Spring - User contributions [en]

LuaCallinReturn

2011-11-16T04:38:16Z

0bliter8or:

[[Engine_Development|Development]] < [[Lua_Scripting|Lua Scripting]] < {{FULLPAGENAME}}

==Engine Source==
If you can understand Lua code well and wish to get the most up to date info, you can refer to:
{{sourcelink|file=cont/base/springcontent/LuaGadgets/actions.lua}},
{{sourcelink|file=cont\LuaUI\widget.lua}} and 
{{sourcelink|file=cont\base\springcontent\LuaGadgets\gadgets.lua}} 
to see how widget/gadget call-ins are distributed, find call-in and widgetHandler function definitions, see how they are processed and what values should be returned from some call ins
(are these the only files?)

==What is a callin anyway?==
Call-ins are calls from the engine, into the gadget or widget script. In other words, these functions are called when a particular â€œeventâ€ happens.
Some call-in functions can return values to the engine.
===Blocking events with return values===
The call-in functions named '''''Allow'''''XXX can block their event by returning ''false''. 
For example ''AllowUnitTransfer()'' 
<code>return true</code> = allow transfer 
<code>return false</code> = deny transfer

==Commands, general-purpose:==

Initialize() --> none.
called when widget/gadget gets (re-)loaded.

Shutdown() --> none.

PlayerChanged --> (playerID).
gadget/widget: Use this to check whether a player has become spectator for instance.

LayoutButtons() --> unknown, please document.

ConfigureLayout() --> "command".

CommandNotify() --> "id, params, options", where id = the CommandID

KeyPress() --> "key, mods, isRepeat", where key = keymap, mods = SHIFT, etc.

KeyRelease() --> "key"

MouseMove() --> "x, y, dx, dy, button"

MousePress() --> "x, y, button" 
button parameter values: left - 1, middle - 2, right - 3

MouseRelease() --> "x, y, button" 
Please note that in order to have Spring call MouseRelease, you need to have a MousePress call-in in the same widget that returns true.

MouseWheel() --> "up, value"

IsAbove() --> "x, y" where x,y = screen coordinates.

GetTooltip() --> "x, y" where x,y = screen coordinates. Returns WorldTooltip.

AddConsoleLine() --> "msg, priority"

MapDrawCmd() --> "playerID, cmdType, px, py, pz, labeltext"

AllowCommand() --> "unitID, unitDefID, unitTeam, cmdID, cmdParams, cmdOptions, cmdTag, synced"

CommandFallback() --> "unitID, unitDefID, unitTeam, cmdID, cmdParams, cmdOptions, cmdTag"

CommandsChanged() --> unknown (none?)

AllowUnitCreation() --> "unitDefID, builderID, builderTeam, x, y, z"

AllowUnitTransfer() --> "unitID, unitDefID, oldTeam, newTeam, capture"

AllowUnitBuildStep() --> "builderID, builderTeam, unitID, unitDefID, part"

AllowFeatureCreation() --> "featureDefID, teamID, x, y, z"

AllowFeatureBuildStep() --> unknown, please document.

AllowResourceLevel() --> "teamID, res, level"

AllowResourceTransfer() --> "teamID, res, level"

Update() --> "dt" 
gets called very often, even if the game is paused. dt is the time since the function was last called (???)

DefaultCommand() --> nothing (???) 
can return an [[Lua_CMDs|CMD]] to change cursor and command. {{forumlink|topic=26438|title=example usage}}

==Unit-Specific:==

UnitPreDamaged() --> "unitID, unitDefID, unitTeam, damage, paralyzer, weaponID, attackerID, attackerDefID, attackerTeam"

UnitDamaged() --> "unitID, unitDefID, unitTeam, damage, paralyzer, weaponID, attackerID, attackerDefID, attackerTeam" 
can overwrite the taken damage by returning a new number value

UnitCreated() --> "unitID, unitDefID, teamID, builderID"

UnitFinished() --> "unitID, unitDefID, teamID"

UnitFromFactory() --> "unitID, unitDefID, unitTeam, factID, factDefID, userOrders"

UnitDestroyed() --> "unitID, unitDefID, teamID, attackerID, attackerDefID, attackerTeamID"

