scripts/startup/bl_ui/properties_data_grease_pencil.py

@@ -71,9 +71,25 @@ class DATA_PT_grease_pencil_layers(DataButtonsPanel, Panel):
             col.prop(layer, "opacity", text="Opacity", slider=True)
 
 
+class DATA_PT_grease_pencil_display(DataButtonsPanel, Panel):
+    bl_label = "Viewport Display"
+    bl_options = {'DEFAULT_CLOSED'}
+
+    def draw(self, context):
+        layout = self.layout
+        layout.use_property_split = True
+        layout.use_property_decorate = False
+
+        ob = context.object
+        grease_pencil = context.grease_pencil
+
+        layout.prop(grease_pencil, "edit_line_color", text="Edit Line Color")
+
+
 classes = (
     DATA_PT_context_grease_pencil,
     DATA_PT_grease_pencil_layers,
+    DATA_PT_grease_pencil_display,
     GREASE_PENCIL_MT_grease_pencil_add_layer_extra,
 )
 

source/blender/blenkernel/intern/grease_pencil.cc

@@ -73,6 +73,8 @@ static void grease_pencil_init_data(ID *id)
   grease_pencil->root_group_ptr = MEM_new<greasepencil::LayerGroup>(__func__);
   grease_pencil->active_layer = nullptr;
   grease_pencil->flag |= GREASE_PENCIL_ANIM_CHANNEL_EXPANDED;
+
+  ARRAY_SET_ITEMS(grease_pencil->line_color, 0.6f, 0.6f, 0.6f, 0.5f);
 }
 
 static void grease_pencil_copy_data(Main * /*bmain*/,
@@ -123,6 +125,8 @@ static void grease_pencil_copy_data(Main * /*bmain*/,
         grease_pencil_dst->find_layer_by_name(grease_pencil_src->active_layer->wrap().name()));
   }
 
+  copy_v4_v4(grease_pencil_dst->line_color, grease_pencil_src->line_color);
+
   /* Make sure the runtime pointer exists. */
   grease_pencil_dst->runtime = MEM_new<bke::GreasePencilRuntime>(__func__);
 }

source/blender/draw/engines/overlay/overlay_edit_curves.cc

@@ -54,11 +54,16 @@ void OVERLAY_edit_curves_cache_init(OVERLAY_Data *vedata)
       DRW_shgroup_uniform_block(grp, "globalsBlock", G_draw.block_ubo);
     }
 
+    float empty_color[4];
+    zero_v4(empty_color);
+
     DRW_PASS_CREATE(psl->edit_curves_lines_ps[i], (state | pd->clipping_state));
     sh = OVERLAY_shader_edit_particle_strand();
     grp = pd->edit_curves_lines_grp[i] = DRW_shgroup_create(sh, psl->edit_curves_lines_ps[i]);
     DRW_shgroup_uniform_block(grp, "globalsBlock", G_draw.block_ubo);
     DRW_shgroup_uniform_bool_copy(grp, "useWeight", false);
+    /* Set to zero so that `globalsBlock.color_wire` will be used. */
+    DRW_shgroup_uniform_vec4_copy(grp, "replaceColor", empty_color);
   }
 }
 

source/blender/draw/engines/overlay/overlay_grease_pencil.cc

@@ -24,6 +24,10 @@ void OVERLAY_edit_grease_pencil_cache_init(OVERLAY_Data *vedata)
                    DRW_STATE_BLEND_ALPHA;
   DRW_PASS_CREATE(psl->edit_grease_pencil_ps, (state | pd->clipping_state));
 
+  sh = OVERLAY_shader_edit_particle_strand();
+  grp = pd->edit_grease_pencil_wires_grp = DRW_shgroup_create(sh, psl->edit_grease_pencil_ps);
+  DRW_shgroup_uniform_block(grp, "globalsBlock", G_draw.block_ubo);
+
   sh = OVERLAY_shader_edit_particle_point();
   grp = pd->edit_grease_pencil_points_grp = DRW_shgroup_create(sh, psl->edit_grease_pencil_ps);
   DRW_shgroup_uniform_block(grp, "globalsBlock", G_draw.block_ubo);
@@ -32,11 +36,22 @@ void OVERLAY_edit_grease_pencil_cache_init(OVERLAY_Data *vedata)
 void OVERLAY_edit_grease_pencil_cache_populate(OVERLAY_Data *vedata, Object *ob)
 {
   OVERLAY_PrivateData *pd = vedata->stl->pd;
+  GreasePencil &grease_pencil = *static_cast<GreasePencil *>(ob->data);
+
+  DRWShadingGroup *lines_grp = pd->edit_grease_pencil_wires_grp;
+  if (lines_grp) {
+    DRWShadingGroup *grp = DRW_shgroup_create_sub(lines_grp);
+    DRW_shgroup_uniform_vec4_copy(grp, "replaceColor", grease_pencil.line_color);
+
+    GPUBatch *geom_lines = DRW_cache_grease_pencil_edit_lines_get(ob, pd->cfra);
+
+    DRW_shgroup_call_no_cull(grp, geom_lines, ob);
+  }
 
