nuttx-apps/examples/nxtext/nxtext_putc.c

/****************************************************************************
 * apps/examples/nxtext/nxtext_putc.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

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

#include <nuttx/config.h>

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <debug.h>

#include <nuttx/nx/nx.h>
#include <nuttx/nx/nxfonts.h>

#include "nxtext_internal.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/* Select renderer -- Some additional logic would be required to support
 * pixel depths that are not directly addressable (1,2,4, and 24).
 */

#if CONFIG_EXAMPLES_NXTEXT_BPP == 1
#  define RENDERER nxf_convert_1bpp
#elif CONFIG_EXAMPLES_NXTEXT_BPP == 2
#  define RENDERER nxf_convert_2bpp
#elif CONFIG_EXAMPLES_NXTEXT_BPP == 4
#  define RENDERER nxf_convert_4bpp
#elif CONFIG_EXAMPLES_NXTEXT_BPP == 8
#  define RENDERER nxf_convert_8bpp
#elif CONFIG_EXAMPLES_NXTEXT_BPP == 16
#  define RENDERER nxf_convert_16bpp
#elif CONFIG_EXAMPLES_NXTEXT_BPP == 24
#  define RENDERER nxf_convert_24bpp
#elif  CONFIG_EXAMPLES_NXTEXT_BPP == 32
#  define RENDERER nxf_convert_32bpp
#else
#  error "Unsupported CONFIG_EXAMPLES_NXTEXT_BPP"
#endif

/****************************************************************************
 * Private Types
 ****************************************************************************/

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

/****************************************************************************
 * Private Data
 ****************************************************************************/

/****************************************************************************
 * Public Data
 ****************************************************************************/

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

/****************************************************************************
 * Name: nxtext_freeglyph
 ****************************************************************************/

static void nxtext_freeglyph(FAR struct nxtext_glyph_s *glyph)
{
  if (glyph->bitmap)
    {
      free(glyph->bitmap);
    }
  memset(glyph, 0, sizeof(struct nxtext_glyph_s));
}

/****************************************************************************
 * Name: nxtext_allocglyph
 ****************************************************************************/

static inline FAR struct nxtext_glyph_s *
nxtext_allocglyph(FAR struct nxtext_state_s *st)
{
  FAR struct nxtext_glyph_s *glyph = NULL;
  FAR struct nxtext_glyph_s *luglyph = NULL;
  uint8_t luusecnt;
  int i;

  /* Search through the glyph cache looking for an unused glyph.  Also, keep
   * track of the least used glyph as well.  We need that if we have to replace
   * a glyph in the cache.
   */

   for (i = 0; i < st->maxglyphs; i++)
    {
      /* Is this glyph in use? */

      glyph = &st->glyph[i];
      if (!glyph->usecnt)
        {
          /* No.. return this glyph with a use count of one */

          glyph->usecnt = 1;
          return glyph;
        }

      /* Yes.. check for the least recently used */

      if (!luglyph || glyph->usecnt < luglyph->usecnt)
        {
          luglyph = glyph;
        }
    }

  /* If we get here, the glyph cache is full.  We replace the least used
   * glyph with the one we need now. (luglyph can't be NULL).
   */

  luusecnt = luglyph->usecnt;
  nxtext_freeglyph(luglyph);

  /* But lets decrement all of the usecnts so that the new one one be so
   * far behind in the counts as the older ones.
   */

  if (luusecnt > 1)
    {
       uint8_t decr = luusecnt - 1;

       for (i = 0; i < st->maxglyphs; i++)
        {
          /* Is this glyph in use? */

          glyph = &st->glyph[i];
          if (glyph->usecnt > decr)
            {
              glyph->usecnt -= decr;
            }
        }
    }

  /* Then return the least used glyph */

  luglyph->usecnt = 1;
  return luglyph;
}

/****************************************************************************
 * Name: nxtext_findglyph
 ****************************************************************************/

static FAR struct nxtext_glyph_s *
nxtext_findglyph(FAR struct nxtext_state_s *st, uint8_t ch)
{
  int i;

  /* First, try to find the glyph in the cache of pre-rendered glyphs */

   for (i = 0; i < st->maxglyphs; i++)
    {
      FAR struct nxtext_glyph_s *glyph = &st->glyph[i];
      if (glyph->usecnt > 0 && glyph->code == ch)
        {
          /* Increment the use count (unless it is already at the max) */

          if (glyph->usecnt < MAX_USECNT)
            {
               glyph->usecnt++;
            }

          /* And return the glyph that we found */

          return glyph;
        }
    }
  return NULL;
}

/****************************************************************************
 * Name: nxtext_renderglyph
 ****************************************************************************/

static inline FAR struct nxtext_glyph_s *
nxtext_renderglyph(FAR struct nxtext_state_s *st,
                   FAR const struct nx_fontbitmap_s *fbm, uint8_t ch)
{
  FAR struct nxtext_glyph_s *glyph = NULL;
  FAR nxgl_mxpixel_t *ptr;
#if CONFIG_EXAMPLES_NXTEXT_BPP < 8
  nxgl_mxpixel_t pixel;
#endif
  int bmsize;
  int row;
  int col;
  int ret;