UnitTaken() --> "unitID, unitDefID, unitTeam, newTeam"

UnitGiven() --> "unitID, unitDefID, unitTeam, oldTeam"

UnitIdle() --> "unitID, unitDefID, teamID"

UnitCommand() --> "unitID, unitDefID, unitTeam, cmdID, cmdOpts, cmdParams"

UnitSeismicPing() --> "x, y, z, strength"

UnitEnteredRadar() --> "unitID, unitTeam"

UnitEnteredLos() --> "unitID, teamID"

UnitLeftRadar() --> "unitID, unitTeam"

UnitLeftLos() --> "unitID, unitDefID, teamID"

UnitLoaded() --> "unitID, unitDefID, unitTeam, transportID, transportTeam"

UnitUnloaded() --> "unitID, unitDefID, teamID, transportID"

UnitCloaked() --> "unitID, unitDefID, teamID"

UnitDecloaked)--> "unitID, unitDefID, teamID"

UnitMoveFailed() --> "unitID, unitDefID, unitTeam"

StockpileChanged() --> "unitID, unitDefID, unitTeam, weaponNum, oldCount, newCount"

UnitEnteredWater() --> "unitID, unitDefID, teamID"

UnitEnteredAir() --> "unitID, unitDefID, teamID"

UnitLeftWater() --> "unitID, unitDefID, teamID"

UnitLeftAir() --> "unitID, unitDefID, teamID"

ShieldPreDamaged() --> "proID, proOwnerID, shieldEmitterWeaponNum, shieldCarrierUnitID, bounceProjectile"

==Feature-Specific:==

FeatureCreated() --> "featureID, allyTeam"

FeatureDestroyed() --> "featureID, allyTeam"

TerraformComplete() --> "unitID, unitDefID, unitTeam, buildUnitID, buildUnitDefID, buildUnitTeam"

UnitCmdDone() --> "unitID, unitDefID, unitTeam, cmdID, cmdTag"

==Drawing:==
Inside these functions, you can use the [[Lua_OpenGL_Api | Lua OpenGL Api]] to draw graphics.

* DrawGenesis() --> none. Don't render here.

Spring draws the sky, the map, some water types, and unit selection.

* DrawWorldPreUnit() --> none.

Spring draws units, features, some water types, cloaked units, and the sun.

* DrawWorld() --> none.

Spring draws command queues, 'map stuff', and map marks.

Each unit might also have a DrawUnit call, [[Lua_UnitRendering|enabled here.]]

DrawUnit(unitID,DrawMode) 
With enum DrawMode { 
notDrawing = 0, 
normalDraw = 1, 
shadowDraw = 2, 
reflectionDraw = 3, 
refractionDraw = 4 
};

DrawScreenEffects() --> "vsx, vsy" where vsx, vsy are screen coords.

DrawScreen() --> none.

DrawInMiniMap() --> "sx, sy" where sx,sy are values relative to the minimap's position and scale.

DrawWorldShadow() --> none.

DrawWorldReflection() --> none.

DrawWorldRefraction() --> none.

==Game Events:==

Explosion() --> "weaponID, px, py, pz, ownerID"

ShockFront() --> "power, dx, dy, dz"

GameFrame() --> "frameNum"

CobCallback() --> unknown, marked FIXME.

GroupChanged() --> "groupID" where groupID is the value of Group whose table value changed.

WorldTooltip() --> "ttType, data1, data2, data3" special, should be documented in detail.

GamePreload() --> none.

GameStart() --> none.

GameProgress() --> "serverFrameNum" ( called every 60 frames, calculating delta between GameFrame and GameProgress can give an ETA about catching up with simulation ) New in 0.83.x

GameOver() --> "[ [1] = allyTeamID1, [2] = allyTeamID2, ... ]", a list of winning allyteams, if empty the game result was undecided ( like when dropping from an host ) Will return nil in pre 0.83.x

TeamDied() --> "TeamID" where TeamID = the team that has been eliminated.

