togles: fix alpha test on some GPUs( fixes #119 )

togles/linuxwin/cglmprogram.cpp

@@ -693,6 +693,7 @@ CGLMShaderPair::CGLMShaderPair( GLMContext *ctx  )
 	m_program = gGL->glCreateProgram();
 
 	m_locVertexParams = -1;
+	m_locAlphaRef = -1;
 	m_locVertexBoneParams = -1;
 	m_locVertexScreenParams = -1;
 	m_nScreenWidthHeight = 0xFFFFFFFF;

togles/linuxwin/glmgr_flush.inl

@@ -480,7 +480,7 @@ FORCEINLINE void GLMContext::FlushDrawStates( uint nStartIndex, uint nEndIndex,
 	}
 
 
-	if( !gGL->m_bHave_GL_QCOM_alpha_test && m_pBoundPair->m_locAlphaRef )
+	if( !gGL->m_bHave_GL_QCOM_alpha_test && m_pBoundPair->m_locAlphaRef != -1 )
 	{
 		if( !m_AlphaTestEnable.GetData().enable )
 			gGL->glUniform1f( m_pBoundPair->m_locAlphaRef, 0.0 );