Fix T77156: GPencil view layer filter by layer not working

This was removed by error during the refactor done in 2.83.

Differential Revision: https://developer.blender.org/D7909

Reviewers: @fclem

source/blender/blenkernel/BKE_gpencil.h

@@ -41,6 +41,7 @@ struct Object;
 struct Scene;
 struct SpaceImage;
 struct ToolSettings;
+struct ViewLayer;
 struct bDeformGroup;
 struct bGPDframe;
 struct bGPDlayer;
@@ -253,7 +254,8 @@ typedef void (*gpIterCb)(struct bGPDlayer *layer,
                          struct bGPDstroke *stroke,
                          void *thunk);
 
-void BKE_gpencil_visible_stroke_iter(struct Object *ob,
+void BKE_gpencil_visible_stroke_iter(struct ViewLayer *view_layer,
+                                     struct Object *ob,
                                      gpIterCb layer_cb,
                                      gpIterCb stroke_cb,
                                      void *thunk,

source/blender/blenkernel/intern/gpencil.c

@@ -1840,8 +1840,13 @@ bool BKE_gpencil_from_image(SpaceImage *sima, bGPDframe *gpf, const float size,
  *
  * \{ */
 
-void BKE_gpencil_visible_stroke_iter(
-    Object *ob, gpIterCb layer_cb, gpIterCb stroke_cb, void *thunk, bool do_onion, int cfra)
+void BKE_gpencil_visible_stroke_iter(ViewLayer *view_layer,
+                                     Object *ob,
+                                     gpIterCb layer_cb,
+                                     gpIterCb stroke_cb,
+                                     void *thunk,
+                                     bool do_onion,
+                                     int cfra)
 {
   bGPdata *gpd = (bGPdata *)ob->data;
   const bool is_multiedit = GPENCIL_MULTIEDIT_SESSIONS_ON(gpd);
@@ -1863,6 +1868,14 @@ void BKE_gpencil_visible_stroke_iter(
       continue;
     }
 
+    /* Hide the layer if it's defined a view layer filter. This is used to
+     * generate renders, putting only selected GP layers for each View Layer.
+     * This is used only in final render and never in Viewport. */
+    if ((view_layer != NULL) && (gpl->viewlayername[0] != '\0') &&
+        (!STREQ(view_layer->name, gpl->viewlayername))) {
+      continue;
+    }
+
     if (is_multiedit) {
       sta_gpf = end_gpf = NULL;
       /* Check the whole range and tag the editable frames. */

source/blender/draw/engines/gpencil/gpencil_engine.c

@@ -91,6 +91,7 @@ void GPENCIL_engine_init(void *ved)
   stl->pd->gp_object_pool = vldata->gp_object_pool;
   stl->pd->gp_layer_pool = vldata->gp_layer_pool;
   stl->pd->gp_vfx_pool = vldata->gp_vfx_pool;
+  stl->pd->view_layer = ctx->view_layer;
   stl->pd->scene = ctx->scene;
   stl->pd->v3d = ctx->v3d;
   stl->pd->last_light_pool = NULL;
@@ -598,6 +599,7 @@ void GPENCIL_cache_populate(void *ved, Object *ob)
   GPENCIL_Data *vedata = (GPENCIL_Data *)ved;
   GPENCIL_PrivateData *pd = vedata->stl->pd;
   GPENCIL_TextureList *txl = vedata->txl;
+  const bool is_final_render = DRW_state_is_image_render();
 
   /* object must be visible */
   if (!(DRW_object_visibility_in_active_context(ob) & OB_VISIBLE_SELF)) {
@@ -617,7 +619,8 @@ void GPENCIL_cache_populate(void *ved, Object *ob)
     bGPdata *gpd = (bGPdata *)ob->data;
     bool do_onion = (!pd->is_render) ? pd->do_onion : (gpd->onion_flag & GP_ONION_GHOST_ALWAYS);
 
-    BKE_gpencil_visible_stroke_iter(ob,
+    BKE_gpencil_visible_stroke_iter(is_final_render ? pd->view_layer : NULL,
+                                    ob,
                                     gpencil_layer_cache_populate,
                                     gpencil_stroke_cache_populate,
                                     &iter,

source/blender/draw/engines/gpencil/gpencil_engine.h

@@ -307,6 +307,8 @@ typedef struct GPENCIL_PrivateData {
   float dof_params[2];
   /* Used for DoF Setup. */
   Object *camera;
+  /* Copy of draw_ctx->view_layer for convenience. */
+  struct ViewLayer *view_layer;
   /* Copy of draw_ctx->scene for convenience. */
   struct Scene *scene;
   /* Copy of draw_ctx->vie3d for convenience. */

source/blender/draw/engines/overlay/overlay_gpencil.c

@@ -358,7 +358,7 @@ static void OVERLAY_gpencil_color_names(Object *ob)
   int cfra = DEG_get_ctime(draw_ctx->depsgraph);
 
