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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 16:23:22 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 16:23:22 +0000
commite42129241681dde7adae7d20697e7b421682fbb4 (patch)
treeaf1fe815a5e639e68e59fabd8395ec69458b3e5e /app/operations/layer-modes/gimpoperationlayermode-blend.c
parentInitial commit. (diff)
downloadgimp-e42129241681dde7adae7d20697e7b421682fbb4.tar.xz
gimp-e42129241681dde7adae7d20697e7b421682fbb4.zip
Adding upstream version 2.10.22.upstream/2.10.22upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'app/operations/layer-modes/gimpoperationlayermode-blend.c')
-rw-r--r--app/operations/layer-modes/gimpoperationlayermode-blend.c1215
1 files changed, 1215 insertions, 0 deletions
diff --git a/app/operations/layer-modes/gimpoperationlayermode-blend.c b/app/operations/layer-modes/gimpoperationlayermode-blend.c
new file mode 100644
index 0000000..e107462
--- /dev/null
+++ b/app/operations/layer-modes/gimpoperationlayermode-blend.c
@@ -0,0 +1,1215 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpoperationlayermode-blend.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ * 2017 Øyvind Kolås <pippin@gimp.org>
+ * 2017 Ell
+ *
+ * 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 <cairo.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+
+#include "libgimpcolor/gimpcolor.h"
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "../operations-types.h"
+
+#include "gimpoperationlayermode-blend.h"
+
+
+#define EPSILON 1e-6f
+
+#define SAFE_DIV_MIN EPSILON
+#define SAFE_DIV_MAX (1.0f / SAFE_DIV_MIN)
+
+
+/* local function prototypes */
+
+static inline gfloat safe_div (gfloat a,
+ gfloat b);
+
+
+/* private functions */
+
+
+/* returns a / b, clamped to [-SAFE_DIV_MAX, SAFE_DIV_MAX].
+ * if -SAFE_DIV_MIN <= a <= SAFE_DIV_MIN, returns 0.
+ */
+static inline gfloat
+safe_div (gfloat a,
+ gfloat b)
+{
+ gfloat result = 0.0f;
+
+ if (fabsf (a) > SAFE_DIV_MIN)
+ {
+ result = a / b;
+ result = CLAMP (result, -SAFE_DIV_MAX, SAFE_DIV_MAX);
+ }
+
+ return result;
+}
+
+
+/* public functions */
+
+
+/* non-subtractive blending functions. these functions must set comp[ALPHA]
+ * to the same value as layer[ALPHA]. when in[ALPHA] or layer[ALPHA] are
+ * zero, the value of comp[RED..BLUE] is unconstrained (in particular, it may
+ * be NaN).
+ */
+
+
+void /* aka linear_dodge */
+gimp_operation_layer_mode_blend_addition (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c] + layer[c];
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_burn (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = 1.0f - safe_div (1.0f - in[c], layer[c]);
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_darken_only (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = MIN (in[c], layer[c]);
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_difference (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = fabsf (in[c] - layer[c]);
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_divide (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = safe_div (in[c], layer[c]);
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_dodge (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = safe_div (in[c], 1.0f - layer[c]);
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_exclusion (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = 0.5f - 2.0f * (in[c] - 0.5f) * (layer[c] - 0.5f);
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_grain_extract (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c] - layer[c] + 0.5f;
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_grain_merge (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c] + layer[c] - 0.5f;
