[Bf-blender-cvs] [928ad8e5b8c] temp-gpencil-bezier-stroke-type: GPencil: Add flags for polyline regeneration

[Falk David]

Commit: 928ad8e5b8cf618748a1b4e0cadf0e7fc715daf0
Author: Falk David
Date:   Fri Apr 16 18:45:38 2021 +0200
Branches: temp-gpencil-bezier-stroke-type
https://developer.blender.org/rB928ad8e5b8cf618748a1b4e0cadf0e7fc715daf0

GPencil: Add flags for polyline regeneration

===================================================================

M	source/blender/blenkernel/BKE_gpencil_geom.h
M	source/blender/blenkernel/intern/gpencil_geom.c

===================================================================

diff --git a/source/blender/blenkernel/BKE_gpencil_geom.h b/source/blender/blenkernel/BKE_gpencil_geom.h
index 82a6283a20c..22eea69477c 100644
--- a/source/blender/blenkernel/BKE_gpencil_geom.h
+++ b/source/blender/blenkernel/BKE_gpencil_geom.h
@@ -40,8 +40,15 @@ struct bGPdata;
 
 typedef enum eGPStrokeGeoUpdateFlag {
   /* Default geometry update. Triangulate the stroke, update UVs and bounding box. If the stroke
-     type is bezier, regenerate the polyline first. */
+     type is bezier, regenerate the polyline first (GP_GEO_UPDATE_POLYLINE_REGENERATE_ALL). */
   GP_GEO_UPDATE_DEFAULT = 0,
+
+  /* == Curve refitting flags == */
+  /* On a stroke geometry update, if the stroke is of type bézier, there is the option to use the
+     points in the polyline to do a curve fitting. This is useful when an operation writes to the
+     polyline and the shape of the curve is out of sync and needs to be refitted. These flags
+     control what attributes the curve should be fitted to. */
+
   /* Refit the curve point positions. */
   GP_GEO_UPDATE_CURVE_REFIT_POSITION = (1 << 1),
   /* Refit the curve point pressures. */
@@ -53,11 +60,27 @@ typedef enum eGPStrokeGeoUpdateFlag {
   /* Refit the curve point weights. */
   GP_GEO_UPDATE_CURVE_REFIT_WEIGHT = (1 << 5),
   /* Do a partial refit. Uses the `GP_SPOINT_TAG` point flag to determin what curve segments need
-     to be refitted. */
+     to be refitted. Only affected curve segments will be updated. */
   GP_GEO_UPDATE_CURVE_PARTIAL_REFIT = (1 << 6),
 
-  /* Add additional flags here: (1 << 7), (2 << 7), ... */
-  /* GP_GEO_UPDATE_XXX = (1 << 7), */
+  /* == Polyline regeneration flags == */
+  /* The polyline is regenerated when the curve geometry is updated. This is because the polyline
+     is used for rendering instead of the actual curve data. These flag control what attributes
+     should be regenerated when the curve was updated. */
+
+  /* Regenerate the polyline positions from the curve data. */
+  GP_GEO_UPDATE_POLYLINE_POSITION = (1 << 7),
+  /* Regenerate the polyline point pressure from the curve data. */
+  GP_GEO_UPDATE_POLYLINE_PRESSURE = (1 << 8),
+  /* Regenerate the polyline point strength from the curve data. */
+  GP_GEO_UPDATE_POLYLINE_STRENGTH = (1 << 9),
+  /* Regenerate the polyline vertex colors from the curve data. */
+  GP_GEO_UPDATE_POLYLINE_COLOR = (1 << 10),
+  /* Regenerate the polyline weights from the curve data. */
+  GP_GEO_UPDATE_POLYLINE_WEIGHT = (1 << 11),
+
+  /* Add additional flags here: (1 << 12), (2 << 12), ... */
+  /* GP_GEO_UPDATE_XXX = (1 << 12), */
 } eGPStrokeGeoUpdateFlag;
 
 /* Refit all attributes. */
@@ -69,6 +92,17 @@ typedef enum eGPStrokeGeoUpdateFlag {
 /* Check if any curve refitting is done. */
 #define GP_GEO_UPDATE_CURVE_REFIT_ANY(flag) (flag & GP_GEO_UPDATE_CURVE_REFIT_ALL)
 
+/* Regenerate all attributes of the polyline from the curve data. */
+#define GP_GEO_UPDATE_POLYLINE_REGENERATE_ALL \
+  (GP_GEO_UPDATE_POLYLINE_POSITION | GP_GEO_UPDATE_POLYLINE_PRESSURE | \
+   GP_GEO_UPDATE_POLYLINE_STRENGTH | GP_GEO_UPDATE_POLYLINE_COLOR | \
+   GP_GEO_UPDATE_POLYLINE_WEIGHT)
+
+/* Check if any atttributes of the polyline need to be regenerated. Note that we update all
+ * attributes by default (GP_GEO_UPDATE_DEFAULT). */
+#define GP_GEO_UPDATE_POLYLINE_REGENERATE_ANY(flag) \
+  ((flag & GP_GEO_UPDATE_POLYLINE_REGENERATE_ALL) || flag == GP_GEO_UPDATE_DEFAULT)
+
 /* Object boundbox. */
 bool BKE_gpencil_data_minmax(const struct bGPdata *gpd, float r_min[3], float r_max[3]);
 bool BKE_gpencil_stroke_minmax(const struct bGPDstroke *gps,
diff --git a/source/blender/blenkernel/intern/gpencil_geom.c b/source/blender/blenkernel/intern/gpencil_geom.c
index 58b62afdfdb..26d1f0bb6f1 100644
--- a/source/blender/blenkernel/intern/gpencil_geom.c
+++ b/source/blender/blenkernel/intern/gpencil_geom.c
@@ -1297,17 +1297,19 @@ void BKE_gpencil_stroke_geometry_update(bGPdata *gpd,
 
   /* Update curve points first if it's a bezier stroke. */
   if (GPENCIL_STROKE_TYPE_BEZIER(gps)) {
+    /* Refit the curve to the polyline points. */
     if (GP_GEO_UPDATE_CURVE_REFIT_ANY(flag)) {
-      /* TODO: Make do-partial-update variable */
       const float threshold = gpd->curve_edit_threshold;
       const float corner_angle = gpd->curve_edit_corner_angle;
       BKE_gpencil_stroke_editcurve_update(gps, threshold, corner_angle, flag);
     }
 
-    /* If curve geometry was updated, stroke points need recalculation. */
-    const uint resolution = gpd->curve_edit_resolution;
-    const bool is_adaptive = gpd->flag & GP_DATA_CURVE_ADAPTIVE_RESOLUTION;
-    BKE_gpencil_stroke_update_geometry_from_editcurve(gps, resolution, is_adaptive, flag);
+    /* Regenerate the polyline points from the curve data. */
+    if (GP_GEO_UPDATE_POLYLINE_REGENERATE_ANY(flag)) {
+      const uint resolution = gpd->curve_edit_resolution;
+      const bool is_adaptive = gpd->flag & GP_DATA_CURVE_ADAPTIVE_RESOLUTION;
+      BKE_gpencil_stroke_update_geometry_from_editcurve(gps, resolution, is_adaptive, flag);
+    }
   }
 
   /* Triangulate the stroke. */