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-rw-r--r--plug-ins/flame/rect.c397
1 files changed, 397 insertions, 0 deletions
diff --git a/plug-ins/flame/rect.c b/plug-ins/flame/rect.c
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+/*
+ flame - cosmic recursive fractal flames
+ Copyright (C) 1992 Scott Draves <spot@cs.cmu.edu>
+
+ 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 3 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, see <https://www.gnu.org/licenses/>.
+*/
+
+#include "rect.h"
+
+#include <string.h>
+
+
+/* for batch
+ * interpolate
+ * compute colormap
+ * for subbatch
+ * compute samples
+ * buckets += cmap[samples]
+ * accum += time_filter[batch] * log(buckets)
+ * image = filter(accum)
+ */
+
+
+typedef short bucket[4];
+
+/* if you use longs instead of shorts, you
+ get higher quality, and spend more memory */
+
+#if 1
+typedef short accum_t;
+#define MAXBUCKET (1<<14)
+#define SUB_BATCH_SIZE 10000
+#else
+typedef long accum_t;
+#define MAXBUCKET (1<<30)
+#define SUB_BATCH_SIZE 10000
+#endif
+
+typedef accum_t abucket[4];
+
+
+
+/* allow this many iterations for settling into attractor */
+#define FUSE 15
+
+/* clamp spatial filter to zero at this std dev (2.5 ~= 0.0125) */
+#define FILTER_CUTOFF 2.5
+
+/* should be MAXBUCKET / (OVERSAMPLE^2) */
+#define PREFILTER_WHITE (MAXBUCKET>>4)
+
+
+#define bump_no_overflow(dest, delta, type) { \
+ type tt_ = dest + delta; \
+ if (tt_ > dest) dest = tt_; \
+}
+
+/* sum of entries of vector to 1 */
+static void
+normalize_vector(double *v,
+ int n)
+{
+ double t = 0.0;
+ int i;
+ for (i = 0; i < n; i++)
+ t += v[i];
+ t = 1.0 / t;
+ for (i = 0; i < n; i++)
+ v[i] *= t;
+}
+
+void
+render_rectangle (frame_spec *spec,
+ unsigned char *out,
+ int out_width,
+ int field,
+ int nchan,
+ int progress(double))
+{
+ int i, j, k, nsamples, nbuckets, batch_size, batch_num, sub_batch;
+ bucket *buckets;
+ abucket *accumulate;
+ point *points;
+ double *filter, *temporal_filter, *temporal_deltas;
+ double bounds[4], size[2], ppux, ppuy;
+ int image_width, image_height; /* size of the image to produce */
+ int width, height; /* size of histogram */
+ int filter_width;
+ int oversample = spec->cps[0].spatial_oversample;
+ int nbatches = spec->cps[0].nbatches;
+ bucket cmap[CMAP_SIZE];
+ int gutter_width;
+ int sbc;
+
+ image_width = spec->cps[0].width;
+ if (field)
+ {
+ image_height = spec->cps[0].height / 2;
+ if (field == field_odd)
+ out += nchan * out_width;
+ out_width *= 2;
+ }
+ else
+ image_height = spec->cps[0].height;
+
+ if (1)
+ {
+ filter_width = (2.0 * FILTER_CUTOFF * oversample *
+ spec->cps[0].spatial_filter_radius);
+ /* make sure it has same parity as oversample */
+ if ((filter_width ^ oversample) & 1)
+ filter_width++;
+
+ filter = malloc (sizeof (double) * filter_width * filter_width);
+ /* fill in the coefs */
+ for (i = 0; i < filter_width; i++)
+ for (j = 0; j < filter_width; j++)
+ {
+ double ii = ((2.0 * i + 1.0) / filter_width - 1.0) * FILTER_CUTOFF;
+ double jj = ((2.0 * j + 1.0) / filter_width - 1.0) * FILTER_CUTOFF;
+ if (field)
+ jj *= 2.0;
+ filter[i + j * filter_width] = exp(-2.0 * (ii * ii + jj * jj));
+ }
+ normalize_vector(filter, filter_width * filter_width);
+ }
+ temporal_filter = malloc (sizeof (double) * nbatches);
+ temporal_deltas = malloc (sizeof (double) * nbatches);
+ if (nbatches > 1)
+ {
+ double t;
+ /* fill in the coefs */
+ for (i = 0; i < nbatches; i++)
+ {
+ t = temporal_deltas[i] = (2.0 * ((double) i / (nbatches - 1)) - 1.0)
+ * spec->temporal_filter_radius;
+ temporal_filter[i] = exp(-2.0 * t * t);
+ }
