1 files changed, 47 insertions, 0 deletions
diff --git a/source/blender/editors/gpencil/gpencil_utils.c b/source/blender/editors/gpencil/gpencil_utils.c
index 1962eba5017..876fa7c9874 100644
--- a/source/blender/editors/gpencil/gpencil_utils.c
+++ b/source/blender/editors/gpencil/gpencil_utils.c
@@ -31,6 +31,7 @@
 #include "BLI_blenlib.h"
 #include "BLI_ghash.h"
 #include "BLI_hash.h"
+#include "BLI_lasso_2d.h"
 #include "BLI_math.h"
 #include "BLI_rand.h"
 #include "BLI_utildefines.h"
@@ -2799,3 +2800,49 @@ bool ED_gpencil_stroke_check_collision(GP_SpaceConversion *gsc,
   /* Check collision between both rectangles. */
   return BLI_rcti_isect(&rect_stroke, &rect_mouse, NULL);
 }
+
+/**
+ * Check if a point is inside of the stroke
+ * \param gps: Stroke to check
+ * \param gsc: SpaceConversion data
+ * \param mouse:  Mouse position
+ * \param diff_mat:  View matrix
+ * \return  True if the point is inside
+ */
+bool ED_gpencil_stroke_point_is_inside(bGPDstroke *gps,
+                                       GP_SpaceConversion *gsc,
+                                       int mouse[2],
+                                       const float diff_mat[4][4])
+{
+  bool hit = false;
+  if (gps->totpoints == 0) {
+    return hit;
+  }
+
+  int(*mcoords)[2] = NULL;
+  int len = gps->totpoints;
+  mcoords = MEM_mallocN(sizeof(int) * 2 * len, __func__);
+
+  /* Convert stroke to 2D array of points. */
+  bGPDspoint *pt;
+  int i;
+  for (i = 0, pt = gps->points; i < gps->totpoints; i++, pt++) {
+    bGPDspoint pt2;
+    gp_point_to_parent_space(pt, diff_mat, &pt2);
+    gp_point_to_xy(gsc, gps, &pt2, &mcoords[i][0], &mcoords[i][1]);
+  }
+
+  /* Compute boundbox of lasso (for faster testing later). */
+  rcti rect;
+  BLI_lasso_boundbox(&rect, mcoords, len);
+
+  /* Test if point inside stroke. */
+  hit = ((!ELEM(V2D_IS_CLIPPED, mouse[0], mouse[1])) &&
+         BLI_rcti_isect_pt(&rect, mouse[0], mouse[1]) &&
+         BLI_lasso_is_point_inside(mcoords, len, mouse[0], mouse[1], INT_MAX));
+
+  /* Free memory. */
+  MEM_SAFE_FREE(mcoords);
+
+  return hit;
+}