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_hard_mix (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c] + layer[c] < 1.0f ? 0.0f : 1.0f;
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_hardlight (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ {
+ gfloat val;
+
+ if (layer[c] > 0.5f)
+ {
+ val = (1.0f - in[c]) * (1.0f - (layer[c] - 0.5f) * 2.0f);
+ val = MIN (1.0f - val, 1.0f);
+ }
+ else
+ {
+ val = in[c] * (layer[c] * 2.0f);
+ val = MIN (val, 1.0f);
+ }
+
+ comp[c] = val;
+ }
+ }
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_hsl_color (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gfloat dest_min, dest_max, dest_l;
+ gfloat src_min, src_max, src_l;
+
+ dest_min = MIN (in[0], in[1]);
+ dest_min = MIN (dest_min, in[2]);
+ dest_max = MAX (in[0], in[1]);
+ dest_max = MAX (dest_max, in[2]);
+ dest_l = (dest_min + dest_max) / 2.0f;
+
+ src_min = MIN (layer[0], layer[1]);
+ src_min = MIN (src_min, layer[2]);
+ src_max = MAX (layer[0], layer[1]);
+ src_max = MAX (src_max, layer[2]);
+ src_l = (src_min + src_max) / 2.0f;
+
+ if (fabs (src_l) > EPSILON && fabs (1.0 - src_l) > EPSILON)
+ {
+ gboolean dest_high;
+ gboolean src_high;
+ gfloat ratio;
+ gfloat offset;
+ gint c;
+
+ dest_high = dest_l > 0.5f;
+ src_high = src_l > 0.5f;
+
+ dest_l = MIN (dest_l, 1.0f - dest_l);
+ src_l = MIN (src_l, 1.0f - src_l);
+
+ ratio = dest_l / src_l;
+
+ offset = 0.0f;
+ if (dest_high) offset += 1.0f - 2.0f * dest_l;
+ if (src_high) offset += 2.0f * dest_l - ratio;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = layer[c] * ratio + offset;
+ }
+ else
+ {
+ comp[RED] = dest_l;
+ comp[GREEN] = dest_l;
+ comp[BLUE] = dest_l;
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_hsv_hue (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gfloat src_min, src_max, src_delta;
+ gfloat dest_min, dest_max, dest_delta, dest_s;
+
+ src_min = MIN (layer[0], layer[1]);
+ src_min = MIN (src_min, layer[2]);
+ src_max = MAX (layer[0], layer[1]);
+ src_max = MAX (src_max, layer[2]);
+ src_delta = src_max - src_min;
+
+ if (src_delta > EPSILON)
+ {
+ gfloat ratio;
+ gfloat offset;
+ gint c;
+
+ dest_min = MIN (in[0], in[1]);
+ dest_min = MIN (dest_min, in[2]);
+ dest_max = MAX (in[0], in[1]);
+ dest_max = MAX (dest_max, in[2]);
+ dest_delta = dest_max - dest_min;
+ dest_s = dest_max ? dest_delta / dest_max : 0.0f;
+
+ ratio = dest_s * dest_max / src_delta;
+ offset = dest_max - src_max * ratio;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = layer[c] * ratio + offset;
+ }
+ else
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c];
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_hsv_saturation (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gfloat src_min, src_max, src_delta, src_s;
+ gfloat dest_min, dest_max, dest_delta;
+
+ dest_min = MIN (in[0], in[1]);
+ dest_min = MIN (dest_min, in[2]);
+ dest_max = MAX (in[0], in[1]);
+ dest_max = MAX (dest_max, in[2]);
+ dest_delta = dest_max - dest_min;
+
+ if (dest_delta > EPSILON)
+ {
+ gfloat ratio;
+ gfloat offset;
+ gint c;
+
+ src_min = MIN (layer[0], layer[1]);
+ src_min = MIN (src_min, layer[2]);
+ src_max = MAX (layer[0], layer[1]);
+ src_max = MAX (src_max, layer[2]);
+ src_delta = src_max - src_min;
+ src_s = src_max ? src_delta / src_max : 0.0f;
+
+ ratio = src_s * dest_max / dest_delta;
+ offset = (1.0f - ratio) * dest_max;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c] * ratio + offset;
+ }
+ else
+ {
+ comp[RED] = dest_max;
+ comp[GREEN] = dest_max;
+ comp[BLUE] = dest_max;
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_hsv_value (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gfloat dest_v;
+ gfloat src_v;
+
+ dest_v = MAX (in[0], in[1]);
+ dest_v = MAX (dest_v, in[2]);
+
+ src_v = MAX (layer[0], layer[1]);
