title: OpenGL Shading Language TRANSFORM_TEX
body: <p>In unity3d there is a piece of code for a vertex shader :</p>
  
  <pre><code>v2f vert(appdata_full v) {
      v2f o;
  
      o.pos = mul (UNITY_MATRIX_MVP, v.vertex);   
      o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
      o.vertexColor = v.color * _TintColor;
  
      return o; 
  }
  </code></pre>
  
  <p>In lines below :</p>
  
  <pre><code>o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
  </code></pre>
  
  <p>what is the main task of TRANSFORM_TEX function and what is it's equiavalent in CgFx !</p>