GPencil: Merge GSoC curve edit mode

Differential Revision: https://developer.blender.org/D8660

This patch is the result of the GSoC 2020 "Editing Grease Pencil Strokes
Using Curves" project. It adds a submode to greasepencil edit mode that
allows for the transformation of greasepencil strokes using bezier
curves. More information about the project can be found
here: https://wiki.blender.org/wiki/User:Filedescriptor/GSoC_2020.

1 files changed, 57 insertions, 27 deletions

diff --git a/source/blender/blenkernel/intern/gpencil_geom.c b/source/blender/blenkernel/intern/gpencil_geom.c
index ff7dde27db8..d2cfb36cb15 100644
--- a/source/blender/blenkernel/intern/gpencil_geom.c
+++ b/source/blender/blenkernel/intern/gpencil_geom.c
@@ -45,8 +45,11 @@
 #include "DNA_meshdata_types.h"
 #include "DNA_scene_types.h"
 
+#include "BLT_translation.h"
+
 #include "BKE_deform.h"
 #include "BKE_gpencil.h"
+#include "BKE_gpencil_curve.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_main.h"
 #include "BKE_material.h"
@@ -415,10 +418,11 @@ static void stroke_interpolate_deform_weights(
 
 /**
  * Resample a stroke
+ * \param gpd: Grease pencil data-block
  * \param gps: Stroke to sample
  * \param dist: Distance of one segment
  */
-bool BKE_gpencil_stroke_sample(bGPDstroke *gps, const float dist, const bool select)
+bool BKE_gpencil_stroke_sample(bGPdata *gpd, bGPDstroke *gps, const float dist, const bool select)
 {
   bGPDspoint *pt = gps->points;
   bGPDspoint *pt1 = NULL;
@@ -515,7 +519,7 @@ bool BKE_gpencil_stroke_sample(bGPDstroke *gps, const float dist, const bool sel
   gps->totpoints = i;
 
   /* Calc geometry data. */
-  BKE_gpencil_stroke_geometry_update(gps);
+  BKE_gpencil_stroke_geometry_update(gpd, gps);
 
   return true;
 }
@@ -628,13 +632,15 @@ bool BKE_gpencil_stroke_trim_points(bGPDstroke *gps, const int index_from, const
 
 /**
  * Split stroke.
+ * \param gpd: Grease pencil data-block
  * \param gpf: Grease pencil frame
  * \param gps: Grease pencil original stroke
  * \param before_index: Position of the point to split
  * \param remaining_gps: Secondary stroke after split.
  * \return True if the split was done
  */
-bool BKE_gpencil_stroke_split(bGPDframe *gpf,
+bool BKE_gpencil_stroke_split(bGPdata *gpd,
+                              bGPDframe *gpf,
                               bGPDstroke *gps,
                               const int before_index,
                               bGPDstroke **remaining_gps)
@@ -684,7 +690,7 @@ bool BKE_gpencil_stroke_split(bGPDframe *gpf,
    * Keep the end point. */
 
   BKE_gpencil_stroke_trim_points(gps, 0, old_count);
-  BKE_gpencil_stroke_geometry_update(gps);
+  BKE_gpencil_stroke_geometry_update(gpd, gps);
   return true;
 }
 
@@ -1273,14 +1279,31 @@ void BKE_gpencil_stroke_uv_update(bGPDstroke *gps)
 
 /**
  * Recalc all internal geometry data for the stroke
+ * \param gpd: Grease pencil data-block
  * \param gps: Grease pencil stroke
  */
-void BKE_gpencil_stroke_geometry_update(bGPDstroke *gps)
+void BKE_gpencil_stroke_geometry_update(bGPdata *gpd, bGPDstroke *gps)
 {
   if (gps == NULL) {
     return;
   }
 
+  if (gps->editcurve != NULL) {
+    if (GPENCIL_CURVE_EDIT_SESSIONS_ON(gpd)) {
+      /* curve geometry was updated: stroke needs recalculation */
+      if (gps->flag & GP_STROKE_NEEDS_CURVE_UPDATE) {
+        bool is_adaptive = gpd->flag & GP_DATA_CURVE_ADAPTIVE_RESOLUTION;
+        BKE_gpencil_stroke_update_geometry_from_editcurve(
+            gps, gpd->curve_edit_resolution, is_adaptive);
+        gps->flag &= ~GP_STROKE_NEEDS_CURVE_UPDATE;
+      }
+    }
+    else {
+      /* stroke geometry was updated: editcurve needs recalculation */
+      gps->editcurve->flag |= GP_CURVE_NEEDS_STROKE_UPDATE;
+    }
+  }
+
   if (gps->totpoints > 2) {
     BKE_gpencil_stroke_fill_triangulate(gps);
   }
@@ -1326,7 +1349,7 @@ float BKE_gpencil_stroke_length(const bGPDstroke *gps, bool use_3d)
  * Trim stroke to the first intersection or loop.
  * \param gps: Stroke data
  */
-bool BKE_gpencil_stroke_trim(bGPDstroke *gps)
+bool BKE_gpencil_stroke_trim(bGPdata *gpd, bGPDstroke *gps)
 {
   if (gps->totpoints < 4) {
     return false;
@@ -1413,7 +1436,7 @@ bool BKE_gpencil_stroke_trim(bGPDstroke *gps)
     MEM_SAFE_FREE(old_dvert);
   }
 