AllowStartPosition() --> nobody cares 
returns nobody cares

==Projectiles:==

ProjectileCreated() --> "proID, proOwnerID"

ProjectileDestroyed() --> "proID"

[[category: Lua]]

LuaCallinReturn

2011-11-16T04:37:34Z

0bliter8or:

[[Engine_Development|Development]] < [[Lua_Scripting|Lua Scripting]] < {{FULLPAGENAME}}

==Engine Source==
If you can understand Lua code well and wish to get the most up to date info, you can refer to: 
{{sourcelink|file=cont/base/springcontent/LuaGadgets/actions.lua}}, 
{{sourcelink|file=cont\LuaUI\widget.lua}} and 
{{sourcelink|file=cont\base\springcontent\LuaGadgets\gadgets.lua}} 
to see how widget/gadget call-ins are distributed, find call-in and widgetHandler function definitions, see how they are processed and what values should be returned from some call ins
(are these the only files?)

==What is a callin anyway?==
Call-ins are calls from the engine, into the gadget or widget script. In other words, these functions are called when a particular â€œeventâ€ happens.
Some call-in functions can return values to the engine.
===Blocking events with return values===
The call-in functions named '''''Allow'''''XXX can block their event by returning ''false''. 
For example ''AllowUnitTransfer()'' 
<code>return true</code> = allow transfer 
<code>return false</code> = deny transfer

==Commands, general-purpose:==

Initialize() --> none.
called when widget/gadget gets (re-)loaded.

Shutdown() --> none.

PlayerChanged --> (playerID).
gadget/widget: Use this to check whether a player has become spectator for instance.

LayoutButtons() --> unknown, please document.

ConfigureLayout() --> "command".

CommandNotify() --> "id, params, options", where id = the CommandID

KeyPress() --> "key, mods, isRepeat", where key = keymap, mods = SHIFT, etc.

KeyRelease() --> "key"

MouseMove() --> "x, y, dx, dy, button"

MousePress() --> "x, y, button" 
button parameter values: left - 1, middle - 2, right - 3

MouseRelease() --> "x, y, button" 
Please note that in order to have Spring call MouseRelease, you need to have a MousePress call-in in the same widget that returns true.

MouseWheel() --> "up, value"

IsAbove() --> "x, y" where x,y = screen coordinates.

GetTooltip() --> "x, y" where x,y = screen coordinates. Returns WorldTooltip.

AddConsoleLine() --> "msg, priority"

MapDrawCmd() --> "playerID, cmdType, px, py, pz, labeltext"

AllowCommand() --> "unitID, unitDefID, unitTeam, cmdID, cmdParams, cmdOptions, cmdTag, synced"

CommandFallback() --> "unitID, unitDefID, unitTeam, cmdID, cmdParams, cmdOptions, cmdTag"

CommandsChanged() --> unknown (none?)

AllowUnitCreation() --> "unitDefID, builderID, builderTeam, x, y, z"

AllowUnitTransfer() --> "unitID, unitDefID, oldTeam, newTeam, capture"

AllowUnitBuildStep() --> "builderID, builderTeam, unitID, unitDefID, part"

AllowFeatureCreation() --> "featureDefID, teamID, x, y, z"

AllowFeatureBuildStep() --> unknown, please document.

AllowResourceLevel() --> "teamID, res, level"

AllowResourceTransfer() --> "teamID, res, level"

Update() --> "dt" 
gets called very often, even if the game is paused. dt is the time since the function was last called (???)

DefaultCommand() --> nothing (???) 
can return an [[Lua_CMDs|CMD]] to change cursor and command. {{forumlink|topic=26438|title=example usage}}

==Unit-Specific:==

UnitPreDamaged() --> "unitID, unitDefID, unitTeam, damage, paralyzer, weaponID, attackerID, attackerDefID, attackerTeam"

UnitDamaged() --> "unitID, unitDefID, unitTeam, damage, paralyzer, weaponID, attackerID, attackerDefID, attackerTeam" 
can overwrite the taken damage by returning a new number value

UnitCreated() --> "unitID, unitDefID, teamID, builderID"

UnitFinished() --> "unitID, unitDefID, teamID"

UnitFromFactory() --> "unitID, unitDefID, unitTeam, factID, factDefID, userOrders"

UnitDestroyed() --> "unitID, unitDefID, teamID, attackerID, attackerDefID, attackerTeamID"

