6 files changed, 55 insertions, 13 deletions
diff --git a/servers/visual/shader_language.cpp b/servers/visual/shader_language.cpp
index 1783ef4525..d4fb8d98b0 100644
--- a/servers/visual/shader_language.cpp
+++ b/servers/visual/shader_language.cpp
@@ -2306,24 +2306,54 @@ bool ShaderLanguage::_is_operator_assign(Operator p_op) const {
 	return false;
 }
 
-bool ShaderLanguage::_validate_assign(Node *p_node, const Map<StringName, BuiltInInfo> &p_builtin_types) {
+bool ShaderLanguage::_validate_assign(Node *p_node, const Map<StringName, BuiltInInfo> &p_builtin_types, String *r_message) {
 
 	if (p_node->type == Node::TYPE_OPERATOR) {
 
 		OperatorNode *op = static_cast<OperatorNode *>(p_node);
+
 		if (op->op == OP_INDEX) {
-			return _validate_assign(op->arguments[0], p_builtin_types);
+			return _validate_assign(op->arguments[0], p_builtin_types, r_message);
+
+		} else if (_is_operator_assign(op->op)) {
+			//chained assignment
+			return _validate_assign(op->arguments[1], p_builtin_types, r_message);
+
+		} else if (op->op == OP_CALL) {
+			if (r_message)
+				*r_message = RTR("Assignment to function.");
+			return false;
 		}
-	}
 
-	if (p_node->type == Node::TYPE_VARIABLE) {
+	} else if (p_node->type == Node::TYPE_MEMBER) {
+
+		MemberNode *member = static_cast<MemberNode *>(p_node);
+		return _validate_assign(member->owner, p_builtin_types, r_message);
+
+	} else if (p_node->type == Node::TYPE_VARIABLE) {
 
 		VariableNode *var = static_cast<VariableNode *>(p_node);
-		if (p_builtin_types.has(var->name) && p_builtin_types[var->name].constant) {
-			return false; //ops not valid
+
+		if (shader->uniforms.has(var->name)) {
+			if (r_message)
+				*r_message = RTR("Assignment to uniform.");
+			return false;
+		}
+
+		if (shader->varyings.has(var->name) && current_function != String("vertex")) {
+			if (r_message)
+				*r_message = RTR("Varyings can only be assigned in vertex function.");
+			return false;
+		}
+
+		if (!(p_builtin_types.has(var->name) && p_builtin_types[var->name].constant)) {
+			return true;
 		}
 	}
-	return true;
+
+	if (r_message)
+		*r_message = "Assignment to constant expression.";
+	return false;
 }
 
 ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, const Map<StringName, BuiltInInfo> &p_builtin_types) {
@@ -3090,10 +3120,14 @@ ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, cons
 				ERR_FAIL_V(NULL);
 			}
 
-			if (_is_operator_assign(op->op) && !_validate_assign(expression[next_op - 1].node, p_builtin_types)) {
+			if (_is_operator_assign(op->op)) {
 
-				_set_error("Assignment to constant expression.");
-				return NULL;
+				String assign_message;
+				if (!_validate_assign(expression[next_op - 1].node, p_builtin_types, &assign_message)) {
+
+					_set_error(assign_message);
+					return NULL;
+				}
 			}
 
 			if (expression[next_op + 1].is_op) {
diff --git a/servers/visual/shader_language.h b/servers/visual/shader_language.h
index 9b84c5f195..b5fd567c07 100644
--- a/servers/visual/shader_language.h
+++ b/servers/visual/shader_language.h
@@ -617,7 +617,7 @@ private:
 	bool _find_identifier(const BlockNode *p_block, const Map<StringName, BuiltInInfo> &p_builtin_types, const StringName &p_identifier, DataType *r_data_type = NULL, IdentifierType *r_type = NULL);
 
 	bool _is_operator_assign(Operator p_op) const;
-	bool _validate_assign(Node *p_node, const Map<StringName, BuiltInInfo> &p_builtin_types);
+	bool _validate_assign(Node *p_node, const Map<StringName, BuiltInInfo> &p_builtin_types, String *r_message = NULL);
 
 	bool _validate_operator(OperatorNode *p_op, DataType *r_ret_type = NULL);
 
diff --git a/servers/visual/visual_server_canvas.cpp b/servers/visual/visual_server_canvas.cpp
index a1c6e83296..0b4bbffddf 100644
--- a/servers/visual/visual_server_canvas.cpp
+++ b/servers/visual/visual_server_canvas.cpp
@@ -669,7 +669,7 @@ void VisualServerCanvas::canvas_item_add_polygon(RID p_item, const Vector<Point2
 	int color_size = p_colors.size();
 	int uv_size = p_uvs.size();
 	ERR_FAIL_COND(color_size != 0 && color_size != 1 && color_size != pointcount);
-	ERR_FAIL_COND(uv_size != 0 && (uv_size != pointcount || !p_texture.is_valid()));
+	ERR_FAIL_COND(uv_size != 0 && (uv_size != pointcount));
 #endif
 	Vector<int> indices = Geometry::triangulate_polygon(p_points);
 
diff --git a/servers/visual/visual_server_raster.cpp b/servers/visual/visual_server_raster.cpp
index 6bf3670e5a..c7d33ec43c 100644
--- a/servers/visual/visual_server_raster.cpp
+++ b/servers/visual/visual_server_raster.cpp
@@ -161,6 +161,7 @@ void VisualServerRaster::set_boot_image(const Ref<Image> &p_image, const Color &
 	VSG::rasterizer->set_boot_image(p_image, p_color, p_scale);
 }
 void VisualServerRaster::set_default_clear_color(const Color &p_color) {
+	VSG::viewport->set_default_clear_color(p_color);
 }
 
 bool VisualServerRaster::has_feature(Features p_feature) const {
diff --git a/servers/visual/visual_server_viewport.cpp b/servers/visual/visual_server_viewport.cpp
index dd6bc3cf26..a700fcf11b 100644
--- a/servers/visual/visual_server_viewport.cpp
+++ b/servers/visual/visual_server_viewport.cpp
@@ -252,7 +252,9 @@ void VisualServerViewport::draw_viewports() {
 	// process all our active interfaces
 	ARVRServer::get_singleton()->_process();
 
-	clear_color = GLOBAL_GET("rendering/environment/default_clear_color");
+	if (Engine::get_singleton()->is_editor_hint()) {
+		clear_color = GLOBAL_GET("rendering/environment/default_clear_color");
+	}
 
 	//sort viewports
 	active_viewports.sort_custom<ViewportSort>();
@@ -660,5 +662,9 @@ bool VisualServerViewport::free(RID p_rid) {
 	return false;
 }
 
+void VisualServerViewport::set_default_clear_color(const Color &p_color) {
+	clear_color = p_color;
+}
+
 VisualServerViewport::VisualServerViewport() {
 }
diff --git a/servers/visual/visual_server_viewport.h b/servers/visual/visual_server_viewport.h
index c0c83c0450..f915e26b81 100644
--- a/servers/visual/visual_server_viewport.h
+++ b/servers/visual/visual_server_viewport.h
@@ -188,6 +188,7 @@ public:
 	virtual int viewport_get_render_info(RID p_viewport, VS::ViewportRenderInfo p_info);
 	virtual void viewport_set_debug_draw(RID p_viewport, VS::ViewportDebugDraw p_draw);
 
+	void set_default_clear_color(const Color &p_color);
 	void draw_viewports();
 
 	bool free(RID p_rid);