6 files changed, 30 insertions, 14 deletions
diff --git a/scene/resources/audio_stream_sample.cpp b/scene/resources/audio_stream_sample.cpp
index 9ee85b64b6..35132c1195 100644
--- a/scene/resources/audio_stream_sample.cpp
+++ b/scene/resources/audio_stream_sample.cpp
@@ -249,6 +249,10 @@ void AudioStreamPlaybackSample::mix(AudioFrame *p_buffer, float p_rate_scale, in
 
 	int32_t todo = p_frames;
 
+	if (base->loop_mode == AudioStreamSample::LOOP_BACKWARD) {
+		sign = -1;
+	}
+
 	float base_rate = AudioServer::get_singleton()->get_mix_rate();
 	float srate = base->mix_rate;
 	srate *= p_rate_scale;
@@ -621,7 +625,7 @@ void AudioStreamSample::_bind_methods() {
 
 	ADD_PROPERTY(PropertyInfo(Variant::POOL_BYTE_ARRAY, "data", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_data", "get_data");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "format", PROPERTY_HINT_ENUM, "8-Bit,16-Bit,IMA-ADPCM"), "set_format", "get_format");
-	ADD_PROPERTY(PropertyInfo(Variant::INT, "loop_mode", PROPERTY_HINT_ENUM, "Disabled,Forward,Ping-Pong"), "set_loop_mode", "get_loop_mode");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "loop_mode", PROPERTY_HINT_ENUM, "Disabled,Forward,Ping-Pong,Backward"), "set_loop_mode", "get_loop_mode");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "loop_begin"), "set_loop_begin", "get_loop_begin");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "loop_end"), "set_loop_end", "get_loop_end");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "mix_rate"), "set_mix_rate", "get_mix_rate");
@@ -634,6 +638,7 @@ void AudioStreamSample::_bind_methods() {
 	BIND_ENUM_CONSTANT(LOOP_DISABLED);
 	BIND_ENUM_CONSTANT(LOOP_FORWARD);
 	BIND_ENUM_CONSTANT(LOOP_PING_PONG);
+	BIND_ENUM_CONSTANT(LOOP_BACKWARD);
 }
 
 AudioStreamSample::AudioStreamSample() {
diff --git a/scene/resources/audio_stream_sample.h b/scene/resources/audio_stream_sample.h
index a27acc92b7..2c39e0a11e 100644
--- a/scene/resources/audio_stream_sample.h
+++ b/scene/resources/audio_stream_sample.h
@@ -94,7 +94,8 @@ public:
 	enum LoopMode {
 		LOOP_DISABLED,
 		LOOP_FORWARD,
-		LOOP_PING_PONG
+		LOOP_PING_PONG,
+		LOOP_BACKWARD
 	};
 
 private:
diff --git a/scene/resources/material.cpp b/scene/resources/material.cpp
index cc3c882169..f6dc60900f 100644
--- a/scene/resources/material.cpp
+++ b/scene/resources/material.cpp
@@ -258,7 +258,7 @@ ShaderMaterial::~ShaderMaterial() {
 /////////////////////////////////
 
 Mutex *SpatialMaterial::material_mutex = NULL;
-SelfList<SpatialMaterial>::List SpatialMaterial::dirty_materials;
+SelfList<SpatialMaterial>::List *SpatialMaterial::dirty_materials = NULL;
 Map<SpatialMaterial::MaterialKey, SpatialMaterial::ShaderData> SpatialMaterial::shader_map;
 SpatialMaterial::ShaderNames *SpatialMaterial::shader_names = NULL;
 
@@ -268,6 +268,8 @@ void SpatialMaterial::init_shaders() {
 	material_mutex = Mutex::create();
 #endif
 
+	dirty_materials = memnew(SelfList<SpatialMaterial>::List);
+
 	shader_names = memnew(ShaderNames);
 
 	shader_names->albedo = "albedo";
@@ -348,12 +350,15 @@ void SpatialMaterial::finish_shaders() {
 	memdelete(material_mutex);
 #endif
 
+	memdelete(dirty_materials);
+	dirty_materials = NULL;
+
 	memdelete(shader_names);
 }
 
 void SpatialMaterial::_update_shader() {
 
-	dirty_materials.remove(&element);
+	dirty_materials->remove(&element);
 
