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nr-pixblock.cpp

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#define __NR_PIXBLOCK_C__

/** \file
 * \brief Allocation/Setup of NRPixBlock objects. Pixel store functions.
 *
 * Authors:
 *   (C) 1999-2002 Lauris Kaplinski <lauris@kaplinski.com>
 *
 * This code is in the Public Domain
 */

#include <cstring>
#include <string>
#include <string.h>
#include <glib/gmem.h>
#include "nr-pixblock.h"

/// Size of buffer that needs no allocation (default 4).
00019 #define NR_TINY_MAX sizeof (unsigned char *)

/**
 * Pixbuf initialisation using homegrown memory handling ("pixelstore").
 *
 * Pixbuf sizes are differentiated into tiny, <4K, <16K, <64K, and more,
 * with each type having its own method of memory handling. After allocating
 * memory, the buffer is cleared if the clear flag is set. Intended to
 * reduce memory fragmentation.
 * \param pb Pointer to the pixbuf struct.
 * \param mode Indicates grayscale/RGB/RGBA.
 * \param clear True if buffer should be cleared.
 * \pre x1>=x0 && y1>=y0 && pb!=NULL
 */
void
00034 nr_pixblock_setup_fast (NRPixBlock *pb, NR_PIXBLOCK_MODE mode, int x0, int y0, int x1, int y1, bool clear)
{
      int w, h, bpp;
      size_t size;

      w = x1 - x0;
      h = y1 - y0;
      bpp = (mode == NR_PIXBLOCK_MODE_A8) ? 1 : (mode == NR_PIXBLOCK_MODE_R8G8B8) ? 3 : 4;

      size = bpp * w * h;

      if (size <= NR_TINY_MAX) {
            pb->size = NR_PIXBLOCK_SIZE_TINY;
            if (clear) memset (pb->data.p, 0x0, size);
      } else if (size <= 4096) {
            pb->size = NR_PIXBLOCK_SIZE_4K;
            pb->data.px = nr_pixelstore_4K_new (clear, 0x0);
      } else if (size <= 16384) {
            pb->size = NR_PIXBLOCK_SIZE_16K;
            pb->data.px = nr_pixelstore_16K_new (clear, 0x0);
      } else if (size <= 65536) {
            pb->size = NR_PIXBLOCK_SIZE_64K;
            pb->data.px = nr_pixelstore_64K_new (clear, 0x0);
      } else if (size <= 262144) {
            pb->size = NR_PIXBLOCK_SIZE_256K;
            pb->data.px = nr_pixelstore_256K_new (clear, 0x0);
      } else if (size <= 1048576) {
            pb->size = NR_PIXBLOCK_SIZE_1M;
            pb->data.px = nr_pixelstore_1M_new (clear, 0x0);
      } else {
            pb->size = NR_PIXBLOCK_SIZE_BIG;
             pb->data.px = NULL;
            if (size > 100000000) { // Don't even try to allocate more than 100Mb (5000x5000 RGBA
                            // pixels). It'll just bog the system down even if successful. FIXME:
                            // Can anyone suggest something better than the magic number?
                g_warning ("%lu bytes requested for pixel buffer, I won't try to allocate that.", (long unsigned) size);
                return;
             }
            pb->data.px = g_try_new (unsigned char, size);
            if (pb->data.px == NULL) { // memory allocation failed
                g_warning ("Could not allocate %lu bytes for pixel buffer!", (long unsigned) size);
                return;
             }
            if (clear) memset (pb->data.px, 0x0, size);
      }

      pb->mode = mode;
      pb->empty = 1;
    pb->visible_area.x0 = pb->area.x0 = x0;
    pb->visible_area.y0 = pb->area.y0 = y0;
    pb->visible_area.x1 = pb->area.x1 = x1;
    pb->visible_area.y1 = pb->area.y1 = y1;
      pb->rs = bpp * w;
}

/**
 * Pixbuf initialisation using g_new.
 *
 * After allocating memory, the buffer is cleared if the clear flag is set.
 * \param pb Pointer to the pixbuf struct.
 * \param mode Indicates grayscale/RGB/RGBA.
 * \param clear True if buffer should be cleared.
 * \pre x1>=x0 && y1>=y0 && pb!=NULL
 FIXME: currently unused except for nr_pixblock_new and pattern tiles, replace with _fast and delete?
 */
void
00100 nr_pixblock_setup (NRPixBlock *pb, NR_PIXBLOCK_MODE mode, int x0, int y0, int x1, int y1, bool clear)
{
      int w, h, bpp;
      size_t size;

      w = x1 - x0;
      h = y1 - y0;
      bpp = (mode == NR_PIXBLOCK_MODE_A8) ? 1 : (mode == NR_PIXBLOCK_MODE_R8G8B8) ? 3 : 4;

