[gegl] stereographic-projection: little planet rendering for panoramas
- From: Øyvind Kolås <ok src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gegl] stereographic-projection: little planet rendering for panoramas
- Date: Fri, 2 May 2014 01:17:31 +0000 (UTC)
commit eaeed4ab80b57aa21e20a198774089d00dfb64d6
Author: Øyvind Kolås <pippin gimp org>
Date: Fri May 2 02:07:42 2014 +0200
stereographic-projection: little planet rendering for panoramas
Operation performing little-planet style rendering of equirectangular
panoramas.
operations/common/Makefile.am | 1 +
operations/common/gnomonic-projection.c | 12 +-
operations/common/stereographic-projection.c | 229 ++++++++++++++++++++++++++
po/POTFILES.in | 1 +
4 files changed, 237 insertions(+), 6 deletions(-)
---
diff --git a/operations/common/Makefile.am b/operations/common/Makefile.am
index b7948d2..d4bc15d 100644
--- a/operations/common/Makefile.am
+++ b/operations/common/Makefile.am
@@ -100,6 +100,7 @@ op_LTLIBRARIES = \
shift.la \
snn-mean.la \
softglow.la \
+ stereographic-projection.la \
stress.la \
stretch-contrast-hsv.la \
stretch-contrast.la \
diff --git a/operations/common/gnomonic-projection.c b/operations/common/gnomonic-projection.c
index 647531b..02a5bdc 100644
--- a/operations/common/gnomonic-projection.c
+++ b/operations/common/gnomonic-projection.c
@@ -82,14 +82,14 @@ calc_long_lat (float x, float y,
sin_c = sinf(c);
cos_c = cosf(c);
- longtitude = asinf (cos_c * sin_tilt + ( y * sin_c * cos_tilt) / p);
- latitude = pan + atan2f ( x * sin_c, p * cos_tilt * cos_c - y * sin_tilt * sin_c);
+ latitude = asinf (cos_c * sin_tilt + ( y * sin_c * cos_tilt) / p);
+ longtitude = pan + atan2f ( x * sin_c, p * cos_tilt * cos_c - y * sin_tilt * sin_c);
- if (latitude < 0)
- latitude += M_PI * 2;
+ if (longtitude < 0)
+ longtitude += M_PI * 2;
- *in_long = (latitude / (M_PI * 2));
- *in_lat = ((longtitude + M_PI/2) / M_PI);
+ *in_long = (longtitude / (M_PI * 2));
+ *in_lat = ((latitude + M_PI/2) / M_PI);
}
static gboolean
diff --git a/operations/common/stereographic-projection.c b/operations/common/stereographic-projection.c
new file mode 100644
index 0000000..82361b4
--- /dev/null
+++ b/operations/common/stereographic-projection.c
@@ -0,0 +1,229 @@
+/* This file is an image processing operation for GEGL
+ *
+ * GEGL 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.
+ *
+ * GEGL 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GEGL; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2014 <pippin gimp org>
+ *
+ */
+
+#include <math.h>
+
+#ifdef GEGL_CHANT_PROPERTIES
+
+gegl_chant_double (pan, _("pan"), -180.0, 360, 0.0,
+ _("pan degree of ground for planet"))
+gegl_chant_double (tilt, _("tilt"), -180.0, 180.0, 90.0,
+ _("tilt degree of ground for planet"))
+gegl_chant_double (spin, _("spin"), -360.0, 360.0, 0.0,
+ _("spin of camera / rendering"))
+gegl_chant_double (zoom, _("zoom"), 0.01, 1000.0, 50.0,
+ _("scale factor"))
+gegl_chant_double (radius, _("local radius"), 0.01, 100.0, 5.0,
+ _("factor determining dimension of planet"))
+
+gegl_chant_enum (sampler_type, _("Sampler"), GeglSamplerType, gegl_sampler_type,
+ GEGL_SAMPLER_CUBIC, _("Image resampling method to use"))
+
+#else
+
+#define GEGL_CHANT_TYPE_FILTER
+#define GEGL_CHANT_C_FILE "stereographic-projection.c"
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+#include "gegl-chant.h"
+
+
+static void
+prepare (GeglOperation *operation)
+{
+ const Babl *format = babl_format ("RaGaBaA float");
+
+ gegl_operation_set_format (operation, "input", format);
+ gegl_operation_set_format (operation, "output", format);
+}
+
+static GeglRectangle
+get_required_for_output (GeglOperation *operation,
+ const gchar *input_pad,
+ const GeglRectangle *region)
+{
+ GeglRectangle result = *gegl_operation_source_get_bounding_box (operation, "input");
+
+ return result;
+}
+
+/* formulas from:
+ * http://mathworld.wolfram.com/StereographicProjection.html
+ */
+
+static void inline
+calc_long_lat (float x, float y,
+ float tilt, float pan, float spin, float radius,
+ float sin_tilt, float cos_tilt,
+ float *in_long, float *in_lat)
+{
