GP: New Cutter, Constraints and Segment selection

This commit groups a set of new tools that were tested in grease pencil object branch before moving to master. We decide to do all the development in a separated branch because it could break master during days or weeks before the new tools were ready to deploy.

The commit includes:

- New Cutter tool to trim strokes and help cleaning up drawings.

- New set of constraints and guides to draw different types of shapes. All the credits for this development goes to Charlie Jolly (@charlie), thanks for your help!

- Segment selection mode to select strokes between intersections.

- New operator to change strokes cap mode.

- New option to display only keyframed frames. This option is very important when fill strokes with color.

- Multiple small fixes and tweaks.

Thanks to @pepeland and @mendio for their ideas, tests, reviews and support.

Note: Still pending the final icons for Cutter in Toolbar and Segment Selection in Topbar. @billreynish could help us here?

1 files changed, 4 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_gpencil.h b/source/blender/blenkernel/BKE_gpencil.h
index 989bec1957b..02495f861ab 100644
--- a/source/blender/blenkernel/BKE_gpencil.h
+++ b/source/blender/blenkernel/BKE_gpencil.h
@@ -170,6 +170,10 @@ void BKE_gpencil_subdivide(struct bGPDstroke *gps, int level, int flag);
 
 void BKE_gpencil_stroke_2d_flat(
 	const struct bGPDspoint *points, int totpoints, float(*points2d)[2], int *r_direction);
+void BKE_gpencil_stroke_2d_flat_ref(
+	const struct bGPDspoint *ref_points, int ref_totpoints,
+	const struct bGPDspoint *points, int totpoints,
+	float(*points2d)[2], const float scale, int *r_direction);
 
 void BKE_gpencil_transform(struct bGPdata *gpd, float mat[4][4]);