      size = bpp * w * h;

      if (size <= NR_TINY_MAX) {
            pb->size = NR_PIXBLOCK_SIZE_TINY;
            if (clear) memset (pb->data.p, 0x0, size);
      } else {
            pb->size = NR_PIXBLOCK_SIZE_BIG;
            pb->data.px = g_new (unsigned char, size);
            if (clear) memset (pb->data.px, 0x0, size);
      }

      pb->mode = mode;
      pb->empty = 1;
    pb->visible_area.x0 = pb->area.x0 = x0;
    pb->visible_area.y0 = pb->area.y0 = y0;
    pb->visible_area.x1 = pb->area.x1 = x1;
    pb->visible_area.y1 = pb->area.y1 = y1;
      pb->rs = bpp * w;
}

/**
 * Pixbuf initialisation with preset values.
 *
 * After copying all parameters into the NRPixBlock struct, the pixel buffer is cleared if the clear flag is set.
 * \param pb Pointer to the pixbuf struct.
 * \param mode Indicates grayscale/RGB/RGBA.
 * \param clear True if buffer should be cleared.
 * \pre x1>=x0 && y1>=y0 && pb!=NULL
 */
void
00139 nr_pixblock_setup_extern (NRPixBlock *pb, NR_PIXBLOCK_MODE mode, int x0, int y0, int x1, int y1, unsigned char *px, int rs, bool empty, bool clear)
{
      int w, bpp;

      w = x1 - x0;
      bpp = (mode == NR_PIXBLOCK_MODE_A8) ? 1 : (mode == NR_PIXBLOCK_MODE_R8G8B8) ? 3 : 4;

      pb->size = NR_PIXBLOCK_SIZE_STATIC; 
      pb->mode = mode;
      pb->empty = empty;
      pb->visible_area.x0 = pb->area.x0 = x0;
      pb->visible_area.y0 = pb->area.y0 = y0;
      pb->visible_area.x1 = pb->area.x1 = x1;
      pb->visible_area.y1 = pb->area.y1 = y1;
      pb->data.px = px;
      pb->rs = rs;

        g_assert (pb->data.px != NULL);
      if (clear) {
            if (rs == bpp * w) {
                  /// \todo How do you recognise if 
                        /// px was an uncleared tiny buffer? 
                  if (pb->data.px) 
                        memset (pb->data.px, 0x0, bpp * (y1 - y0) * w);
            } else {
                  int y;
                  for (y = y0; y < y1; y++) {
                        memset (pb->data.px + (y - y0) * rs, 0x0, bpp * w);
                  }
            }
      }
}

/**
 * Frees memory taken by pixel data in NRPixBlock.
 * \param pb Pointer to pixblock.
 * \pre pb and pb->data.px point to valid addresses.
 *
 * According to pb->size, one of the functions for freeing the pixelstore
 * is called. May be called regardless of how pixbuf was set up.
 */
void
00181 nr_pixblock_release (NRPixBlock *pb)
{
      switch (pb->size) {
      case NR_PIXBLOCK_SIZE_TINY:
            break;
      case NR_PIXBLOCK_SIZE_4K:
            nr_pixelstore_4K_free (pb->data.px);
            break;
      case NR_PIXBLOCK_SIZE_16K:
            nr_pixelstore_16K_free (pb->data.px);
            break;
      case NR_PIXBLOCK_SIZE_64K:
            nr_pixelstore_64K_free (pb->data.px);
            break;
      case NR_PIXBLOCK_SIZE_256K:
            nr_pixelstore_256K_free (pb->data.px);
            break;
      case NR_PIXBLOCK_SIZE_1M:
            nr_pixelstore_1M_free (pb->data.px);
            break;
      case NR_PIXBLOCK_SIZE_BIG:
            g_free (pb->data.px);
            break;
      case NR_PIXBLOCK_SIZE_STATIC:
            break;
      default:
            break;
      }
}

/**
 * Allocates NRPixBlock and sets it up.
 *
 * \return Pointer to fresh pixblock.
 * Calls g_new() and nr_pixblock_setup().
FIXME: currently unused, delete?
 */
NRPixBlock *
00219 nr_pixblock_new (NR_PIXBLOCK_MODE mode, int x0, int y0, int x1, int y1, bool clear)
{
      NRPixBlock *pb;

      pb = g_new (NRPixBlock, 1);

      nr_pixblock_setup (pb, mode, x0, y0, x1, y1, clear);

      return pb;
}

/**
 * Frees all memory taken by pixblock.
 *
 * \return NULL
 */
NRPixBlock *
00236 nr_pixblock_free (NRPixBlock *pb)
{
      nr_pixblock_release (pb);

      g_free (pb);