+ normalize_vector(temporal_filter, nbatches);
+ }
+ else
+ {
+ temporal_filter[0] = 1.0;
+ temporal_deltas[0] = 0.0;
+ }
+
+ /* the number of additional rows of buckets we put at the edge so
+ that the filter doesn't go off the edge */
+ gutter_width = (filter_width - oversample) / 2;
+ height = oversample * image_height + 2 * gutter_width;
+ width = oversample * image_width + 2 * gutter_width;
+
+ nbuckets = width * height;
+ if (1)
+ {
+ static char *last_block = NULL;
+ static int last_block_size = 0;
+ int memory_rqd = (sizeof (bucket) * nbuckets +
+ sizeof (abucket) * nbuckets +
+ sizeof (point) * SUB_BATCH_SIZE);
+ if (memory_rqd > last_block_size)
+ {
+ if (last_block != NULL)
+ free (last_block);
+ last_block = malloc (memory_rqd);
+ if (last_block == NULL)
+ {
+ fprintf (stderr, "render_rectangle: cannot malloc %d bytes.\n",
+ memory_rqd);
+ exit (1);
+ }
+ last_block_size = memory_rqd;
+ }
+ buckets = (bucket *) last_block;
+ accumulate = (abucket *) (last_block + sizeof (bucket) * nbuckets);
+ points = (point *) (last_block + (sizeof (bucket) + sizeof (abucket)) * nbuckets);
+ }
+
+ memset ((char *) accumulate, 0, sizeof (abucket) * nbuckets);
+ for (batch_num = 0; batch_num < nbatches; batch_num++)
+ {
+ double batch_time;
+ double sample_density;
+ control_point cp;
+ memset ((char *) buckets, 0, sizeof (bucket) * nbuckets);
+ batch_time = spec->time + temporal_deltas[batch_num];
+
+ /* interpolate and get a control point */
+ interpolate (spec->cps, spec->ncps, batch_time, &cp);
+
+ /* compute the colormap entries. the input colormap is 256 long with
+ entries from 0 to 1.0 */
+ for (j = 0; j < CMAP_SIZE; j++)
+ {
+ for (k = 0; k < 3; k++)
+ {
+#if 1
+ cmap[j][k] = (int) (cp.cmap[(j * 256) / CMAP_SIZE][k] *
+ cp.white_level);
+#else
+ /* monochrome if you don't have any cmaps */
+ cmap[j][k] = cp.white_level;
+#endif
+ }
+ cmap[j][3] = cp.white_level;
+ }
+ /* compute camera */
+ if (1)
+ {
+ double t0, t1, shift = 0.0, corner0, corner1;
+ double scale;
+
+ scale = pow (2.0, cp.zoom);
+ sample_density = cp.sample_density * scale * scale;
+
+ ppux = cp.pixels_per_unit * scale;
+ ppuy = field ? (ppux / 2.0) : ppux;
+ switch (field)
+ {
+ case field_both:
+ shift = 0.0;
+ break;
+ case field_even:
+ shift = -0.5;
+ break;
+ case field_odd:
+ shift = 0.5;
+ break;
+ }
+ shift = shift / ppux;
+ t0 = (double) gutter_width / (oversample * ppux);
+ t1 = (double) gutter_width / (oversample * ppuy);
+ corner0 = cp.center[0] - image_width / ppux / 2.0;
+ corner1 = cp.center[1] - image_height / ppuy / 2.0;
+ bounds[0] = corner0 - t0;
+ bounds[1] = corner1 - t1 + shift;
+ bounds[2] = corner0 + image_width / ppux + t0;
+ bounds[3] = corner1 + image_height / ppuy + t1 + shift;
+ size[0] = 1.0 / (bounds[2] - bounds[0]);
+ size[1] = 1.0 / (bounds[3] - bounds[1]);
+ }
+ nsamples = (int) (sample_density * nbuckets /
+ (oversample * oversample));
+ batch_size = nsamples / cp.nbatches;
+
+ sbc = 0;
+ for (sub_batch = 0;
+ sub_batch < batch_size;
+ sub_batch += SUB_BATCH_SIZE)
+ {
+ if (progress && (sbc++ % 32) == 0)
+ (*progress)(0.5 * sub_batch / (double) batch_size);
+ /* generate a sub_batch_size worth of samples */
+ points[0][0] = random_uniform11 ();
+ points[0][1] = random_uniform11 ();
+ points[0][2] = random_uniform01 ();
+ iterate (&cp, SUB_BATCH_SIZE, FUSE, points);
+
+ /* merge them into buckets, looking up colors */
+ for (j = 0; j < SUB_BATCH_SIZE; j++)
+ {
+ int k, color_index;
+ double *p = points[j];
+ bucket *b;
+
+ /* Note that we must test if p[0] and p[1] is "within"
+ * the valid bounds rather than "not outside", because
+ * p[0] and p[1] might be NaN.