-  BKE_gpencil_stroke_geometry_update(gps);
+  BKE_gpencil_stroke_geometry_update(gpd, gps);
 
   return intersect;
 }
@@ -1509,11 +1532,12 @@ bool BKE_gpencil_stroke_close(bGPDstroke *gps)
 
 /**
  * Dissolve points in stroke.
+ * \param gpd: Grease pencil data-block
  * \param gpf: Grease pencil frame
  * \param gps: Grease pencil stroke
  * \param tag: Type of tag for point
  */
-void BKE_gpencil_dissolve_points(bGPDframe *gpf, bGPDstroke *gps, const short tag)
+void BKE_gpencil_dissolve_points(bGPdata *gpd, bGPDframe *gpf, bGPDstroke *gps, const short tag)
 {
   bGPDspoint *pt;
   MDeformVert *dvert = NULL;
@@ -1589,7 +1613,7 @@ void BKE_gpencil_dissolve_points(bGPDframe *gpf, bGPDstroke *gps, const short ta
     gps->totpoints = tot;
 
     /* triangles cache needs to be recalculated */
-    BKE_gpencil_stroke_geometry_update(gps);
+    BKE_gpencil_stroke_geometry_update(gpd, gps);
   }
 }
 
@@ -1635,10 +1659,11 @@ void BKE_gpencil_stroke_normal(const bGPDstroke *gps, float r_normal[3])
  *
  * Ramer - Douglas - Peucker algorithm
  * by http ://en.wikipedia.org/wiki/Ramer-Douglas-Peucker_algorithm
+ * \param gpd: Grease pencil data-block
  * \param gps: Grease pencil stroke
  * \param epsilon: Epsilon value to define precision of the algorithm
  */
-void BKE_gpencil_stroke_simplify_adaptive(bGPDstroke *gps, float epsilon)
+void BKE_gpencil_stroke_simplify_adaptive(bGPdata *gpd, bGPDstroke *gps, float epsilon)
 {
   bGPDspoint *old_points = MEM_dupallocN(gps->points);
   int totpoints = gps->totpoints;
@@ -1735,7 +1760,7 @@ void BKE_gpencil_stroke_simplify_adaptive(bGPDstroke *gps, float epsilon)
   gps->totpoints = j;
 
   /* Calc geometry data. */
-  BKE_gpencil_stroke_geometry_update(gps);
+  BKE_gpencil_stroke_geometry_update(gpd, gps);
 
   MEM_SAFE_FREE(old_points);
   MEM_SAFE_FREE(old_dvert);
@@ -1744,9 +1769,10 @@ void BKE_gpencil_stroke_simplify_adaptive(bGPDstroke *gps, float epsilon)
 
 /**
  * Simplify alternate vertex of stroke except extremes.
+ * \param gpd: Grease pencil data-block
  * \param gps: Grease pencil stroke
  */
-void BKE_gpencil_stroke_simplify_fixed(bGPDstroke *gps)
+void BKE_gpencil_stroke_simplify_fixed(bGPdata *gpd, bGPDstroke *gps)
 {
   if (gps->totpoints < 5) {
     return;
@@ -1800,19 +1826,20 @@ void BKE_gpencil_stroke_simplify_fixed(bGPDstroke *gps)
 
   gps->totpoints = j;
   /* Calc geometry data. */
-  BKE_gpencil_stroke_geometry_update(gps);
+  BKE_gpencil_stroke_geometry_update(gpd, gps);
 
   MEM_SAFE_FREE(old_points);
   MEM_SAFE_FREE(old_dvert);
 }
 
 /**
- * Subdivide grease pencil stroke.
- * \param gps: Grease pencil stroke
+ * Subdivide a stroke
+ * \param gpd: Grease pencil data-block
+ * \param gps: Stroke
  * \param level: Level of subdivision
  * \param type: Type of subdivision
  */
-void BKE_gpencil_stroke_subdivide(bGPDstroke *gps, int level, int type)
+void BKE_gpencil_stroke_subdivide(bGPdata *gpd, bGPDstroke *gps, int level, int type)
 {
   bGPDspoint *temp_points;
   MDeformVert *temp_dverts = NULL;
@@ -1921,7 +1948,7 @@ void BKE_gpencil_stroke_subdivide(bGPDstroke *gps, int level, int type)
   }
 
