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gimp/app/base/tile-pyramid.c

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/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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.
*/
#include "config.h"
#include <glib-object.h>
#include "base-types.h"
#include "tile.h"
#include "tile-manager.h"
#include "tile-pyramid.h"
#define PYRAMID_MAX_LEVELS 10
struct _TilePyramid
{
GimpImageType type;
guint width;
guint height;
gint bytes;
TileManager *tiles[PYRAMID_MAX_LEVELS];
gint top_level;
};
static gint tile_pyramid_alloc_levels (TilePyramid *pyramid,
gint top_level);
static void tile_pyramid_validate_tile (TileManager *tm,
Tile *tile,
TileManager *tm_below);
static void tile_pyramid_validate_upper_tile (TileManager *tm,
Tile *tile,
TileManager *tm_below);
static void tile_pyramid_write_quarter (Tile *dest,
Tile *src,
const gint i,
const gint j);
static void tile_pyramid_write_upper_quarter (Tile *dest,
Tile *src,
const gint i,
const gint j);
/**
* tile_pyramid_new:
* @type: type of pixel data stored in the pyramid
* @width: bottom level width
* @height: bottom level height
*
* Creates a new #TilePyramid, managing a set of tile-managers where
* each level is a sized-down version of the level below.
*
* This only works correctly if you set a validate procedure using
* tile_pyramid_set_validate_proc() and invalidate areas. With some
* small changes, it could be made to work for non-validating tile
* managers also. But currently only the projection uses it.
*
* Only the bottom-most tile-manager is allocated at this point. Upper
* levels are created only if they are requested.
*
* Return value: a newly allocate #TilePyramid
**/
TilePyramid *
tile_pyramid_new (GimpImageType type,
gint width,
gint height)
{
TilePyramid *pyramid;
g_return_val_if_fail (width > 0, NULL);
g_return_val_if_fail (height > 0, NULL);
pyramid = g_slice_new0 (TilePyramid);
pyramid->type = type;
pyramid->width = width;
pyramid->height = height;
switch (type)
{
case GIMP_GRAY_IMAGE:
pyramid->bytes = 1;
break;
case GIMP_GRAYA_IMAGE:
pyramid->bytes = 2;
break;
case GIMP_RGB_IMAGE:
pyramid->bytes = 3;
break;
case GIMP_RGBA_IMAGE:
pyramid->bytes = 4;
break;
case GIMP_INDEXED_IMAGE:
case GIMP_INDEXEDA_IMAGE:
g_assert_not_reached ();
break;
}
pyramid->tiles[0] = tile_manager_new (width, height, pyramid->bytes);
return pyramid;
}
/**
* tile_pyramid_destroy:
* @pyramid: a #TilePyramid
*
* Destroys resources allocated for @pyramid and unrefs all contained
* tile-managers.
**/
void
tile_pyramid_destroy (TilePyramid *pyramid)
{
gint level;
g_return_if_fail (pyramid != NULL);
for (level = 0; level <= pyramid->top_level; level++)
tile_manager_unref (pyramid->tiles[level]);
g_slice_free (TilePyramid, pyramid);
}
/**
* tile_pyramid_get_level:
* @width: width of the bottom level
* @height: height of the bottom level
* @scale: zoom ratio
*
* Calculates the optimal level to request from a #TilePyramid in order
* to display at a certain @scale.
*
* Return value: the level to use for @scale
**/
gint
tile_pyramid_get_level (gint width,
gint height,
gdouble scale)
{
gdouble next = 1.0;
guint w = (guint) width;
guint h = (guint) height;
gint level;
for (level = 0; level < PYRAMID_MAX_LEVELS; level++)
{
w >>= 1;
h >>= 1;
if (w == 0 || h == 0)
break;
if (w <= TILE_WIDTH && h <= TILE_HEIGHT)
break;
next /= 2;
if (next < scale)
break;
}
return level;
}
/**
* tile_pyramid_get_tiles:
* @pyramid: a #TilePyramid
* @level: level, typically obtained using tile_pyramid_get_level()
* @is_premult: location to store whether the pixel data has the alpha
* channel pre-multiplied or not
*
* Gives access to the #TileManager at @level of the @pyramid.
