Edit Mode: Reduce number of edges drawn

This make sure only one line is drawn per edge.

It makes the function mesh_create_edit_loops_points_lines() non-thread safe
but this is fine as of now because nothing is multithreaded at this point.
Also this is the only function use this flag so it might be OK.

The side effect is that we don't need to use depth test in edit mode
overlay so the masking artifact will not appear.

1 files changed, 27 insertions, 9 deletions

diff --git a/source/blender/draw/intern/draw_cache_impl_mesh.c b/source/blender/draw/intern/draw_cache_impl_mesh.c
index b51c684a0fd..80d753a58d7 100644
--- a/source/blender/draw/intern/draw_cache_impl_mesh.c
+++ b/source/blender/draw/intern/draw_cache_impl_mesh.c
@@ -3797,6 +3797,8 @@ static void mesh_create_loops_tris(
 	}
 }
 
+/* Warning! this function is not thread safe!
+ * It writes to MEdge->flag with ME_EDGE_TMP_TAG. */
 static void mesh_create_edit_loops_points_lines(MeshRenderData *rdata, GPUIndexBuf *ibo_verts, GPUIndexBuf *ibo_edges)
 {
 	BMIter iter_efa, iter_loop;
@@ -3804,6 +3806,7 @@ static void mesh_create_edit_loops_points_lines(MeshRenderData *rdata, GPUIndexB
 	BMLoop *loop;
 	int i;
 
+	const int edge_len = mesh_render_data_edges_len_get_maybe_mapped(rdata);
 	const int loop_len = mesh_render_data_loops_len_get_maybe_mapped(rdata);
 	const int poly_len = mesh_render_data_polys_len_get_maybe_mapped(rdata);
 	const int lvert_len = mesh_render_data_loose_verts_len_get_maybe_mapped(rdata);
@@ -3812,7 +3815,7 @@ static void mesh_create_edit_loops_points_lines(MeshRenderData *rdata, GPUIndexB
 
 	GPUIndexBufBuilder elb_vert, elb_edge;
 	if (DRW_TEST_ASSIGN_IBO(ibo_edges)) {
-		GPU_indexbuf_init(&elb_edge, GPU_PRIM_LINES, loop_len + ledge_len, tot_loop_len);
+		GPU_indexbuf_init(&elb_edge, GPU_PRIM_LINES, edge_len, tot_loop_len);
 	}
 	if (DRW_TEST_ASSIGN_IBO(ibo_verts)) {
 		GPU_indexbuf_init(&elb_vert, GPU_PRIM_POINTS, tot_loop_len, tot_loop_len);
@@ -3821,6 +3824,17 @@ static void mesh_create_edit_loops_points_lines(MeshRenderData *rdata, GPUIndexB
 	int loop_idx = 0;
 	if (rdata->edit_bmesh && (rdata->mapped.use == false)) {
 		BMesh *bm = rdata->edit_bmesh->bm;
+		BMEdge *eed;
+		/* Edges not loose. */
+		BM_ITER_MESH (eed, &iter_efa, bm, BM_EDGES_OF_MESH) {
+			if (!BM_elem_flag_test(eed, BM_ELEM_HIDDEN)) {
+				if (ibo_edges && eed->l != NULL) {
+					int v1 = BM_elem_index_get(eed->l);
+					int v2 = BM_elem_index_get(eed->l->next);
+					GPU_indexbuf_add_line_verts(&elb_edge, v1, v2);
+				}
+			}
+		}
 		/* Face Loops */
 		BM_ITER_MESH (efa, &iter_efa, bm, BM_FACES_OF_MESH) {
 			if (!BM_elem_flag_test(efa, BM_ELEM_HIDDEN)) {
@@ -3828,11 +3842,6 @@ static void mesh_create_edit_loops_points_lines(MeshRenderData *rdata, GPUIndexB
 					if (ibo_verts) {
 						GPU_indexbuf_add_generic_vert(&elb_vert, loop_idx + i);
 					}
-					if (ibo_edges) {
-						int v1 = loop_idx + i;
-						int v2 = loop_idx + ((i + 1) % efa->len);
-						GPU_indexbuf_add_line_verts(&elb_edge, v1, v2);
-					}
 				}
 			}
 			loop_idx += efa->len;
@@ -3858,13 +3867,19 @@ static void mesh_create_edit_loops_points_lines(MeshRenderData *rdata, GPUIndexB
 	}
 	else if (rdata->mapped.use) {
 		const MPoly *mpoly = rdata->mapped.me_cage->mpoly;
-		const MEdge *medge = rdata->mapped.me_cage->medge;
+		MEdge *medge = rdata->mapped.me_cage->medge;
 		BMesh *bm = rdata->edit_bmesh->bm;
 
 		const int *v_origindex = rdata->mapped.v_origindex;
 		const int *e_origindex = rdata->mapped.e_origindex;
 		const int *p_origindex = rdata->mapped.p_origindex;
 
+		/* Reset flag */
+		for (int edge = 0; edge < edge_len; ++edge) {
+			/* NOTE: not thread safe. */
+			medge[edge].flag &= ~ME_EDGE_TMP_TAG;
+		}
+
 		/* Face Loops */
 		for (int poly = 0; poly < poly_len; poly++, mpoly++) {
 			int fidx = p_origindex[poly];
@@ -3876,7 +3891,10 @@ static void mesh_create_edit_loops_points_lines(MeshRenderData *rdata, GPUIndexB
 						if (ibo_verts && (v_origindex[mloop->v] != ORIGINDEX_NONE)) {
 							GPU_indexbuf_add_generic_vert(&elb_vert, loop_idx + i);
 						}
-						if (ibo_edges && (e_origindex[mloop->e] != ORIGINDEX_NONE)) {
+						if (ibo_edges && (e_origindex[mloop->e] != ORIGINDEX_NONE) &&
+						    ((medge[mloop->e].flag & ME_EDGE_TMP_TAG) == 0))
+						{
+							medge[mloop->e].flag |= ME_EDGE_TMP_TAG;
 							int v1 = loop_idx + i;
 							int v2 = loop_idx + ((i + 1) % mpoly->totloop);
 							GPU_indexbuf_add_line_verts(&elb_edge, v1, v2);
@@ -4781,7 +4799,7 @@ void DRW_mesh_batch_cache_create_requested(
 		DRW_vbo_request(cache->batch.edit_edges, &cache->edit.loop_data);
 	}
 	if (DRW_batch_requested(cache->batch.edit_lnor, GPU_PRIM_POINTS)) {
-		DRW_ibo_request(cache->batch.edit_lnor, &cache->ibo.edit_loops_lines);
+		DRW_ibo_request(cache->batch.edit_lnor, &cache->ibo.edit_loops_tris);
 		DRW_vbo_request(cache->batch.edit_lnor, &cache->edit.loop_pos_nor);
 		DRW_vbo_request(cache->batch.edit_lnor, &cache->edit.loop_lnor);
 	}