   /* Calc geometry data. */
-  BKE_gpencil_stroke_geometry_update(gps);
+  BKE_gpencil_stroke_geometry_update(gpd, gps);
 }
 
 /* Merge by distance ------------------------------------- */
@@ -1930,12 +1957,14 @@ void BKE_gpencil_stroke_subdivide(bGPDstroke *gps, int level, int type)
  * Reduce a series of points when the distance is below a threshold.
  * Special case for first and last points (both are keeped) for other points,
  * the merge point always is at first point.
+ * \param gpd: Grease pencil data-block
  * \param gpf: Grease Pencil frame
  * \param gps: Grease Pencil stroke
  * \param threshold: Distance between points
  * \param use_unselected: Set to true to analyze all stroke and not only selected points
  */
-void BKE_gpencil_stroke_merge_distance(bGPDframe *gpf,
+void BKE_gpencil_stroke_merge_distance(bGPdata *gpd,
+                                       bGPDframe *gpf,
                                        bGPDstroke *gps,
                                        const float threshold,
                                        const bool use_unselected)
@@ -2000,11 +2029,11 @@ void BKE_gpencil_stroke_merge_distance(bGPDframe *gpf,
 
   /* Dissolve tagged points */
   if (tagged) {
-    BKE_gpencil_dissolve_points(gpf, gps, GP_SPOINT_TAG);
+    BKE_gpencil_dissolve_points(gpd, gpf, gps, GP_SPOINT_TAG);
   }
 
   /* Calc geometry data. */
-  BKE_gpencil_stroke_geometry_update(gps);
+  BKE_gpencil_stroke_geometry_update(gpd, gps);
 }
 
 typedef struct GpEdge {
@@ -2093,6 +2122,7 @@ static int gpencil_walk_edge(GHash *v_table,
 }
 
 static void gpencil_generate_edgeloops(Object *ob,
+                                       bGPdata *gpd,
                                        bGPDframe *gpf_stroke,
                                        int stroke_mat_index,
                                        const float angle,
@@ -2218,7 +2248,7 @@ static void gpencil_generate_edgeloops(Object *ob,
       pt->strength = 1.0f;
     }
 
-    BKE_gpencil_stroke_geometry_update(gps_stroke);
+    BKE_gpencil_stroke_geometry_update(gpd, gps_stroke);
   }
 
   /* Free memory. */
@@ -2397,10 +2427,10 @@ bool BKE_gpencil_convert_mesh(Main *bmain,
         }
         /* If has only 3 points subdivide. */
         if (mp->totloop == 3) {
-          BKE_gpencil_stroke_subdivide(gps_fill, 1, GP_SUBDIV_SIMPLE);
+          BKE_gpencil_stroke_subdivide(gpd, gps_fill, 1, GP_SUBDIV_SIMPLE);
         }
 
-        BKE_gpencil_stroke_geometry_update(gps_fill);
+        BKE_gpencil_stroke_geometry_update(gpd, gps_fill);
       }
     }
   }
@@ -2417,7 +2447,7 @@ bool BKE_gpencil_convert_mesh(Main *bmain,
       gpl_stroke, CFRA + frame_offset, GP_GETFRAME_ADD_NEW);
 
   gpencil_generate_edgeloops(
-      ob_eval, gpf_stroke, stroke_mat_index, angle, thickness, offset, matrix, use_seams);
+      ob_eval, gpd, gpf_stroke, stroke_mat_index, angle, thickness, offset, matrix, use_seams);
 
   /* Tag for recalculation */
   DEG_id_tag_update(&gpd->id, ID_RECALC_GEOMETRY | ID_RECALC_COPY_ON_WRITE);
@@ -2457,7 +2487,7 @@ void BKE_gpencil_transform(bGPdata *gpd, const float mat[4][4])
         }
 
         /* Distortion may mean we need to re-triangulate. */
-        BKE_gpencil_stroke_geometry_update(gps);
+        BKE_gpencil_stroke_geometry_update(gpd, gps);
       }
     }
   }
@@ -2549,7 +2579,7 @@ void BKE_gpencil_point_coords_apply(bGPdata *gpd, const GPencilPointCoordinates
         }
 
         /* Distortion may mean we need to re-triangulate. */
-        BKE_gpencil_stroke_geometry_update(gps);
+        BKE_gpencil_stroke_geometry_update(gpd, gps);
       }
     }
   }
@@ -2586,7 +2616,7 @@ void BKE_gpencil_point_coords_apply_with_mat4(bGPdata *gpd,
         }
 
         /* Distortion may mean we need to re-triangulate. */
-        BKE_gpencil_stroke_geometry_update(gps);
+        BKE_gpencil_stroke_geometry_update(gpd, gps);
       }
     }
   }