summaryrefslogtreecommitdiffstats
path: root/app/operations/layer-modes-legacy/gimpoperationsubtractlegacy.c
diff options
context:
space:
mode:
Diffstat (limited to 'app/operations/layer-modes-legacy/gimpoperationsubtractlegacy.c')
-rw-r--r--app/operations/layer-modes-legacy/gimpoperationsubtractlegacy.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/app/operations/layer-modes-legacy/gimpoperationsubtractlegacy.c b/app/operations/layer-modes-legacy/gimpoperationsubtractlegacy.c
new file mode 100644
index 0000000..0bf3b5e
--- /dev/null
+++ b/app/operations/layer-modes-legacy/gimpoperationsubtractlegacy.c
@@ -0,0 +1,125 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpoperationsubtractmode.c
+ * Copyright (C) 2008 Michael Natterer <mitch@gimp.org>
+ * 2012 Ville Sokk <ville.sokk@gmail.com>
+ *
+ * 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 <gegl-plugin.h>
+
+#include "../operations-types.h"
+
+#include "gimpoperationsubtractlegacy.h"
+
+
+static gboolean gimp_operation_subtract_legacy_process (GeglOperation *op,
+ void *in,
+ void *layer,
+ void *mask,
+ void *out,
+ glong samples,
+ const GeglRectangle *roi,
+ gint level);
+
+
+G_DEFINE_TYPE (GimpOperationSubtractLegacy, gimp_operation_subtract_legacy,
+ GIMP_TYPE_OPERATION_LAYER_MODE)
+
+
+static void
+gimp_operation_subtract_legacy_class_init (GimpOperationSubtractLegacyClass *klass)
+{
+ GeglOperationClass *operation_class = GEGL_OPERATION_CLASS (klass);
+ GimpOperationLayerModeClass *layer_mode_class = GIMP_OPERATION_LAYER_MODE_CLASS (klass);
+
+ gegl_operation_class_set_keys (operation_class,
+ "name", "gimp:subtract-legacy",
+ "description", "GIMP subtract mode operation",
+ NULL);
+
+ layer_mode_class->process = gimp_operation_subtract_legacy_process;
+}
+
+static void
+gimp_operation_subtract_legacy_init (GimpOperationSubtractLegacy *self)
+{
+}
+
+static gboolean
+gimp_operation_subtract_legacy_process (GeglOperation *op,
+ void *in_p,
+ void *layer_p,
+ void *mask_p,
+ void *out_p,
+ glong samples,
+ const GeglRectangle *roi,
+ gint level)
+{
+ GimpOperationLayerMode *layer_mode = (gpointer) op;
+ gfloat *in = in_p;
+ gfloat *out = out_p;
+ gfloat *layer = layer_p;
+ gfloat *mask = mask_p;
+ gfloat opacity = layer_mode->opacity;
+
+ while (samples--)
+ {
+ gfloat comp_alpha, new_alpha;
+
+ comp_alpha = MIN (in[ALPHA], layer[ALPHA]) * opacity;
+ if (mask)
+ comp_alpha *= *mask;
+
+ new_alpha = in[ALPHA] + (1.0f - in[ALPHA]) * comp_alpha;
+
+ if (comp_alpha && new_alpha)
+ {
+ gint b;
+ gfloat ratio = comp_alpha / new_alpha;
+
+ for (b = RED; b < ALPHA; b++)
+ {
+ gfloat comp = in[b] - layer[b];
+ comp = CLAMP (comp, 0.0f, 1.0f);
+
+ out[b] = comp * ratio + in[b] * (1.0f - ratio);
+ }
+ }
+ else
+ {
+ gint b;
+
+ for (b = RED; b < ALPHA; b++)
+ {
+ out[b] = in[b];
+ }
+ }
+
+ out[ALPHA] = in[ALPHA];
+
+ in += 4;
+ layer += 4;
+ out += 4;
+
+ if (mask)
+ mask++;
+ }
+
+ return TRUE;
+}