+ src_v = MAX (src_v, layer[2]);
+
+ if (fabs (dest_v) > EPSILON)
+ {
+ gfloat ratio = src_v / dest_v;
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c] * ratio;
+ }
+ else
+ {
+ comp[RED] = src_v;
+ comp[GREEN] = src_v;
+ comp[BLUE] = src_v;
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_lch_chroma (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gfloat A1 = in[1];
+ gfloat B1 = in[2];
+ gfloat c1 = hypotf (A1, B1);
+
+ if (c1 > EPSILON)
+ {
+ gfloat A2 = layer[1];
+ gfloat B2 = layer[2];
+ gfloat c2 = hypotf (A2, B2);
+ gfloat A = c2 * A1 / c1;
+ gfloat B = c2 * B1 / c1;
+
+ comp[0] = in[0];
+ comp[1] = A;
+ comp[2] = B;
+ }
+ else
+ {
+ comp[0] = in[0];
+ comp[1] = in[1];
+ comp[2] = in[2];
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_lch_color (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ comp[0] = in[0];
+ comp[1] = layer[1];
+ comp[2] = layer[2];
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_lch_hue (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gfloat A2 = layer[1];
+ gfloat B2 = layer[2];
+ gfloat c2 = hypotf (A2, B2);
+
+ if (c2 > EPSILON)
+ {
+ gfloat A1 = in[1];
+ gfloat B1 = in[2];
+ gfloat c1 = hypotf (A1, B1);
+ gfloat A = c1 * A2 / c2;
+ gfloat B = c1 * B2 / c2;
+
+ comp[0] = in[0];
+ comp[1] = A;
+ comp[2] = B;
+ }
+ else
+ {
+ comp[0] = in[0];
+ comp[1] = in[1];
+ comp[2] = in[2];
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_lch_lightness (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ comp[0] = layer[0];
+ comp[1] = in[1];
+ comp[2] = in[2];
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_lighten_only (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = MAX (in[c], layer[c]);
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_linear_burn (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c] + layer[c] - 1.0f;
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+/* added according to:
+ http://www.deepskycolors.com/archivo/2010/04/21/formulas-for-Photoshop-blending-modes.html */
+void
+gimp_operation_layer_mode_blend_linear_light (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ {
+ gfloat val;
+
+ if (layer[c] <= 0.5f)
+ val = in[c] + 2.0f * layer[c] - 1.0f;
+ else
+ val = in[c] + 2.0f * (layer[c] - 0.5f);
+
+ comp[c] = val;
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_luma_darken_only (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gfloat dest_luminance;
+ gfloat src_luminance;
+ gint c;
+
+ dest_luminance = GIMP_RGB_LUMINANCE (in[0], in[1], in[2]);
+ src_luminance = GIMP_RGB_LUMINANCE (layer[0], layer[1], layer[2]);
+
+ if (dest_luminance <= src_luminance)
+ {
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c];
+ }
+ else
+ {
+ for (c = 0; c < 3; c++)
+ comp[c] = layer[c];
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_luma_lighten_only (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gfloat dest_luminance;
+ gfloat src_luminance;
+ gint c;
+
+ dest_luminance = GIMP_RGB_LUMINANCE (in[0], in[1], in[2]);
+ src_luminance = GIMP_RGB_LUMINANCE (layer[0], layer[1], layer[2]);
+
+ if (dest_luminance >= src_luminance)
+ {
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c];
+ }
+ else
+ {
+ for (c = 0; c < 3; c++)
+ comp[c] = layer[c];
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_luminance (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ static const Babl *fish;
+ gfloat *scratch;
+ gfloat *in_Y;
+ gfloat *layer_Y;
+
+ if (! fish)
+ fish = babl_fish ("RGBA float", "Y float");
+
+ scratch = gegl_scratch_new (gfloat, 2 * samples);
+
+ in_Y = scratch;
+ layer_Y = scratch + samples;
+
+ babl_process (fish, in, in_Y, samples);
+ babl_process (fish, layer, layer_Y, samples);
+
+ while (samples--)
+ {
