptrdiff_t)strEndStr - (ptrdiff_t)strCurrPos);
+
+		if(iStrLen > 255)
+			return;
+
+		strncpy(strWorkBuff, strCurrPos, iStrLen);
+		strWorkBuff[iStrLen] = '\0';
+
+		LoadExtByName(strWorkBuff);
+
+		strCurrPos = strEndStr + 1;
+		if(iStop) break;
+	}
+}
+
+static int ProcExtsFromExtList(void)
 {
 	GLint iLoop;
 	GLint iNumExtensions = 0;
@@ -2387,6 +2420,8 @@ static void ProcExtsFromExtList(void)
 		const char *strExtensionName = (const char *)_ptrc_glGetStringi(GL_EXTENSIONS, iLoop);
 		LoadExtByName(strExtensionName);
 	}
+
+	return iNumExtensions;
 }
 
 int ogl_LoadFunctions()
@@ -2398,8 +2433,15 @@ int ogl_LoadFunctions()
 	if(!_ptrc_glGetIntegerv) return ogl_LOAD_FAILED;
 	_ptrc_glGetStringi = (const GLubyte * (CODEGEN_FUNCPTR *)(GLenum, GLuint))IntGetProcAddress("glGetStringi");
 	if(!_ptrc_glGetStringi) return ogl_LOAD_FAILED;
-	
-	ProcExtsFromExtList();
+
+	if (0 == ProcExtsFromExtList())
+	{
+		_ptrc_glGetString = (const GLubyte * (CODEGEN_FUNCPTR *)(GLenum))IntGetProcAddress("glGetString");
+		if(!_ptrc_glGetString) return ogl_LOAD_FAILED;
+
+		ProcExtsFromExtString((const char *)_ptrc_glGetString(GL_EXTENSIONS));
+	}
+
 	numFailed = Load_Version_3_3();
 	
 	if(numFailed == 0)