Depsgraph: add a new operation node for computing B-Bone segments.

Computing the shape of a B-Bone is a quite expensive operation, and
there are multiple constraints that can access this information in
a variety of useful ways. This means computing the shape once per
bone and saving it is good for performance.

Since the shape may depend on the position of up to two other bones,
often in a "cyclic" manner, this computation has to be a separate
node with its own dependencies.

Reviewers: sergey

Differential Revision: https://developer.blender.org/D3975

1 files changed, 61 insertions, 29 deletions

diff --git a/source/blender/blenkernel/intern/armature.c b/source/blender/blenkernel/intern/armature.c
index 967e2ac921c..2004b66c1ef 100644
--- a/source/blender/blenkernel/intern/armature.c
+++ b/source/blender/blenkernel/intern/armature.c
@@ -822,26 +822,46 @@ typedef struct ObjectBBoneDeform {
 	int num_pchan;
 } ObjectBBoneDeform;
 
-static void pchan_b_bone_defmats(bPoseChannel *pchan, bPoseChanDeform *pdef_info, const bool use_quaternion)
+static void allocate_bbone_cache(bPoseChannel *pchan, int segments)
 {
+	bPoseChannelRuntime *runtime = &pchan->runtime;
+
+	if (runtime->bbone_segments != segments) {
+		if (runtime->bbone_segments != 0) {
+			BKE_pose_channel_free_bbone_cache(pchan);
+		}
+
+		runtime->bbone_segments = segments;
+		runtime->bbone_rest_mats = MEM_malloc_arrayN(sizeof(Mat4), (uint)segments, "bPoseChannelRuntime::bbone_rest_mats");
+		runtime->bbone_pose_mats = MEM_malloc_arrayN(sizeof(Mat4), (uint)segments, "bPoseChannelRuntime::bbone_pose_mats");
+		runtime->bbone_deform_mats = MEM_malloc_arrayN(sizeof(Mat4), 1 + (uint)segments, "bPoseChannelRuntime::bbone_deform_mats");
+		runtime->bbone_dual_quats = MEM_malloc_arrayN(sizeof(DualQuat), (uint)segments, "bPoseChannelRuntime::bbone_dual_quats");
+	}
+}
+
+/** Compute and cache the B-Bone shape in the channel runtime struct. */
+void BKE_pchan_cache_bbone_segments(bPoseChannel *pchan)
+{
+	bPoseChannelRuntime *runtime = &pchan->runtime;
 	Bone *bone = pchan->bone;
-	Mat4 b_bone[MAX_BBONE_SUBDIV], b_bone_rest[MAX_BBONE_SUBDIV];
-	Mat4 *b_bone_mats;
-	DualQuat *b_bone_dual_quats = NULL;
+	int segments = bone->segments;
+
+	BLI_assert(segments > 1);
+
+	/* Allocate the cache if needed. */
+	allocate_bbone_cache(pchan, segments);
+
+	/* Compute the shape. */
+	Mat4 *b_bone = runtime->bbone_pose_mats;
+	Mat4 *b_bone_rest = runtime->bbone_rest_mats;
+	Mat4 *b_bone_mats = runtime->bbone_deform_mats;
+	DualQuat *b_bone_dual_quats = runtime->bbone_dual_quats;
 	int a;
 
 	b_bone_spline_setup(pchan, false, b_bone);
 	b_bone_spline_setup(pchan, true, b_bone_rest);
 
-	/* allocate b_bone matrices and dual quats */
-	b_bone_mats = MEM_mallocN((1 + bone->segments) * sizeof(Mat4), "BBone defmats");
-	pdef_info->b_bone_mats = b_bone_mats;
-
-	if (use_quaternion) {
-		b_bone_dual_quats = MEM_mallocN((bone->segments) * sizeof(DualQuat), "BBone dqs");
-		pdef_info->b_bone_dual_quats = b_bone_dual_quats;
-	}
-
+	/* Compute deform matrices. */
 	/* first matrix is the inverse arm_mat, to bring points in local bone space
 	 * for finding out which segment it belongs to */
 	invert_m4_m4(b_bone_mats[0].mat, bone->arm_mat);
@@ -858,8 +878,27 @@ static void pchan_b_bone_defmats(bPoseChannel *pchan, bPoseChanDeform *pdef_info
 		invert_m4_m4(tmat, b_bone_rest[a].mat);
 		mul_m4_series(b_bone_mats[a + 1].mat, pchan->chan_mat, bone->arm_mat, b_bone[a].mat, tmat, b_bone_mats[0].mat);
 
