Code: 3d_underwater_world/regulargrid.h

This is an example OpenGL SDL application which creates an animated 3D underwater world (screenshot), with "Thunderbird 4" with headlights moving on a spline path, a randomly generated sand terrain, sunken ship/submarine/treasure chest models, and swaying fish and seaweed. It is designed to demonstrate basic OpenGL features, and the structure is as follows:

#include "global.h"
#include "vectors.h"
#include "textures.h"
#include "clipping.h"

/*
* RegularGridVertex
* Entry in the regular grid
*/
typedef struct {
       // y coordinate
       GLfloat y;
       // normal value for lighting
       Vec3 normal;
       // colour and material information about the vertex
} 
RegularGridVertex;

/*
* RegularGrid class
* ----------------------
* Used to hold regular polygon meshes for holding
* landscapes etc...
* -------------------------
* Tristan Aubrey-Jones 18/12/2007
*/
class RegularGrid 
{
      private:
              // the grid of element that holds the
              // mesh data
              RegularGridVertex* grid;
              // the width and height in elements of the grid.
              int w, d;
              Vec3 sz;
              // unsafe (no checking) accessors
              // gets the value of a given vertex
              RegularGridVertex getV(int x, int z) {
                  return grid[((x*d)+z)];
              }
              // sets the value of a given vertex
              void setV(int x, int z, RegularGridVertex v) {
                   grid[((x*d)+z)] = v;
              }
      public:
              // texture if any
              Texture* tex;
             // creates a regular grid with
             // xsz x zsz entries
             // v diamensions - to draw in real world
             // tex - the texture to map onto the mesh
             RegularGrid(int xsz, int zsz, Vec3 sz, Texture* tex);
             // destructor
             ~RegularGrid();
             // draws the grid as x,z plane in
             // the unit cubed.
             int draw(CameraView* view);
             //void draw() { draw(NULL); }
             // get dimensions
             int width() { return w; }
             int depth() { return d; }
             // gets the value of a given vertex,
             // and if exceeds size wraps roung
             RegularGridVertex get(int x, int z) {
                 if (x < 0) x = w-x;
                 if (z < 0) z = d-z;
                 return getV(x%w, z%d);
             }
             // sets the value of a given vertex, 
             // and if exceeds size wraps round
             void set(int x, int z, RegularGridVertex v) {
                 if (x < 0) x = w-x;
                 if (z < 0) z = d-z;
                 setV(x%w, z%d, v);
             }
             // sets all entries to the given value
             void setAll(RegularGridVertex v);
             // clear, sets all vertices to default values
             void clear() {
                 RegularGridVertex v;
                 v.y = 0.0;
                 v.normal.set(0.0, 1.0, 0.0);
                 setAll(v);
             }
             // computes the normal value for each vertex
             // by averaging the normal vector to each adjacent face
             void computeNormals();
};

3D Underwater World (using OpenGL and SDL)

regulargrid.h