*
* Return value: pointer to a #TileManager
**/
TileManager *
tile_pyramid_get_tiles (TilePyramid *pyramid,
gint level,
gboolean *is_premult)
{
g_return_val_if_fail (pyramid != NULL, NULL);
level = tile_pyramid_alloc_levels (pyramid, level);
g_return_val_if_fail (pyramid->tiles[level] != NULL, NULL);
if (is_premult)
*is_premult = (level > 0);
return pyramid->tiles[level];
}
/**
* tile_pyramid_invalidate_area:
* @pyramid: a #TilePyramid
* @x:
* @y:
* @width:
* @height:
*
* Invalidates the tiles in the given area on all levels.
**/
void
tile_pyramid_invalidate_area (TilePyramid *pyramid,
gint x,
gint y,
gint width,
gint height)
{
gint level;
g_return_if_fail (pyramid != NULL);
g_return_if_fail (x >= 0 && y >= 0);
g_return_if_fail (width >= 0 && height >= 0);
if (width == 0 || height == 0)
return;
for (level = 0; level <= pyramid->top_level; level++)
{
/* Tile invalidation must propagate all the way up in the pyramid,
* so keep width and height > 0.
*/
tile_manager_invalidate_area (pyramid->tiles[level],
x, y, MAX (width, 1), MAX (height, 1));
x >>= 1;
y >>= 1;
width >>= 1;
height >>= 1;
}
}
/**
* tile_pyramid_set_validate_proc:
* @pyramid: a #TilePyramid
* @proc: a function to validate the bottom level tiles
* @user_data: data to pass to the validation @proc
*
* Sets a validation procedure on the bottom-most tile manager.
**/
void
tile_pyramid_set_validate_proc (TilePyramid *pyramid,
TileValidateProc proc,
gpointer user_data)
{
g_return_if_fail (pyramid != NULL);
tile_manager_set_validate_proc (pyramid->tiles[0], proc, user_data);
}
/**
* tile_pyramid_get_width:
* @pyramid: a #TilePyramid
*
* Return value: the width of the pyramid's bottom level
**/
gint
tile_pyramid_get_width (const TilePyramid *pyramid)
{
g_return_val_if_fail (pyramid != NULL, 0);
return pyramid->width;
}
/**
* tile_pyramid_get_height:
* @pyramid: a #TilePyramid
*
* Return value: the height of the pyramid's bottom level
**/
gint
tile_pyramid_get_height (const TilePyramid *pyramid)
{
g_return_val_if_fail (pyramid != NULL, 0);
return pyramid->height;
}
/**
* tile_pyramid_get_bpp:
* @pyramid: a #TilePyramid
*
* Return value: the number of bytes per pixel stored in the @pyramid
**/
gint
tile_pyramid_get_bpp (const TilePyramid *pyramid)
{
g_return_val_if_fail (pyramid != NULL, 0);
return pyramid->bytes;
}
/**
* tile_pyramid_get_memsize:
* @pyramid: a #TilePyramid
*
* Return value: size of memory allocated for the @pyramid
**/
gint64
tile_pyramid_get_memsize (const TilePyramid *pyramid)
{
gint64 memsize = sizeof (TilePyramid);
gint level;
g_return_val_if_fail (pyramid != NULL, 0);
for (level = 0; level <= pyramid->top_level; level++)
memsize += tile_manager_get_memsize (pyramid->tiles[level], TRUE);
return memsize;
}
/* This function make sure that levels are allocated up to the level
* it returns. The return value may be smaller than the level that
* was actually requested.
*/
static gint
tile_pyramid_alloc_levels (TilePyramid *pyramid,
gint top_level)
{
gint level;
top_level = MIN (top_level, PYRAMID_MAX_LEVELS - 1);
if (top_level <= pyramid->top_level)
return top_level;
for (level = pyramid->top_level + 1; level <= top_level; level++)
{
TileValidateProc proc;
gint width = pyramid->width >> level;
gint height = pyramid->height >> level;
if (width == 0 || height == 0)
return pyramid->top_level;
/* There is no use having levels that have the same number of
* tiles as the parent level.
*/
if (width <= TILE_WIDTH / 2 && height <= TILE_HEIGHT / 2)
return pyramid->top_level;
pyramid->top_level = level;
pyramid->tiles[level] = tile_manager_new (width, height, pyramid->bytes);
/* Use the level below to validate tiles. */
if (level == 1)
proc = (TileValidateProc) tile_pyramid_validate_tile;
else
proc = (TileValidateProc) tile_pyramid_validate_upper_tile;
tile_manager_set_validate_proc (pyramid->tiles[level],
proc,
pyramid->tiles[level - 1]);
}
return pyramid->top_level;
}
/* This method is used to validate a pyramid tile from four tiles on
* the base level. It needs to pre-multiply the alpha channel because
* upper levels are pre-multiplied.
