1 files changed, 279 insertions, 0 deletions
diff --git a/src/script/lua_api/l_particleparams.h b/src/script/lua_api/l_particleparams.h
new file mode 100644
index 000000000..4fefc5e3a
--- /dev/null
+++ b/src/script/lua_api/l_particleparams.h
@@ -0,0 +1,279 @@
+/*
+Minetest
+Copyright (C) 2021 velartrill, Lexi Hale <lexi@hale.su>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser 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.
+*/
+
+#pragma once
+#include "lua_api/l_particles.h"
+#include "lua_api/l_object.h"
+#include "lua_api/l_internal.h"
+#include "common/c_converter.h"
+#include "common/c_content.h"
+#include "server.h"
+#include "particles.h"
+
+namespace LuaParticleParams
+{
+	using namespace ParticleParamTypes;
+
+	template<typename T>
+	inline void readNumericLuaValue(lua_State* L, T& ret)
+	{
+		if (lua_isnil(L,-1))
+			return;
+
+		if (std::is_integral<T>())
+			ret = lua_tointeger(L, -1);
+		else
+			ret = lua_tonumber(L, -1);
+	}
+
+	template <typename T, size_t N>
+	inline void readNumericLuaValue(lua_State* L, Parameter<T,N>& ret)
+	{
+		readNumericLuaValue<T>(L, ret.val);
+	}
+
+	// these are unfortunately necessary as C++ intentionally disallows function template
+	// specialization and there's no way to make template overloads reliably resolve correctly
+	inline void readLuaValue(lua_State* L, f32Parameter& ret) { readNumericLuaValue(L, ret); }
+	inline void readLuaValue(lua_State* L, f32& ret)          { readNumericLuaValue(L, ret); }
+	inline void readLuaValue(lua_State* L, u16& ret)          { readNumericLuaValue(L, ret); }
+	inline void readLuaValue(lua_State* L, u8& ret)           { readNumericLuaValue(L, ret); }
+
+	inline void readLuaValue(lua_State* L, v3fParameter& ret)
+	{
+		if (lua_isnil(L, -1))
+			return;
+
+		if (lua_isnumber(L, -1)) { // shortcut for uniform vectors
+			auto n = lua_tonumber(L, -1);
+			ret = v3fParameter(n,n,n);
+		} else {
+			ret = (v3fParameter)check_v3f(L, -1);
+		}
+	}
+
+	inline void readLuaValue(lua_State* L, v2fParameter& ret)
+	{
+		if (lua_isnil(L, -1))
+			return;
+
+		if (lua_isnumber(L, -1)) { // shortcut for uniform vectors
+			auto n = lua_tonumber(L, -1);
+			ret = v2fParameter(n,n);
+		} else {
+			ret = (v2fParameter)check_v2f(L, -1);
+		}
+	}
+
+	inline void readLuaValue(lua_State* L, TweenStyle& ret)
+	{
+		if (lua_isnil(L, -1))
+			return;
+
+		static const EnumString opts[] = {
+			{(int)TweenStyle::fwd,     "fwd"},
+			{(int)TweenStyle::rev,     "rev"},
+			{(int)TweenStyle::pulse,   "pulse"},
+			{(int)TweenStyle::flicker, "flicker"},
+			{0, nullptr},
+		};
+
+		luaL_checktype(L, -1, LUA_TSTRING);
+		int v = (int)TweenStyle::fwd;
+		if (!string_to_enum(opts, v, lua_tostring(L, -1))) {
+			throw LuaError("tween style must be one of ('fwd', 'rev', 'pulse', 'flicker')");
+		}
+		ret = (TweenStyle)v;
+	}
+
+	inline void readLuaValue(lua_State* L, AttractorKind& ret)
+	{
+		if (lua_isnil(L, -1))
+			return;
+
+		static const EnumString opts[] = {
+			{(int)AttractorKind::none,  "none"},
+			{(int)AttractorKind::point, "point"},
+			{(int)AttractorKind::line,  "line"},
+			{(int)AttractorKind::plane, "plane"},
+			{0, nullptr},
+		};
+
+		luaL_checktype(L, -1, LUA_TSTRING);
+		int v = (int)AttractorKind::none;
+		if (!string_to_enum(opts, v, lua_tostring(L, -1))) {
+			throw LuaError("attractor kind must be one of ('none', 'point', 'line', 'plane')");
+		}
+		ret = (AttractorKind)v;
+	}
+
+	inline void readLuaValue(lua_State* L, BlendMode& ret)
+	{
+		if (lua_isnil(L, -1))
+			return;
+
+		static const EnumString opts[] = {
+			{(int)BlendMode::alpha,  "alpha"},
+			{(int)BlendMode::add,    "add"},
+			{(int)BlendMode::sub,    "sub"},
+			{(int)BlendMode::screen, "screen"},
+			{0, nullptr},
+		};
+
+		luaL_checktype(L, -1, LUA_TSTRING);
+		int v = (int)BlendMode::alpha;
+		if (!string_to_enum(opts, v, lua_tostring(L, -1))) {
+			throw LuaError("blend mode must be one of ('alpha', 'add', 'sub', 'screen')");
+		}
+		ret = (BlendMode)v;
+	}
+
+	template <typename T> void
+	readLuaValue(lua_State* L, RangedParameter<T>& field)
+	{
+		if (lua_isnil(L,-1))
+			return;
+		if (!lua_istable(L,-1)) // is this is just a literal value?