+ float p, c;
+ float longtitude, latitude;
+ float sin_c, cos_c;
+ float R = radius;
+
+ p = sqrtf (x*x+y*y);
+ c = 2 * atanf (p / 2 * R);
+
+ sin_c = sinf(c);
+ cos_c = cosf(c);
+
+ latitude = asinf (cos_c * sin_tilt + ( y * sin_c * cos_tilt) / p);
+ longtitude = pan + atan2f ( x * sin_c, p * cos_tilt * cos_c - y * sin_tilt * sin_c);
+
+ if (longtitude < 0)
+ longtitude += M_PI * 2;
+
+ *in_long = (longtitude / (M_PI * 2));
+ *in_lat = ((latitude + M_PI/2) / M_PI);
+}
+
+static gboolean
+process (GeglOperation *operation,
+ GeglBuffer *input,
+ GeglBuffer *output,
+ const GeglRectangle *result,
+ gint level)
+{
+ GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);
+ float pan = o->pan / 360 * M_PI * 2;
+ float spin = o->spin / 360 * M_PI * 2;
+ float zoom = o->zoom / 100.0;
+ float tilt = o->tilt / 360 * M_PI * 2;
+ float width;
+ float height;
+ const Babl *format_io;
+ GeglSampler *sampler;
+ GeglBufferIterator *it;
+ float sin_tilt, cos_tilt;
+ float cos_spin, sin_spin;
+ gint index_in, index_out;
+ float xoffset = 0.5;
+ GeglRectangle in_rect = *gegl_operation_source_get_bounding_box (operation, "input");
+ GeglMatrix2 scale_matrix;
+ GeglMatrix2 *scale = NULL;
+ float radius = o->radius;
+
+ format_io = babl_format ("RaGaBaA float");
+ sampler = gegl_buffer_sampler_new (input, format_io, o->sampler_type);
+
+ while (pan > M_PI)
+ pan -= M_PI;
+
+ sin_tilt = sinf (tilt);
+ cos_tilt = cosf (tilt);
+ sin_spin = sinf (spin);
+ cos_spin = cosf (spin);
+
+ width = in_rect.height;
+ height = width;
+ xoffset = ((in_rect.width - height)/height) / 2 + 0.5;
+
+ if (o->sampler_type == GEGL_SAMPLER_NOHALO ||
+ o->sampler_type == GEGL_SAMPLER_LOHALO)
+ scale = &scale_matrix;
+
+ {
+ it = gegl_buffer_iterator_new (output, result, level, format_io, GEGL_BUFFER_WRITE, GEGL_ABYSS_NONE);
+ index_out = 0;
+
+ while (gegl_buffer_iterator_next (it))
+ {
+ gint i;
+ gint n_pixels = it->length;
+ gint x = it->roi->x; /* initial x */
+ gint y = it->roi->y; /* and y coordinates */
+ float *in = it->data[index_in];
+ float *out = it->data[index_out];
+
+ for (i=0; i<n_pixels; i++)
+ {
+ float cx, cy;
+ float u, v;
+
+ u = ((x/width) - xoffset) / zoom;
+ v = ((y/height) - 0.5) / zoom;
+
+ if (scale)
+ {
+#define gegl_unmap(xx,yy,ud,vd) { \
+ float rx, ry;\
+ calc_long_lat (\
+ xx * cos_spin - yy * sin_spin,\
+ yy * cos_spin + xx * sin_spin,\
+ tilt, pan, spin, radius,\
+ sin_tilt, cos_tilt,\
+ &rx, &ry);\
+ ud = rx;vd = ry;}
+ gegl_sampler_compute_scale (scale_matrix, u, v);
+ gegl_unmap(u,v, cx, cy);
+#undef gegl_unmap
+ }
+ else
+ {
+ calc_long_lat (
+ u * cos_spin - v * sin_spin,
+ v * cos_spin + u * sin_spin,
+ tilt, pan, spin, radius,
+ sin_tilt, cos_tilt,
+ &cx, &cy);
+ }
+
+ gegl_sampler_get (sampler, cx * in_rect.width, cy * in_rect.height,
+ scale, out, GEGL_ABYSS_NONE);
+
+ in += 4;
+ out += 4;
+
+ /* update x and y coordinates */
+ x++;
+ if (x >= (it->roi->x + it->roi->width))
+ {
+ x = it->roi->x;
+ y++;
+ }
+ }
+ }
+ }
+
+ g_object_unref (sampler);
+
+ return TRUE;
+}
+
+static void
+gegl_chant_class_init (GeglChantClass *klass)
+{
+ GeglOperationClass *operation_class;
+ GeglOperationFilterClass *filter_class;
+ operation_class = GEGL_OPERATION_CLASS (klass);
+ filter_class = GEGL_OPERATION_FILTER_CLASS (klass);
+
+ filter_class->process = process;
+ operation_class->prepare = prepare;
+ operation_class->get_required_for_output = get_required_for_output;
+
+ gegl_operation_class_set_keys (operation_class,
+ "name" , "gegl:stereographic-projection",
+ "categories" , "misc",
+ "description", _("Perform a stereographics / little planet projection of a equirectangular input
image."),
+ NULL);
+}
+#endif
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 61f3e05..f5d8943 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -93,6 +93,7 @@ operations/common/save.c
operations/common/shift.c
operations/common/snn-mean.c
operations/common/softglow.c
+operations/common/stereographic-projection.c
operations/common/stress.c
operations/common/stretch-contrast.c
operations/common/stretch-contrast-hsv.c
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