How can I bypass texture isReadable

It is possible when using opengl.

in c

 void EXPORT_API SetTexture(int textureID) 
 {
     freopen("debug.txt", "a", stdout);
     printf("SetTexture id:%d\n" ,textureID);

     glBindTexture(GL_TEXTURE_2D, textureID);

     glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &textureWidth);
     glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &textureHeight);
     printf("w:%d h:%d\n" ,textureWidth ,textureHeight);

     buffer = (GLfloat *)malloc(textureWidth * textureHeight * (sizeof(GLfloat) * 4));
     glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_FLOAT, buffer);
 }
     
 bool EXPORT_API GetTexture(float* resultPixels, int* resultPixelLength)
 {
     *resultPixelLength = (textureWidth * textureHeight) * 4;
     printf("GetTexture pixels%d \n", resultPixelLength);
     
     for(int i = 0; i < *resultPixelLength; i++)
     {
         resultPixels[+i] = (float) buffer[i];
     }
     
     count++;
     return true;
 }

 void EXPORT_API FreeMemory() 
 {
     printf("\n");
     //delete(buffer);
     free(buffer);
     //free(bufferTest);
 }
 
 void EXPORT_API Close() 
 {
     fclose (stdout);
 }

in c#

 [DllImport("Unity3dTextureSteal")]
 private static extern void SetTexture(int textureId);
 [DllImport("Unity3dTextureSteal")]
 private static extern bool GetTexture(System.IntPtr ptrResultVerts, ref int resultVertLength);
 [DllImport("Unity3dTextureSteal")]
 private static extern void FreeMemory();
 [DllImport("Unity3dTextureSteal")]
 private static extern void Close();

 public static Texture2D FindTexture(Texture2D tex)
 {
     //Debug.Log(tex.name + " " + tex.format);
     SetTexture(tex.GetNativeTextureID());

     float[] pix = new float[tex.width * tex.height * 4];
     int resultVertLength = 0;
     GCHandle pArray = GCHandle.Alloc(pix, GCHandleType.Pinned);

     if (GetTexture(pArray.AddrOfPinnedObject(), ref resultVertLength))
     {
         pArray.Free();
         Color[] colors = new Color[tex.width * tex.height];
         //Debug.Log(pix.Length + " " + resultVertLength);
         int i, c;
         for (c = 0, i = 0; c < colors.Length; c++)
         {
             Color co = new Color();
             co[0] = pix[i];
             i++;
             co[1] = pix[i];
             i++;
             co[2] = pix[i];
             i++;
             co[3] = pix[i];
             i++;
             colors[c] = co;
         }
 
         Texture2D texture = new Texture2D(tex.width, tex.height, TextureFormat.RGBA32, false);
         texture.SetPixels(colors, 0);
         texture.Apply(false);

         FreeMemory();

         return texture;
     }
     return null;
 }