UnitTaken() --> "unitID, unitDefID, unitTeam, newTeam"

UnitGiven() --> "unitID, unitDefID, unitTeam, oldTeam"

UnitIdle() --> "unitID, unitDefID, teamID"

UnitCommand() --> "unitID, unitDefID, unitTeam, cmdID, cmdOpts, cmdParams"

UnitSeismicPing() --> "x, y, z, strength"

UnitEnteredRadar() --> "unitID, unitTeam"

UnitEnteredLos() --> "unitID, teamID"

UnitLeftRadar() --> "unitID, unitTeam"

UnitLeftLos() --> "unitID, unitDefID, teamID"

UnitLoaded() --> "unitID, unitDefID, unitTeam, transportID, transportTeam"

UnitUnloaded() --> "unitID, unitDefID, teamID, transportID"

UnitCloaked() --> "unitID, unitDefID, teamID"

UnitDecloaked)--> "unitID, unitDefID, teamID"

UnitMoveFailed() --> "unitID, unitDefID, unitTeam"

StockpileChanged() --> "unitID, unitDefID, unitTeam, weaponNum, oldCount, newCount"

UnitEnteredWater() --> "unitID, unitDefID, teamID"

UnitEnteredAir() --> "unitID, unitDefID, teamID"

UnitLeftWater() --> "unitID, unitDefID, teamID"

UnitLeftAir() --> "unitID, unitDefID, teamID"

ShieldPreDamaged() --> "proID, proOwnerID, shieldEmitterWeaponNum, shieldCarrierUnitID, bounceProjectile"

==Feature-Specific:==

FeatureCreated() --> "featureID, allyTeam"

FeatureDestroyed() --> "featureID, allyTeam"

TerraformComplete() --> "unitID, unitDefID, unitTeam, buildUnitID, buildUnitDefID, buildUnitTeam"

UnitCmdDone() --> "unitID, unitDefID, unitTeam, cmdID, cmdTag"

==Drawing:==
Inside these functions, you can use the [[Lua_OpenGL_Api | Lua OpenGL Api]] to draw graphics.

* DrawGenesis() --> none. Don't render here.

Spring draws the sky, the map, some water types, and unit selection.

* DrawWorldPreUnit() --> none.

Spring draws units, features, some water types, cloaked units, and the sun.

* DrawWorld() --> none.

Spring draws command queues, 'map stuff', and map marks.

Each unit might also have a DrawUnit call, [[Lua_UnitRendering|enabled here.]]

DrawUnit(unitID,DrawMode) 
With enum DrawMode { 
notDrawing = 0, 
normalDraw = 1, 
shadowDraw = 2, 
reflectionDraw = 3, 
refractionDraw = 4 
};

DrawScreenEffects() --> "vsx, vsy" where vsx, vsy are screen coords.

DrawScreen() --> none.

DrawInMiniMap() --> "sx, sy" where sx,sy are values relative to the minimap's position and scale.

DrawWorldShadow() --> none.

DrawWorldReflection() --> none.

DrawWorldRefraction() --> none.

==Game Events:==

Explosion() --> "weaponID, px, py, pz, ownerID"

ShockFront() --> "power, dx, dy, dz"

GameFrame() --> "frameNum"

CobCallback() --> unknown, marked FIXME.

GroupChanged() --> "groupID" where groupID is the value of Group whose table value changed.

WorldTooltip() --> "ttType, data1, data2, data3" special, should be documented in detail.

GamePreload() --> none.

GameStart() --> none.

GameProgress() --> "serverFrameNum" ( called every 60 frames, calculating delta between GameFrame and GameProgress can give an ETA about catching up with simulation ) New in 0.83.x

GameOver() --> "[ [1] = allyTeamID1, [2] = allyTeamID2, ... ]", a list of winning allyteams, if empty the game result was undecided ( like when dropping from an host ) Will return nil in pre 0.83.x

TeamDied() --> "TeamID" where TeamID = the team that has been eliminated.

