nuttx/graphics/nxglib/cursor/nxglib_cursor_erase.c

/****************************************************************************
 * graphics/nxglib/nxglib_cursor_erase.c
 *
 *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <assert.h>

#include <nuttx/nx/nxglib.h>

#include "nxglib_bitblit.h"
#include "../nxbe/nxbe.h"
#include "nxglib.h"

#ifdef CONFIG_NX_SWCURSOR

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: nxglib_cursor_erase
 *
 * Description:
 *   Erase the cursor region by writing the saved background to the graphics
 *   device memory.
 *
 * Input Parameters:
 *   be      - The back-end state structure instance
 *   bounds  - The region of the display that has been modified.
 *   planeno - The color plane being drawn
 *
 * Returned Value:
 *   None
 *
 ****************************************************************************/

void NXGL_FUNCNAME(nxglib_cursor_erase, NXGLIB_SUFFIX)
(FAR struct nxbe_state_s *be, FAR const struct nxgl_rect_s *bounds, int planeno)
{
  struct nxgl_rect_s intersection;
  struct nxgl_point_s origin;
  FAR struct nxbe_plane_s *plane;
  FAR uint8_t *fbmem;
  FAR const uint8_t *sline;
  FAR uint8_t *dline;
  FAR const NXGL_PIXEL_T *src;
  FAR NXGL_PIXEL_T *dest;
  nxgl_coord_t width;
  nxgl_coord_t height;
  nxgl_coord_t swidth;
  nxgl_coord_t sstride;
  nxgl_coord_t dstride;
  int row;
  int col;

  /* Handle the case some or all of the cursor image is off of the display. */

  nxgl_rectintersect(&intersection, &be->cursor.bounds, &be->bkgd.bounds);

  /* Check if there is anything in the modified region that we need to handle. */

  nxgl_rectintersect(&intersection, &intersection, bounds);
  if (!nxgl_nullrect(&intersection))
    {
      /* Get the width and the height of the images to copy in pixels/rows */

      width   = intersection.pt2.x - intersection.pt1.x + 1;
      height  = intersection.pt2.y - intersection.pt1.y + 1;

      /* Get the width of the images in bytes. */

      swidth  = be->cursor.bounds.pt2.x - be->cursor.bounds.pt1.x + 1;
      sstride = NXGL_SCALEX(swidth);

      plane   = &be->plane[planeno];
      dstride = plane->pinfo.stride;

      /* Get the origin position in the background image */

      nxgl_vectsubtract(&origin, &intersection.pt1, &be->cursor.bounds.pt1);

      /* Get the source and destination addresses */

      fbmem  = (FAR uint8_t *)plane->pinfo.fbmem;
      sline  = (FAR uint8_t *)be->cursor.bkgd + sstride * origin.y +
                NXGL_SCALEX(origin.x);
      dline  = (FAR uint8_t *)fbmem + dstride * intersection.pt1.y +
                NXGL_SCALEX(intersection.pt1.x);

      /* Erase the old cursor position by copying the previous content */

      /* Loop for each row */

      for (row = 0; row < height; row++)
        {
          /* Reset to the beginning of the line */

          src  = (FAR NXGL_PIXEL_T *)sline;
          dest = (FAR NXGL_PIXEL_T *)dline;

          /* Loop for each column */

          for (col = 0; col < width; col++)
            {
              *dest++ = *src++;
            }

          /* Update the row addresses to the next row */

          sline += sstride;
          dline += dstride;
       }
    }
}

#endif /* CONFIG_NX_SWCURSOR */