+ if (layer[ALPHA] != 0.0f && in[ALPHA] != 0.0f)
+ {
+ gfloat ratio = safe_div (layer_Y[0], in_Y[0]);
+ gint c;
+
+ for (c = 0; c < 3; c ++)
+ comp[c] = in[c] * ratio;
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ in += 4;
+ layer += 4;
+ in_Y ++;
+ layer_Y ++;
+ }
+
+ gegl_scratch_free (scratch);
+}
+
+void
+gimp_operation_layer_mode_blend_multiply (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c] * layer[c];
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_overlay (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ {
+ gfloat val;
+
+ if (in[c] < 0.5f)
+ val = 2.0f * in[c] * layer[c];
+ else
+ val = 1.0f - 2.0f * (1.0f - layer[c]) * (1.0f - in[c]);
+
+ comp[c] = val;
+ }
+ }
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+/* added according to:
+ http://www.deepskycolors.com/archivo/2010/04/21/formulas-for-Photoshop-blending-modes.html */
+void
+gimp_operation_layer_mode_blend_pin_light (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ {
+ gfloat val;
+
+ if (layer[c] > 0.5f)
+ val = MAX(in[c], 2.0f * (layer[c] - 0.5f));
+ else
+ val = MIN(in[c], 2.0f * layer[c]);
+
+ comp[c] = val;
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_screen (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = 1.0f - (1.0f - in[c]) * (1.0f - layer[c]);
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_softlight (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ {
+ gfloat multiply = in[c] * layer[c];
+ gfloat screen = 1.0f - (1.0f - in[c]) * (1.0f - layer[c]);
+ gfloat val = (1.0f - in[c]) * multiply + in[c] * screen;
+
+ comp[c] = val;
+ }
+ }
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+void
+gimp_operation_layer_mode_blend_subtract (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = in[c] - layer[c];
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+/* added according to:
+ http://www.simplefilter.de/en/basics/mixmods.html */
+void
+gimp_operation_layer_mode_blend_vivid_light (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ gint c;
+
+ for (c = 0; c < 3; c++)
+ {
+ gfloat val;
+
+ if (layer[c] <= 0.5f)
+ {
+ val = 1.0f - safe_div (1.0f - in[c], 2.0f * layer[c]);
+ val = MAX (val, 0.0f);
+ }
+ else
+ {
+ val = safe_div (in[c], 2.0f * (1.0f - layer[c]));
+ val = MIN (val, 1.0f);
+ }
+
+ comp[c] = val;
+ }
+ }
+
+ comp[ALPHA] = layer[ALPHA];
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}
+
+
+/* subtractive blending functions. these functions must set comp[ALPHA] to
+ * the modified alpha of the overlapping content, as a fraction of the
+ * original overlapping content (i.e., an alpha of 1.0 specifies that no
+ * content is subtracted.) when in[ALPHA] or layer[ALPHA] are zero, the value
+ * of comp[RED..BLUE] is unconstrained (in particular, it may be NaN).
+ */
+
+
+void
+gimp_operation_layer_mode_blend_color_erase (GeglOperation *operation,
+ const gfloat *in,
+ const gfloat *layer,
+ gfloat *comp,
+ gint samples)
+{
+ while (samples--)
+ {
+ if (in[ALPHA] != 0.0f && layer[ALPHA] != 0.0f)
+ {
+ const gfloat *color = in;
+ const gfloat *bgcolor = layer;
+ gfloat alpha;
+ gint c;
+
+ alpha = 0.0f;
+
+ for (c = 0; c < 3; c++)
+ {
+ gfloat col = CLAMP (color[c], 0.0f, 1.0f);
+ gfloat bgcol = CLAMP (bgcolor[c], 0.0f, 1.0f);
+
+ if (fabs (col - bgcol) > EPSILON)
+ {
+ gfloat a;
+
+ if (col > bgcol)
+ a = (col - bgcol) / (1.0f - bgcol);
+ else
+ a = (bgcol - col) / bgcol;
+
+ alpha = MAX (alpha, a);
+ }
+ }
+
+ if (alpha > EPSILON)
+ {
+ gfloat alpha_inv = 1.0f / alpha;
+
+ for (c = 0; c < 3; c++)
+ comp[c] = (color[c] - bgcolor[c]) * alpha_inv + bgcolor[c];
+ }
+ else
+ {
+ comp[RED] = comp[GREEN] = comp[BLUE] = 0.0f;
+ }
+
+ comp[ALPHA] = alpha;
+ }
+ else
+ comp[ALPHA] = 0.0f;
+
+ comp += 4;
+ layer += 4;
+ in += 4;
+ }
+}