GPencil: Add Layer and Material to Blank objects

Instead to create only the Blank object, now a new Layer and a simple material is added.

This is a common request of artists.

Reviewed By: mendio, pepeland

Differential Revision: https://developer.blender.org/D11110

source/blender/editors/gpencil/CMakeLists.txt

@@ -36,6 +36,7 @@ set(SRC
   annotate_paint.c
   drawgpencil.c
   editaction_gpencil.c
+  gpencil_add_blank.c
   gpencil_add_lineart.c
   gpencil_add_monkey.c
   gpencil_add_stroke.c

source/blender/editors/gpencil/gpencil_add_blank.c

@@ -0,0 +1,101 @@
+/*
+ * 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 2
+ * 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, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2017 Blender Foundation
+ * This is a new part of Blender
+ */
+
+/** \file
+ * \ingroup edgpencil
+ */
+
+#include "BLI_math.h"
+#include "BLI_utildefines.h"
+
+#include "DNA_gpencil_types.h"
+#include "DNA_material_types.h"
+#include "DNA_object_types.h"
+#include "DNA_scene_types.h"
+
+#include "BKE_context.h"
+#include "BKE_gpencil.h"
+#include "BKE_gpencil_geom.h"
+#include "BKE_main.h"
+#include "BKE_material.h"
+
+#include "DEG_depsgraph.h"
+
+#include "ED_gpencil.h"
+
+/* Definition of the most important info from a color */
+typedef struct ColorTemplate {
+  const char *name;
+  float line[4];
+  float fill[4];
+} ColorTemplate;
+
+/* Add color an ensure duplications (matched by name) */
+static int gpencil_stroke_material(Main *bmain, Object *ob, const ColorTemplate *pct)
+{
+  int index;
+  Material *ma = BKE_gpencil_object_material_ensure_by_name(bmain, ob, pct->name, &index);
+
+  copy_v4_v4(ma->gp_style->stroke_rgba, pct->line);
+  srgb_to_linearrgb_v4(ma->gp_style->stroke_rgba, ma->gp_style->stroke_rgba);
+
+  copy_v4_v4(ma->gp_style->fill_rgba, pct->fill);
+  srgb_to_linearrgb_v4(ma->gp_style->fill_rgba, ma->gp_style->fill_rgba);
+
+  return index;
+}
+
+/* ***************************************************************** */
+/* Stroke Geometry */
+
+/* ***************************************************************** */
+/* Color Data */
+
+static const ColorTemplate gp_stroke_material_black = {
+    "Black",
+    {0.0f, 0.0f, 0.0f, 1.0f},
+    {0.0f, 0.0f, 0.0f, 0.0f},
+};
+
+/* ***************************************************************** */
+/* Blank API */
+
+/* Add a Simple empty object with one layer and one color. */
+void ED_gpencil_create_blank(bContext *C, Object *ob, float mat[4][4])
+{
+  Main *bmain = CTX_data_main(C);
+  Scene *scene = CTX_data_scene(C);
+  bGPdata *gpd = (bGPdata *)ob->data;
+
+  /* create colors */
+  int color_black = gpencil_stroke_material(bmain, ob, &gp_stroke_material_black);
+
+  /* set first color as active and in brushes */
+  ob->actcol = color_black + 1;
+
+  /* layers */
+  bGPDlayer *layer = BKE_gpencil_layer_addnew(gpd, "GP_Layer", true);
+
+  /* frames */
+  BKE_gpencil_frame_addnew(layer, CFRA);
+
+  /* update depsgraph */
+  DEG_id_tag_update(&gpd->id, ID_RECALC_TRANSFORM | ID_RECALC_GEOMETRY);
+  gpd->flag |= GP_DATA_CACHE_IS_DIRTY;
+}

source/blender/editors/include/ED_gpencil.h

@@ -249,6 +249,7 @@ void ED_gpencil_brush_draw_eraser(struct Brush *brush, int x, int y);
 
 /* ----------- Add Primitive Utilities -------------- */
 
+void ED_gpencil_create_blank(struct bContext *C, struct Object *ob, float mat[4][4]);
 void ED_gpencil_create_monkey(struct bContext *C, struct Object *ob, float mat[4][4]);
 void ED_gpencil_create_stroke(struct bContext *C, struct Object *ob, float mat[4][4]);
 void ED_gpencil_create_lineart(struct bContext *C, struct Object *ob);

source/blender/editors/object/object_add.c

@@ -1321,12 +1321,14 @@ static int object_gpencil_add_exec(bContext *C, wmOperator *op)
   if (!ED_object_add_generic_get_opts(C, op, 'Y', loc, rot, NULL, NULL, &local_view_bits, NULL)) {
     return OPERATOR_CANCELLED;
   }
-  /* add new object if not currently editing a GP object,
-   * or if "empty" was chosen (i.e. user wants a blank GP canvas)
-   */
-  if ((gpd == NULL) || (GPENCIL_ANY_MODE(gpd) == false) || (type == GP_EMPTY)) {
+  /* Add new object if not currently editing a GP object. */
+  if ((gpd == NULL) || (GPENCIL_ANY_MODE(gpd) == false)) {
     const char *ob_name = NULL;
     switch (type) {
+      case GP_EMPTY: {
+        ob_name = "GPencil";
+        break;
+      }
       case GP_MONKEY: {
         ob_name = "Suzanne";
         break;
@@ -1356,6 +1358,13 @@ static int object_gpencil_add_exec(bContext *C, wmOperator *op)
 
   /* create relevant geometry */
   switch (type) {
+    case GP_EMPTY: {
+      float mat[4][4];
+
+      ED_object_new_primitive_matrix(C, ob, loc, rot, mat);
+      ED_gpencil_create_blank(C, ob, mat);
+      break;
+    }
     case GP_STROKE: {
       float radius = RNA_float_get(op->ptr, "radius");
       float mat[4][4];
@@ -1423,10 +1432,6 @@ static int object_gpencil_add_exec(bContext *C, wmOperator *op)
       /* Stroke object is drawn in front of meshes by default. */
       ob->dtx |= OB_DRAW_IN_FRONT;
     }
-    case GP_EMPTY:
-      /* do nothing */
-      break;
-
     default:
       BKE_report(op->reports, RPT_WARNING, "Not implemented");
       break;