GPencil: Layers with alpha = 0 should not be editable

* Added a new API function to test if a GPencil layer is visible or not
* Replaced all editability checks with this new "super check"
* Replaced all magic number thresholds for opacity visiblity with a single define

4 files changed, 5 insertions, 7 deletions

diff --git a/source/blender/editors/gpencil/drawgpencil.c b/source/blender/editors/gpencil/drawgpencil.c
index 66d86285470..b5d9283f6c6 100644
--- a/source/blender/editors/gpencil/drawgpencil.c
+++ b/source/blender/editors/gpencil/drawgpencil.c
@@ -993,7 +993,7 @@ static void gp_draw_data_layers(bGPdata *gpd, int offsx, int offsy, int winx, in
 		
 		/* fill strokes... */
 		// XXX: this is not a very good limit
-		GP_DRAWFLAG_APPLY((gpl->fill[3] > 0.001f), GP_DRAWDATA_FILL);
+		GP_DRAWFLAG_APPLY((gpl->fill[3] > GPENCIL_ALPHA_OPACITY_THRESH), GP_DRAWDATA_FILL);
 #undef GP_DRAWFLAG_APPLY
 		
 		/* draw 'onionskins' (frame left + right) */
diff --git a/source/blender/editors/gpencil/gpencil_brush.c b/source/blender/editors/gpencil/gpencil_brush.c
index 0d1698e9ec7..ef80f25bb9b 100644
--- a/source/blender/editors/gpencil/gpencil_brush.c
+++ b/source/blender/editors/gpencil/gpencil_brush.c
@@ -1118,9 +1118,7 @@ static void gpsculpt_brush_init_stroke(tGP_BrushEditData *gso)
 	/* go through each layer, and ensure that we've got a valid frame to use */
 	for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
 		/* only editable and visible layers are considered */
-		if ((gpl->flag & (GP_LAYER_HIDE | GP_LAYER_LOCKED)) == 0 &&
-		    (gpl->actframe != NULL))
-		{
+		if (gpencil_layer_is_editable(gpl) && (gpl->actframe != NULL)) {
 			bGPDframe *gpf = gpl->actframe;
 			
 			/* Make a new frame to work on if the layer's frame and the current scene frame don't match up 
diff --git a/source/blender/editors/gpencil/gpencil_edit.c b/source/blender/editors/gpencil/gpencil_edit.c
index 4852723c747..03d5ed3e24f 100644
--- a/source/blender/editors/gpencil/gpencil_edit.c
+++ b/source/blender/editors/gpencil/gpencil_edit.c
@@ -391,7 +391,7 @@ static int gp_strokes_paste_exec(bContext *C, wmOperator *op)
 		/* no active layer - let's just create one */
 		gpl = gpencil_layer_addnew(gpd, DATA_("GP_Layer"), true);
 	}
-	else if (gpl->flag & (GP_LAYER_HIDE | GP_LAYER_LOCKED)) {
+	else if (gpencil_layer_is_editable(gpl) == false) {
 		BKE_report(op->reports, RPT_ERROR, "Can not paste strokes when active layer is hidden or locked");
 		return OPERATOR_CANCELLED;
 	}
diff --git a/source/blender/editors/gpencil/gpencil_paint.c b/source/blender/editors/gpencil/gpencil_paint.c
index ab6253c5cdb..b76ed90a0f1 100644
--- a/source/blender/editors/gpencil/gpencil_paint.c
+++ b/source/blender/editors/gpencil/gpencil_paint.c
@@ -931,7 +931,7 @@ static void gp_stroke_doeraser(tGPsdata *p)
 		bGPDframe *gpf = gpl->actframe;
 		
 		/* only affect layer if it's editable (and visible) */
-		if (gpl->flag & (GP_LAYER_HIDE | GP_LAYER_LOCKED)) {
+		if (gpencil_layer_is_editable(gpl) == false) {
 			continue;
 		}
 		else if (gpf == NULL) {
@@ -1220,7 +1220,7 @@ static void gp_paint_initstroke(tGPsdata *p, eGPencil_PaintModes paintmode)
 		bGPDlayer *gpl;
 		for (gpl = p->gpd->layers.first; gpl; gpl = gpl->next) {
 			/* Skip if layer not editable */
-			if (gpl->flag & (GP_LAYER_HIDE | GP_LAYER_LOCKED))
+			if (gpencil_layer_is_editable(gpl) == false)
 				continue;
 			
 			/* Add a new frame if needed (and based off the active frame,