tri_surface_display_opengl():
  C++ version:
  Compiled on May 11 2025 at 20:30:38.
  This program reads files defining the nodes and elements
  of a triangular mesh that forms a surface in 3D. 

  An image of the surface is displayed using OpenGL.

  The image rotates slowly around the X, Y or Z axis.
  Click the mouse to change the axis.

  The node file has been examined.

  The spatial dimension DIM_NUM =  3
  The number of nodes NODE_NUM =   58

  Minimum: -1  -1  -1
  Maximum: 1  1  1
  Range:   2  2  2

  First five nodes:

  Row:       1             2             3       
  Col

    1              0             0            -1
    2       0.382683             0      -0.92388
    3       0.270598      0.270598      -0.92388
    4    2.34326e-17      0.382683      -0.92388
    5      -0.270598      0.270598      -0.92388

  The element file has been examined.

  The element order =  3
  The number of elements =  112

  First five elements:

  Row:      1       2       3  
  Col

    1       3       2       1  
    2       4       3       1  
    3       5       4       1  
    4       6       5       1  
    5       7       6       1  

MESH_BASE_ZERO:
  The element indexing appears to be 1-based!
  This will be converted to 0-based.
  Pixels:  500  500