   DRWShadingGroup *points_grp = pd->edit_grease_pencil_points_grp;
   if (points_grp) {
-    GPUBatch *geom = DRW_cache_grease_pencil_edit_points_get(ob, pd->cfra);
+    GPUBatch *geom_points = DRW_cache_grease_pencil_edit_points_get(ob, pd->cfra);
-    DRW_shgroup_call_no_cull(points_grp, geom, ob);
+    DRW_shgroup_call_no_cull(points_grp, geom_points, ob);
   }
 }
 

source/blender/draw/engines/overlay/overlay_particle.cc

@@ -37,11 +37,16 @@ void OVERLAY_edit_particle_cache_init(OVERLAY_Data *vedata)
   DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS_EQUAL;
   DRW_PASS_CREATE(psl->edit_particle_ps, state | pd->clipping_state);
 
+  float empty_color[4];
+  zero_v4(empty_color);
+
   sh = OVERLAY_shader_edit_particle_strand();
   pd->edit_particle_strand_grp = grp = DRW_shgroup_create(sh, psl->edit_particle_ps);
   DRW_shgroup_uniform_block(grp, "globalsBlock", G_draw.block_ubo);
   DRW_shgroup_uniform_bool_copy(grp, "useWeight", pd->edit_particle.use_weight);
   DRW_shgroup_uniform_texture(grp, "weightTex", G_draw.weight_ramp);
+  /* Set to zero so that `globalsBlock.color_wire` will be used. */
+  DRW_shgroup_uniform_vec4_copy(grp, "replaceColor", empty_color);
 
   sh = OVERLAY_shader_edit_particle_point();
   pd->edit_particle_point_grp = grp = DRW_shgroup_create(sh, psl->edit_particle_ps);

source/blender/draw/engines/overlay/overlay_private.hh

@@ -251,6 +251,7 @@ struct OVERLAY_PrivateData {
   DRWShadingGroup *edit_lattice_wires_grp;
   DRWShadingGroup *edit_gpencil_points_grp;
   DRWShadingGroup *edit_gpencil_wires_grp;
+  DRWShadingGroup *edit_grease_pencil_wires_grp;
   DRWShadingGroup *edit_grease_pencil_points_grp;
   DRWShadingGroup *edit_gpencil_curve_handle_grp;
   DRWShadingGroup *edit_gpencil_curve_points_grp;

source/blender/draw/engines/overlay/shaders/infos/overlay_edit_mode_info.hh

@@ -531,6 +531,7 @@ GPU_SHADER_CREATE_INFO(overlay_edit_particle_strand)
     .vertex_in(1, Type::FLOAT, "selection")
     .sampler(0, ImageType::FLOAT_1D, "weightTex")
     .push_constant(Type::BOOL, "useWeight")
+    .push_constant(Type::VEC4, "replaceColor")
     .vertex_out(overlay_edit_smooth_color_iface)
     .fragment_out(0, Type::VEC4, "fragColor")
     .vertex_source("overlay_edit_particle_strand_vert.glsl")

source/blender/draw/engines/overlay/shaders/overlay_edit_particle_strand_vert.glsl

@@ -7,11 +7,13 @@
 
 #define no_active_weight 666.0
 
+#define base_color (replaceColor == 0.0 ? colorWire : replaceColor)
+
 vec3 weight_to_rgb(float t)
 {
   if (t == no_active_weight) {
     /* No weight. */
-    return colorWire.rgb;
+    return base_color.rgb;
   }
   if (t > 1.0 || t < 0.0) {
     /* Error color */
@@ -31,7 +33,7 @@ void main()
     finalColor = vec4(weight_to_rgb(selection), 1.0);
   }
   else {
-    finalColor = mix(colorWire, colorVertexSelect, selection);
+    finalColor = mix(base_color, colorVertexSelect, selection);
   }
 
   view_clipping_distances(world_pos);

source/blender/draw/intern/draw_cache.h

@@ -281,6 +281,7 @@ void DRW_cache_gpencil_sbuffer_clear(struct Object *ob);
 
