/* LIBPIKA - The PIKA 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
* .
*/
#include "config.h"
#include
#include
#include "libpikamath/pikamath.h"
#include "pikacolortypes.h"
#include "pikaadaptivesupersample.h"
#include "pikargb.h"
/**
* SECTION: pikaadaptivesupersample
* @title: PikaAdaptiveSupersample
* @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 _PikaSampleType PikaSampleType;
struct _PikaSampleType
{
guchar ready;
PikaRGB color;
};
static gulong
pika_render_sub_pixel (gint max_depth,
gint depth,
PikaSampleType **block,
gint x,
gint y,
gint x1,
gint y1,
gint x3,
gint y3,
gdouble threshold,
gint sub_pixel_size,
PikaRGB *color,
PikaRenderFunc 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 */
PikaRGB c[4]; /* Sample colors */
gulong num_samples = 0;
gint cnt;
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, &c[0], render_data);
block[y1][x1].ready = TRUE;
block[y1][x1].color = c[0];
}
else
{
c[0] = block[y1][x1].color;
}
/* Render upper right sample */
if (! block[y1][x3].ready)
{
num_samples++;
render_func (x + dx3, y + dy1, &c[1], render_data);
block[y1][x3].ready = TRUE;
block[y1][x3].color = c[1];
}
else
{
c[1] = block[y1][x3].color;
}
/* Render lower left sample */
if (! block[y3][x1].ready)
{
num_samples++;
render_func (x + dx1, y + dy3, &c[2], render_data);
block[y3][x1].ready = TRUE;
block[y3][x1].color = c[2];
}
else
{
c[2] = block[y3][x1].color;
}
/* Render lower right sample */
if (! block[y3][x3].ready)
{
num_samples++;
render_func (x + dx3, y + dy3, &c[3], render_data);
block[y3][x3].ready = TRUE;
block[y3][x3].color = c[3];
}
else
{
c[3] = block[y3][x3].color;
}
/* Check for supersampling */
if (depth <= max_depth)
{
/* Check whether we have to supersample */
if ((pika_rgba_distance (&c[0], &c[1]) >= threshold) ||
(pika_rgba_distance (&c[0], &c[2]) >= threshold) ||
(pika_rgba_distance (&c[0], &c[3]) >= threshold) ||
(pika_rgba_distance (&c[1], &c[2]) >= threshold) ||
(pika_rgba_distance (&c[1], &c[3]) >= threshold) ||
(pika_rgba_distance (&c[2], &c[3]) >= threshold))
{
/* Calc coordinates of center subsample */
x2 = (x1 + x3) / 2;
y2 = (y1 + y3) / 2;
/* Render sub-blocks */
num_samples += pika_render_sub_pixel (max_depth, depth + 1, block,
x, y, x1, y1, x2, y2,
threshold, sub_pixel_size,
&c[0],
render_func, render_data);
num_samples += pika_render_sub_pixel (max_depth, depth + 1, block,
x, y, x2, y1, x3, y2,
threshold, sub_pixel_size,
&c[1],
render_func, render_data);
num_samples += pika_render_sub_pixel (max_depth, depth + 1, block,
x, y, x1, y2, x2, y3,
threshold, sub_pixel_size,
&c[2],
render_func, render_data);
num_samples += pika_render_sub_pixel (max_depth, depth + 1, block,
x, y, x2, y2, x3, y3,
threshold, sub_pixel_size,
&c[3],
render_func, render_data);
}
}
if (c[0].a == 0.0 || c[1].a == 0.0 || c[2].a == 0.0 || c[3].a == 0.0)
{
PikaRGB tmpcol;
gdouble weight;
pika_rgb_set (&tmpcol, 0.0, 0.0, 0.0);
weight = 2.0;
for (cnt = 0; cnt < 4; cnt++)
{
if (c[cnt].a != 0.0)
{
tmpcol.r += c[cnt].r;
tmpcol.g += c[cnt].g;
tmpcol.b += c[cnt].b;
weight /= 2.0;
}
}
color->r = weight * tmpcol.r;
color->g = weight * tmpcol.g;
color->b = weight * tmpcol.b;
}
else
{
color->r = 0.25 * (c[0].r + c[1].r + c[2].r + c[3].r);
color->g = 0.25 * (c[0].g + c[1].g + c[2].g + c[3].g);
color->b = 0.25 * (c[0].b + c[1].b + c[2].b + c[3].b);
}
color->a = 0.25 * (c[0].a + c[1].a + c[2].a + c[3].a);
return num_samples;
}
/**
* pika_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
pika_adaptive_supersample_area (gint x1,
gint y1,
gint x2,
gint y2,
gint max_depth,
gdouble threshold,
PikaRenderFunc render_func,
gpointer render_data,
PikaPutPixelFunc put_pixel_func,
gpointer put_pixel_data,
PikaProgressFunc 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) */
PikaRGB color; /* Rendered pixel's color */
PikaSampleType tmp_sample; /* For swapping samples */
PikaSampleType *top_row, *bot_row, *tmp_row; /* Sample rows */
PikaSampleType **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 */
pika_rgba_set (&color, 0.0, 0.0, 0.0, 0.0);
/* Calculate sub-pixel size */
sub_pixel_size = 1 << max_depth;
/* Create row arrays */
width = x2 - x1 + 1;
top_row = gegl_scratch_new (PikaSampleType, sub_pixel_size * width + 1);
bot_row = gegl_scratch_new (PikaSampleType, sub_pixel_size * width + 1);
for (x = 0; x < (sub_pixel_size * width + 1); x++)
{
top_row[x].ready = FALSE;
pika_rgba_set (&top_row[x].color, 0.0, 0.0, 0.0, 0.0);
bot_row[x].ready = FALSE;
pika_rgba_set (&bot_row[x].color, 0.0, 0.0, 0.0, 0.0);
}
/* Allocate block matrix */
block = gegl_scratch_new (PikaSampleType *, sub_pixel_size + 1); /* Rows */
for (y = 0; y < (sub_pixel_size + 1); y++)
{
block[y] = gegl_scratch_new (PikaSampleType, sub_pixel_size + 1); /* Columns */
for (x = 0; x < (sub_pixel_size + 1); x++)
{
block[y][x].ready = FALSE;
pika_rgba_set (&block[y][x].color, 0.0, 0.0, 0.0, 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 += pika_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;
}