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-rw-r--r--app/core/gimpcurve-map.c253
1 files changed, 253 insertions, 0 deletions
diff --git a/app/core/gimpcurve-map.c b/app/core/gimpcurve-map.c
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--- /dev/null
+++ b/app/core/gimpcurve-map.c
@@ -0,0 +1,253 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * 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 <string.h>
+
+#include <gdk-pixbuf/gdk-pixbuf.h>
+#include <gegl.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "core-types.h"
+
+#include "gimpcurve.h"
+#include "gimpcurve-map.h"
+
+
+#if defined (HAVE_ISFINITE)
+#define FINITE(x) isfinite(x)
+#elif defined (HAVE_FINITE)
+#define FINITE(x) finite(x)
+#elif defined (G_OS_WIN32)
+#define FINITE(x) _finite(x)
+#else
+#error "no FINITE() implementation available?!"
+#endif
+
+
+enum
+{
+ CURVE_NONE = 0,
+ CURVE_COLORS = 1 << 0,
+ CURVE_RED = 1 << 1,
+ CURVE_GREEN = 1 << 2,
+ CURVE_BLUE = 1 << 3,
+ CURVE_ALPHA = 1 << 4
+};
+
+static guint gimp_curve_get_apply_mask (GimpCurve *curve_colors,
+ GimpCurve *curve_red,
+ GimpCurve *curve_green,
+ GimpCurve *curve_blue,
+ GimpCurve *curve_alpha);
+static inline gdouble gimp_curve_map_value_inline (GimpCurve *curve,
+ gdouble value);
+
+
+gdouble
+gimp_curve_map_value (GimpCurve *curve,
+ gdouble value)
+{
+ g_return_val_if_fail (GIMP_IS_CURVE (curve), 0.0);
+
+ return gimp_curve_map_value_inline (curve, value);
+}
+
+void
+gimp_curve_map_pixels (GimpCurve *curve_colors,
+ GimpCurve *curve_red,
+ GimpCurve *curve_green,
+ GimpCurve *curve_blue,
+ GimpCurve *curve_alpha,
+ gfloat *src,
+ gfloat *dest,
+ glong samples)
+{
+ g_return_if_fail (GIMP_IS_CURVE (curve_colors));
+ g_return_if_fail (GIMP_IS_CURVE (curve_red));
+ g_return_if_fail (GIMP_IS_CURVE (curve_green));
+ g_return_if_fail (GIMP_IS_CURVE (curve_blue));
+ g_return_if_fail (GIMP_IS_CURVE (curve_alpha));
+
+ switch (gimp_curve_get_apply_mask (curve_colors,
+ curve_red,
+ curve_green,
+ curve_blue,
+ curve_alpha))
+ {
+ case CURVE_NONE:
+ memcpy (dest, src, samples * 4 * sizeof (gfloat));
+ break;
+
+ case CURVE_COLORS:
+ while (samples--)
+ {
+ dest[0] = gimp_curve_map_value_inline (curve_colors, src[0]);
+ dest[1] = gimp_curve_map_value_inline (curve_colors, src[1]);
+ dest[2] = gimp_curve_map_value_inline (curve_colors, src[2]);
+ /* don't apply the colors curve to the alpha channel */
+ dest[3] = src[3];
+
+ src += 4;
+ dest += 4;
+ }
+ break;
+
+ case CURVE_RED:
+ while (samples--)
+ {
+ dest[0] = gimp_curve_map_value_inline (curve_red, src[0]);
+ dest[1] = src[1];
+ dest[2] = src[2];
+ dest[3] = src[3];
+
+ src += 4;
+ dest += 4;
+ }
+ break;
+
+ case CURVE_GREEN:
+ while (samples--)
+ {
+ dest[0] = src[0];
+ dest[1] = gimp_curve_map_value_inline (curve_green, src[1]);
+ dest[2] = src[2];
+ dest[3] = src[3];
+
+ src += 4;
+ dest += 4;
+ }
+ break;
+
+ case CURVE_BLUE:
+ while (samples--)
+ {
+ dest[0] = src[0];
+ dest[1] = src[1];
+ dest[2] = gimp_curve_map_value_inline (curve_blue, src[2]);
+ dest[3] = src[3];
+
+ src += 4;
+ dest += 4;
+ }
+ break;
+
+ case CURVE_ALPHA:
+ while (samples--)
+ {
+ dest[0] = src[0];
+ dest[1] = src[1];
+ dest[2] = src[2];
+ dest[3] = gimp_curve_map_value_inline (curve_alpha, src[3]);
+
+ src += 4;
+ dest += 4;
+ }
+ break;
+
+ case (CURVE_RED | CURVE_GREEN | CURVE_BLUE):
+ while (samples--)
+ {
+ dest[0] = gimp_curve_map_value_inline (curve_red, src[0]);
+ dest[1] = gimp_curve_map_value_inline (curve_green, src[1]);
+ dest[2] = gimp_curve_map_value_inline (curve_blue, src[2]);
+ dest[3] = src[3];
+
+ src += 4;
+ dest += 4;
+ }
+ break;
+
+ default:
+ while (samples--)
+ {
+ dest[0] = gimp_curve_map_value_inline (curve_colors,
+ gimp_curve_map_value_inline (curve_red,
+ src[0]));
+ dest[1] = gimp_curve_map_value_inline (curve_colors,
+ gimp_curve_map_value_inline (curve_green,
+ src[1]));
+ dest[2] = gimp_curve_map_value_inline (curve_colors,
+ gimp_curve_map_value_inline (curve_blue,
+ src[2]));
+ /* don't apply the colors curve to the alpha channel */
+ dest[3] = gimp_curve_map_value_inline (curve_alpha, src[3]);
+
+ src += 4;
+ dest += 4;
+ }
+ break;
+ }
+}
+
+static guint
+gimp_curve_get_apply_mask (GimpCurve *curve_colors,
+ GimpCurve *curve_red,
+ GimpCurve *curve_green,
+ GimpCurve *curve_blue,
+ GimpCurve *curve_alpha)
+{
+ return ((gimp_curve_is_identity (curve_colors) ? 0 : CURVE_COLORS) |
+ (gimp_curve_is_identity (curve_red) ? 0 : CURVE_RED) |
+ (gimp_curve_is_identity (curve_green) ? 0 : CURVE_GREEN) |
+ (gimp_curve_is_identity (curve_blue) ? 0 : CURVE_BLUE) |
+ (gimp_curve_is_identity (curve_alpha) ? 0 : CURVE_ALPHA));
+}
+
+static inline gdouble
+gimp_curve_map_value_inline (GimpCurve *curve,
+ gdouble value)
+{
+ if (curve->identity)
+ {
+ if (FINITE (value))
+ return CLAMP (value, 0.0, 1.0);
+
+ return 0.0;
+ }
+
+ /* check for known values first, so broken values like NaN
+ * delivered by broken drivers don't run into the interpolation
+ * code
+ */
+ if (value > 0.0 && value < 1.0) /* interpolate the curve */
+ {
+ gdouble f;
+ gint index;
+
+ /* map value to the sample space */
+ value = value * (curve->n_samples - 1);
+
+ /* determine the indices of the closest sample points */
+ index = (gint) value;
+
+ /* calculate the position between the sample points */
+ f = value - index;
+
+ return (1.0 - f) * curve->samples[index] + f * curve->samples[index + 1];
+ }
+ else if (value >= 1.0)
+ {
+ return curve->samples[curve->n_samples - 1];
+ }
+ else
+ {
+ return curve->samples[0];
+ }
+}