AllowStartPosition() --> nobody cares 
returns nobody cares

==Projectiles:==

ProjectileCreated() --> "proID, proOwnerID"

ProjectileDestroyed() --> "proID"

[[category: Lua]]

LuaCallinReturn

2011-11-16T04:35:50Z

0bliter8or:

[[Engine_Development|Development]] < [[Lua_Scripting|Lua Scripting]] < {{FULLPAGENAME}}

==Engine Source==
If you can understand Lua code well and wish to get the most up to date info, you can refer to: 
{{sourcelink|file=cont/base/springcontent/LuaGadgets/actions.lua}},
{{sourcelink|file=cont\LuaUI\widget.lua}} and 
{{sourcelink|file=cont\base\springcontent\LuaGadgets\gadgets.lua}} 
to see how widget/gadget call-ins are distributed, find call-in and widgetHandler function definitions, see how they are processed and what values should be returned from some call ins
(are these the only files?)

==What is a callin anyway?==
Call-ins are calls from the engine, into the gadget or widget script. In other words, these functions are called when a particular â€œeventâ€ happens.
Some call-in functions can return values to the engine.
===Blocking events with return values===
The call-in functions named '''''Allow'''''XXX can block their event by returning ''false''. 
For example ''AllowUnitTransfer()'' 
<code>return true</code> = allow transfer 
<code>return false</code> = deny transfer

==Commands, general-purpose:==

Initialize() --> none.
called when widget/gadget gets (re-)loaded.

Shutdown() --> none.

PlayerChanged --> (playerID).
gadget/widget: Use this to check whether a player has become spectator for instance.

LayoutButtons() --> unknown, please document.

ConfigureLayout() --> "command".

CommandNotify() --> "id, params, options", where id = the CommandID

KeyPress() --> "key, mods, isRepeat", where key = keymap, mods = SHIFT, etc.

KeyRelease() --> "key"

MouseMove() --> "x, y, dx, dy, button"

MousePress() --> "x, y, button" 
button parameter values: left - 1, middle - 2, right - 3

MouseRelease() --> "x, y, button" 
Please note that in order to have Spring call MouseRelease, you need to have a MousePress call-in in the same widget that returns true.

MouseWheel() --> "up, value"

IsAbove() --> "x, y" where x,y = screen coordinates.

GetTooltip() --> "x, y" where x,y = screen coordinates. Returns WorldTooltip.

AddConsoleLine() --> "msg, priority"

MapDrawCmd() --> "playerID, cmdType, px, py, pz, labeltext"

AllowCommand() --> "unitID, unitDefID, unitTeam, cmdID, cmdParams, cmdOptions, cmdTag, synced"

CommandFallback() --> "unitID, unitDefID, unitTeam, cmdID, cmdParams, cmdOptions, cmdTag"

CommandsChanged() --> unknown (none?)

AllowUnitCreation() --> "unitDefID, builderID, builderTeam, x, y, z"

AllowUnitTransfer() --> "unitID, unitDefID, oldTeam, newTeam, capture"

AllowUnitBuildStep() --> "builderID, builderTeam, unitID, unitDefID, part"

AllowFeatureCreation() --> "featureDefID, teamID, x, y, z"

AllowFeatureBuildStep() --> unknown, please document.

AllowResourceLevel() --> "teamID, res, level"

AllowResourceTransfer() --> "teamID, res, level"

Update() --> "dt" 
gets called very often, even if the game is paused. dt is the time since the function was last called (???)

DefaultCommand() --> nothing (???) 
can return an [[Lua_CMDs|CMD]] to change cursor and command. {{forumlink|topic=26438|title=example usage}}

==Unit-Specific:==

UnitPreDamaged() --> "unitID, unitDefID, unitTeam, damage, paralyzer, weaponID, attackerID, attackerDefID, attackerTeam"

UnitDamaged() --> "unitID, unitDefID, unitTeam, damage, paralyzer, weaponID, attackerID, attackerDefID, attackerTeam" 
can overwrite the taken damage by returning a new number value

UnitCreated() --> "unitID, unitDefID, teamID, builderID"

UnitFinished() --> "unitID, unitDefID, teamID"

UnitFromFactory() --> "unitID, unitDefID, unitTeam, factID, factDefID, userOrders"

