glPushMatrix();	glLoadIdentity();    glLightfv(GL_LIGHT0, GL_POSITION, lightPosition);	glPopMatrix();

   varying vec4 diffuse, ambient;   varying vec3 normal, lightDir, halfVector;   varying vec2 blendmap_texCoord, texture_coord;        void main()   {      vec3 n,halfV,viewV,ldir;      float NdotL,NdotHV;               /* The ambient term will always be present */      vec4 color = ambient;            /* a fragment shader can't write a varying variable, hence we need      a new variable to store the normalized interpolated normal */      n = normalize(normal);            /* compute the dot product between normal and ldir */      NdotL = max(dot(n,lightDir),0.0);         if (NdotL > 0.0) {         color += diffuse * NdotL;         halfV = normalize(halfVector);         NdotHV = max(dot(n,halfV),0.0);         color += gl_FrontMaterial.specular *                gl_LightSource[0].specular *                pow(NdotHV, gl_FrontMaterial.shininess);      }      gl_FragColor = color;   }

   varying vec4 diffuse, ambient;   varying vec3 normal, lightDir, halfVector;   varying vec2 blendmap_texCoord, texture_coord;          void main()   {         //gl_TexCoord[0] = gl_MultiTexCoord0;      blendmap_texCoord = vec2(gl_MultiTexCoord0);      texture_coord = blendmap_texCoord * 20;                           /* first transform the normal into eye space and       normalize the result */      normal = normalize(gl_NormalMatrix * gl_Normal);            /* now normalize the light's direction. Note that       according to the OpenGL specification, the light       is stored in eye space. Also since we're talking about       a directional light, the position field is actually direction */      lightDir = normalize(vec3(gl_LightSource[0].position));         /* Normalize the halfVector to pass it to the fragment shader */      halfVector = normalize(gl_LightSource[0].halfVector.xyz);                     /* Compute the diffuse, ambient and globalAmbient terms */      diffuse = gl_FrontMaterial.diffuse * gl_LightSource[0].diffuse;      ambient = gl_FrontMaterial.ambient * gl_LightSource[0].ambient;      ambient += gl_LightModel.ambient * gl_FrontMaterial.ambient;           gl_Position = ftransform();   } 

	//reset viewport to our original viewport size	glViewport(0, 0, gWidth, gHeight);	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	glLoadIdentity();		g_Camera.LookAt();	//reset light position or else the light position will jump all over	glPushMatrix();	glLoadIdentity();        glLightfv(GL_LIGHT0, GL_POSITION, terrain.lightPosition);	glPopMatrix();	glTranslatef(0.0f, -move_y, 0.0f);		//move height based on mouse wheel	glPushMatrix();	terrain.DrawTerrainVBO(timer.speedfactor, false); 	glPopMatrix();