GPencil: Improve Vertex Paint in filled areas

When use the Tint tool, it was very difficult to tint the filled areas if the strokes had very few points or the area was big.

Differential Revision: https://developer.blender.org/D7936

1 files changed, 34 insertions, 9 deletions

diff --git a/source/blender/editors/gpencil/gpencil_vertex_paint.c b/source/blender/editors/gpencil/gpencil_vertex_paint.c
index 10867bd1e0d..581a5d977c2 100644
--- a/source/blender/editors/gpencil/gpencil_vertex_paint.c
+++ b/source/blender/editors/gpencil/gpencil_vertex_paint.c
@@ -36,6 +36,7 @@
 #include "BKE_colortools.h"
 #include "BKE_context.h"
 #include "BKE_gpencil.h"
+#include "BKE_material.h"
 #include "BKE_report.h"
 
 #include "WM_api.h"
@@ -433,10 +434,9 @@ static bool brush_tint_apply(tGP_BrushVertexpaintData *gso,
   CLAMP(inf, 0.0f, 1.0f);
   CLAMP(inf_fill, 0.0f, 1.0f);
 
-  bGPDspoint *pt = &gps->points[pt_index];
-
   /* Apply color to Stroke point. */
-  if (GPENCIL_TINT_VERTEX_COLOR_STROKE(brush)) {
+  if (GPENCIL_TINT_VERTEX_COLOR_STROKE(brush) && (pt_index > -1)) {
+    bGPDspoint *pt = &gps->points[pt_index];
     if (brush_invert_check(gso)) {
       pt->vert_color[3] -= inf;
       CLAMP_MIN(pt->vert_color[3], 0.0f);
@@ -813,15 +813,18 @@ static void gp_save_selected_point(tGP_BrushVertexpaintData *gso,
   selected = &gso->pbuffer[gso->pbuffer_used];
   selected->gps = gps;
   selected->pt_index = index;
-  copy_v2_v2_int(selected->pc, pc);
-  copy_v4_v4(selected->color, pt->vert_color);
-
+  /* Check the index is not a special case for fill. */
+  if (index > -1) {
+    copy_v2_v2_int(selected->pc, pc);
+    copy_v4_v4(selected->color, pt->vert_color);
+  }
   gso->pbuffer_used++;
 }
 
 /* Select points in this stroke and add to an array to be used later. */
 static void gp_vertexpaint_select_stroke(tGP_BrushVertexpaintData *gso,
                                          bGPDstroke *gps,
+                                         const char tool,
                                          const float diff_mat[4][4])
 {
   GP_SpaceConversion *gsc = &gso->gsc;
@@ -869,6 +872,7 @@ static void gp_vertexpaint_select_stroke(tGP_BrushVertexpaintData *gso,
     /* Loop over the points in the stroke, checking for intersections
      * - an intersection means that we touched the stroke
      */
+    bool hit = false;
     for (i = 0; (i + 1) < gps->totpoints; i++) {
       /* Get points to work with */
       pt1 = gps->points + i;
@@ -904,6 +908,7 @@ static void gp_vertexpaint_select_stroke(tGP_BrushVertexpaintData *gso,
           pt_active = (pt->runtime.pt_orig) ? pt->runtime.pt_orig : pt;
           index = (pt->runtime.pt_orig) ? pt->runtime.idx_orig : i;
           if (pt_active != NULL) {
+            hit = true;
             gp_save_selected_point(gso, gps_active, index, pc1);
           }
 
@@ -920,6 +925,7 @@ static void gp_vertexpaint_select_stroke(tGP_BrushVertexpaintData *gso,
             pt_active = (pt->runtime.pt_orig) ? pt->runtime.pt_orig : pt;
             index = (pt->runtime.pt_orig) ? pt->runtime.idx_orig : i + 1;
             if (pt_active != NULL) {
+              hit = true;
               gp_save_selected_point(gso, gps_active, index, pc2);
               include_last = false;
             }
@@ -938,6 +944,7 @@ static void gp_vertexpaint_select_stroke(tGP_BrushVertexpaintData *gso,
           pt_active = (pt->runtime.pt_orig) ? pt->runtime.pt_orig : pt;
           index = (pt->runtime.pt_orig) ? pt->runtime.idx_orig : i;
           if (pt_active != NULL) {
+            hit = true;
             gp_save_selected_point(gso, gps_active, index, pc1);
 
             include_last = false;
@@ -945,6 +952,24 @@ static void gp_vertexpaint_select_stroke(tGP_BrushVertexpaintData *gso,
         }
       }
     }
+
+    /* If nothing hit, check if the mouse is inside any filled stroke. */
+    if ((!hit) && (ELEM(tool, GPAINT_TOOL_TINT, GPVERTEX_TOOL_DRAW))) {
+      MaterialGPencilStyle *gp_style = BKE_gpencil_material_settings(gso->object,
+                                                                     gps_active->mat_nr + 1);
+      if (gp_style->flag & GP_MATERIAL_FILL_SHOW) {
+        int mval[2];
+        round_v2i_v2fl(mval, gso->mval);
+        bool hit_fill = ED_gpencil_stroke_point_is_inside(gps_active, gsc, mval, diff_mat);
+        if (hit_fill) {
+          /* Need repeat the effect because if we don't do that the tint process
+           * is very slow. */
+          for (int repeat = 0; repeat < 50; repeat++) {
+            gp_save_selected_point(gso, gps_active, -1, NULL);
+          }
+        }
+      }
+    }
   }
 }
 
@@ -956,8 +981,8 @@ static bool gp_vertexpaint_brush_do_frame(bContext *C,
                                           const float diff_mat[4][4])
 {
   Object *ob = CTX_data_active_object(C);
-  char tool = ob->mode == OB_MODE_VERTEX_GPENCIL ? gso->brush->gpencil_vertex_tool :
-                                                   gso->brush->gpencil_tool;
+  const char tool = ob->mode == OB_MODE_VERTEX_GPENCIL ? gso->brush->gpencil_vertex_tool :
+                                                         gso->brush->gpencil_tool;
   const int radius = (gso->brush->flag & GP_BRUSH_USE_PRESSURE) ?
                          gso->brush->size * gso->pressure :
                          gso->brush->size;
@@ -980,7 +1005,7 @@ static bool gp_vertexpaint_brush_do_frame(bContext *C,
     }
 
     /* Check points below the brush. */
-    gp_vertexpaint_select_stroke(gso, gps, diff_mat);
+    gp_vertexpaint_select_stroke(gso, gps, tool, diff_mat);
   }
 
   /* For Average tool, need calculate the average resulting color from all colors