something about OpenGL ，codes and datas

float mat[16];
  glGetFloatv(GL_MODELVIEW_MATRIX, mat);
  vector3_t X(mat[0], mat[4], mat[8]);
  vector3_t Z(mat[1], mat[5], mat[9]); 
  glBindTexture(GL_TEXTURE_2D, g_cactus[cactus]);
  vector3_t pos(x,0.0,-z);
  pos.y = GetHeight(x, -z) + h + s;
  glBegin(GL_QUADS);
	 glTexCoord2f(0.0,0.0);glVertex3fv((pos+(X+Z)*-h).v);	 glTexCoord2f(1.0,0.0);glVertex3fv((pos+(X-Z)* h).v);
	 glTexCoord2f(1.0,1.0);glVertex3fv((pos+(X+Z)* h).v);
	 glTexCoord2f(0.0,1.0);glVertex3fv((pos+(Z-X)* h).v);
  glEnd();