UnitDestroyed() --> "unitID, unitDefID, teamID, attackerID, attackerDefID, attackerTeamID"

UnitTaken() --> "unitID, unitDefID, unitTeam, newTeam"

UnitGiven() --> "unitID, unitDefID, unitTeam, oldTeam"

UnitIdle() --> "unitID, unitDefID, teamID"

UnitCommand() --> "unitID, unitDefID, unitTeam, cmdID, cmdOpts, cmdParams"

UnitSeismicPing() --> "x, y, z, strength"

UnitEnteredRadar() --> "unitID, unitTeam"

UnitEnteredLos() --> "unitID, teamID"

UnitLeftRadar() --> "unitID, unitTeam"

UnitLeftLos() --> "unitID, unitDefID, teamID"

UnitLoaded() --> "unitID, unitDefID, unitTeam, transportID, transportTeam"

UnitUnloaded() --> "unitID, unitDefID, teamID, transportID"

UnitCloaked() --> "unitID, unitDefID, teamID"

UnitDecloaked)--> "unitID, unitDefID, teamID"

UnitMoveFailed() --> "unitID, unitDefID, unitTeam"

StockpileChanged() --> "unitID, unitDefID, unitTeam, weaponNum, oldCount, newCount"

UnitEnteredWater() --> "unitID, unitDefID, teamID"

UnitEnteredAir() --> "unitID, unitDefID, teamID"

UnitLeftWater() --> "unitID, unitDefID, teamID"

UnitLeftAir() --> "unitID, unitDefID, teamID"

ShieldPreDamaged() --> "proID, proOwnerID, shieldEmitterWeaponNum, shieldCarrierUnitID, bounceProjectile"

==Feature-Specific:==

FeatureCreated() --> "featureID, allyTeam"

FeatureDestroyed() --> "featureID, allyTeam"

TerraformComplete() --> "unitID, unitDefID, unitTeam, buildUnitID, buildUnitDefID, buildUnitTeam"

UnitCmdDone() --> "unitID, unitDefID, unitTeam, cmdID, cmdTag"

==Drawing:==
Inside these functions, you can use the [[Lua_OpenGL_Api | Lua OpenGL Api]] to draw graphics.

* DrawGenesis() --> none. Don't render here.

Spring draws the sky, the map, some water types, and unit selection.

* DrawWorldPreUnit() --> none.

Spring draws units, features, some water types, cloaked units, and the sun.

* DrawWorld() --> none.

Spring draws command queues, 'map stuff', and map marks.

Each unit might also have a DrawUnit call, [[Lua_UnitRendering|enabled here.]]

DrawUnit(unitID,DrawMode) 
With enum DrawMode { 
notDrawing = 0, 
normalDraw = 1, 
shadowDraw = 2, 
reflectionDraw = 3, 
refractionDraw = 4 
};

DrawScreenEffects() --> "vsx, vsy" where vsx, vsy are screen coords.

DrawScreen() --> none.

DrawInMiniMap() --> "sx, sy" where sx,sy are values relative to the minimap's position and scale.

DrawWorldShadow() --> none.

DrawWorldReflection() --> none.

DrawWorldRefraction() --> none.

==Game Events:==

Explosion() --> "weaponID, px, py, pz, ownerID"

ShockFront() --> "power, dx, dy, dz"

GameFrame() --> "frameNum"

CobCallback() --> unknown, marked FIXME.

GroupChanged() --> "groupID" where groupID is the value of Group whose table value changed.

WorldTooltip() --> "ttType, data1, data2, data3" special, should be documented in detail.

GamePreload() --> none.

GameStart() --> none.

GameProgress() --> "serverFrameNum" ( called every 60 frames, calculating delta between GameFrame and GameProgress can give an ETA about catching up with simulation ) New in 0.83.x

GameOver() --> "[ [1] = allyTeamID1, [2] = allyTeamID2, ... ]", a list of winning allyteams, if empty the game result was undecided ( like when dropping from an host ) Will return nil in pre 0.83.x

TeamDied() --> "TeamID" where TeamID = the team that has been eliminated.

