1 files changed, 140 insertions, 0 deletions
diff --git a/app/operations/gimpoperationbrightnesscontrast.c b/app/operations/gimpoperationbrightnesscontrast.c
new file mode 100644
index 0000000..1dd9186
--- /dev/null
+++ b/app/operations/gimpoperationbrightnesscontrast.c
@@ -0,0 +1,140 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpoperationbrightnesscontrast.c
+ * Copyright (C) 2012 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 <gegl.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "operations-types.h"
+
+#include "gimpbrightnesscontrastconfig.h"
+#include "gimpoperationbrightnesscontrast.h"
+
+#include "gimp-intl.h"
+
+
+static gboolean gimp_operation_brightness_contrast_process (GeglOperation       *operation,
+                                                            void                *in_buf,
+                                                            void                *out_buf,
+                                                            glong                samples,
+                                                            const GeglRectangle *roi,
+                                                            gint                 level);
+
+
+G_DEFINE_TYPE (GimpOperationBrightnessContrast, gimp_operation_brightness_contrast,
+               GIMP_TYPE_OPERATION_POINT_FILTER)
+
+#define parent_class gimp_operation_brightness_contrast_parent_class
+
+
+static void
+gimp_operation_brightness_contrast_class_init (GimpOperationBrightnessContrastClass *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:brightness-contrast",
+                                 "categories",  "color",
+                                 "description", _("Adjust brightness and contrast"),
+                                 NULL);
+
+  point_class->process         = gimp_operation_brightness_contrast_process;
+
+  g_object_class_install_property (object_class,
+                                   GIMP_OPERATION_POINT_FILTER_PROP_CONFIG,
+                                   g_param_spec_object ("config",
+                                                        "Config",
+                                                        "The config object",
+                                                        GIMP_TYPE_BRIGHTNESS_CONTRAST_CONFIG,
+                                                        G_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT));
+}
+
+static void
+gimp_operation_brightness_contrast_init (GimpOperationBrightnessContrast *self)
+{
+}
+
+static inline gfloat
+gimp_operation_brightness_contrast_map (gfloat  value,
+                                        gdouble brightness,
+                                        gdouble slant)
+{
+  /* apply brightness */
+  if (brightness < 0.0)
+    value = value * (1.0 + brightness);
+  else
+    value = value + ((1.0 - value) * brightness);
+
+  value = (value - 0.5) * slant + 0.5;
+
+  return value;
+}
+
+static gboolean
+gimp_operation_brightness_contrast_process (GeglOperation       *operation,
+                                            void                *in_buf,
+                                            void                *out_buf,
+                                            glong                samples,
+                                            const GeglRectangle *roi,
+                                            gint                 level)
+{
+  GimpOperationPointFilter     *point  = GIMP_OPERATION_POINT_FILTER (operation);
+  GimpBrightnessContrastConfig *config = GIMP_BRIGHTNESS_CONTRAST_CONFIG (point->config);
+  gfloat                       *src    = in_buf;
+  gfloat                       *dest   = out_buf;
+  gdouble                       brightness;
+  gdouble                       slant;
+
+  if (! config)
+    return FALSE;
+
+  brightness = config->brightness / 2.0;
+  slant = tan ((config->contrast + 1) * G_PI_4);
+
+  while (samples--)
+    {
+      dest[RED] = gimp_operation_brightness_contrast_map (src[RED],
+                                                          brightness,
+                                                          slant);
+      dest[GREEN] = gimp_operation_brightness_contrast_map (src[GREEN],
+                                                            brightness,
+                                                            slant);
+      dest[BLUE] = gimp_operation_brightness_contrast_map (src[BLUE],
+                                                           brightness,
+                                                           slant);
+      dest[ALPHA] = src[ALPHA];
+
+      src  += 4;
+      dest += 4;
+    }
+
+  return TRUE;
+}