 struct GPUBatch *DRW_cache_grease_pencil_get(struct Object *ob, int cfra);
 struct GPUBatch *DRW_cache_grease_pencil_edit_points_get(struct Object *ob, int cfra);
+struct GPUBatch *DRW_cache_grease_pencil_edit_lines_get(struct Object *ob, int cfra);
 struct GPUVertBuf *DRW_cache_grease_pencil_position_buffer_get(struct Object *ob, int cfra);
 struct GPUVertBuf *DRW_cache_grease_pencil_color_buffer_get(struct Object *ob, int cfra);
 

source/blender/draw/intern/draw_cache_impl_grease_pencil.cc

@@ -37,11 +37,14 @@ struct GreasePencilBatchCache {
   /** Batches */
   GPUBatch *geom_batch;
   GPUBatch *edit_points;
+  GPUBatch *edit_lines;
 
   /* Crazy-space point positions for original points. */
   GPUVertBuf *edit_points_pos;
   /* Selection of original points. */
   GPUVertBuf *edit_points_selection;
+  /* Indices for lines segments. */
+  GPUIndexBuf *edit_line_indices;
 
   /** Cache is dirty. */
   bool is_dirty;
@@ -139,8 +142,10 @@ static void grease_pencil_batch_cache_clear(GreasePencil &grease_pencil)
   GPU_INDEXBUF_DISCARD_SAFE(cache->ibo);
 
   GPU_BATCH_DISCARD_SAFE(cache->edit_points);
+  GPU_BATCH_DISCARD_SAFE(cache->edit_lines);
   GPU_VERTBUF_DISCARD_SAFE(cache->edit_points_pos);
   GPU_VERTBUF_DISCARD_SAFE(cache->edit_points_selection);
+  GPU_INDEXBUF_DISCARD_SAFE(cache->edit_line_indices);
 
   cache->is_dirty = true;
 }
@@ -212,6 +217,7 @@ static void grease_pencil_geom_batch_ensure(GreasePencil &grease_pencil, int cfr
   int total_points_num = 0;
   int total_verts_num = 0;
   int total_triangles_num = 0;
+  int total_line_ids_num = 0;
   int v_offset = 0;
   Vector<Array<int>> verts_start_offsets_per_visible_drawing;
   Vector<Array<int>> tris_start_offsets_per_visible_drawing;
@@ -241,6 +247,19 @@ static void grease_pencil_geom_batch_ensure(GreasePencil &grease_pencil, int cfr
         t_offset += points.size() - 2;
       }
 
+      if (points.size() > 1) {
+        /* Add one id for the first point in the curve. */
+        total_line_ids_num++;
+        /* Add ids for the segments. */
+        total_line_ids_num += points.size() - 1;
+        /* Add one segment for the cycle line. */
+        if (points.size() > 2 && is_cyclic) {
+          total_line_ids_num++;
+        }
+        /* Add one id for the jump to the next curve. */
+        total_line_ids_num++;
+      }
+
       verts_start_offsets[curve_i] = v_offset;
       v_offset += 1 + points.size() + (is_cyclic ? 1 : 0) + 1;
     }
@@ -291,6 +310,7 @@ static void grease_pencil_geom_batch_ensure(GreasePencil &grease_pencil, int cfr
   GPU_vertbuf_data_alloc(cache->vbo_col, total_verts_num + 2);
 
   GPUIndexBufBuilder ibo;
+  GPUIndexBufBuilder elb;
   MutableSpan<GreasePencilStrokeVert> verts = {
       static_cast<GreasePencilStrokeVert *>(GPU_vertbuf_get_data(cache->vbo)),
       GPU_vertbuf_get_vertex_len(cache->vbo)};
@@ -305,6 +325,10 @@ static void grease_pencil_geom_batch_ensure(GreasePencil &grease_pencil, int cfr
       GPU_vertbuf_get_vertex_len(cache->edit_points_selection)};
   /* Create IBO. */
   GPU_indexbuf_init(&ibo, GPU_PRIM_TRIS, total_triangles_num, 0xFFFFFFFFu);
+  GPU_indexbuf_init_ex(&elb,
+                       GPU_PRIM_LINE_STRIP,
+                       total_line_ids_num,
+                       GPU_vertbuf_get_vertex_len(cache->edit_points_pos));
 
   /* Fill buffers with data. */
   int drawing_start_offset = 0;
@@ -334,7 +358,6 @@ static void grease_pencil_geom_batch_ensure(GreasePencil &grease_pencil, int cfr
     MutableSpan<float> selection_slice = edit_points_selection.slice(drawing_start_offset,
                                                                      curves.points_num());
     selection_float.materialize(selection_slice);
-    drawing_start_offset += curves.points_num();
 
     auto populate_point = [&](IndexRange verts_range,
                               int curve_i,
@@ -394,6 +417,18 @@ static void grease_pencil_geom_batch_ensure(GreasePencil &grease_pencil, int cfr
           }
         }
 
