gimp/libgimpcolor/gimpadaptivesupersample.c

455 lines
14 KiB
C

/* LIBGIMP - The GIMP Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* This library is free software: you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <gegl.h>
#include <glib-object.h>
#include "libgimpmath/gimpmath.h"
#include "gimpcolortypes.h"
#include "gimpadaptivesupersample.h"
/**
* SECTION: gimpadaptivesupersample
* @title: GimpAdaptiveSupersample
* @short_description: Functions to perform adaptive supersampling on
* an area.
*
* Functions to perform adaptive supersampling on an area.
**/
/*********************************************************************/
/* Sumpersampling code (Quartic) */
/* This code is *largely* based on the sources for POV-Ray 3.0. I am */
/* grateful to the POV-Team for such a great program and for making */
/* their sources available. All comments / bug reports / */
/* etc. regarding this code should be addressed to me, not to the */
/* POV-Ray team. Any bugs are my responsibility, not theirs. */
/*********************************************************************/
typedef struct _GimpSampleType GimpSampleType;
struct _GimpSampleType
{
guchar ready;
gdouble color[4];
};
static gdouble
gimp_rgba_distance_legacy (gdouble *rgba1,
gdouble *rgba2)
{
g_return_val_if_fail (rgba1 != NULL, 0.0);
g_return_val_if_fail (rgba2 != NULL, 0.0);
return (fabs (rgba1[0] - rgba2[0]) +
fabs (rgba1[1] - rgba2[1]) +
fabs (rgba1[2] - rgba2[2]) +
fabs (rgba1[3] - rgba2[3]));
}
static gulong
gimp_render_sub_pixel (gint max_depth,
gint depth,
GimpSampleType **block,
gint x,
gint y,
gint x1,
gint y1,
gint x3,
gint y3,
gdouble threshold,
gint sub_pixel_size,
gdouble *color,
GimpRenderFunc render_func,
gpointer render_data)
{
gint x2, y2; /* Coords of center sample */
gdouble dx1, dy1; /* Delta to upper left sample */
gdouble dx3, dy3; /* Delta to lower right sample */
gdouble c0[4], c1[4], c2[4], c3[4]; /* Sample colors */
gulong num_samples = 0;
g_return_val_if_fail (render_func != NULL, 0);
/* Get offsets for corners */
dx1 = (gdouble) (x1 - sub_pixel_size / 2) / sub_pixel_size;
dx3 = (gdouble) (x3 - sub_pixel_size / 2) / sub_pixel_size;
dy1 = (gdouble) (y1 - sub_pixel_size / 2) / sub_pixel_size;
dy3 = (gdouble) (y3 - sub_pixel_size / 2) / sub_pixel_size;
/* Render upper left sample */
if (! block[y1][x1].ready)
{
num_samples++;
render_func (x + dx1, y + dy1, c0, render_data);
block[y1][x1].ready = TRUE;
for (gint i = 0; i < 4; i++)
block[y1][x1].color[i] = c0[i];
}
else
{
for (gint i = 0; i < 4; i++)
c0[i] = block[y1][x1].color[i];
}
/* Render upper right sample */
if (! block[y1][x3].ready)
{
num_samples++;
render_func (x + dx3, y + dy1, c1, render_data);
block[y1][x3].ready = TRUE;
for (gint i = 0; i < 4; i++)
block[y1][x3].color[i] = c1[i];
}
else
{
for (gint i = 0; i < 4; i++)
c1[i] = block[y1][x3].color[i];
}
/* Render lower left sample */
if (! block[y3][x1].ready)
{
num_samples++;
render_func (x + dx1, y + dy3, c2, render_data);
block[y3][x1].ready = TRUE;
for (gint i = 0; i < 4; i++)
block[y3][x1].color[i] = c2[i];
}
else
{
for (gint i = 0; i < 4; i++)