+ */
+ if (p[0] >= bounds[0] &&
+ p[1] >= bounds[1] &&
+ p[0] <= bounds[2] &&
+ p[1] <= bounds[3])
+ {
+ color_index = (int) (p[2] * CMAP_SIZE);
+
+ if (color_index < 0)
+ color_index = 0;
+ else if (color_index > CMAP_SIZE - 1)
+ color_index = CMAP_SIZE - 1;
+
+ b = buckets +
+ (int) (width * (p[0] - bounds[0]) * size[0]) +
+ width * (int) (height * (p[1] - bounds[1]) * size[1]);
+
+ for (k = 0; k < 4; k++)
+ bump_no_overflow(b[0][k], cmap[color_index][k], short);
+ }
+ }
+ }
+
+ if (1)
+ {
+ double k1 = (cp.contrast * cp.brightness *
+ PREFILTER_WHITE * 268.0 *
+ temporal_filter[batch_num]) / 256;
+ double area = image_width * image_height / (ppux * ppuy);
+ double k2 = (oversample * oversample * nbatches) /
+ (cp.contrast * area * cp.white_level * sample_density);
+
+ /* log intensity in hsv space */
+ for (j = 0; j < height; j++)
+ for (i = 0; i < width; i++)
+ {
+ abucket *a = accumulate + i + j * width;
+ bucket *b = buckets + i + j * width;
+ double c[4], ls;
+ c[0] = (double) b[0][0];
+ c[1] = (double) b[0][1];
+ c[2] = (double) b[0][2];
+ c[3] = (double) b[0][3];
+ if (0.0 == c[3])
+ continue;
+
+ ls = (k1 * log(1.0 + c[3] * k2))/c[3];
+ c[0] *= ls;
+ c[1] *= ls;
+ c[2] *= ls;
+ c[3] *= ls;
+
+ bump_no_overflow(a[0][0], c[0] + 0.5, accum_t);
+ bump_no_overflow(a[0][1], c[1] + 0.5, accum_t);
+ bump_no_overflow(a[0][2], c[2] + 0.5, accum_t);
+ bump_no_overflow(a[0][3], c[3] + 0.5, accum_t);
+ }
+ }
+ }
+ /*
+ * filter the accumulation buffer down into the image
+ */
+ if (1)
+ {
+ int x, y;
+ double t[4];
+ double g = 1.0 / spec->cps[0].gamma;
+ y = 0;
+ for (j = 0; j < image_height; j++)
+ {
+ if (progress && (j % 32) == 0)
+ (*progress)(0.5 + 0.5 * j / (double)image_height);
+ x = 0;
+ for (i = 0; i < image_width; i++)
+ {
+ int ii, jj, a;
+ unsigned char *p;
+ t[0] = t[1] = t[2] = t[3] = 0.0;
+ for (ii = 0; ii < filter_width; ii++)
+ for (jj = 0; jj < filter_width; jj++)
+ {
+ double k = filter[ii + jj * filter_width];
+ abucket *a = accumulate + x + ii + (y + jj) * width;
+
+ t[0] += k * a[0][0];
+ t[1] += k * a[0][1];
+ t[2] += k * a[0][2];
+ t[3] += k * a[0][3];
+ }
+ /* FIXME: we should probably use glib facilities to make
+ * this code readable
+ */
+ p = out + nchan * (i + j * out_width);
+ a = 256.0 * pow((double) t[0] / PREFILTER_WHITE, g) + 0.5;
+ if (a < 0) a = 0; else if (a > 255) a = 255;
+ p[0] = a;
+ a = 256.0 * pow((double) t[1] / PREFILTER_WHITE, g) + 0.5;
+ if (a < 0) a = 0; else if (a > 255) a = 255;
+ p[1] = a;
+ a = 256.0 * pow((double) t[2] / PREFILTER_WHITE, g) + 0.5;
+ if (a < 0) a = 0; else if (a > 255) a = 255;
+ p[2] = a;
+ if (nchan > 3)
+ {
+ a = 256.0 * pow((double) t[3] / PREFILTER_WHITE, g) + 0.5;
+ if (a < 0) a = 0; else if (a > 255) a = 255;
+ p[3] = a;
+ }
+ x += oversample;
+ }
+ y += oversample;
+ }
+ }
+
+ free (filter);
+ free (temporal_filter);
+ free (temporal_deltas);
+}
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