+        if (points.size() > 1) {
+          for (const int point : points) {
+            GPU_indexbuf_add_generic_vert(&elb, point + drawing_start_offset);
+          }
+
+          if (points.size() > 2 && is_cyclic) {
+            GPU_indexbuf_add_generic_vert(&elb, points.first() + drawing_start_offset);
+          }
+
+          GPU_indexbuf_add_primitive_restart(&elb);
+        }
+
         /* Write all the point attributes to the vertex buffers. Create a quad for each point. */
         for (const int i : IndexRange(points.size())) {
           const int idx = i + 1;
@@ -423,6 +458,7 @@ static void grease_pencil_geom_batch_ensure(GreasePencil &grease_pencil, int cfr
         verts_slice.last().mat = -1;
       }
     });
+    drawing_start_offset += curves.points_num();
   }
 
   if (grease_pencil.runtime->has_stroke_buffer()) {
@@ -488,6 +524,12 @@ static void grease_pencil_geom_batch_ensure(GreasePencil &grease_pencil, int cfr
   cache->edit_points = GPU_batch_create(GPU_PRIM_POINTS, cache->edit_points_pos, nullptr);
   GPU_batch_vertbuf_add(cache->edit_points, cache->edit_points_selection, false);
 
+  cache->edit_line_indices = GPU_indexbuf_build(&elb);
+
+  cache->edit_lines = GPU_batch_create(
+      GPU_PRIM_LINE_STRIP, cache->edit_points_pos, cache->edit_line_indices);
+  GPU_batch_vertbuf_add(cache->edit_lines, cache->edit_points_selection, false);
+
   cache->is_dirty = false;
 }
 
@@ -551,6 +593,16 @@ GPUBatch *DRW_cache_grease_pencil_edit_points_get(Object *ob, int cfra)
   return cache->edit_points;
 }
 
+GPUBatch *DRW_cache_grease_pencil_edit_lines_get(Object *ob, int cfra)
+{
+  using namespace blender::draw;
+  GreasePencil &grease_pencil = *static_cast<GreasePencil *>(ob->data);
+  GreasePencilBatchCache *cache = grease_pencil_batch_cache_get(grease_pencil);
+  grease_pencil_geom_batch_ensure(grease_pencil, cfra);
+
+  return cache->edit_lines;
+}
+
 GPUVertBuf *DRW_cache_grease_pencil_position_buffer_get(Object *ob, int cfra)
 {
   using namespace blender::draw;

source/blender/makesdna/DNA_grease_pencil_types.h

@@ -401,6 +401,9 @@ typedef struct GreasePencil {
   int drawing_array_num;
   char _pad[4];
 
+  /* Color for line (edit mode). */
+  float line_color[4];
+
   /* Root group of the layer tree. */
   GreasePencilLayerTreeGroup *root_group_ptr;
 

source/blender/makesrna/intern/rna_grease_pencil.cc

@@ -292,6 +292,8 @@ static void rna_def_grease_pencil_data(BlenderRNA *brna)
   StructRNA *srna;
   PropertyRNA *prop;
 
+  static float default_line_color[4] = {0.6f, 0.6f, 0.6f, 0.5f};
+
   srna = RNA_def_struct(brna, "GreasePencilv3", "ID");
   RNA_def_struct_sdna(srna, "GreasePencil");
   RNA_def_struct_ui_text(srna, "Grease Pencil", "Grease Pencil data-block");
@@ -328,6 +330,15 @@ static void rna_def_grease_pencil_data(BlenderRNA *brna)
                                     nullptr, /* TODO */
                                     nullptr);
   RNA_def_property_ui_text(prop, "Layer Groups", "Grease Pencil layer groups");
+
+  /* Line Color (Edit Mode) */
+  prop = RNA_def_property(srna, "edit_line_color", PROP_FLOAT, PROP_COLOR_GAMMA);
+  RNA_def_property_float_sdna(prop, nullptr, "line_color");
+  RNA_def_property_array(prop, 4);
+  RNA_def_property_range(prop, 0.0f, 1.0f);
+  RNA_def_property_float_array_default(prop, default_line_color);
+  RNA_def_property_ui_text(prop, "Edit Line Color", "Color for editing line");
+  RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, "rna_grease_pencil_update");
 }
 
 void RNA_def_grease_pencil(BlenderRNA *brna)