DrawManager: Add Edge Detection To DisplayLists

Objects that internally uses DispList do not cast shadow in the workbench.
Their outline is also not visible in object mode. The reason for this is
that edge detection was not implemented for Display Lists. This patch will
implement the edge detection.

Reviewed By: fclem

Maniphest Tasks: T62479

Differential Revision: https://developer.blender.org/D4605

1 files changed, 47 insertions, 0 deletions

diff --git a/source/blender/draw/intern/draw_cache_impl_metaball.c b/source/blender/draw/intern/draw_cache_impl_metaball.c
index 811f01aa83a..46c247d67ea 100644
--- a/source/blender/draw/intern/draw_cache_impl_metaball.c
+++ b/source/blender/draw/intern/draw_cache_impl_metaball.c
@@ -47,6 +47,7 @@ static void metaball_batch_cache_clear(MetaBall *mb);
 typedef struct MetaBallBatchCache {
 	GPUBatch *batch;
 	GPUBatch **shaded_triangles;
+
 	int mat_len;
 
 	/* Shared */
@@ -57,8 +58,15 @@ typedef struct MetaBallBatchCache {
 		GPUBatch *batch;
 	} face_wire;
 
+	/* Edge detection */
+	GPUBatch *edge_detection;
+	GPUIndexBuf *edges_adj_lines;
+
 	/* settings to determine if cache is invalid */
 	bool is_dirty;
+
+	/* Valid only if edge_detection is up to date. */
+	bool is_manifold;
 } MetaBallBatchCache;
 
 /* GPUBatch cache management. */
@@ -87,6 +95,9 @@ static void metaball_batch_cache_init(MetaBall *mb)
 	cache->is_dirty = false;
 	cache->pos_nor_in_order = NULL;
 	cache->face_wire.batch = NULL;
+	cache->edge_detection = NULL;
+	cache->edges_adj_lines = NULL;
+	cache->is_manifold = false;
 }
 
 static MetaBallBatchCache *metaball_batch_cache_get(MetaBall *mb)
@@ -122,10 +133,13 @@ static void metaball_batch_cache_clear(MetaBall *mb)
 
 	GPU_BATCH_DISCARD_SAFE(cache->face_wire.batch);
 	GPU_BATCH_DISCARD_SAFE(cache->batch);
+	GPU_BATCH_DISCARD_SAFE(cache->edge_detection);
 	GPU_VERTBUF_DISCARD_SAFE(cache->pos_nor_in_order);
+	GPU_INDEXBUF_DISCARD_SAFE(cache->edges_adj_lines);
 	/* Note: shaded_triangles[0] is already freed by cache->batch */
 	MEM_SAFE_FREE(cache->shaded_triangles);
 	cache->mat_len = 0;
+	cache->is_manifold = false;
 }
 
 void DRW_mball_batch_cache_free(MetaBall *mb)
@@ -144,6 +158,16 @@ static GPUVertBuf *mball_batch_cache_get_pos_and_normals(Object *ob, MetaBallBat
 	return cache->pos_nor_in_order;
 }
 
+static GPUIndexBuf *mball_batch_cache_get_edges_adj_lines(Object *ob, MetaBallBatchCache *cache)
+{
+	if (cache->edges_adj_lines == NULL) {
+		ListBase *lb = &ob->runtime.curve_cache->disp;
+		cache->edges_adj_lines = MEM_callocN(sizeof(GPUVertBuf), __func__);
+		DRW_displist_indexbuf_create_edges_adjacency_lines(lb, cache->edges_adj_lines, &cache->is_manifold);
+	}
+	return cache->edges_adj_lines;
+}
+
 /* -------------------------------------------------------------------- */
 /** \name Public Object/MetaBall API
  * \{ */
@@ -219,3 +243,26 @@ GPUBatch *DRW_metaball_batch_cache_get_wireframes_face(Object *ob)
 
 	return cache->face_wire.batch;
 }
+
+struct GPUBatch *DRW_metaball_batch_cache_get_edge_detection(struct Object *ob, bool *r_is_manifold)
+{
+	if (!BKE_mball_is_basis(ob)) {
+		return NULL;
+	}
+
+	MetaBall *mb = ob->data;
+	MetaBallBatchCache *cache = metaball_batch_cache_get(mb);
+
+	if (cache->edge_detection == NULL) {
+		cache->edge_detection = GPU_batch_create(
+		        GPU_PRIM_LINES_ADJ,
+		        mball_batch_cache_get_pos_and_normals(ob, cache),
+		        mball_batch_cache_get_edges_adj_lines(ob, cache));
+	}
+
+	if (r_is_manifold) {
+		*r_is_manifold = cache->is_manifold;
+	}
+
+	return cache->edge_detection;
+}
\ No newline at end of file