Cleanup: BLI_task - API changes.

Based on usages so far:
- Split callback worker func in two, 'basic' and 'extended' versions. The former goes back
  to the simplest verion, while the later keeps the 'userdata_chunk', and gets the thread_id too.
- Add use_threading to simple BLI_task_parallel_range(), turns out we need this pretty much systematically,
  and allows to get rid of most usages of BLI_task_parallel_range_ex().
- Now BLI_task_parallel_range() expects 'basic' version of callback, while BLI_task_parallel_range_ex()
  expectes 'extended' version of the callback.

All in all, this should make common usage of BLI_task_parallel_range simpler (less verbose), and add
access to advanced callback to thread id, which is mandatory in some (future) cases.

4 files changed, 15 insertions, 12 deletions

diff --git a/source/blender/modifiers/intern/MOD_meshdeform.c b/source/blender/modifiers/intern/MOD_meshdeform.c
index 5f2f51df528..e3c94a1a4df 100644
--- a/source/blender/modifiers/intern/MOD_meshdeform.c
+++ b/source/blender/modifiers/intern/MOD_meshdeform.c
@@ -234,7 +234,7 @@ typedef struct MeshdeformUserdata {
 	float (*icagemat)[3];
 } MeshdeformUserdata;
 
-static void meshdeform_vert_task(void *userdata, void *UNUSED(userdata_chunck), int iter)
+static void meshdeform_vert_task(void *userdata, const int iter)
 {
 	MeshdeformUserdata *data = userdata;
 	/*const*/ MeshDeformModifierData *mmd = data->mmd;
@@ -413,7 +413,7 @@ static void meshdeformModifier_do(
 	data.icagemat = icagemat;
 
 	/* Do deformation. */
-	BLI_task_parallel_range(0, totvert, &data, meshdeform_vert_task);
+	BLI_task_parallel_range(0, totvert, &data, meshdeform_vert_task, totvert > 1000);
 
 	/* release cage derivedmesh */
 	MEM_freeN(dco);
diff --git a/source/blender/modifiers/intern/MOD_ocean.c b/source/blender/modifiers/intern/MOD_ocean.c
index 18fbc99d887..a90a51e9ddc 100644
--- a/source/blender/modifiers/intern/MOD_ocean.c
+++ b/source/blender/modifiers/intern/MOD_ocean.c
@@ -280,7 +280,7 @@ typedef struct GenerateOceanGeometryData {
 	float ix, iy;
 } GenerateOceanGeometryData;
 
-static void generate_ocean_geometry_vertices(void *userdata, void *UNUSED(userdata_chunk), int y)
+static void generate_ocean_geometry_vertices(void *userdata, const int y)
 {
 	GenerateOceanGeometryData *gogd = userdata;
 	int x;
@@ -294,7 +294,7 @@ static void generate_ocean_geometry_vertices(void *userdata, void *UNUSED(userda
 	}
 }
 
-static void generate_ocean_geometry_polygons(void *userdata, void *UNUSED(userdata_chunk), int y)
+static void generate_ocean_geometry_polygons(void *userdata, const int y)
 {
 	GenerateOceanGeometryData *gogd = userdata;
 	int x;
@@ -324,7 +324,7 @@ static void generate_ocean_geometry_polygons(void *userdata, void *UNUSED(userda
 	}
 }
 
-static void generate_ocean_geometry_uvs(void *userdata, void *UNUSED(userdata_chunk), int y)
+static void generate_ocean_geometry_uvs(void *userdata, const int y)
 {
 	GenerateOceanGeometryData *gogd = userdata;
 	int x;
@@ -360,6 +360,8 @@ static DerivedMesh *generate_ocean_geometry(OceanModifierData *omd)
 	int num_verts;
 	int num_polys;
 
+	const bool use_threading = omd->resolution > 4;
+
 	gogd.rx = omd->resolution * omd->resolution;
 	gogd.ry = omd->resolution * omd->resolution;
 	gogd.res_x = gogd.rx * omd->repeat_x;
@@ -385,10 +387,10 @@ static DerivedMesh *generate_ocean_geometry(OceanModifierData *omd)
 	gogd.origindex = CustomData_get_layer(&result->polyData, CD_ORIGINDEX);
 