   BKE_gpencil_visible_stroke_iter(
-      ob, NULL, overlay_gpencil_draw_stroke_color_name, ob, false, cfra);
+      NULL, ob, NULL, overlay_gpencil_draw_stroke_color_name, ob, false, cfra);
 }
 
 void OVERLAY_gpencil_cache_populate(OVERLAY_Data *vedata, Object *ob)

source/blender/draw/engines/overlay/overlay_outline.c

@@ -259,7 +259,7 @@ static void OVERLAY_outline_gpencil(OVERLAY_PrivateData *pd, Object *ob)
   }
 
   BKE_gpencil_visible_stroke_iter(
-      ob, gp_layer_cache_populate, gp_stroke_cache_populate, &iter, false, pd->cfra);
+      NULL, ob, gp_layer_cache_populate, gp_stroke_cache_populate, &iter, false, pd->cfra);
 }
 
 void OVERLAY_outline_cache_populate(OVERLAY_Data *vedata,

source/blender/draw/intern/draw_cache_impl_gpencil.c

@@ -102,6 +102,7 @@ static GpencilBatchCache *gpencil_batch_cache_init(Object *ob, int cfra)
 
   cache->is_dirty = true;
   cache->cache_frame = cfra;
+
   return cache;
 }
 
@@ -385,7 +386,8 @@ static void gpencil_batches_ensure(Object *ob, GpencilBatchCache *cache, int cfr
         .vert_len = 1, /* Start at 1 for the gl_InstanceID trick to work (see vert shader). */
         .tri_len = 0,
     };
-    BKE_gpencil_visible_stroke_iter(ob, NULL, gp_object_verts_count_cb, &iter, do_onion, cfra);
+    BKE_gpencil_visible_stroke_iter(
+        NULL, ob, NULL, gp_object_verts_count_cb, &iter, do_onion, cfra);
 
     /* Create VBOs. */
     GPUVertFormat *format = gpencil_stroke_format();
@@ -401,7 +403,7 @@ static void gpencil_batches_ensure(Object *ob, GpencilBatchCache *cache, int cfr
     GPU_indexbuf_init(&iter.ibo, GPU_PRIM_TRIS, iter.tri_len, iter.vert_len);
 
     /* Fill buffers with data. */
-    BKE_gpencil_visible_stroke_iter(ob, NULL, gpencil_stroke_iter_cb, &iter, do_onion, cfra);
+    BKE_gpencil_visible_stroke_iter(NULL, ob, NULL, gpencil_stroke_iter_cb, &iter, do_onion, cfra);
 
     /* Mark last 2 verts as invalid. */
     for (int i = 0; i < 2; i++) {
@@ -475,7 +477,7 @@ GPUBatch *DRW_cache_gpencil_face_wireframe_get(Object *ob)
 
     /* IMPORTANT: Keep in sync with gpencil_edit_batches_ensure() */
     bool do_onion = true;
-    BKE_gpencil_visible_stroke_iter(ob, NULL, gp_lines_indices_cb, &iter, do_onion, cfra);
+    BKE_gpencil_visible_stroke_iter(NULL, ob, NULL, gp_lines_indices_cb, &iter, do_onion, cfra);
 
     GPUIndexBuf *ibo = GPU_indexbuf_build(&iter.ibo);
 
@@ -724,7 +726,8 @@ static void gpencil_edit_batches_ensure(Object *ob, GpencilBatchCache *cache, in
     iter.verts = (gpEditVert *)cache->edit_vbo->data;
 
     /* Fill buffers with data. */
-    BKE_gpencil_visible_stroke_iter(ob, NULL, gpencil_edit_stroke_iter_cb, &iter, do_onion, cfra);
+    BKE_gpencil_visible_stroke_iter(
+        NULL, ob, NULL, gpencil_edit_stroke_iter_cb, &iter, do_onion, cfra);
 
     /* Create the batches */
     cache->edit_points_batch = GPU_batch_create(GPU_PRIM_POINTS, cache->vbo, NULL);