[gegl] workshop: add adjustment mask viz to band-tune

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 348e946cc765b38cc0c9a807362d4930a00e1b4b
Author: Øyvind Kolås <pippin gimp org>
Date:   Sun May 10 17:24:16 2020 +0200

    workshop: add adjustment mask viz to band-tune
    
    This allows letting the live preview show the adjustment as done on a
    gray image instead of the input image, to directly see where it differs
    from the original, the viz is currently done at 4x magnitude of the
    difference applied.

 operations/workshop/band-tune.c | 51 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 46 insertions(+), 5 deletions(-)
---
diff --git a/operations/workshop/band-tune.c b/operations/workshop/band-tune.c
index d12dab49f..b919da66d 100644
--- a/operations/workshop/band-tune.c
+++ b/operations/workshop/band-tune.c
@@ -29,14 +29,30 @@ property_double (radius1, _("Detail band"), 1.1)
 
 property_double (scale1, _("Detail scale, negative values dimnishes signal in detail band, postivie values 
increases signal."), -1.6)
     description(_("Scaling factor for image features at radius, -1 cancels them out 1.0 edge enhances"))
-    value_range (-3.0, 100.0)
+    value_range (-100.0, 100.0)
     ui_range    (-3.0, 3.0)
 
 property_double (bw1, _("Detail bandwidth"), 0.375)
     description("lower values narrower band, higher values wider band - default value presumed to provide 
good band separation.")
     value_range (0.2, 0.6)
 
-property_boolean (show_mask, _("Show Mask"), FALSE)
+
+
+property_double (radius2, _("Edge band"), 10.0)
+    description(_("Features size for edge band, used to compensate for loos of edges in detail pass."))
+    value_range (0.0, 100.0)
+    ui_range    (0.5, 2.0)
+
+property_double (scale2, _("Edge scale, negative values dimnishes signal in detail band, postivie values 
increases signal."), 0.0)
+    description(_("Scaling factor for image features at radius, -1 cancels them out 1.0 edge enhances"))
+    value_range (-100.0, 100.0)
+    ui_range    (-3.0, 3.0)
+
+property_double (bw2, _("Edge bandwidth"), 0.375)
+    description("lower values narrower band, higher values wider band - default value presumed to provide 
good band separation.")
+    value_range (0.2, 0.6)
+
+property_boolean (show_mask, _("Visualize Adjustment Mask"), FALSE)
 
 #else
 
@@ -46,7 +62,7 @@ property_boolean (show_mask, _("Show Mask"), FALSE)
 
 #include "gegl-op.h"
 
-#define N_BANDS 1
+#define N_BANDS 2
 
 typedef struct
 {
@@ -56,6 +72,11 @@ typedef struct
   GeglNode *blur1[N_BANDS];
   GeglNode *blur2[N_BANDS];
   GeglNode *mul[N_BANDS];
+
+  GeglNode *mask_sub;
+  GeglNode *mask_add;
+  GeglNode *mask_mul;
+
   GeglNode *output;
 } State;
 
@@ -88,10 +109,11 @@ update_graph (GeglOperation *operation)
         radius = o->radius1;
         bw = 1.0 - o->bw1;
         break;
-#if 0
+#if 1
       case 1:
         scale = o->scale2;
         radius = o->radius2;
+        bw = 1.0 - o->bw2;
         break;
 #endif
     }
@@ -125,6 +147,21 @@ update_graph (GeglOperation *operation)
     }
   }
 
+  if (o->show_mask)
+  {
+    gegl_node_connect_from (state->mask_sub, "input",
+                            state->input, "output");
+    gegl_node_connect_from (state->mask_sub, "aux",
+                            iter, "output");
+
+    gegl_node_connect_from (state->mask_mul, "input",
+                            state->mask_sub, "output");
+
+    gegl_node_connect_from (state->mask_add, "input",
+                            state->mask_mul, "output");
+    iter = state->mask_add;
+  }
+
   gegl_node_connect_from (state->output, "input",
                           iter,  "output");
 }
@@ -149,6 +186,10 @@ attach (GeglOperation *operation)
     state->blur2[band] = gegl_node_new_child (gegl, "operation", "gegl:gaussian-blur", NULL);
   }
 
+  state->mask_add = gegl_node_new_child (gegl, "operation", "gegl:add", "value", 0.2, NULL);
+  state->mask_sub = gegl_node_new_child (gegl, "operation", "gegl:subtract", NULL);
+  state->mask_mul = gegl_node_new_child (gegl, "operation", "gegl:multiply", "value", 4.0, NULL);
+
   update_graph (operation);
 }
 
@@ -192,7 +233,7 @@ gegl_op_class_init (GeglOpClass *klass)
     "name",        "gegl:band-tune",
     "title",       _("Band tune"),
     "categories",  "enhance:sharpen:denoise",
-    "description", _("Parametric band equalizer"),
+    "description", _("Parametric band equalizer for tuning frequency bands of image, the op provides 
abstracted input parameters that control two difference of gaussians driven band pass filters used as 
adjustments of the image signal."),
     NULL);
 }