 	/* create vertices */
-	BLI_task_parallel_range(0, gogd.res_y + 1, &gogd, generate_ocean_geometry_vertices);
+	BLI_task_parallel_range(0, gogd.res_y + 1, &gogd, generate_ocean_geometry_vertices, use_threading);
 
 	/* create faces */
-	BLI_task_parallel_range(0, gogd.res_y, &gogd, generate_ocean_geometry_polygons);
+	BLI_task_parallel_range(0, gogd.res_y, &gogd, generate_ocean_geometry_polygons, use_threading);
 
 	CDDM_calc_edges(result);
 
@@ -401,7 +403,7 @@ static DerivedMesh *generate_ocean_geometry(OceanModifierData *omd)
 			gogd.ix = 1.0 / gogd.rx;
 			gogd.iy = 1.0 / gogd.ry;
 
-			BLI_task_parallel_range(0, gogd.res_y, &gogd, generate_ocean_geometry_uvs);
+			BLI_task_parallel_range(0, gogd.res_y, &gogd, generate_ocean_geometry_uvs, use_threading);
 		}
 	}
 
diff --git a/source/blender/modifiers/intern/MOD_uvwarp.c b/source/blender/modifiers/intern/MOD_uvwarp.c
index 3b549ec77d3..89994c3ae22 100644
--- a/source/blender/modifiers/intern/MOD_uvwarp.c
+++ b/source/blender/modifiers/intern/MOD_uvwarp.c
@@ -112,7 +112,7 @@ typedef struct UVWarpData {
 	int axis_v;
 } UVWarpData;
 
-static void uv_warp_compute(void *userdata, void *UNUSED(userdata_chunk), int i)
+static void uv_warp_compute(void *userdata, const int i)
 {
 	const UVWarpData *data = userdata;
 
@@ -210,7 +210,7 @@ static DerivedMesh *applyModifier(ModifierData *md, Object *ob,
 	UVWarpData data = {.mpoly = mpoly, .mloop = mloop, .mloopuv = mloopuv,
 	                   .dvert = dvert, .defgrp_index = defgrp_index,
 	                   .warp_mat = warp_mat, .axis_u = axis_u, .axis_v = axis_v};
-	BLI_task_parallel_range_ex(0, numPolys, &data, NULL, 0, uv_warp_compute, numPolys > 1000, false);
+	BLI_task_parallel_range(0, numPolys, &data, uv_warp_compute, numPolys > 1000);
 
 	dm->dirty |= DM_DIRTY_TESS_CDLAYERS;
 
diff --git a/source/blender/modifiers/intern/MOD_weightvgproximity.c b/source/blender/modifiers/intern/MOD_weightvgproximity.c
index be86dfe4a92..f126e499fc2 100644
--- a/source/blender/modifiers/intern/MOD_weightvgproximity.c
+++ b/source/blender/modifiers/intern/MOD_weightvgproximity.c
@@ -89,7 +89,7 @@ typedef struct Vert2GeomDataChunk {
 /**
  * Callback used by BLI_task 'for loop' helper.
  */
-static void vert2geom_task_cb(void *userdata, void *userdata_chunk, int iter)
+static void vert2geom_task_cb_ex(void *userdata, void *userdata_chunk, const int iter, const int UNUSED(thread_id))
 {
 	Vert2GeomData *data = userdata;
 	Vert2GeomDataChunk *data_chunk = userdata_chunk;
@@ -177,7 +177,8 @@ static void get_vert2geom_distance(int numVerts, float (*v_cos)[3],
 	data.dist[2] = dist_f;
 
 	BLI_task_parallel_range_ex(
-	            0, numVerts, &data, &data_chunk, sizeof(data_chunk), vert2geom_task_cb, numVerts > 10000, false);
+	            0, numVerts, &data, &data_chunk, sizeof(data_chunk), vert2geom_task_cb_ex,
+	            numVerts > 10000, false);
 
 	if (dist_v)
 		free_bvhtree_from_mesh(&treeData_v);