      return NULL;
}

/* PixelStore operations */

#define NR_4K_BLOCK 32
static unsigned char **nr_4K_px = NULL;
static unsigned int nr_4K_len = 0;
static unsigned int nr_4K_size = 0;

unsigned char *
nr_pixelstore_4K_new (bool clear, unsigned char val)
{
      unsigned char *px;

      if (nr_4K_len != 0) {
            nr_4K_len -= 1;
            px = nr_4K_px[nr_4K_len];
      } else {
            px = g_new (unsigned char, 4096);
      }
      
      if (clear) memset (px, val, 4096);

      return px;
}

void
nr_pixelstore_4K_free (unsigned char *px)
{
      if (nr_4K_len == nr_4K_size) {
            nr_4K_size += NR_4K_BLOCK;
            nr_4K_px = g_renew (unsigned char *, nr_4K_px, nr_4K_size);
      }

      nr_4K_px[nr_4K_len] = px;
      nr_4K_len += 1;
}

#define NR_16K_BLOCK 32
static unsigned char **nr_16K_px = NULL;
static unsigned int nr_16K_len = 0;
static unsigned int nr_16K_size = 0;

unsigned char *
nr_pixelstore_16K_new (bool clear, unsigned char val)
{
      unsigned char *px;

      if (nr_16K_len != 0) {
            nr_16K_len -= 1;
            px = nr_16K_px[nr_16K_len];
      } else {
            px = g_new (unsigned char, 16384);
      }
      
      if (clear) memset (px, val, 16384);

      return px;
}

void
nr_pixelstore_16K_free (unsigned char *px)
{
      if (nr_16K_len == nr_16K_size) {
            nr_16K_size += NR_16K_BLOCK;
            nr_16K_px = g_renew (unsigned char *, nr_16K_px, nr_16K_size);
      }

      nr_16K_px[nr_16K_len] = px;
      nr_16K_len += 1;
}

#define NR_64K_BLOCK 32
static unsigned char **nr_64K_px = NULL;
static unsigned int nr_64K_len = 0;
static unsigned int nr_64K_size = 0;

unsigned char *
nr_pixelstore_64K_new (bool clear, unsigned char val)
{
      unsigned char *px;

      if (nr_64K_len != 0) {
            nr_64K_len -= 1;
            px = nr_64K_px[nr_64K_len];
      } else {
            px = g_new (unsigned char, 65536);
      }

      if (clear) memset (px, val, 65536);

      return px;
}

void
nr_pixelstore_64K_free (unsigned char *px)
{
      if (nr_64K_len == nr_64K_size) {
            nr_64K_size += NR_64K_BLOCK;
            nr_64K_px = g_renew (unsigned char *, nr_64K_px, nr_64K_size);
      }

      nr_64K_px[nr_64K_len] = px;
      nr_64K_len += 1;
}

#define NR_256K_BLOCK 32
#define NR_256K 262144
static unsigned char **nr_256K_px = NULL;
static unsigned int nr_256K_len = 0;
static unsigned int nr_256K_size = 0;

unsigned char *
nr_pixelstore_256K_new (bool clear, unsigned char val)
{
      unsigned char *px;

      if (nr_256K_len != 0) {
            nr_256K_len -= 1;
            px = nr_256K_px[nr_256K_len];
      } else {
           px = g_new (unsigned char, NR_256K);
      }

      if (clear) memset (px, val, NR_256K);

      return px;
}

void
nr_pixelstore_256K_free (unsigned char *px)
{
      if (nr_256K_len == nr_256K_size) {
            nr_256K_size += NR_256K_BLOCK;
            nr_256K_px = g_renew (unsigned char *, nr_256K_px, nr_256K_size);
      }

      nr_256K_px[nr_256K_len] = px;
      nr_256K_len += 1;
}

#define NR_1M_BLOCK 32
#define NR_1M 1048576
static unsigned char **nr_1M_px = NULL;
static unsigned int nr_1M_len = 0;
static unsigned int nr_1M_size = 0;

unsigned char *
nr_pixelstore_1M_new (bool clear, unsigned char val)
{
      unsigned char *px;

      if (nr_1M_len != 0) {
            nr_1M_len -= 1;
            px = nr_1M_px[nr_1M_len];
      } else {
           px = g_new (unsigned char, NR_1M);
      }

      if (clear) memset (px, val, NR_1M);

      return px;
}

void
nr_pixelstore_1M_free (unsigned char *px)
{
      if (nr_1M_len == nr_1M_size) {
            nr_1M_size += NR_1M_BLOCK;
            nr_1M_px = g_renew (unsigned char *, nr_1M_px, nr_1M_size);
      }

      nr_1M_px[nr_1M_len] = px;
      nr_1M_len += 1;
}

/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :

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