Bug fixes:

[#19596] Child particle in particle mode show for one redraw, then disappear
[#19598] Draw actual particles options draws in wrong location

3 files changed, 89 insertions, 23 deletions

diff --git a/source/blender/blenkernel/intern/particle.c b/source/blender/blenkernel/intern/particle.c
index ea8562c0ca8..322904136ea 100644
--- a/source/blender/blenkernel/intern/particle.c
+++ b/source/blender/blenkernel/intern/particle.c
@@ -2277,15 +2277,20 @@ static int psys_threads_init_path(ParticleThread *threads, Scene *scene, float c
 	ParticleSettings *part = psys->part;
 	ParticleEditSettings *pset = &scene->toolsettings->particle;
 	int totparent=0, between=0;
-	int steps = (int)pow(2.0,(double)part->draw_step);
+	int steps = (int)pow(2.0, (double)part->draw_step);
 	int totchild = psys->totchild;
 	int i, seed, totthread= threads[0].tot;
 
 	/*---start figuring out what is actually wanted---*/
-	if(psys_in_edit_mode(scene, psys))
+	if(psys_in_edit_mode(scene, psys)) {
+		ParticleEditSettings *pset = &scene->toolsettings->particle;
+
 		if(psys->renderdata==0 && (psys->edit==NULL || pset->flag & PE_DRAW_PART)==0)
 			totchild=0;
 
+		steps = (int)pow(2.0, (double)pset->draw_step);
+	}
+
 	if(totchild && part->from!=PART_FROM_PARTICLE && part->childtype==PART_CHILD_FACES){
 		totparent=(int)(totchild*part->parents*0.3);
 		
@@ -2360,7 +2365,7 @@ static void psys_thread_create_path(ParticleThread *thread, struct ChildParticle
 	ParticleSystem *psys = ctx->sim.psys;
 	ParticleSettings *part = psys->part;
 	ParticleCacheKey **cache= psys->childcache;
-	ParticleCacheKey **pcache= psys->pathcache;
+	ParticleCacheKey **pcache= psys_in_edit_mode(ctx->sim.scene, psys) ? psys->edit->pathcache : psys->pathcache;
 	ParticleCacheKey *state, *par = NULL, *key[4];
 	ParticleData *pa=NULL;
 	ParticleTexture ptex;
@@ -2372,6 +2377,9 @@ static void psys_thread_create_path(ParticleThread *thread, struct ChildParticle
 	int k, cpa_num;
 	short cpa_from;
 
+	if(!pcache)
+		return;
+
 	if(part->flag & PART_BRANCHING) {
 		branch_begin=rng_getFloat(thread->rng_path);
 		branch_end=branch_begin+(1.0f-branch_begin)*rng_getFloat(thread->rng_path);
@@ -2954,7 +2962,7 @@ void psys_cache_edit_paths(Scene *scene, Object *ob, PTCacheEdit *edit, float cf
 	
 	float birthtime = 0.0, dietime = 0.0;
 	float t, time = 0.0, keytime = 0.0, frs_sec;
-	float hairmat[4][4];
+	float hairmat[4][4], rotmat[3][3], prev_tangent[3];
 	int k,i;
 	int steps = (int)pow(2.0, (double)pset->draw_step);
 	int totpart = edit->totpoint;
@@ -2998,8 +3006,12 @@ void psys_cache_edit_paths(Scene *scene, Object *ob, PTCacheEdit *edit, float cf
 		/*--get the first data points--*/
 		init_particle_interpolation(ob, psys, pa, &pind);
 
-		if(psys)
+		if(psys) {
 			psys_mat_hair_to_global(ob, psmd->dm, psys->part->from, pa, hairmat);
+			VECCOPY(rotmat[0], hairmat[2]);
+			VECCOPY(rotmat[1], hairmat[1]);
+			VECCOPY(rotmat[2], hairmat[0]);
+		}
 
 		birthtime = pind.birthtime;
 		dietime = pind.dietime;
@@ -3020,9 +3032,55 @@ void psys_cache_edit_paths(Scene *scene, Object *ob, PTCacheEdit *edit, float cf
 			do_particle_interpolation(psys, i, pa, t, frs_sec, &pind, &result);
 
 			 /* non-hair points are allready in global space */
-			if(psys && !(psys->flag & PSYS_GLOBAL_HAIR))
+			if(psys && !(psys->flag & PSYS_GLOBAL_HAIR)) {
 				Mat4MulVecfl(hairmat, result.co);
 
+				/* create rotations for proper creation of children */
+				if(k) {
+					float cosangle, angle, tangent[3], normal[3], q[4];
+
+					if(k == 1) {
+						/* calculate initial tangent for incremental rotations */
+						VECSUB(tangent, ca->co, (ca - 1)->co);
+						VECCOPY(prev_tangent, tangent);
+						Normalize(prev_tangent);
+
+						/* First rotation is based on emitting face orientation.		*/
+						/* This is way better than having flipping rotations resulting	*/
+						/* from using a global axis as a rotation pole (vec_to_quat()). */
+						/* It's not an ideal solution though since it disregards the	*/
+						/* initial tangent, but taking that in to account will allow	*/
+						/* the possibility of flipping again. -jahka					*/
+						Mat3ToQuat_is_ok(rotmat, (ca-1)->rot);
+					}
+					else {
+						VECSUB(tangent, ca->co, (ca - 1)->co);
+						Normalize(tangent);
+
+						cosangle= Inpf(tangent, prev_tangent);
+
+						/* note we do the comparison on cosangle instead of
+						* angle, since floating point accuracy makes it give
+						* different results across platforms */
+						if(cosangle > 0.999999f) {
+							QUATCOPY((ca - 1)->rot, (ca - 2)->rot);
+						}
+						else {
+							angle= saacos(cosangle);
+							Crossf(normal, prev_tangent, tangent);
+							VecRotToQuat(normal, angle, q);
+							QuatMul((ca - 1)->rot, q, (ca - 2)->rot);
+						}
+
+						VECCOPY(prev_tangent, tangent);
+					}
+
+					if(k == steps)
+						QUATCOPY(ca->rot, (ca - 1)->rot);
+				}
+
+			}
+
 			VECCOPY(ca->co, result.co);
 
