GPencil: lower bounds for gap in dot dash modifier

This patch maximizes the possible bounds for the dash and
gap parameters in the dot dash modifier. This makes e.g.
chopping up lines without gaps possible.

Differential Revision: http://developer.blender.org/D14428

1 files changed, 23 insertions, 9 deletions

diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencildash.c b/source/blender/gpencil_modifiers/intern/MOD_gpencildash.c
index 439073752da..25c7fdca9f6 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencildash.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencildash.c
@@ -97,12 +97,13 @@ static bool stroke_dash(const bGPDstroke *gps,
   int new_stroke_offset = 0;
   int trim_start = 0;
 
+  int sequence_length = 0;
   for (int i = 0; i < dmd->segments_len; i++) {
-    if (dmd->segments[i].dash + real_gap(&dmd->segments[i]) < 1) {
-      BLI_assert_unreachable();
-      /* This means there's a part that doesn't have any length, can't do dot-dash. */
-      return false;
-    }
+    sequence_length += dmd->segments[i].dash + real_gap(&dmd->segments[i]);
+  }
+  if (sequence_length < 1) {
+    /* This means the whole segment has no length, can't do dot-dash. */
+    return false;
   }
 
   const DashGpencilModifierSegment *const first_segment = &dmd->segments[0];
@@ -204,9 +205,10 @@ static void apply_dash_for_frame(
                                        dmd->flag & GP_LENGTH_INVERT_PASS,
                                        dmd->flag & GP_LENGTH_INVERT_LAYERPASS,
                                        dmd->flag & GP_LENGTH_INVERT_MATERIAL)) {
-      stroke_dash(gps, dmd, &result);
-      BLI_remlink(&gpf->strokes, gps);
-      BKE_gpencil_free_stroke(gps);
+      if (stroke_dash(gps, dmd, &result)) {
+        BLI_remlink(&gpf->strokes, gps);
+        BKE_gpencil_free_stroke(gps);
+      }
     }
   }
   bGPDstroke *gps_dash;
@@ -232,6 +234,18 @@ static void bakeModifier(Main *UNUSED(bmain),
 
 /* -------------------------------- */
 
+static bool isDisabled(GpencilModifierData *md, int UNUSED(userRenderParams))
+{
+  DashGpencilModifierData *dmd = (DashGpencilModifierData *)md;
+
+  int sequence_length = 0;
+  for (int i = 0; i < dmd->segments_len; i++) {
+    sequence_length += dmd->segments[i].dash + real_gap(&dmd->segments[i]);
+  }
+  /* This means the whole segment has no length, can't do dot-dash. */
+  return sequence_length < 1;
+}
+
 /* Generic "generateStrokes" callback */
 static void generateStrokes(GpencilModifierData *md, Depsgraph *depsgraph, Object *ob)
 {
@@ -362,7 +376,7 @@ GpencilModifierTypeInfo modifierType_Gpencil_Dash = {
 
     /* initData */ initData,
     /* freeData */ freeData,
-    /* isDisabled */ NULL,
+    /* isDisabled */ isDisabled,
     /* updateDepsgraph */ NULL,
     /* dependsOnTime */ NULL,
     /* foreachIDLink */ foreachIDLink,