mirror of https://github.com/GNOME/gimp.git
342 lines
8.9 KiB
C
342 lines
8.9 KiB
C
/* The GIMP -- an image manipulation program
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* Copyright (C) 1995 Spencer Kimball and Peter Mattis
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*
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* General, non-jittered adaptive supersampling library
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* Copyright (C) 1997 Federico Mena Quintero
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*/
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/* This code is *largely* based on the sources for POV-Ray 3.0. I am
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* grateful to the POV-Team for such a great program and for making
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* their sources available. All comments / bug reports /
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* etc. regarding this library should be addressed to me, not to the
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* POV-Ray team. Any bugs are my responsibility, not theirs.
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*/
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#include "config.h"
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#include <math.h>
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#include <stdlib.h>
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#include <gtk/gtk.h>
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#include "apptypes.h"
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#include "appenv.h"
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#include "asupsample.h"
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/***** Types *****/
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typedef struct {
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char ready;
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color_t color;
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} sample_t;
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/***** Local functions *****/
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static unsigned long render_sub_pixel(int max_depth, int depth, sample_t **block,
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int x, int y, int x1, int y1, int x3, int y3,
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double threshold, int sub_pixel_size, render_func_t render_func,
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color_t *color, void *render_data);
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static double color_dist(color_t c1, color_t c2);
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/***** Functions *****/
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/*****/
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unsigned long
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adaptive_supersample_area(int x1, int y1, int x2, int y2, int max_depth, double threshold,
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render_func_t render_func, void *render_data,
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put_pixel_func_t put_pixel_func, void *put_pixel_data,
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progress_func_t progress_func, void *progress_data)
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{
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int x, y, width; /* Counters, width of region */
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int xt, xtt, yt; /* Temporary counters */
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int sub_pixel_size; /* Numbe of samples per pixel (1D) */
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size_t row_size; /* Memory needed for one row */
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color_t color; /* Rendered pixel's color */
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sample_t tmp_sample; /* For swapping samples */
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sample_t *top_row, *bot_row, *tmp_row; /* Sample rows */
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sample_t **block; /* Sample block matrix */
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unsigned long num_samples;
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/* Initialize color */
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color.r = 0.0;
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color.g = 0.0;
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color.b = 0.0;
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color.a = 0.0;
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/* Calculate sub-pixel size */
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sub_pixel_size = 1 << max_depth; /* 2**max_depth */
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/* Create row arrays */
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width = x2 - x1 + 1;
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row_size = (sub_pixel_size * width + 1) * sizeof(sample_t);
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top_row = g_malloc(row_size);
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bot_row = g_malloc(row_size);
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for (x = 0; x < (sub_pixel_size * width + 1); x++) {
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top_row[x].ready = 0;
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top_row[x].color.r = 0.0;
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top_row[x].color.g = 0.0;
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top_row[x].color.b = 0.0;
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top_row[x].color.a = 0.0;
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bot_row[x].ready = 0;
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bot_row[x].color.r = 0.0;
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bot_row[x].color.g = 0.0;
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bot_row[x].color.b = 0.0;
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bot_row[x].color.a = 0.0;
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} /* for */
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/* Allocate block matrix */
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block = g_malloc((sub_pixel_size + 1) * sizeof(sample_t *)); /* Rows */
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for (y = 0; y < (sub_pixel_size + 1); y++) {
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block[y] = g_malloc((sub_pixel_size + 1) * sizeof(sample_t)); /* Columns */
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for (x = 0; x < (sub_pixel_size + 1); x++) {
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block[y][x].ready = 0;
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block[y][x].color.r = 0;
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block[y][x].color.g = 0;
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block[y][x].color.b = 0;
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block[y][x].color.a = 0;
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}
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}
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/* Render region */
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num_samples = 0;
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for (y = y1; y <= y2; y++) {
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/* Clear the bottom row */
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for (xt = 0; xt < (sub_pixel_size * width + 1); xt++)
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bot_row[xt].ready = 0;
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/* Clear first column */
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for (yt = 0; yt < (sub_pixel_size + 1); yt++)
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block[yt][0].ready = 0;
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/* Render row */
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for (x = x1; x <= x2; x++) {
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/* Initialize block by clearing all but first row/column */
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for (yt = 1; yt < (sub_pixel_size + 1); yt++)
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for (xt = 1; xt < (sub_pixel_size + 1); xt++)
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block[yt][xt].ready = 0;
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/* Copy samples from top row to block */
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for (xtt = 0, xt = (x - x1) * sub_pixel_size;
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xtt < (sub_pixel_size + 1);
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xtt++, xt++)
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block[0][xtt] = top_row[xt];
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/* Render pixel on (x, y) */
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num_samples += render_sub_pixel(max_depth, 1, block, x, y, 0, 0,
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sub_pixel_size, sub_pixel_size,
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threshold, sub_pixel_size, render_func, &color,
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render_data);
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if (put_pixel_func)
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(*put_pixel_func)(x, y, color, put_pixel_data);
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/* Copy block information to rows */
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top_row[((x - x1) + 1) * sub_pixel_size] = block[0][sub_pixel_size];
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for (xtt = 0, xt = (x - x1) * sub_pixel_size;
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xtt < (sub_pixel_size + 1);