+			goto set_uniform;
+
+		lua_getfield(L, -1, "min");
+		// handle convenience syntax for non-range values
+		if (lua_isnil(L,-1)) {
+			lua_pop(L, 1);
+			goto set_uniform;
+		}
+		readLuaValue(L,field.min);
+		lua_pop(L, 1);
+
+		lua_getfield(L, -1, "max");
+		readLuaValue(L,field.max);
+		lua_pop(L, 1);
+
+		lua_getfield(L, -1, "bias");
+		if (!lua_isnil(L,-1))
+			readLuaValue(L,field.bias);
+		lua_pop(L, 1);
+		return;
+
+		set_uniform:
+		readLuaValue(L, field.min);
+		readLuaValue(L, field.max);
+	}
+
+	template <typename T> void
+	readLegacyValue(lua_State* L, const char* name, T& field) {}
+
+	template <typename T> void
+	readLegacyValue(lua_State* L, const char* name, RangedParameter<T>& field)
+	{
+		int tbl = lua_gettop(L);
+		lua_pushliteral(L, "min");
+		lua_pushstring(L, name);
+		lua_concat(L, 2);
+		lua_gettable(L, tbl);
+		if (!lua_isnil(L, -1)) {
+			readLuaValue(L, field.min);
+		}
+		lua_settop(L, tbl);
+
+		lua_pushliteral(L, "max");
+		lua_pushstring(L, name);
+		lua_concat(L, 2);
+		lua_gettable(L, tbl);
+		if (!lua_isnil(L, -1)) {
+			readLuaValue(L, field.max);
+		}
+		lua_settop(L, tbl);
+	}
+
+	template <typename T> void
+	readTweenTable(lua_State* L, const char* name, TweenedParameter<T>& field)
+	{
+		int tbl = lua_gettop(L);
+
+		lua_pushstring(L, name);
+		lua_pushliteral(L, "_tween");
+		lua_concat(L, 2);
+		lua_gettable(L, tbl);
+		if(lua_istable(L, -1)) {
+			int tween = lua_gettop(L);
+			// get the starting value
+			lua_pushinteger(L, 1), lua_gettable(L, tween);
+			readLuaValue(L, field.start);
+			lua_pop(L, 1);
+
+			// get the final value -- use len instead of 2 so that this
+			// gracefully degrades if keyframe support is later added
+			lua_pushinteger(L, (lua_Integer)lua_objlen(L, -1)), lua_gettable(L, tween);
+			readLuaValue(L, field.end);
+			lua_pop(L, 1);
+
+			// get the effect settings
+			lua_getfield(L, -1, "style");
+			lua_isnil(L,-1) || (readLuaValue(L, field.style), true);
+			lua_pop(L, 1);
+
+			lua_getfield(L, -1, "reps");
+			lua_isnil(L,-1) || (readLuaValue(L, field.reps), true);
+			lua_pop(L, 1);
+
+			lua_getfield(L, -1, "start");
+			lua_isnil(L,-1) || (readLuaValue(L, field.beginning), true);
+			lua_pop(L, 1);
+
+			goto done;
+		} else {
+			lua_pop(L,1);
+		}
+		// the table is not present; check for nonanimated values
+
+		lua_getfield(L, tbl, name);
+		if(!lua_isnil(L, -1)) {
+			readLuaValue(L, field.start);
+			lua_settop(L, tbl);
+			goto set_uniform;
+		} else {
+			lua_pop(L,1);
+		}
+
+		// the goto did not trigger, so this table is not present either
+		// check for pre-5.6.0 legacy values
+		readLegacyValue(L, name, field.start);
+
+		set_uniform:
+		field.end = field.start;
+		done:
+		lua_settop(L, tbl); // clean up after ourselves
+	}
+
+	inline u16 readAttachmentID(lua_State* L, const char* name)
+	{
+		u16 id = 0;
+		lua_getfield(L, -1, name);
+		if (!lua_isnil(L, -1)) {
+			ObjectRef *ref = ObjectRef::checkobject(L, -1);
+			if (auto obj = ObjectRef::getobject(ref))
+				id = obj->getId();
+		}
+		lua_pop(L, 1);
+		return id;
+	}
+
+	void readTexValue(lua_State* L, ServerParticleTexture& tex);
+}