Add a material preview to visual shader editor

1 files changed, 74 insertions, 2 deletions

diff --git a/scene/resources/visual_shader.cpp b/scene/resources/visual_shader.cpp
index 1fa52b9c73..aee014a882 100644
--- a/scene/resources/visual_shader.cpp
+++ b/scene/resources/visual_shader.cpp
@@ -32,6 +32,7 @@
 
 #include "core/templates/rb_map.h"
 #include "core/templates/vmap.h"
+#include "core/variant/variant_utility.h"
 #include "servers/rendering/shader_types.h"
 #include "visual_shader_nodes.h"
 #include "visual_shader_particle_nodes.h"
@@ -897,6 +898,44 @@ VisualShader::VaryingType VisualShader::get_varying_type(const String &p_name) {
 	return varyings[p_name].type;
 }
 
+void VisualShader::_set_preview_shader_parameter(const String &p_name, const Variant &p_value) {
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		if (p_value.get_type() == Variant::NIL) {
+			if (!preview_params.erase(p_name)) {
+				return;
+			}
+		} else {
+			Variant *var = preview_params.getptr(p_name);
+			if (var != nullptr && *var == p_value) {
+				return;
+			}
+			preview_params.insert(p_name, p_value);
+		}
+		emit_changed();
+	}
+#endif // TOOLS_ENABLED
+}
+
+Variant VisualShader::_get_preview_shader_parameter(const String &p_name) const {
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		ERR_FAIL_COND_V(!preview_params.has(p_name), Variant());
+		return preview_params.get(p_name);
+	}
+#endif // TOOLS_ENABLED
+	return Variant();
+}
+
+bool VisualShader::_has_preview_shader_parameter(const String &p_name) const {
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return preview_params.has(p_name);
+	}
+#endif // TOOLS_ENABLED
+	return false;
+}
+
 void VisualShader::add_node(Type p_type, const Ref<VisualShaderNode> &p_node, const Vector2 &p_position, int p_id) {
 	ERR_FAIL_COND(p_node.is_null());
 	ERR_FAIL_COND(p_id < 2);
@@ -1695,7 +1734,16 @@ bool VisualShader::_set(const StringName &p_name, const Variant &p_value) {
 		}
 		_queue_update();
 		return true;
-	} else if (prop_name.begins_with("nodes/")) {
+	}
+#ifdef TOOLS_ENABLED
+	else if (prop_name.begins_with("preview_params/") && Engine::get_singleton()->is_editor_hint()) {
+		String param_name = prop_name.get_slicec('/', 1);
+		Variant value = VariantUtilityFunctions::str_to_var(p_value);
+		preview_params[param_name] = value;
+		return true;
+	}
+#endif
+	else if (prop_name.begins_with("nodes/")) {
 		String typestr = prop_name.get_slicec('/', 1);
 		Type type = TYPE_VERTEX;
 		for (int i = 0; i < TYPE_MAX; i++) {
@@ -1767,7 +1815,19 @@ bool VisualShader::_get(const StringName &p_name, Variant &r_ret) const {
 			r_ret = String();
 		}
 		return true;
-	} else if (prop_name.begins_with("nodes/")) {
+	}
+#ifdef TOOLS_ENABLED
+	else if (prop_name.begins_with("preview_params/") && Engine::get_singleton()->is_editor_hint()) {
+		String param_name = prop_name.get_slicec('/', 1);
+		if (preview_params.has(param_name)) {
+			r_ret = VariantUtilityFunctions::var_to_str(preview_params[param_name]);
+		} else {
+			r_ret = String();
+		}
+		return true;
+	}
+#endif // TOOLS_ENABLED
+	else if (prop_name.begins_with("nodes/")) {
 		String typestr = prop_name.get_slicec('/', 1);
 		Type type = TYPE_VERTEX;
 		for (int i = 0; i < TYPE_MAX; i++) {
@@ -1864,6 +1924,14 @@ void VisualShader::_get_property_list(List<PropertyInfo> *p_list) const {
 		p_list->push_back(PropertyInfo(Variant::STRING, vformat("%s/%s", PNAME("varyings"), E.key), PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR));
 	}
 
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		for (const KeyValue<String, Variant> &E : preview_params) {
+			p_list->push_back(PropertyInfo(Variant::STRING, vformat("%s/%s", PNAME("preview_params"), E.key), PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR));
+		}
+	}
+#endif // TOOLS_ENABLED
+
 	for (int i = 0; i < TYPE_MAX; i++) {
 		for (const KeyValue<int, Node> &E : graph[i].nodes) {
 			String prop_name = "nodes/";
@@ -2943,6 +3011,10 @@ void VisualShader::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("remove_varying", "name"), &VisualShader::remove_varying);
 	ClassDB::bind_method(D_METHOD("has_varying", "name"), &VisualShader::has_varying);
 
+	ClassDB::bind_method(D_METHOD("_set_preview_shader_parameter", "name", "value"), &VisualShader::_set_preview_shader_parameter);
+	ClassDB::bind_method(D_METHOD("_get_preview_shader_parameter", "name"), &VisualShader::_get_preview_shader_parameter);
+	ClassDB::bind_method(D_METHOD("_has_preview_shader_parameter", "name"), &VisualShader::_has_preview_shader_parameter);
+
 	ClassDB::bind_method(D_METHOD("_update_shader"), &VisualShader::_update_shader);
 
 	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "graph_offset", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR), "set_graph_offset", "get_graph_offset");