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xtt++, xt++)
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bot_row[xt] = block[sub_pixel_size][xtt];
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/* Swap first and last columns */
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for (yt = 0; yt < (sub_pixel_size + 1); yt++) {
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tmp_sample = block[yt][0];
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block[yt][0] = block[yt][sub_pixel_size];
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block[yt][sub_pixel_size] = tmp_sample;
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} /* for */
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} /* for */
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/* Swap rows */
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tmp_row = top_row;
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top_row = bot_row;
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bot_row = tmp_row;
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/* Call progress display function */
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if (progress_func && !(y & 0xf))
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(*progress_func)(y1, y2, y, progress_data);
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} /* for */
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/* Free memory */
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for (y = 0; y < (sub_pixel_size + 1); y++)
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g_free(block[y]);
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g_free(block);
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g_free(top_row);
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g_free(bot_row);
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return num_samples;
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} /* adaptive_supersample_area */
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/*****/
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static unsigned long
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render_sub_pixel(int max_depth, int depth, sample_t **block,
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int x, int y, int x1, int y1, int x3, int y3,
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double threshold, int sub_pixel_size, render_func_t render_func,
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color_t *color, void *render_data)
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{
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int x2, y2; /* Coords of center sample */
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double dx1, dy1; /* Delta to upper left sample */
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double dx3, dy3; /* Delta to lower right sample */
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color_t c1, c2, c3, c4; /* Sample colors */
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unsigned long num_samples;
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/* Get offsets for corners */
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dx1 = (double) (x1 - sub_pixel_size / 2) / sub_pixel_size;
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dx3 = (double) (x3 - sub_pixel_size / 2) / sub_pixel_size;
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dy1 = (double) (y1 - sub_pixel_size / 2) / sub_pixel_size;
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dy3 = (double) (y3 - sub_pixel_size / 2) / sub_pixel_size;
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num_samples = 0;
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/* Render upper left sample */
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if (!block[y1][x1].ready) {
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num_samples++;
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(*render_func)(x + dx1, y + dy1, &c1, render_data);
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block[y1][x1].ready = 1;
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block[y1][x1].color = c1;
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} else
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c1 = block[y1][x1].color;
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/* Render upper right sample */
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if (!block[y1][x3].ready) {
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num_samples++;
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(*render_func)(x + dx3, y + dy1, &c2, render_data);
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block[y1][x3].ready = 1;
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block[y1][x3].color = c2;
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} else
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c2 = block[y1][x3].color;
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/* Render lower left sample */
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if (!block[y3][x1].ready) {
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num_samples++;
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(*render_func)(x + dx1, y + dy3, &c3, render_data);
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block[y3][x1].ready = 1;
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block[y3][x1].color = c3;
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} else
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c3 = block[y3][x1].color;
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/* Render lower right sample */
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if (!block[y3][x3].ready) {
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num_samples++;
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(*render_func)(x + dx3, y + dy3, &c4, render_data);
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block[y3][x3].ready = 1;
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block[y3][x3].color = c4;
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} else
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c4 = block[y3][x3].color;
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/* Check for supersampling */
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if (depth <= max_depth) {
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/* Check whether we have tu supersample */
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if ((color_dist(c1, c2) >= threshold) ||
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(color_dist(c1, c3) >= threshold) ||
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(color_dist(c1, c4) >= threshold) ||
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(color_dist(c2, c3) >= threshold) ||
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(color_dist(c2, c4) >= threshold) ||
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(color_dist(c3, c4) >= threshold)) {
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/* Calc coordinates of center subsample */
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x2 = (x1 + x3) / 2;
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y2 = (y1 + y3) / 2;
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/* Render sub-blocks */
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num_samples += render_sub_pixel(max_depth, depth + 1, block, x, y, x1, y1, x2, y2,
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threshold, sub_pixel_size, render_func, &c1,
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render_data);
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num_samples += render_sub_pixel(max_depth, depth + 1, block, x, y, x2, y1, x3, y2,
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threshold, sub_pixel_size, render_func, &c2,
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render_data);
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num_samples += render_sub_pixel(max_depth, depth + 1, block, x, y, x1, y2, x2, y3,
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threshold, sub_pixel_size, render_func, &c3,
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render_data);
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num_samples += render_sub_pixel(max_depth, depth + 1, block, x, y, x2, y2, x3, y3,
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threshold, sub_pixel_size, render_func, &c4,
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render_data);
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} /* if */
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} /* if */
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color->r = 0.25 * (c1.r + c2.r + c3.r + c4.r);
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color->g = 0.25 * (c1.g + c2.g + c3.g + c4.g);
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color->b = 0.25 * (c1.b + c2.b + c3.b + c4.b);
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color->a = 0.25 * (c1.a + c2.a + c3.a + c4.a);
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return num_samples;
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} /* render_sub_pixel */
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/*****/
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static double
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color_dist(color_t c1, color_t c2)
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{
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return fabs(c1.r - c2.r) +
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fabs(c1.g - c2.g) +
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fabs(c1.b - c2.b) +
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fabs(c1.a - c2.a);
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} /* color_dist */
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