AllowStartPosition() --> nobody cares 
returns nobody cares

==Projectiles:==

ProjectileCreated() --> "proID, proOwnerID"

ProjectileDestroyed() --> "proID"

[[category: Lua]]

LuaCallinReturn

2011-11-16T04:28:15Z

0bliter8or:

[[Engine_Development|Development]] < [[Lua_Scripting|Lua Scripting]] < {{FULLPAGENAME}}

==Engine Source==
{{sourcelink|file=cont/base/springcontent/LuaGadgets/actions.lua}}
If you can understand Lua code well, you can refer to {{sourcelink|file=cont\LuaUI\widget.lua}} and {{sourcelink|file=cont\base\springcontent\LuaGadgets\gadgets.lua}} to see how widget and gadget call-ins and handling functions definitions and how they are processed
(is that the only file????)

==What is a callin anyway?==
Call-ins are calls from the engine, into the gadget or widget script. In other words, these functions are called when a particular â€œeventâ€ happens.
Some call-in functions can return values to the engine.
===Blocking events with return values===
The call-in functions named '''''Allow'''''XXX can block their event by returning ''false''. 
For example ''AllowUnitTransfer()'' 
<code>return true</code> = allow transfer 
<code>return false</code> = deny transfer

==Commands, general-purpose:==

Initialize() --> none.
called when widget/gadget gets (re-)loaded.

Shutdown() --> none.

PlayerChanged --> (playerID).
gadget/widget: Use this to check whether a player has become spectator for instance.

LayoutButtons() --> unknown, please document.

ConfigureLayout() --> "command".

CommandNotify() --> "id, params, options", where id = the CommandID

KeyPress() --> "key, mods, isRepeat", where key = keymap, mods = SHIFT, etc.

KeyRelease() --> "key"

MouseMove() --> "x, y, dx, dy, button"

MousePress() --> "x, y, button" 
button parameter values: left - 1, middle - 2, right - 3

MouseRelease() --> "x, y, button" 
Please note that in order to have Spring call MouseRelease, you need to have a MousePress call-in in the same widget that returns true.

MouseWheel() --> "up, value"

IsAbove() --> "x, y" where x,y = screen coordinates.

GetTooltip() --> "x, y" where x,y = screen coordinates. Returns WorldTooltip.

AddConsoleLine() --> "msg, priority"

MapDrawCmd() --> "playerID, cmdType, px, py, pz, labeltext"

AllowCommand() --> "unitID, unitDefID, unitTeam, cmdID, cmdParams, cmdOptions, cmdTag, synced"

CommandFallback() --> "unitID, unitDefID, unitTeam, cmdID, cmdParams, cmdOptions, cmdTag"

CommandsChanged() --> unknown (none?)

AllowUnitCreation() --> "unitDefID, builderID, builderTeam, x, y, z"

AllowUnitTransfer() --> "unitID, unitDefID, oldTeam, newTeam, capture"

AllowUnitBuildStep() --> "builderID, builderTeam, unitID, unitDefID, part"

AllowFeatureCreation() --> "featureDefID, teamID, x, y, z"

AllowFeatureBuildStep() --> unknown, please document.

AllowResourceLevel() --> "teamID, res, level"

AllowResourceTransfer() --> "teamID, res, level"

Update() --> "dt" 
gets called very often, even if the game is paused. dt is the time since the function was last called (???)

DefaultCommand() --> nothing (???) 
can return an [[Lua_CMDs|CMD]] to change cursor and command. {{forumlink|topic=26438|title=example usage}}

==Unit-Specific:==

UnitPreDamaged() --> "unitID, unitDefID, unitTeam, damage, paralyzer, weaponID, attackerID, attackerDefID, attackerTeam"

UnitDamaged() --> "unitID, unitDefID, unitTeam, damage, paralyzer, weaponID, attackerID, attackerDefID, attackerTeam" 
can overwrite the taken damage by returning a new number value

UnitCreated() --> "unitID, unitDefID, teamID, builderID"

UnitFinished() --> "unitID, unitDefID, teamID"

UnitFromFactory() --> "unitID, unitDefID, unitTeam, factID, factDefID, userOrders"

UnitDestroyed() --> "unitID, unitDefID, teamID, attackerID, attackerDefID, attackerTeamID"

