/*
Copyright (C) 1996-1997 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
// d_clear: clears a specified rectangle to the specified color

#include "quakedef.h"


/*
================
D_FillRect
================
*/
void D_FillRect (vrect_t *rect, int color)
{
  int       rx, ry, rwidth, rheight;
  unsigned char *dest;
  unsigned    *ldest;

  rx = rect->x;
  ry = rect->y;
  rwidth = rect->width;
  rheight = rect->height;

  if (rx < 0)
  {
    rwidth += rx;
    rx = 0;
  }
  if (ry < 0)
  {
    rheight += ry;
    ry = 0;
  }
  if (rx+rwidth > vid.width)
    rwidth = vid.width - rx;
  if (ry+rheight > vid.height)
    rheight = vid.height - rx;
    
  if (rwidth < 1 || rheight < 1)
    return;

  dest = ((byte *)vid.buffer + ry*vid.rowbytes + rx);

  if (((rwidth & 0x03) == 0) && (((long)dest & 0x03) == 0))
  {
  // faster aligned dword clear
    ldest = (unsigned *)dest;
    color += color << 16;

    rwidth >>= 2;
    color += color << 8;

    for (ry=0 ; ry<rheight ; ry++)
    {
      for (rx=0 ; rx<rwidth ; rx++)
        ldest[rx] = color;
      ldest = (unsigned *)((byte*)ldest + vid.rowbytes);
    }
  }
  else
  {
  // slower byte-by-byte clear for unaligned cases
    for (ry=0 ; ry<rheight ; ry++)
    {
      for (rx=0 ; rx<rwidth ; rx++)
        dest[rx] = color;
      dest += vid.rowbytes;
    }
  }
}