  /* Make sure that there is room for another glyph */

  ginfo("ch=%c [%02x]\n", isprint(ch) ? ch : '.', ch);

  /* Allocate the glyph (always succeeds) */

  glyph         = nxtext_allocglyph(st);
  glyph->code   = ch;

  /* Get the dimensions of the glyph */

  glyph->width  = fbm->metric.width + fbm->metric.xoffset;
  glyph->height = fbm->metric.height + fbm->metric.yoffset;

  /* Allocate memory to hold the glyph with its offsets */

  glyph->stride = (glyph->width * CONFIG_EXAMPLES_NXTEXT_BPP + 7) / 8;
  bmsize        =  glyph->stride * glyph->height;
  glyph->bitmap = (FAR uint8_t *)malloc(bmsize);

  if (glyph->bitmap)
    {
      /* Initialize the glyph memory to the background color */

#if CONFIG_EXAMPLES_NXTEXT_BPP < 8
      pixel  = st->wcolor[0];
#  if CONFIG_EXAMPLES_NXTEXT_BPP == 1
      /* Pack 1-bit pixels into a 2-bits */

      pixel &= 0x01;
      pixel  = (pixel) << 1 |pixel;
#  endif
#  if CONFIG_EXAMPLES_NXTEXT_BPP < 4
      /* Pack 2-bit pixels into a nibble */

      pixel &= 0x03;
      pixel  = (pixel) << 2 |pixel;
#  endif

      /* Pack 4-bit nibbles into a byte */

      pixel &= 0x0f;
      pixel  = (pixel) << 4 | pixel;

      ptr    = (FAR nxgl_mxpixel_t *)glyph->bitmap;
      for (row = 0; row < glyph->height; row++)
        {
          for (col = 0; col < glyph->stride; col++)
            {
              /* Transfer the packed bytes into the buffer */

              *ptr++ = pixel;
            }
        }

#elif CONFIG_EXAMPLES_NXTEXT_BPP == 24
# error "Additional logic is needed here for 24bpp support"

#else /* CONFIG_EXAMPLES_NXTEXT_BPP = {8,16,32} */

      ptr = (FAR nxgl_mxpixel_t *)glyph->bitmap;
      for (row = 0; row < glyph->height; row++)
        {
          /* Just copy the color value into the glyph memory */

          for (col = 0; col < glyph->width; col++)
            {
              *ptr++ = st->wcolor[0];
            }
        }
#endif

      /* Then render the glyph into the allocated memory */

      ret = RENDERER((FAR nxgl_mxpixel_t*)glyph->bitmap,
                      glyph->height, glyph->width, glyph->stride,
                      fbm, st->fcolor[0]);
      if (ret < 0)
        {
          /* Actually, the RENDERER never returns a failure */

          printf("nxtext_renderglyph: RENDERER failed\n");
          nxtext_freeglyph(glyph);
          glyph = NULL;
        }
    }

  return glyph;
}

/****************************************************************************
 * Name: nxtext_fontsize
 ****************************************************************************/

static int nxtext_fontsize(NXHANDLE hfont, uint8_t ch, FAR struct nxgl_size_s *size)
{
  FAR const struct nx_fontbitmap_s *fbm;

  /* No, it is not cached... Does the code map to a font? */

  fbm = nxf_getbitmap(hfont, ch);
  if (fbm)
    {
      /* Yes.. return the font size */

      size->w = fbm->metric.width + fbm->metric.xoffset;
      size->h = fbm->metric.height + fbm->metric.yoffset;
      return OK;
    }

  return ERROR;
}

/****************************************************************************
 * Name: nxtext_getglyph
 ****************************************************************************/

static FAR struct nxtext_glyph_s *
nxtext_getglyph(NXHANDLE hfont, FAR struct nxtext_state_s *st, uint8_t ch)
{
  FAR struct nxtext_glyph_s *glyph;
  FAR const struct nx_fontbitmap_s *fbm;

  /* First, try to find the glyph in the cache of pre-rendered glyphs */

  glyph = nxtext_findglyph(st, ch);
  if (!glyph)
    {
      /* No, it is not cached... Does the code map to a font? */

      fbm = nxf_getbitmap(hfont, ch);
      if (fbm)
        {
          /* Yes.. render the glyph */

          glyph = nxtext_renderglyph(st, fbm, ch);
        }
    }

  return glyph;
}

/****************************************************************************
 * Name: nxtext_addchar
 *
 * Description:
 *   This is part of the nxtext_putc logic.  It creates and positions a
 *   the character and renders (or re-uses) a glyph for font.
 *
 ****************************************************************************/

static FAR const struct nxtext_bitmap_s *
nxtext_addchar(NXHANDLE hfont, FAR struct nxtext_state_s *st, uint8_t ch)
{
  FAR struct nxtext_bitmap_s *bm = NULL;
  FAR struct nxtext_glyph_s *glyph;