 			ca->vel[0] = ca->vel[1] = 0.0f;
@@ -3053,6 +3111,11 @@ void psys_cache_edit_paths(Scene *scene, Object *ob, PTCacheEdit *edit, float cf
 	}
 
 	edit->totcached = totpart;
+
+	if(psys && psys->part->type == PART_HAIR) {
+		ParticleSimulationData sim = {scene, ob, psys, psys_get_modifier(ob, psys), NULL};
+		psys_cache_child_paths(&sim, cfra, 1);
+	}
 }
 /************************************************/
 /*			Particle Key handling				*/
diff --git a/source/blender/editors/space_view3d/drawobject.c b/source/blender/editors/space_view3d/drawobject.c
index 78dd53e7271..d2988772abe 100644
--- a/source/blender/editors/space_view3d/drawobject.c
+++ b/source/blender/editors/space_view3d/drawobject.c
@@ -3658,7 +3658,7 @@ static void draw_new_particle_system(Scene *scene, View3D *v3d, RegionView3D *rv
 	//if(part->flag&PART_GLOB_TIME)
 	cfra=bsystem_time(scene, 0, (float)CFRA, 0.0f);
 
-	if(draw_as==PART_DRAW_PATH && psys->pathcache==NULL)
+	if(draw_as==PART_DRAW_PATH && psys->pathcache==NULL && psys->childcache==NULL)
 		draw_as=PART_DRAW_DOT;
 
 /* 3. */
@@ -4009,6 +4009,8 @@ static void draw_new_particle_system(Scene *scene, View3D *v3d, RegionView3D *rv
 
 		if(totchild && (part->draw&PART_DRAW_PARENT)==0)
 			totpart=0;
+		else if(psys->pathcache==NULL)
+			totpart=0;
 
 		/* draw actual/parent particles */
 		cache=psys->pathcache;
@@ -5709,6 +5711,22 @@ void draw_object(Scene *scene, ARegion *ar, View3D *v3d, Base *base, int flag)
 	}
 	if(ob->pd && ob->pd->forcefield) draw_forcefield(scene, ob);
 
+	/* particle mode has to be drawn first so that possible child particles get cached in edit mode */
+	if(		(warning_recursive==0) &&
+			(flag & DRAW_PICKING)==0 &&
+			(!scene->obedit)	
+	  ) {
+
+		if(ob->mode & OB_MODE_PARTICLE_EDIT && ob==OBACT) {
+			PTCacheEdit *edit = PE_get_current(scene, ob);
+			if(edit) {
+				wmLoadMatrix(rv3d->viewmat);
+				draw_ptcache_edit(scene, v3d, rv3d, ob, edit, dt);
+				wmMultMatrix(ob->obmat);
+			}
+		}
+	}
+
 	/* code for new particle system */
 	if(		(warning_recursive==0) &&
 			(ob->particlesystem.first) &&
@@ -5733,21 +5751,6 @@ void draw_object(Scene *scene, ARegion *ar, View3D *v3d, Base *base, int flag)
 		//glDepthMask(GL_TRUE);
 		if(col) cpack(col);
 	}
-	
-	if(		(warning_recursive==0) &&
-			(flag & DRAW_PICKING)==0 &&
-			(!scene->obedit)	
-	  ) {
-
-		if(ob->mode & OB_MODE_PARTICLE_EDIT && ob==OBACT) {
-			PTCacheEdit *edit = PE_get_current(scene, ob);
-			if(edit) {
-				wmLoadMatrix(rv3d->viewmat);
-				draw_ptcache_edit(scene, v3d, rv3d, ob, edit, dt);
-				wmMultMatrix(ob->obmat);
-			}
-		}
-	}
 
 	/* draw code for smoke */
 	if((md = modifiers_findByType(ob, eModifierType_Smoke)))
diff --git a/source/blender/makesrna/intern/rna_sculpt_paint.c b/source/blender/makesrna/intern/rna_sculpt_paint.c
index 7f8ded7d3ee..481abc983c2 100644
--- a/source/blender/makesrna/intern/rna_sculpt_paint.c
+++ b/source/blender/makesrna/intern/rna_sculpt_paint.c
@@ -405,7 +405,7 @@ static void rna_def_particle_edit(BlenderRNA *brna)
 	prop= RNA_def_property(srna, "draw_particles", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", PE_DRAW_PART);
 	RNA_def_property_ui_text(prop, "Draw Particles", "Draw actual particles.");
-	RNA_def_property_update(prop, NC_OBJECT, NULL);
+	RNA_def_property_update(prop, NC_OBJECT|ND_DRAW, NULL);
 
 	prop= RNA_def_property(srna, "mirror_x", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", PE_X_MIRROR);