Geometry Nodes: Special string characters node

This patch adds a new node called "Special Characters" with two string
outputs: "Line Break" and "Tab". This is necessary because the newline
character cannot be easily typed with a keyboard, but is necessary for
the string to curve node.

Differential Revision: https://developer.blender.org/D12620

release/scripts/startup/nodeitems_builtins.py

@@ -606,6 +606,7 @@ geometry_node_categories = [
         NodeItem("FunctionNodeStringSubstring"),
         NodeItem("FunctionNodeValueToString"),
         NodeItem("GeometryNodeStringJoin"),
+        NodeItem("FunctionNodeInputSpecialCharacters"),
     ]),
     GeometryNodeCategory("GEO_UTILITIES", "Utilities", items=[
         NodeItem("ShaderNodeMapRange"),

source/blender/blenkernel/BKE_node.h

@@ -1517,6 +1517,7 @@ int ntreeTexExecTree(struct bNodeTree *ntree,
 #define FN_NODE_VALUE_TO_STRING 1210
 #define FN_NODE_STRING_LENGTH 1211
 #define FN_NODE_STRING_SUBSTRING 1212
+#define FN_NODE_INPUT_SPECIAL_CHARACTERS 1213
 
 /** \} */
 

source/blender/blenkernel/intern/node.cc

@@ -5812,6 +5812,7 @@ static void registerFunctionNodes()
   register_node_type_fn_boolean_math();
   register_node_type_fn_float_compare();
   register_node_type_fn_float_to_int();
+  register_node_type_fn_input_special_characters();
   register_node_type_fn_input_string();
   register_node_type_fn_input_vector();
   register_node_type_fn_random_float();

source/blender/nodes/CMakeLists.txt

@@ -136,6 +136,7 @@ set(SRC
   function/nodes/node_fn_boolean_math.cc
   function/nodes/node_fn_float_compare.cc
   function/nodes/node_fn_float_to_int.cc
+  function/nodes/node_fn_input_special_characters.cc
   function/nodes/node_fn_input_string.cc
   function/nodes/node_fn_input_vector.cc
   function/nodes/node_fn_random_float.cc

source/blender/nodes/NOD_function.h

@@ -23,6 +23,7 @@ extern "C" {
 void register_node_type_fn_boolean_math(void);
 void register_node_type_fn_float_compare(void);
 void register_node_type_fn_float_to_int(void);
+void register_node_type_fn_input_special_characters(void);
 void register_node_type_fn_input_string(void);
 void register_node_type_fn_input_vector(void);
 void register_node_type_fn_random_float(void);

source/blender/nodes/NOD_static_types.h

@@ -265,6 +265,7 @@ DefNode(TextureNode,    TEX_NODE_PROC+TEX_DISTNOISE, 0,                  "TEX_DI
 DefNode(FunctionNode, FN_NODE_BOOLEAN_MATH,  def_boolean_math,  "BOOLEAN_MATH",  BooleanMath,  "Boolean Math", "")
 DefNode(FunctionNode, FN_NODE_FLOAT_COMPARE, def_float_compare, "FLOAT_COMPARE", FloatCompare, "Float Compare", "")
 DefNode(FunctionNode, FN_NODE_FLOAT_TO_INT, def_float_to_int, "FLOAT_TO_INT", FloatToInt, "Float to Integer", "")
+DefNode(FunctionNode, FN_NODE_INPUT_SPECIAL_CHARACTERS, 0, "INPUT_SPECIAL_CHARACTERS", InputSpecialCharacters, "Special Characters", "")
 DefNode(FunctionNode, FN_NODE_INPUT_STRING, def_fn_input_string, "INPUT_STRING", InputString, "String", "")
 DefNode(FunctionNode, FN_NODE_INPUT_VECTOR, def_fn_input_vector, "INPUT_VECTOR", InputVector, "Vector", "")
 DefNode(FunctionNode, FN_NODE_RANDOM_FLOAT, 0, "RANDOM_FLOAT", RandomFloat, "Random Float", "")

source/blender/nodes/function/nodes/node_fn_input_special_characters.cc

@@ -0,0 +1,74 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "node_function_util.hh"
+
+namespace blender::nodes {
+
+static void fn_node_input_special_characters_declare(NodeDeclarationBuilder &b)
+{
+  b.add_output<decl::String>("Line Break");
+  b.add_output<decl::String>("Tab");
+};
+
+class MF_SpecialCharacters : public fn::MultiFunction {
+ public:
+  MF_SpecialCharacters()
+  {
+    static fn::MFSignature signature = create_signature();
+    this->set_signature(&signature);
+  }
+
+  static fn::MFSignature create_signature()
+  {
+    fn::MFSignatureBuilder signature{"Special Characters"};
+    signature.single_output<std::string>("Line Break");
+    signature.single_output<std::string>("Tab");
+    return signature.build();
+  }
+
+  void call(IndexMask mask, fn::MFParams params, fn::MFContext UNUSED(context)) const override
+  {
+    MutableSpan<std::string> lb = params.uninitialized_single_output<std::string>(0, "Line Break");
+    MutableSpan<std::string> tab = params.uninitialized_single_output<std::string>(1, "Tab");
+
+    for (const int i : mask) {
+      new (&lb[i]) std::string("\n");
+      new (&tab[i]) std::string("\t");
+    }
+  }
+};
+
+static void fn_node_input_special_characters_build_multi_function(
+    NodeMultiFunctionBuilder &builder)
+{
+  static MF_SpecialCharacters special_characters_fn;
+  builder.set_matching_fn(special_characters_fn);
+}
+
+}  // namespace blender::nodes
+
+void register_node_type_fn_input_special_characters()
+{
+  static bNodeType ntype;
+
+  fn_node_type_base(
+      &ntype, FN_NODE_INPUT_SPECIAL_CHARACTERS, "Special Characters", NODE_CLASS_INPUT, 0);
+  ntype.declare = blender::nodes::fn_node_input_special_characters_declare;
+  ntype.build_multi_function =
+      blender::nodes::fn_node_input_special_characters_build_multi_function;
+  nodeRegisterType(&ntype);
+}