c2[i] = block[y3][x1].color[i];
}
/* Render lower right sample */
if (! block[y3][x3].ready)
{
num_samples++;
render_func (x + dx3, y + dy3, c3, render_data);
block[y3][x3].ready = TRUE;
for (gint i = 0; i < 4; i++)
block[y3][x3].color[i] = c3[i];
}
else
{
for (gint i = 0; i < 4; i++)
c3[i] = block[y3][x3].color[i];
}
/* Check for supersampling */
if (depth <= max_depth)
{
/* Check whether we have to supersample */
if ((gimp_rgba_distance_legacy (c0, c1) >= threshold) ||
(gimp_rgba_distance_legacy (c0, c2) >= threshold) ||
(gimp_rgba_distance_legacy (c0, c3) >= threshold) ||
(gimp_rgba_distance_legacy (c1, c2) >= threshold) ||
(gimp_rgba_distance_legacy (c1, c3) >= threshold) ||
(gimp_rgba_distance_legacy (c2, c3) >= threshold))
{
/* Calc coordinates of center subsample */
x2 = (x1 + x3) / 2;
y2 = (y1 + y3) / 2;
/* Render sub-blocks */
num_samples += gimp_render_sub_pixel (max_depth, depth + 1, block,
x, y, x1, y1, x2, y2,
threshold, sub_pixel_size,
c0,
render_func, render_data);
num_samples += gimp_render_sub_pixel (max_depth, depth + 1, block,
x, y, x2, y1, x3, y2,
threshold, sub_pixel_size,
c1,
render_func, render_data);
num_samples += gimp_render_sub_pixel (max_depth, depth + 1, block,
x, y, x1, y2, x2, y3,
threshold, sub_pixel_size,
c2,
render_func, render_data);
num_samples += gimp_render_sub_pixel (max_depth, depth + 1, block,
x, y, x2, y2, x3, y3,
threshold, sub_pixel_size,
c3,
render_func, render_data);
}
}
if (c0[3] == 0.0 || c1[3] == 0.0 || c2[3] == 0.0 || c3[3] == 0.0)
{
gdouble tmpcol[3] = { 0.0, 0.0, 0.0 };
gdouble weight;
weight = 2.0;
if (c0[3] != 0.0)
{
tmpcol[0] += c0[0];
tmpcol[1] += c0[1];
tmpcol[2] += c0[2];
weight /= 2.0;
}
if (c1[3] != 0.0)
{
tmpcol[0] += c1[0];
tmpcol[1] += c1[1];
tmpcol[2] += c1[2];
weight /= 2.0;
}
if (c2[3] != 0.0)
{
tmpcol[0] += c2[0];
tmpcol[1] += c2[1];
tmpcol[2] += c2[2];
weight /= 2.0;
}
if (c3[3] != 0.0)
{
tmpcol[0] += c3[0];
tmpcol[1] += c3[1];
tmpcol[2] += c3[2];
weight /= 2.0;
}
color[0] = weight * tmpcol[0];
color[1] = weight * tmpcol[1];
color[2] = weight * tmpcol[2];
}
else
{
color[0] = 0.25 * (c0[0] + c1[0] + c2[0] + c3[0]);
color[1] = 0.25 * (c0[1] + c1[1] + c2[1] + c3[1]);
color[2] = 0.25 * (c0[2] + c1[2] + c2[2] + c3[2]);
}
color[3] = 0.25 * (c0[3] + c1[3] + c2[3] + c3[3]);
return num_samples;
}
/**
* gimp_adaptive_supersample_area:
* @x1: left x coordinate of the area to process.
* @y1: top y coordinate of the area to process.
* @x2: right x coordinate of the area to process.
* @y2: bottom y coordinate of the area to process.
* @max_depth: maximum depth of supersampling.
* @threshold: lower threshold of pixel difference that stops
* supersampling.
* @render_func: (scope call): function calculate the color value at
* given coordinates.
* @render_data: user data passed to @render_func.
* @put_pixel_func: (scope call): function to a pixels to a color at
* given coordinates.
* @put_pixel_data: user data passed to @put_pixel_func.
* @progress_func: (scope call): function to report progress.
* @progress_data: user data passed to @progress_func.
*
* Returns: the number of pixels processed.
