[gimp/wip/gradient-edit: 20/43] app: add gimp_gradient_segment_range_merge()

[N/A <ell src gnome org>]

commit 12b5440fd30d79413002f61969200a871510af5b
Author: Ell <ell_se yahoo com>
Date:   Sun Jul 30 15:11:02 2017 -0400

    app: add gimp_gradient_segment_range_merge()
    
    ... which merges a segment range into a single segment, that spans
    the entire range, and has the same endpoint colors.  The merged
    segment's midpoint is at its center, and its blend function and
    coloring type are those of the range's segments if they're uniform,
    or the default ones otherwise.

 app/core/gimpgradient.c |   64 +++++++++++++++++++++++++++++++++++++++++++++++
 app/core/gimpgradient.h |    6 ++++
 2 files changed, 70 insertions(+), 0 deletions(-)
---
diff --git a/app/core/gimpgradient.c b/app/core/gimpgradient.c
index 15a40b0..4d99a8e 100644
--- a/app/core/gimpgradient.c
+++ b/app/core/gimpgradient.c
@@ -1792,6 +1792,70 @@ gimp_gradient_segment_range_delete (GimpGradient         *gradient,
 }
 
 void
+gimp_gradient_segment_range_merge (GimpGradient         *gradient,
+                                   GimpGradientSegment  *start_seg,
+                                   GimpGradientSegment  *end_seg,
+                                   GimpGradientSegment **final_start_seg,
+                                   GimpGradientSegment **final_end_seg)
+{
+  GimpGradientSegment *seg;
+
+  g_return_if_fail (GIMP_IS_GRADIENT (gradient));
+
+  if (! end_seg)
+    end_seg = gimp_gradient_segment_get_last (start_seg);
+
+  gimp_data_freeze (GIMP_DATA (gradient));
+
+  /* Copy the end segment's right position and color to the start segment */
+
+  start_seg->right            = end_seg->right;
+  start_seg->right_color_type = end_seg->right_color_type;
+  start_seg->right_color      = end_seg->right_color;
+
+  /* Center the start segment's midpoint */
+
+  start_seg->middle = (start_seg->left + start_seg->right) / 2.0;
+
+  /* Remove range segments past the start segment from the segment list */
+
+  start_seg->next = end_seg->next;
+
+  if (start_seg->next)
+    start_seg->next->prev = start_seg;
+
+  /* Merge the range's blend function and coloring type, and free the rest of
+   * the segments.
+   */
+
+  seg = end_seg;
+
+  while (seg != start_seg)
+    {
+      GimpGradientSegment *prev = seg->prev;
+
+      /* If the blend function and/or coloring type aren't uniform, reset them. */
+
+      if (seg->type != start_seg->type)
+        start_seg->type = GIMP_GRADIENT_SEGMENT_LINEAR;
+
+      if (seg->color != start_seg->color)
+        start_seg->color = GIMP_GRADIENT_SEGMENT_RGB;
+
+      gimp_gradient_segment_free (seg);
+
+      seg = prev;
+    }
+
+  if (final_start_seg)
+    *final_start_seg = start_seg;
+  if (final_end_seg)
+    *final_end_seg = start_seg;
+
+  gimp_data_thaw (GIMP_DATA (gradient));
+}
+
+void
 gimp_gradient_segment_range_recenter_handles (GimpGradient        *gradient,
                                               GimpGradientSegment *start_seg,
                                               GimpGradientSegment *end_seg)
diff --git a/app/core/gimpgradient.h b/app/core/gimpgradient.h
index f9f9987..c550ba1 100644
--- a/app/core/gimpgradient.h
+++ b/app/core/gimpgradient.h
@@ -265,6 +265,12 @@ void    gimp_gradient_segment_range_delete    (GimpGradient         *gradient,
                                                GimpGradientSegment **final_start_seg,
                                                GimpGradientSegment **final_end_seg);
 
+void    gimp_gradient_segment_range_merge     (GimpGradient         *gradient,
+                                               GimpGradientSegment  *start_seg,
+                                               GimpGradientSegment  *end_seg,
+                                               GimpGradientSegment **final_start_seg,
+                                               GimpGradientSegment **final_end_seg);
+
 void    gimp_gradient_segment_range_recenter_handles
                                               (GimpGradient         *gradient,
                                                GimpGradientSegment  *start_seg,