Fix T48658: Cycles render & render preview corrupts particles

Replaces `G.is_rendering` with `use_render_params` argument.

This is needed for Cycles, which attempts to restore render-preview settings from particles,
after it gets its own particle data, but fails to restore because
`G.is_rendering` was being checked in psys_cache_paths (and other places).

1 files changed, 18 insertions, 14 deletions

diff --git a/source/blender/blenkernel/intern/particle.c b/source/blender/blenkernel/intern/particle.c
index 633227d68f3..d1f5afa26a6 100644
--- a/source/blender/blenkernel/intern/particle.c
+++ b/source/blender/blenkernel/intern/particle.c
@@ -283,7 +283,7 @@ bool psys_in_edit_mode(Scene *scene, ParticleSystem *psys)
 {
 	return (scene->basact && (scene->basact->object->mode & OB_MODE_PARTICLE_EDIT) && psys == psys_get_current((scene->basact)->object) && (psys->edit || psys->pointcache->edit) && !psys->renderdata);
 }
-bool psys_check_enabled(Object *ob, ParticleSystem *psys)
+bool psys_check_enabled(Object *ob, ParticleSystem *psys, const bool use_render_params)
 {
 	ParticleSystemModifierData *psmd;
 
@@ -291,7 +291,7 @@ bool psys_check_enabled(Object *ob, ParticleSystem *psys)
 		return 0;
 
 	psmd = psys_get_modifier(ob, psys);
-	if (psys->renderdata || G.is_rendering) {
+	if (psys->renderdata || use_render_params) {
 		if (!(psmd->modifier.mode & eModifierMode_Render))
 			return 0;
 	}
@@ -2007,7 +2007,7 @@ float *psys_cache_vgroup(DerivedMesh *dm, ParticleSystem *psys, int vgroup)
 	}
 	return vg;
 }
-void psys_find_parents(ParticleSimulationData *sim)
+void psys_find_parents(ParticleSimulationData *sim, const bool use_render_params)
 {
 	ParticleSystem *psys = sim->psys;
 	ParticleSettings *part = sim->psys->part;
@@ -2019,7 +2019,7 @@ void psys_find_parents(ParticleSimulationData *sim)
 	int from = PART_FROM_FACE;
 	totparent = (int)(totchild * part->parents * 0.3f);
 
-	if ((sim->psys->renderdata || G.is_rendering) && part->child_nbr && part->ren_child_nbr)
+	if ((sim->psys->renderdata || use_render_params) && part->child_nbr && part->ren_child_nbr)
 		totparent *= (float)part->child_nbr / (float)part->ren_child_nbr;
 
 	/* hard limit, workaround for it being ignored above */
@@ -2050,7 +2050,9 @@ void psys_find_parents(ParticleSimulationData *sim)
 	BLI_kdtree_free(tree);
 }
 
-static bool psys_thread_context_init_path(ParticleThreadContext *ctx, ParticleSimulationData *sim, Scene *scene, float cfra, int editupdate)
+static bool psys_thread_context_init_path(
+        ParticleThreadContext *ctx, ParticleSimulationData *sim, Scene *scene,
+        float cfra, const bool editupdate, const bool use_render_params)
 {
 	ParticleSystem *psys = sim->psys;
 	ParticleSettings *part = psys->part;
@@ -2064,7 +2066,7 @@ static bool psys_thread_context_init_path(ParticleThreadContext *ctx, ParticleSi
 	if (psys_in_edit_mode(scene, psys)) {
 		ParticleEditSettings *pset = &scene->toolsettings->particle;
 
-		if ((psys->renderdata == 0 && G.is_rendering == 0) && (psys->edit == NULL || pset->flag & PE_DRAW_PART) == 0)
+		if ((psys->renderdata == 0 && use_render_params == 0) && (psys->edit == NULL || pset->flag & PE_DRAW_PART) == 0)
 			totchild = 0;
 
 		segments = 1 << pset->draw_step;
@@ -2073,14 +2075,14 @@ static bool psys_thread_context_init_path(ParticleThreadContext *ctx, ParticleSi
 	if (totchild && part->childtype == PART_CHILD_FACES) {
 		totparent = (int)(totchild * part->parents * 0.3f);
 		