  /* Is there space for another character on the display? */

  if (st->nchars < st->maxchars)
    {
       /* Yes, setup the bitmap information */

       bm        = &st->bm[st->nchars];
       bm->code  = ch;
       bm->flags = 0;
       bm->pos.x = st->fpos.x;
       bm->pos.y = st->fpos.y;

       /* Find (or create) the matching glyph */

       glyph = nxtext_getglyph(hfont, st, ch);
       if (!glyph)
         {
            /* No, there is no font for this code.  Just mark this as a space. */

            bm->flags |= BMFLAGS_NOGLYPH;

            /* Set up the next character position */

            st->fpos.x += st->spwidth;
         }
       else
         {
            /* Set up the next character position */

            st->fpos.x += glyph->width;
         }

       /* Success.. increment nchars to retain this character */

       st->nchars++;
    }

  return bm;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: nxtext_home
 *
 * Description:
 *   Set the next character position to the top-left corner of the display.
 *
 ****************************************************************************/

void nxtext_home(FAR struct nxtext_state_s *st)
{
  /* The first character is one space from the left */

  st->fpos.x = st->spwidth;

  /* And LINE_SEPARATION lines from the top */

  st->fpos.y = LINE_SEPARATION;
}

/****************************************************************************
 * Name: nxtext_newline
 *
 * Description:
 *   Set the next character position to the beginning of the next line.
 *
 ****************************************************************************/

void nxtext_newline(FAR struct nxtext_state_s *st)
{
  /* Carriage return: The first character is one space from the left */

  st->fpos.x = st->spwidth;

  /* Linefeed: Down the max font height + LINE_SEPARATION */

  st->fpos.y += (st->fheight + LINE_SEPARATION);
}

/****************************************************************************
 * Name: nxtext_putc
 *
 * Description:
 *   Render the specified character at the current display position.
 *
 ****************************************************************************/

void nxtext_putc(NXWINDOW hwnd, FAR struct nxtext_state_s *st, NXHANDLE hfont, uint8_t ch)
{
  FAR const struct nxtext_bitmap_s *bm;

  /* If it is a newline character, then just perform the logical newline
   * operation.
   */

  if (ch == '\n')
    {
      nxtext_newline(st);
    }

  /* Otherwise, find the glyph associated with the character and render it
   * onto the display.
   */

  else
    {
      bm = nxtext_addchar(hfont, st, ch);
      if (bm)
        {
          nxtext_fillchar(hwnd, NULL, st, hfont, bm);
        }
    }
}

/****************************************************************************
 * Name: nxtext_fillchar
 *
 * Description:
 *   This implements the character display.  It is part of the nxtext_putc
 *   operation but may also be used when redrawing an existing display.
 *
 ****************************************************************************/

void nxtext_fillchar(NXWINDOW hwnd, FAR const struct nxgl_rect_s *rect,
                     FAR struct nxtext_state_s *st,
                     NXHANDLE hfont, FAR const struct nxtext_bitmap_s *bm)
{
  FAR struct nxtext_glyph_s *glyph;
  struct nxgl_rect_s bounds;
  struct nxgl_rect_s intersection;
  struct nxgl_size_s fsize;
  int ret;

  /* Handle the special case of spaces which have no glyph bitmap */

  if (BM_ISSPACE(bm))
    {
      return;
    }

  /* Get the size of the font glyph (which may not have been created yet) */

  ret = nxtext_fontsize(hfont, bm->code, &fsize);
  if (ret < 0)
    {
      /* This would mean that there is no bitmap for the character code and
       * that the font would be rendered as a space.  But this case should
       * never happen here because the BM_ISSPACE() should have already
       * found all such cases.
       */

      return;
    }

  /* Construct a bounding box for the glyph */

  bounds.pt1.x = bm->pos.x;
  bounds.pt1.y = bm->pos.y;
  bounds.pt2.x = bm->pos.x + fsize.w - 1;
  bounds.pt2.y = bm->pos.y + fsize.h - 1;

  /* Should this also be clipped to a region in the window? */

  if (rect)
    {
      /* Get the intersection of the redraw region and the character bitmap */

      nxgl_rectintersect(&intersection, rect, &bounds);
    }
  else
    {
      /* The intersection is the whole glyph */

      nxgl_rectcopy(&intersection, &bounds);
    }

  /* Check for empty intersections */

  if (!nxgl_nullrect(&intersection))
    {
      FAR const void *src;

      /* Find (or create) the glyph that goes with this font */

       glyph = nxtext_getglyph(hfont, st, bm->code);
       if (!glyph)
         {
           /* Shouldn't happen */

           return;
         }

      /* Blit the font bitmap into the window */

      src = glyph->bitmap;
      ret = nx_bitmap((NXWINDOW)hwnd, &intersection, &src,
                      &bm->pos, (unsigned int)glyph->stride);
      if (ret < 0)
        {
          printf("nxtext_fillchar: nx_bitmapwindow failed: %d\n", errno);
        }
    }
}