libigl_Martin/include/igl/draw_floor.cpp

#include "draw_floor.h"
#ifndef IGL_NO_OPENGL

#include "OpenGL_convenience.h"

IGL_INLINE void igl::draw_floor(const float * colorA, const float * colorB)
{
  // old settings
  int old_lighting=0,old_color_material=0;
  float old_line_width =0;
  glGetIntegerv(GL_LIGHTING,&old_lighting);
  glGetIntegerv(GL_COLOR_MATERIAL,&old_color_material);
  glGetFloatv(GL_LINE_WIDTH,&old_line_width);
  glDisable(GL_LIGHTING);
  glColorMaterial( GL_FRONT, GL_EMISSION);
  glEnable(GL_COLOR_MATERIAL);
  glColorMaterial( GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
  // Set material
  const float black[] = {0.,0.,0.,1.};
  glMaterialfv(GL_FRONT, GL_AMBIENT, black);
  glMaterialfv(GL_FRONT, GL_DIFFUSE, black);
  glMaterialfv(GL_FRONT, GL_SPECULAR, black);
  glMaterialfv(GL_FRONT, GL_EMISSION, black);
  glMaterialf(GL_FRONT, GL_SHININESS,0);
  const bool use_lighting = false;
  if(use_lighting)
  {
    glEnable(GL_LIGHTING);
  }else
  {
    glDisable(GL_LIGHTING);
  }

  int GridSizeX = 100;
  int GridSizeY = 100;
  //int GridSizeX = 5;
  //int GridSizeY = 5;
  float SizeX = 0.5f;
  float SizeY = 0.5f;

  glBegin(GL_QUADS);
  glNormal3f(0,1,0);
  for (int x =-GridSizeX/2;x<GridSizeX/2;++x)
  {
    for (int y =-GridSizeY/2;y<GridSizeY/2;++y)
    {
      if ((x+y)&0x00000001) //modulo 2
      {
        glColor4fv(colorA);
      }else
      {
        glColor4fv(colorB);
      }
      glVertex3f(    x*SizeX,0,(y+1)*SizeY);
      glVertex3f((x+1)*SizeX,0,(y+1)*SizeY);
      glVertex3f((x+1)*SizeX,0,    y*SizeY);
      glVertex3f(    x*SizeX,0,    y*SizeY);
    }
  }
  glEnd();

  glLineWidth(2.0f);
  glBegin(GL_LINES);
  for (int x =-GridSizeX/2;x<=GridSizeX/2;++x)
  {
    if(x!=(GridSizeX/2))
    {
      for(int s = -1;s<2;s+=2)
      {
        int y = s*(GridSizeY/2);
        int cy = y==(GridSizeY/2) ? y-1 : y;
        if ((x+cy)&0x00000001) //modulo 2
        {
          glColor4fv(colorA);
          //glColor3f(1,0,0);
        }else
        {
          glColor4fv(colorB);
          //glColor3f(0,0,1);
        }
        glVertex3f((x+1)*SizeX,0,y*SizeY);
        glVertex3f(    x*SizeX,0,y*SizeY);
      }
    }
    if(x==-(GridSizeX/2) || x==(GridSizeX/2))
    {
      int cx = x==(GridSizeX/2) ? x-1 : x;
      for (int y =-GridSizeY/2;y<GridSizeY/2;++y)
      {
        if ((cx+y)&0x00000001) //modulo 2
        {
          glColor4fv(colorA);
          //glColor3f(1,0,0);
        }else
        {
          glColor4fv(colorB);
          //glColor3f(0,0,1);
        }
        glVertex3f(x*SizeX,0,(y+1)*SizeY);
        glVertex3f(x*SizeX,0,    y*SizeY);
      }
    }
  }
  glEnd();

  (old_lighting ? glEnable(GL_LIGHTING) : glDisable(GL_LIGHTING));
  (old_color_material? glEnable(GL_COLOR_MATERIAL) : glDisable(GL_COLOR_MATERIAL));
  glLineWidth(old_line_width);
}

IGL_INLINE void igl::draw_floor()
{
  const float grey[] = {0.80,0.80,0.80,1.};
  const float white[] = {0.95,0.95,0.95,1.};
  igl::draw_floor(grey,white);
}
#endif