 	MaterialKey mk = _compute_key();
 	if (mk.key == current_key.key)
@@ -1002,9 +1007,9 @@ void SpatialMaterial::flush_changes() {
 	if (material_mutex)
 		material_mutex->lock();
 
-	while (dirty_materials.first()) {
+	while (dirty_materials->first()) {
 
-		dirty_materials.first()->self()->_update_shader();
+		dirty_materials->first()->self()->_update_shader();
 	}
 
 	if (material_mutex)
@@ -1017,7 +1022,7 @@ void SpatialMaterial::_queue_shader_change() {
 		material_mutex->lock();
 
 	if (!element.in_list()) {
-		dirty_materials.add(&element);
+		dirty_materials->add(&element);
 	}
 
 	if (material_mutex)
diff --git a/scene/resources/material.h b/scene/resources/material.h
index 54fceaddc1..921f3baeaa 100644
--- a/scene/resources/material.h
+++ b/scene/resources/material.h
@@ -360,7 +360,7 @@ private:
 	};
 
 	static Mutex *material_mutex;
-	static SelfList<SpatialMaterial>::List dirty_materials;
+	static SelfList<SpatialMaterial>::List *dirty_materials;
 	static ShaderNames *shader_names;
 
 	SelfList<SpatialMaterial> element;
diff --git a/scene/resources/particles_material.cpp b/scene/resources/particles_material.cpp
index dae01e8d96..92c185712a 100644
--- a/scene/resources/particles_material.cpp
+++ b/scene/resources/particles_material.cpp
@@ -31,7 +31,7 @@
 #include "particles_material.h"
 
 Mutex *ParticlesMaterial::material_mutex = NULL;
-SelfList<ParticlesMaterial>::List ParticlesMaterial::dirty_materials;
+SelfList<ParticlesMaterial>::List *ParticlesMaterial::dirty_materials = NULL;
 Map<ParticlesMaterial::MaterialKey, ParticlesMaterial::ShaderData> ParticlesMaterial::shader_map;
 ParticlesMaterial::ShaderNames *ParticlesMaterial::shader_names = NULL;
 
@@ -41,6 +41,8 @@ void ParticlesMaterial::init_shaders() {
 	material_mutex = Mutex::create();
 #endif
 
+	dirty_materials = memnew(SelfList<ParticlesMaterial>::List);
+
 	shader_names = memnew(ShaderNames);
 
 	shader_names->spread = "spread";
@@ -106,12 +108,15 @@ void ParticlesMaterial::finish_shaders() {
 	memdelete(material_mutex);
 #endif
 
+	memdelete(dirty_materials);
+	dirty_materials = NULL;
+
 	memdelete(shader_names);
 }
 
 void ParticlesMaterial::_update_shader() {
 
-	dirty_materials.remove(&element);
+	dirty_materials->remove(&element);
 
 	MaterialKey mk = _compute_key();
 	if (mk.key == current_key.key)
@@ -584,9 +589,9 @@ void ParticlesMaterial::flush_changes() {
 	if (material_mutex)
 		material_mutex->lock();
 
-	while (dirty_materials.first()) {
+	while (dirty_materials->first()) {
 
-		dirty_materials.first()->self()->_update_shader();
+		dirty_materials->first()->self()->_update_shader();
 	}
 
 	if (material_mutex)
@@ -599,7 +604,7 @@ void ParticlesMaterial::_queue_shader_change() {
 		material_mutex->lock();
 
 	if (!element.in_list()) {
-		dirty_materials.add(&element);
+		dirty_materials->add(&element);
 	}
 
 	if (material_mutex)
diff --git a/scene/resources/particles_material.h b/scene/resources/particles_material.h
index 06ebb3c4dc..20b505532e 100644
--- a/scene/resources/particles_material.h
+++ b/scene/resources/particles_material.h
@@ -126,7 +126,7 @@ private:
 	}
 
 	static Mutex *material_mutex;
-	static SelfList<ParticlesMaterial>::List dirty_materials;
+	static SelfList<ParticlesMaterial>::List *dirty_materials;
 
 	struct ShaderNames {
 		StringName spread;