-		if (use_quaternion)
-			mat4_to_dquat(&b_bone_dual_quats[a], bone->arm_mat, b_bone_mats[a + 1].mat);
+		mat4_to_dquat(&b_bone_dual_quats[a], bone->arm_mat, b_bone_mats[a + 1].mat);
+	}
+}
+
+/** Copy cached B-Bone segments from one channel to another */
+void BKE_pchan_copy_bbone_segments_cache(bPoseChannel *pchan, bPoseChannel *pchan_from)
+{
+	bPoseChannelRuntime *runtime = &pchan->runtime;
+	bPoseChannelRuntime *runtime_from = &pchan_from->runtime;
+	int segments = runtime_from->bbone_segments;
+
+	if (segments <= 1) {
+		BKE_pose_channel_free_bbone_cache(pchan);
+	}
+	else {
+		allocate_bbone_cache(pchan, segments);
+
+		memcpy(runtime->bbone_rest_mats, runtime_from->bbone_rest_mats, sizeof(Mat4) * segments);
+		memcpy(runtime->bbone_pose_mats, runtime_from->bbone_pose_mats, sizeof(Mat4) * segments);
+		memcpy(runtime->bbone_deform_mats, runtime_from->bbone_deform_mats, sizeof(Mat4) * (1 + segments));
+		memcpy(runtime->bbone_dual_quats, runtime_from->bbone_dual_quats, sizeof(DualQuat) * segments);
 	}
 }
 
@@ -978,7 +1017,7 @@ static float dist_bone_deform(bPoseChannel *pchan, const bPoseChanDeform *pdef_i
 		contrib = fac;
 		if (contrib > 0.0f) {
 			if (vec) {
-				if (bone->segments > 1)
+				if (bone->segments > 1 && pdef_info->b_bone_mats != NULL)
 					/* applies on cop and bbonemat */
 					b_bone_deform(pdef_info, bone, cop, NULL, (mat) ? bbonemat : NULL);
 				else
@@ -992,7 +1031,7 @@ static float dist_bone_deform(bPoseChannel *pchan, const bPoseChanDeform *pdef_i
 					pchan_deform_mat_add(pchan, fac, bbonemat, mat);
 			}
 			else {
-				if (bone->segments > 1) {
+				if (bone->segments > 1 && pdef_info->b_bone_mats != NULL) {
 					b_bone_deform(pdef_info, bone, cop, &bbonedq, NULL);
 					add_weighted_dq_dq(dq, &bbonedq, fac);
 				}
@@ -1059,7 +1098,10 @@ static void armature_bbone_defmats_cb(void *userdata, Link *iter, int index)
 		const bool use_quaternion = data->use_quaternion;
 
 		if (pchan->bone->segments > 1) {
-			pchan_b_bone_defmats(pchan, pdef_info, use_quaternion);
+			BLI_assert(pchan->runtime.bbone_segments == pchan->bone->segments);
+
+			pdef_info->b_bone_mats = pchan->runtime.bbone_deform_mats;
+			pdef_info->b_bone_dual_quats = pchan->runtime.bbone_dual_quats;
 		}
 
 		if (use_quaternion) {
@@ -2498,16 +2540,6 @@ void BKE_armature_cached_bbone_deformation_free_data(Object *object)
 	if (bbone_deform == NULL) {
 		return;
 	}
-	/* free B_bone matrices */
-	for (int i = 0; i < bbone_deform->num_pchan; i++) {
-		bPoseChanDeform *pdef_info = &bbone_deform->pdef_info_array[i];
-		if (pdef_info->b_bone_mats != NULL) {
-			MEM_freeN(pdef_info->b_bone_mats);
-		}
-		if (pdef_info->b_bone_dual_quats != NULL) {
-			MEM_freeN(pdef_info->b_bone_dual_quats);
-		}
-	}
 	/* Free arrays. */
 	MEM_SAFE_FREE(bbone_deform->pdef_info_array);
 	MEM_SAFE_FREE(bbone_deform->dualquats);
@@ -2560,7 +2592,7 @@ void BKE_armature_cached_bbone_deformation_update(Object *object)
 	BLI_task_parallel_listbase(&pose->chanbase,
 	                           &data,
 	                           armature_bbone_defmats_cb,
-	                           totchan > 512);
+	                           totchan > 1024);
 	/* Store pointers. */
 	bbone_deform->dualquats = dualquats;
 	atomic_cas_ptr((void **)&bbone_deform->pdef_info_array,