GPencil: New Dots gradient

This commit adds support for drawing Dots strokes with a gradient factor to get artistic effects like watercolor.

Currently, the option is only supported by Dots materials, and in the future will be added to line strokes, but now there is a limitation on drawing engine and we will keep disabled on Line materials.

Also, added the option to align Dots and Boxes strokes textures aligned with the drawing path to get more fluid strokes.

3 files changed, 44 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_brush.c b/source/blender/makesrna/intern/rna_brush.c
index ce5b18331c6..23ae314f885 100644
--- a/source/blender/makesrna/intern/rna_brush.c
+++ b/source/blender/makesrna/intern/rna_brush.c
@@ -1197,6 +1197,25 @@ static void rna_def_gpencil_options(BlenderRNA *brna)
 	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
 	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, NULL);
 
+	/* gradient control */
+	prop = RNA_def_property(srna, "gradient_factor", PROP_FLOAT, PROP_FACTOR);
+	RNA_def_property_float_sdna(prop, NULL, "gradient_f");
+	RNA_def_property_range(prop, 0.001f, 1.0f);
+	RNA_def_property_float_default(prop, 1.0f);
+	RNA_def_property_ui_text(
+		prop, "Border Opacity Factor",
+		"Amount of gradient for Dot strokes (set to 1 for full solid)");
+	RNA_def_parameter_clear_flags(prop, PROP_ANIMATABLE, 0);
+
+	/* gradient shape ratio */
+	prop = RNA_def_property(srna, "gradient_shape", PROP_FLOAT, PROP_XYZ);
+	RNA_def_property_float_sdna(prop, NULL, "gradient_s");
+	RNA_def_property_array(prop, 2);
+	RNA_def_property_range(prop, 0.01f, 1.0f);
+	RNA_def_property_float_default(prop, 1.0f);
+	RNA_def_property_ui_text(prop, "Aspect Ratio", "");
+	RNA_def_parameter_clear_flags(prop, PROP_ANIMATABLE, 0);
+
 	prop = RNA_def_property(srna, "input_samples", PROP_INT, PROP_NONE);
 	RNA_def_property_int_sdna(prop, NULL, "input_samples");
 	RNA_def_property_range(prop, 0, GP_MAX_INPUT_SAMPLES);
diff --git a/source/blender/makesrna/intern/rna_gpencil.c b/source/blender/makesrna/intern/rna_gpencil.c
index 73203beb3e2..d154f8de4ad 100644
--- a/source/blender/makesrna/intern/rna_gpencil.c
+++ b/source/blender/makesrna/intern/rna_gpencil.c
@@ -998,6 +998,24 @@ static void rna_def_gpencil_stroke(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Thickness", "Thickness of stroke (in pixels)");
 	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, "rna_GPencil_update");
 
+	/* gradient control along y */
+	prop = RNA_def_property(srna, "gradient_factor", PROP_FLOAT, PROP_FACTOR);
+	RNA_def_property_float_sdna(prop, NULL, "gradient_f");
+	RNA_def_property_range(prop, 0.001f, 1.0f);
+	RNA_def_property_float_default(prop, 1.0f);
+	RNA_def_property_ui_text(prop, "Border Opacity Factor",
+		"Amount of gradient along section of stroke");
+	RNA_def_parameter_clear_flags(prop, PROP_ANIMATABLE, 0);
+	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, "rna_GPencil_update");
+
+	/* gradient shape ratio */
+	prop = RNA_def_property(srna, "gradient_shape", PROP_FLOAT, PROP_XYZ);
+	RNA_def_property_float_sdna(prop, NULL, "gradient_s");
+	RNA_def_property_array(prop, 2);
+	RNA_def_property_range(prop, 0.01f, 1.0f);
+	RNA_def_property_float_default(prop, 1.0f);
+	RNA_def_property_ui_text(prop, "Aspect Ratio", "");
+	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, "rna_GPencil_update");
 }
 
 static void rna_def_gpencil_strokes_api(BlenderRNA *brna, PropertyRNA *cprop)
diff --git a/source/blender/makesrna/intern/rna_material.c b/source/blender/makesrna/intern/rna_material.c
index 8e5f486fea1..a57f47a8090 100644
--- a/source/blender/makesrna/intern/rna_material.c
+++ b/source/blender/makesrna/intern/rna_material.c
@@ -585,6 +585,13 @@ static void rna_def_material_greasepencil(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Show Fill", "Show stroke fills of this material");
 	RNA_def_property_update(prop, NC_GPENCIL | ND_SHADING, "rna_MaterialGpencil_update");
 
+	/* keep Dots and Boxes aligned to screen and not to drawing path */
+	prop = RNA_def_property(srna, "use_follow_path", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_negative_sdna(prop, NULL, "flag", GP_STYLE_COLOR_LOCK_DOTS);
+	RNA_def_property_ui_text(prop, "Follow Path",
+		"Keep Dots and Boxes aligned to drawing path");
+	RNA_def_property_update(prop, NC_GPENCIL | ND_SHADING, "rna_MaterialGpencil_nopreview_update");
+
 	/* pass index for future compositing and editing tools */
 	prop = RNA_def_property(srna, "pass_index", PROP_INT, PROP_UNSIGNED);
 	RNA_def_property_int_sdna(prop, NULL, "index");