UnitTaken() --> "unitID, unitDefID, unitTeam, newTeam"

UnitGiven() --> "unitID, unitDefID, unitTeam, oldTeam"

UnitIdle() --> "unitID, unitDefID, teamID"

UnitCommand() --> "unitID, unitDefID, unitTeam, cmdID, cmdOpts, cmdParams"

UnitSeismicPing() --> "x, y, z, strength"

UnitEnteredRadar() --> "unitID, unitTeam"

UnitEnteredLos() --> "unitID, teamID"

UnitLeftRadar() --> "unitID, unitTeam"

UnitLeftLos() --> "unitID, unitDefID, teamID"

UnitLoaded() --> "unitID, unitDefID, unitTeam, transportID, transportTeam"

UnitUnloaded() --> "unitID, unitDefID, teamID, transportID"

UnitCloaked() --> "unitID, unitDefID, teamID"

UnitDecloaked)--> "unitID, unitDefID, teamID"

UnitMoveFailed() --> "unitID, unitDefID, unitTeam"

StockpileChanged() --> "unitID, unitDefID, unitTeam, weaponNum, oldCount, newCount"

UnitEnteredWater() --> "unitID, unitDefID, teamID"

UnitEnteredAir() --> "unitID, unitDefID, teamID"

UnitLeftWater() --> "unitID, unitDefID, teamID"

UnitLeftAir() --> "unitID, unitDefID, teamID"

ShieldPreDamaged() --> "proID, proOwnerID, shieldEmitterWeaponNum, shieldCarrierUnitID, bounceProjectile"

==Feature-Specific:==

FeatureCreated() --> "featureID, allyTeam"

FeatureDestroyed() --> "featureID, allyTeam"

TerraformComplete() --> "unitID, unitDefID, unitTeam, buildUnitID, buildUnitDefID, buildUnitTeam"

UnitCmdDone() --> "unitID, unitDefID, unitTeam, cmdID, cmdTag"

==Drawing:==
Inside these functions, you can use the [[Lua_OpenGL_Api | Lua OpenGL Api]] to draw graphics.

* DrawGenesis() --> none. Don't render here.

Spring draws the sky, the map, some water types, and unit selection.

* DrawWorldPreUnit() --> none.

Spring draws units, features, some water types, cloaked units, and the sun.

* DrawWorld() --> none.

Spring draws command queues, 'map stuff', and map marks.

Each unit might also have a DrawUnit call, [[Lua_UnitRendering|enabled here.]]

DrawUnit(unitID,DrawMode) 
With enum DrawMode { 
notDrawing = 0, 
normalDraw = 1, 
shadowDraw = 2, 
reflectionDraw = 3, 
refractionDraw = 4 
};

DrawScreenEffects() --> "vsx, vsy" where vsx, vsy are screen coords.

DrawScreen() --> none.

DrawInMiniMap() --> "sx, sy" where sx,sy are values relative to the minimap's position and scale.

DrawWorldShadow() --> none.

DrawWorldReflection() --> none.

DrawWorldRefraction() --> none.

==Game Events:==

Explosion() --> "weaponID, px, py, pz, ownerID"

ShockFront() --> "power, dx, dy, dz"

GameFrame() --> "frameNum"

CobCallback() --> unknown, marked FIXME.

GroupChanged() --> "groupID" where groupID is the value of Group whose table value changed.

WorldTooltip() --> "ttType, data1, data2, data3" special, should be documented in detail.

GamePreload() --> none.

GameStart() --> none.

GameProgress() --> "serverFrameNum" ( called every 60 frames, calculating delta between GameFrame and GameProgress can give an ETA about catching up with simulation ) New in 0.83.x

GameOver() --> "[ [1] = allyTeamID1, [2] = allyTeamID2, ... ]", a list of winning allyteams, if empty the game result was undecided ( like when dropping from an host ) Will return nil in pre 0.83.x

TeamDied() --> "TeamID" where TeamID = the team that has been eliminated.

AllowStartPosition() --> nobody cares 
returns nobody cares

==Projectiles:==

ProjectileCreated() --> "proID, proOwnerID"

ProjectileDestroyed() --> "proID"

[[category: Lua]]