**/
gulong
gimp_adaptive_supersample_area (gint x1,
gint y1,
gint x2,
gint y2,
gint max_depth,
gdouble threshold,
GimpRenderFunc render_func,
gpointer render_data,
GimpPutPixelFunc put_pixel_func,
gpointer put_pixel_data,
GimpProgressFunc progress_func,
gpointer progress_data)
{
gint x, y, width; /* Counters, width of region */
gint xt, xtt, yt; /* Temporary counters */
gint sub_pixel_size; /* Number of samples per pixel (1D) */
gdouble color[4]; /* Rendered pixel's color */
GimpSampleType tmp_sample; /* For swapping samples */
GimpSampleType *top_row, *bot_row, *tmp_row; /* Sample rows */
GimpSampleType **block; /* Sample block matrix */
gulong num_samples;
g_return_val_if_fail (render_func != NULL, 0);
g_return_val_if_fail (put_pixel_func != NULL, 0);
/* Initialize color */
for (gint i = 0; i < 4; i++)
color[i] = 0.0;
/* Calculate sub-pixel size */
sub_pixel_size = 1 << max_depth;
/* Create row arrays */
width = x2 - x1 + 1;
top_row = gegl_scratch_new (GimpSampleType, sub_pixel_size * width + 1);
bot_row = gegl_scratch_new (GimpSampleType, sub_pixel_size * width + 1);
for (x = 0; x < (sub_pixel_size * width + 1); x++)
{
top_row[x].ready = FALSE;
bot_row[x].ready = FALSE;
for (gint i = 0; i < 4; i++)
{
top_row[x].color[i] = 0.0;
bot_row[x].color[i] = 0.0;
}
}
/* Allocate block matrix */
block = gegl_scratch_new (GimpSampleType *, sub_pixel_size + 1); /* Rows */
for (y = 0; y < (sub_pixel_size + 1); y++)
{
block[y] = gegl_scratch_new (GimpSampleType, sub_pixel_size + 1); /* Columns */
for (x = 0; x < (sub_pixel_size + 1); x++)
{
block[y][x].ready = FALSE;
for (gint i = 0; i < 4; i++)
block[y][x].color[i] = 0.0;
}
}
/* Render region */
num_samples = 0;
for (y = y1; y <= y2; y++)
{
/* Clear the bottom row */
for (xt = 0; xt < (sub_pixel_size * width + 1); xt++)
bot_row[xt].ready = FALSE;
/* Clear first column */
for (yt = 0; yt < (sub_pixel_size + 1); yt++)
block[yt][0].ready = FALSE;
/* Render row */
for (x = x1; x <= x2; x++)
{
/* Initialize block by clearing all but first row/column */
for (yt = 1; yt < (sub_pixel_size + 1); yt++)
for (xt = 1; xt < (sub_pixel_size + 1); xt++)
block[yt][xt].ready = FALSE;
/* Copy samples from top row to block */
for (xtt = 0, xt = (x - x1) * sub_pixel_size;
xtt < (sub_pixel_size + 1);
xtt++, xt++)
block[0][xtt] = top_row[xt];
/* Render pixel on (x, y) */
num_samples += gimp_render_sub_pixel (max_depth, 1, block, x, y, 0, 0,
sub_pixel_size, sub_pixel_size,
threshold, sub_pixel_size,
color,
render_func, render_data);
if (put_pixel_func)
(* put_pixel_func) (x, y, color, put_pixel_data);
/* Copy block information to rows */
top_row[(x - x1 + 1) * sub_pixel_size] = block[0][sub_pixel_size];
for (xtt = 0, xt = (x - x1) * sub_pixel_size;
xtt < (sub_pixel_size + 1);
xtt++, xt++)
bot_row[xt] = block[sub_pixel_size][xtt];
/* Swap first and last columns */
for (yt = 0; yt < (sub_pixel_size + 1); yt++)
{
tmp_sample = block[yt][0];
block[yt][0] = block[yt][sub_pixel_size];
block[yt][sub_pixel_size] = tmp_sample;
}
}
/* Swap rows */
tmp_row = top_row;
top_row = bot_row;
bot_row = tmp_row;
/* Call progress display function (if any) */
if (progress_func != NULL)
(* progress_func) (y1, y2, y, progress_data);
}
/* Free memory */
for (y = 0; y < (sub_pixel_size + 1); y++)
gegl_scratch_free (block[y]);
gegl_scratch_free (block);
gegl_scratch_free (top_row);
gegl_scratch_free (bot_row);
return num_samples;
}