*/
static void
tile_pyramid_validate_tile (TileManager *tm,
Tile *tile,
TileManager *tm_below)
{
gint tile_col;
gint tile_row;
gint i, j;
tile_manager_get_tile_col_row (tm, tile, &tile_col, &tile_row);
for (i = 0; i < 2; i++)
for (j = 0; j < 2; j++)
{
Tile *source = tile_manager_get_at (tm_below,
tile_col * 2 + i,
tile_row * 2 + j,
TRUE, FALSE);
if (source)
{
tile_pyramid_write_quarter (tile, source, i, j);
tile_release (source, FALSE);
}
}
}
/* This method is used to validate tiles in the upper pyramid levels.
* Here all data has the alpha channel pre-multiplied.
*/
static void
tile_pyramid_validate_upper_tile (TileManager *tm,
Tile *tile,
TileManager *tm_below)
{
gint tile_col;
gint tile_row;
gint i, j;
tile_manager_get_tile_col_row (tm, tile, &tile_col, &tile_row);
for (i = 0; i < 2; i++)
for (j = 0; j < 2; j++)
{
Tile *source = tile_manager_get_at (tm_below,
tile_col * 2 + i,
tile_row * 2 + j,
TRUE, FALSE);
if (source)
{
tile_pyramid_write_upper_quarter (tile, source, i, j);
tile_release (source, FALSE);
}
}
}
/* Average the src tile to one quarter of the destination tile. The
* source tile doesn't have pre-multiplied alpha, but the destination
* tile does.
*/
static void
tile_pyramid_write_quarter (Tile *dest,
Tile *src,
const gint i,
const gint j)
{
const guchar *src_data = tile_data_pointer (src, 0, 0);
guchar *dest_data = tile_data_pointer (dest,
i * TILE_WIDTH / 2,
j * TILE_WIDTH / 2);
const gint src_ewidth = tile_ewidth (src);
const gint src_eheight = tile_eheight (src);
const gint dest_ewidth = tile_ewidth (dest);
const gint bpp = tile_bpp (dest);
gint y;
for (y = 0; y < src_eheight / 2; y++)
{
const guchar *src0 = src_data;
const guchar *src1 = src_data + bpp;
const guchar *src2 = src0 + bpp * src_ewidth;
const guchar *src3 = src1 + bpp * src_ewidth;
guchar *dst = dest_data;
gint x;
switch (bpp)
{
case 1:
for (x = 0; x < src_ewidth / 2; x++)
{
dst[0] = (src0[0] + src1[0] + src2[0] + src3[0] + 2) >> 2;
dst += 1;
src0 += 2;
src1 += 2;
src2 += 2;
src3 += 2;
}
break;
case 2:
for (x = 0; x < src_ewidth / 2; x++)
{
const guint a = src0[1] + src1[1] + src2[1] + src3[1];
switch (a)
{
case 0: /* all transparent */
dst[0] = dst[1] = 0;
break;
case 1020: /* all opaque */
dst[0] = (src0[0] + src1[0] + src2[0] + src3[0] + 2) >> 2;
dst[1] = 255;
break;
default:
dst[0] = ((src0[0] * (src0[1] + 1) +
src1[0] * (src1[1] + 1) +
src2[0] * (src2[1] + 1) +
src3[0] * (src3[1] + 1)) >> 10);
dst[1] = (a + 2) >> 2;
break;
}
dst += 2;
src0 += 4;
src1 += 4;
src2 += 4;
src3 += 4;
}
break;
case 3:
for (x = 0; x < src_ewidth / 2; x++)
{
dst[0] = (src0[0] + src1[0] + src2[0] + src3[0] + 2) >> 2;
dst[1] = (src0[1] + src1[1] + src2[1] + src3[1] + 2) >> 2;
dst[2] = (src0[2] + src1[2] + src2[2] + src3[2] + 2) >> 2;
dst += 3;
src0 += 6;
src1 += 6;
src2 += 6;
src3 += 6;
}
break;
case 4:
for (x = 0; x < src_ewidth / 2; x++)
