jburkardt

XYF_DISPLAY_OPENGL\ Display 2D Points and Faces Using OpenGL {#xyf_display_opengl-display-2d-points-and-faces-using-opengl align=”center”} ========================================

---

XYF_DISPLAY_OPENGL is a C++ program which reads XYF information defining points and faces in 2D, and draws a picture using OPENGL.

The point and face information is stored in a pair of files, called the XYF format. Essentially, the first file stores a list of point coordinates, and the second lists point indices which can be connected to form faces.

Usage: {#usage align=”center”}

xyf_display_opengl prefix

where

• prefix is the common prefix for the point coordinate data in prefix.xy and the point index lists in prefix.xyf.

Licensing: {#licensing align=”center”}

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages: {#languages align=”center”}

XYF_DISPLAY_OPENGL is available in a C++ version.

Related Data and Programs: {#related-data-and-programs align=”center”}

BOX_PLOT, a MATLAB program which can color in specified entries of a checkerboard, corresponding to pairs of integer data.

CAUSTIC_OPENGL, a C++ program which computes a caustic curve and displays it using OpenGL.

FERN_OPENGL, a C++ program which uses OpenGL to display the Barnsley fractal fern.

FLOOD_OPENGL, a C program which allows a user to select a region and flood it with color, using OpenGL, by Art Wetzel.

LIFE_OPENGL, a C program which plays John Conway’s “Game of Life”, using OpenGL to display the results.

LISSAJOUS_OPENGL, a C++ program which computes a Lissajous figure and displays it using OpenGL.

OPENGL, C++ programs which illustrate the use of the OpenGL graphics library;

PLOT_POINTS, a FORTRAN90 program which reads a file of point coordinates and makes a PostScript image of them.

POLYGONAL_SURFACE_DISPLAY_OPENGL, a C++ program which displays a surface in 3D described as a set of polygons, using OpenGL.

ROTATING_CUBE_DISPLAY_OPENGL, a C++ program which displays a rotating color cube in 3D, using OpenGL;

SPHERE_XYZ_DISPLAY_OPENGL, a C++ program which reads XYZ information defining points in 3D, and displays a unit sphere and the points, using OpenGL.

TABLE_DELAUNAY, a FORTRAN90 program which computes the Delaunay triangulation of a set of points.

TABLE_VORONOI, a C++ program which computes information about the Voronoi diagram of the points.

TRIANGULATION_DISPLAY_OPENGL, a C++ program which reads files defining a triangulation and displays an image using Open GL.

XY_DISPLAY_OPENGL, a C++ program which reads an XY file of 2D point coordinates, and displays an image of those points using OpenGL.

XYF, a data directory which contains examples of XYF files, a simple 2D graphics point and face format;

XYL_DISPLAY, a MATLAB program which reads XYL information defining points and lines in 2D, and displays an image in a MATLAB graphics window.

Reference: {#reference align=”center”}

1. Edward Angel,\ Interactive Computer Graphics, a Top-Down Approach with OpenGL,\ Addison-Wesley, 2000,\ ISBN: 0-201-38597-X,\ LC: T385.A514.
2. Renate Kempf, Chris Frazier, editors,\ OpenGL Reference Manual,\ Fourth Edition,\ Addison-Wesley, 2004,\ ISBN: 032117383X,\ LC: T385.O642
3. Mason Woo, Jackie Neider, Tom Davis,\ OpenGL Programming Guide,\ Addison-Wesley, 1997,\ ISBN: 0-201-46138-2,\ LC: T385.N435
4. Richard Wright, Michael Sweet,\ OpenGL Superbible,\ Third Edition,\ Sams, 2004,\ ISBN: 0672326019,\ LC: T385.W73
5. http://www.opengl.org/\ The official OpenGL site.

Source Code: {#source-code align=”center”}

• xyf_display_opengl.cpp, the source code.

Examples and Tests: {#examples-and-tests align=”center”}

• annulus.xy, point coordinates.
• annulus.xyf, point indices to be connected as faces.
• annulus.png, a PNG image of the screen generated by Open GL.

List of Routines: {#list-of-routines align=”center”}

• MAIN is the main program for XYF_DISPLAY_OPENGL.
• CH_EQI is true if two characters are equal, disregarding case.
• CH_TO_DIGIT returns the integer value of a base 10 digit.
• DISPLAY generates the graphics output.
• I4VEC_MAX returns the value of the maximum element in an I4VEC.
• I4VEC_MIN returns the value of the minimum element in an I4VEC.
• MYINIT initializes OpenGL state variables dealing with viewing and attributes.
• R8_MAX returns the maximum of two R8.
• R82VEC_MAX returns the maximum value in a R82VEC.
• R82VEC_MIN returns the minimum value in a R82VEC.
• S_CAT concatenates two strings to make a third string.
• S_LEN_TRIM returns the length of a string to the last nonblank.
• S_TO_I4 reads an I4 from a string.
• S_TO_I4VEC reads an I4VEC from a string.
• S_TO_R8 reads an R8 from a string.
• S_TO_R8VEC reads an R8VEC from a string.
• S_WORD_COUNT counts the number of “words” in a string.
• TIMESTAMP prints the current YMDHMS date as a time stamp.
• XY_DATA_READ reads the data in an XY file.
• XY_HEADER_READ reads the header of an XY file.
• XYF_DATA_READ reads the data in an XYF file.
• XYF_HEADER_READ determines the number of face items in an XYF file.

You can go up one level to the C++ source codes.

---

Last revised on 07 January 2009.