-		if ((psys->renderdata || G.is_rendering) && part->child_nbr && part->ren_child_nbr)
+		if ((psys->renderdata || use_render_params) && part->child_nbr && part->ren_child_nbr)
 			totparent *= (float)part->child_nbr / (float)part->ren_child_nbr;
 
 		/* part->parents could still be 0 so we can't test with totparent */
 		between = 1;
 	}
 
-	if (psys->renderdata || G.is_rendering)
+	if (psys->renderdata || use_render_params)
 		segments = 1 << part->ren_step;
 	else {
 		totchild = (int)((float)totchild * (float)part->disp / 100.0f);
@@ -2417,7 +2419,9 @@ static void exec_child_path_cache(TaskPool * __restrict UNUSED(pool), void *task
 	}
 }
 
-void psys_cache_child_paths(ParticleSimulationData *sim, float cfra, int editupdate)
+void psys_cache_child_paths(
+        ParticleSimulationData *sim, float cfra,
+        const bool editupdate, const bool use_render_params)
 {
 	TaskScheduler *task_scheduler;
 	TaskPool *task_pool;
@@ -2430,7 +2434,7 @@ void psys_cache_child_paths(ParticleSimulationData *sim, float cfra, int editupd
 		return;
 	
 	/* create a task pool for child path tasks */
-	if (!psys_thread_context_init_path(&ctx, sim, sim->scene, cfra, editupdate))
+	if (!psys_thread_context_init_path(&ctx, sim, sim->scene, cfra, editupdate, use_render_params))
 		return;
 	
 	task_scheduler = BLI_task_scheduler_get();
@@ -2522,7 +2526,7 @@ static void cache_key_incremental_rotation(ParticleCacheKey *key0, ParticleCache
  * - Useful for making use of opengl vertex arrays for super fast strand drawing.
  * - Makes child strands possible and creates them too into the cache.
  * - Cached path data is also used to determine cut position for the editmode tool. */
-void psys_cache_paths(ParticleSimulationData *sim, float cfra)
+void psys_cache_paths(ParticleSimulationData *sim, float cfra, const bool use_render_params)
 {
 	PARTICLE_PSMD;
 	ParticleEditSettings *pset = &sim->scene->toolsettings->particle;
@@ -2546,7 +2550,7 @@ void psys_cache_paths(ParticleSimulationData *sim, float cfra)
 	float prev_tangent[3] = {0.0f, 0.0f, 0.0f}, hairmat[4][4];
 	float rotmat[3][3];
 	int k;
-	int segments = (int)pow(2.0, (double)((psys->renderdata || G.is_rendering) ? part->ren_step : part->draw_step));
+	int segments = (int)pow(2.0, (double)((psys->renderdata || use_render_params) ? part->ren_step : part->draw_step));
 	int totpart = psys->totpart;
 	float length, vec[3];
 	float *vg_effector = NULL;
@@ -2725,7 +2729,7 @@ void psys_cache_paths(ParticleSimulationData *sim, float cfra)
 	if (vg_length)
 		MEM_freeN(vg_length);
 }
-void psys_cache_edit_paths(Scene *scene, Object *ob, PTCacheEdit *edit, float cfra)
+void psys_cache_edit_paths(Scene *scene, Object *ob, PTCacheEdit *edit, float cfra, const bool use_render_params)
 {
 	ParticleCacheKey *ca, **cache = edit->pathcache;
 	ParticleEditSettings *pset = &scene->toolsettings->particle;
@@ -2921,7 +2925,7 @@ void psys_cache_edit_paths(Scene *scene, Object *ob, PTCacheEdit *edit, float cf
 		sim.psys = psys;
 		sim.psmd = psys_get_modifier(ob, psys);
 
-		psys_cache_child_paths(&sim, cfra, 1);
+		psys_cache_child_paths(&sim, cfra, true, use_render_params);
 	}
 
 	/* clear recalc flag if set here */