From 36c4b396885e154ad7cf3c817306b2f84667316a Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Mon, 26 Apr 2010 01:56:25 +0000
Subject: [PATCH] - Added DavidPH's A_FadeTo patch:    A_FadeTo(float target,
 float amount = 0.10, bool remove = false)   Alters transparency towards
 target by amount. If remove is true, the actor is destroyed if it reaches
 target.

SVN r2305 (trunk)
---
 src/thingdef/thingdef_codeptr.cpp | 60 +++++++++++++++++++++++++++----
 wadsrc/static/actors/actor.txt    |  1 +
 2 files changed, 55 insertions(+), 6 deletions(-)

diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index df4861f72..7d22f11d7 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -1810,11 +1810,13 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_FadeIn)
 	ACTION_PARAM_START(1);
 	ACTION_PARAM_FIXED(reduce, 0);
 
-	if (reduce == 0) reduce = FRACUNIT/10;
-
+	if (reduce == 0)
+	{
+		reduce = FRACUNIT/10;
+	}
 	self->RenderStyle.Flags &= ~STYLEF_Alpha1;
 	self->alpha += reduce;
-	//if (self->alpha<=0) self->Destroy();
+	// Should this clamp alpha to 1.0?
 }
 
 //===========================================================================
@@ -1830,11 +1832,57 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_FadeOut)
 	ACTION_PARAM_FIXED(reduce, 0);
 	ACTION_PARAM_BOOL(remove, 1);
 
-	if (reduce == 0) reduce = FRACUNIT/10;
-
+	if (reduce == 0)
+	{
+		reduce = FRACUNIT/10;
+	}
 	self->RenderStyle.Flags &= ~STYLEF_Alpha1;
 	self->alpha -= reduce;
-	if (self->alpha<=0 && remove) self->Destroy();
+	if (self->alpha <= 0 && remove)
+	{
+		self->Destroy();
+	}
+}
+
+//===========================================================================
+//
+// A_FadeTo
+//
+// fades the actor to a specified transparency by a specified amount and
+// destroys it if so desired
+//
+//===========================================================================
+DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_FadeTo)
+{
+	ACTION_PARAM_START(3);
+	ACTION_PARAM_FIXED(target, 0);
+	ACTION_PARAM_FIXED(amount, 1);
+	ACTION_PARAM_BOOL(remove, 2);
+
+	self->RenderStyle.Flags &= ~STYLEF_Alpha1;
+
+	if (self->alpha > target)
+	{
+		self->alpha -= amount;
+
+		if (self->alpha < target)
+		{
+			self->alpha = target;
+		}
+	}
+	else if (self->alpha < target)
+	{
+		self->alpha += amount;
+
+		if (self->alpha > target)
+		{
+			self->alpha = target;
+		}
+	}
+	if (self->alpha == target && remove)
+	{
+		self->Destroy();
+	}
 }
 
 //===========================================================================
diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index 5037968e2..50d7369d2 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -201,6 +201,7 @@ ACTOR Actor native //: Thinker
 	action native A_SetTranslucent(float alpha, int style = 0);
 	action native A_FadeIn(float reduce = 0.1);
 	action native A_FadeOut(float reduce = 0.1, bool remove = true);
+	action native A_FadeTo(float target, float amount = 0.1, bool remove = false);
 	action native A_SpawnDebris(class<Actor> spawntype, bool transfer_translation = false, float mult_h = 1, float mult_v = 1);
 	action native A_CheckSight(state label);
 	action native A_ExtChase(bool usemelee, bool usemissile, bool playactive = true, bool nightmarefast = false);