{
const guint a = src0[3] + src1[3] + src2[3] + src3[3];
switch (a)
{
case 0: /* all transparent */
dst[0] = dst[1] = dst[2] = dst[3] = 0;
break;
case 1020: /* all opaque */
dst[0] = (src0[0] + src1[0] + src2[0] + src3[0] + 2) >> 2;
dst[1] = (src0[1] + src1[1] + src2[1] + src3[1] + 2) >> 2;
dst[2] = (src0[2] + src1[2] + src2[2] + src3[2] + 2) >> 2;
dst[3] = 255;
break;
default:
{
const guint a0 = src0[3] + 1;
const guint a1 = src1[3] + 1;
const guint a2 = src2[3] + 1;
const guint a3 = src3[3] + 1;
dst[0] = (src0[0] * a0 +
src1[0] * a1 +
src2[0] * a2 +
src3[0] * a3) >> 10;
dst[1] = (src0[1] * a0 +
src1[1] * a1 +
src2[1] * a2 +
src3[1] * a3) >> 10;
dst[2] = (src0[2] * a0 +
src1[2] * a1 +
src2[2] * a2 +
src3[2] * a3) >> 10;
dst[3] = (a + 2) >> 2;
}
break;
}
dst += 4;
src0 += 8;
src1 += 8;
src2 += 8;
src3 += 8;
}
break;
}
dest_data += dest_ewidth * bpp;
src_data += src_ewidth * bpp * 2;
}
}
/* Average the src tile to one quarter of the destination tile.
* The source and destination tiles have pre-multiplied alpha.
*/
static void
tile_pyramid_write_upper_quarter (Tile *dest,
Tile *src,
const gint i,
const gint j)
{
const guchar *src_data = tile_data_pointer (src, 0, 0);
guchar *dest_data = tile_data_pointer (dest,
i * TILE_WIDTH / 2,
j * TILE_WIDTH / 2);
const gint src_ewidth = tile_ewidth (src);
const gint src_eheight = tile_eheight (src);
const gint dest_ewidth = tile_ewidth (dest);
const gint bpp = tile_bpp (dest);
gint y;
for (y = 0; y < src_eheight / 2; y++)
{
const guchar *src0 = src_data;
const guchar *src1 = src_data + bpp;
const guchar *src2 = src0 + bpp * src_ewidth;
const guchar *src3 = src1 + bpp * src_ewidth;
guchar *dst = dest_data;
gint x;
switch (bpp)
{
case 1:
for (x = 0; x < src_ewidth / 2; x++)
{
dst[0] = (src0[0] + src1[0] + src2[0] + src3[0] + 2) >> 2;
dst += 1;
src0 += 2;
src1 += 2;
src2 += 2;
src3 += 2;
}
break;
case 2:
for (x = 0; x < src_ewidth / 2; x++)
{
dst[0] = (src0[0] + src1[0] + src2[0] + src3[0] + 2) >> 2;
dst[1] = (src0[1] + src1[1] + src2[1] + src3[1] + 2) >> 2;
dst += 2;
src0 += 4;
src1 += 4;
src2 += 4;
src3 += 4;
}
break;
case 3:
for (x = 0; x < src_ewidth / 2; x++)
{
dst[0] = (src0[0] + src1[0] + src2[0] + src3[0] + 2) >> 2;
dst[1] = (src0[1] + src1[1] + src2[1] + src3[1] + 2) >> 2;
dst[2] = (src0[2] + src1[2] + src2[2] + src3[2] + 2) >> 2;
dst += 3;
src0 += 6;
src1 += 6;
src2 += 6;
src3 += 6;
}
break;
case 4:
for (x = 0; x < src_ewidth / 2; x++)
{
dst[0] = (src0[0] + src1[0] + src2[0] + src3[0] + 2) >> 2;
dst[1] = (src0[1] + src1[1] + src2[1] + src3[1] + 2) >> 2;
dst[2] = (src0[2] + src1[2] + src2[2] + src3[2] + 2) >> 2;
dst[3] = (src0[3] + src1[3] + src2[3] + src3[3] + 2) >> 2;
dst += 4;
src0 += 8;
src1 += 8;
src2 += 8;
src3 += 8;
}
break;
}
dest_data += dest_ewidth * bpp;
src_data += src_ewidth * bpp * 2;
}
}
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