/* tilegrid.c - Don Yang (uguu.org)

   05/31/03
                                                                           */

#include"global.h"
#include"core.h"
#include"tilegrid.h"


static GLuint ObjTile = 0;

static void DrawTileGrid(void);

/*********************************************************** DrawTileGridD */
void DrawTileGridD(void)
{
   static const GLfloat tileambient[4] = {0.2f, 0.2f, 0.5f, 1.0f};
   static const GLfloat tilediffuse[4] = {1.0f, 1.0f, 1.0f, 1.0f};
   static const GLfloat tilespecular[4] = {0.2f, 0.2f, 0.22f, 1.0f};
   static const GLfloat tileemission[4] = {0.1f, 0.1f, 0.1f, 1.0f};

   glMaterialfv(GL_FRONT, GL_AMBIENT, tileambient);
   glMaterialfv(GL_FRONT, GL_DIFFUSE, tilediffuse);
   glMaterialfv(GL_FRONT, GL_SPECULAR, tilespecular);
   glMaterialfv(GL_FRONT, GL_EMISSION, tileemission);
   DrawTileGrid();

} /* DrawTileGridD() */

/*********************************************************** DrawTileGridN */
void DrawTileGridN(void)
{
   static const GLfloat tileambient[4] = {0.0f, 0.0f, 0.0f, 1.0f};
   static const GLfloat tilediffuse[4] = {0.1f, 0.1f, 0.1f, 1.0f};
   static const GLfloat tilespecular[4] = {0.0f, 0.0f, 0.0f, 1.0f};
   static const GLfloat tileemission[4] = {0.0f, 0.0f, 0.0f, 1.0f};

   glMaterialfv(GL_FRONT, GL_AMBIENT, tileambient);
   glMaterialfv(GL_FRONT, GL_DIFFUSE, tilediffuse);
   glMaterialfv(GL_FRONT, GL_SPECULAR, tilespecular);
   glMaterialfv(GL_FRONT, GL_EMISSION, tileemission);
   DrawTileGrid();

} /* DrawTileGridN() */

/************************************************************ InitTileGrid */
void InitTileGrid(void)
{
   static const double tx[4][2] =
      { {1.0, 0.0}, { 0.0, 1.0}, {-1.0, 0.0}, {0.0,-1.0} };
   static const double tz[4][2] =
      { {0.0, 1.0}, {-1.0, 0.0}, { 0.0,-1.0}, {1.0, 0.0} };
   static const double edge = 1.78;
   static const double bevel = 0.2;
   double u, v, a;
   int i, c;

   glNewList(ObjTile = glGenLists(1), GL_COMPILE);
      for(c = 0; c < 4; c++)
      {
         glBegin(GL_QUAD_STRIP);
            for(i = 0; i <= TILE_CORNER_RESOLUTION; i++)
            {
               a = (double)i * PI / (TILE_CORNER_RESOLUTION * 2.0);
               u = cos(a);
               v = sin(a);
               glNormal3d(u * tx[4][0], v, u * tx[4][1]);
               glVertex3d((edge + bevel * u) * (tx[c][0] + tx[c][1]),
                          v * bevel - bevel,
                          (edge + bevel * u) * (tz[c][0] + tz[c][1]));
               glVertex3d((edge + bevel * u) * (tx[c][0] - tx[c][1]),
                          v * bevel - bevel,
                          (edge + bevel * u) * (tz[c][0] - tz[c][1]));
            }
         glEnd();
      }

      glBegin(GL_QUADS);
         glNormal3d(0.0, 1.0, 0.0);
         glVertex3d(-edge, 0.0,  edge);
         glVertex3d( edge, 0.0,  edge);
         glVertex3d( edge, 0.0, -edge);
         glVertex3d(-edge, 0.0, -edge);
      glEnd();
   glEndList();

} /* InitTileGrid() */

/********************************************************** UninitTileGrid */
void UninitTileGrid(void)
{
   glDeleteLists(ObjTile, 1);

} /* UninitTileGrid() */


/************************************************************ DrawTileGrid */
static void DrawTileGrid(void)
{
   double d;
   int i, j;

   d = fmod(CurrentTime * DRIFT_DISTANCE, 4.0);
   for(i = -30; i <= 30; i += 4)
   {
      for(j = -32; j <= 32; j += 4)
      {
         glPushMatrix();
            glTranslated((double)i - d, 0.0, (double)j);
            glCallList(ObjTile);
         glPopMatrix();
      }
   }

} /* DrawTileGrid() */