summaryrefslogtreecommitdiffstats
path: root/app/operations/gimpoperationlevels.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--app/operations/gimpoperationlevels.c208
1 files changed, 208 insertions, 0 deletions
diff --git a/app/operations/gimpoperationlevels.c b/app/operations/gimpoperationlevels.c
new file mode 100644
index 0000000..1bf0b06
--- /dev/null
+++ b/app/operations/gimpoperationlevels.c
@@ -0,0 +1,208 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpoperationlevels.c
+ * Copyright (C) 2007 Michael Natterer <mitch@gimp.org>
+ *
+ * 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 "config.h"
+
+#include <cairo.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+#include <gegl.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "operations-types.h"
+
+#include "gimplevelsconfig.h"
+#include "gimpoperationlevels.h"
+
+#include "gimp-intl.h"
+
+
+static gboolean gimp_operation_levels_process (GeglOperation *operation,
+ void *in_buf,
+ void *out_buf,
+ glong samples,
+ const GeglRectangle *roi,
+ gint level);
+
+
+G_DEFINE_TYPE (GimpOperationLevels, gimp_operation_levels,
+ GIMP_TYPE_OPERATION_POINT_FILTER)
+
+#define parent_class gimp_operation_levels_parent_class
+
+
+static void
+gimp_operation_levels_class_init (GimpOperationLevelsClass *klass)
+{
+ GObjectClass *object_class = G_OBJECT_CLASS (klass);
+ GeglOperationClass *operation_class = GEGL_OPERATION_CLASS (klass);
+ GeglOperationPointFilterClass *point_class = GEGL_OPERATION_POINT_FILTER_CLASS (klass);
+
+ object_class->set_property = gimp_operation_point_filter_set_property;
+ object_class->get_property = gimp_operation_point_filter_get_property;
+
+ gegl_operation_class_set_keys (operation_class,
+ "name", "gimp:levels",
+ "categories", "color",
+ "description", _("Adjust color levels"),
+ NULL);
+
+ point_class->process = gimp_operation_levels_process;
+
+ g_object_class_install_property (object_class,
+ GIMP_OPERATION_POINT_FILTER_PROP_LINEAR,
+ g_param_spec_boolean ("linear",
+ "Linear",
+ "Whether to operate on linear RGB",
+ FALSE,
+ G_PARAM_READWRITE));
+
+ g_object_class_install_property (object_class,
+ GIMP_OPERATION_POINT_FILTER_PROP_CONFIG,
+ g_param_spec_object ("config",
+ "Config",
+ "The config object",
+ GIMP_TYPE_LEVELS_CONFIG,
+ G_PARAM_READWRITE |
+ G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_operation_levels_init (GimpOperationLevels *self)
+{
+}
+
+static inline gdouble
+gimp_operation_levels_map (gdouble value,
+ gdouble low_input,
+ gdouble high_input,
+ gboolean clamp_input,
+ gdouble inv_gamma,
+ gdouble low_output,
+ gdouble high_output,
+ gboolean clamp_output)
+{
+ /* determine input intensity */
+ if (high_input != low_input)
+ value = (value - low_input) / (high_input - low_input);
+ else
+ value = (value - low_input);
+
+ if (clamp_input)
+ value = CLAMP (value, 0.0, 1.0);
+
+ if (inv_gamma != 1.0 && value > 0)
+ value = pow (value, inv_gamma);
+
+ /* determine the output intensity */
+ if (high_output >= low_output)
+ value = value * (high_output - low_output) + low_output;
+ else if (high_output < low_output)
+ value = low_output - value * (low_output - high_output);
+
+ if (clamp_output)
+ value = CLAMP (value, 0.0, 1.0);
+
+ return value;
+}
+
+static gboolean
+gimp_operation_levels_process (GeglOperation *operation,
+ void *in_buf,
+ void *out_buf,
+ glong samples,
+ const GeglRectangle *roi,
+ gint level)
+{
+ GimpOperationPointFilter *point = GIMP_OPERATION_POINT_FILTER (operation);
+ GimpLevelsConfig *config = GIMP_LEVELS_CONFIG (point->config);
+ gfloat *src = in_buf;
+ gfloat *dest = out_buf;
+ gfloat inv_gamma[5];
+ gint channel;
+
+ if (! config)
+ return FALSE;
+
+ for (channel = 0; channel < 5; channel++)
+ {
+ g_return_val_if_fail (config->gamma[channel] != 0.0, FALSE);
+
+ inv_gamma[channel] = 1.0 / config->gamma[channel];
+ }
+
+ while (samples--)
+ {
+ for (channel = 0; channel < 4; channel++)
+ {
+ gdouble value;
+
+ value = gimp_operation_levels_map (src[channel],
+ config->low_input[channel + 1],
+ config->high_input[channel + 1],
+ config->clamp_input,
+ inv_gamma[channel + 1],
+ config->low_output[channel + 1],
+ config->high_output[channel + 1],
+ config->clamp_output);
+
+ /* don't apply the overall curve to the alpha channel */
+ if (channel != ALPHA)
+ value = gimp_operation_levels_map (value,
+ config->low_input[0],
+ config->high_input[0],
+ config->clamp_input,
+ inv_gamma[0],
+ config->low_output[0],
+ config->high_output[0],
+ config->clamp_output);
+
+ dest[channel] = value;
+ }
+
+ src += 4;
+ dest += 4;
+ }
+
+ return TRUE;
+}
+
+
+/* public functions */
+
+gdouble
+gimp_operation_levels_map_input (GimpLevelsConfig *config,
+ GimpHistogramChannel channel,
+ gdouble value)
+{
+ g_return_val_if_fail (GIMP_IS_LEVELS_CONFIG (config), 0.0);
+
+ /* determine input intensity */
+ if (config->high_input[channel] != config->low_input[channel])
+ value = ((value - config->low_input[channel]) /
+ (config->high_input[channel] - config->low_input[channel]));
+ else
+ value = (value - config->low_input[channel]);
+
+ if (config->gamma[channel] != 0.0 && value > 0.0)
+ value = pow (value, 1.0 / config->gamma[channel]);
+
+ return value;
+}