From 3f83453ee70a0e747cace0627e34018832b00336 Mon Sep 17 00:00:00 2001
From: Marisa Kirisame <marisa@sayachan.org>
Date: Sat, 5 Feb 2022 22:48:15 +0100
Subject: [PATCH] Updates to palette filter.

---
 gldefs.txt                  |   1 +
 shaders/glsl/mfx_palette.fp |  36 +++++++++---------------------------
 textures/mfxdither.png      | Bin 0 -> 140 bytes
 zscript/mfx_menu.zsc        |  18 ++++++++++++------
 4 files changed, 22 insertions(+), 33 deletions(-)
 create mode 100644 textures/mfxdither.png

diff --git a/gldefs.txt b/gldefs.txt
index 65ac1f2..865cef0 100644
--- a/gldefs.txt
+++ b/gldefs.txt
@@ -174,6 +174,7 @@ HardwareShader postprocess scene
 {
 	Name "mfx_palette"
 	Shader "shaders/glsl/mfx_palette.fp" 330
+	Texture DitherTexture "textures/mfxdither.png"
 	Texture PalLUTTexture "textures/mfxpal.png"
 	Uniform vec2 sfact
 	Uniform float palsat
diff --git a/shaders/glsl/mfx_palette.fp b/shaders/glsl/mfx_palette.fp
index 4b5daaf..046aafb 100644
--- a/shaders/glsl/mfx_palette.fp
+++ b/shaders/glsl/mfx_palette.fp
@@ -1,51 +1,33 @@
 /*
    RetroFX palette reduction from MariENB
-   (C)2012-2021 Marisa Kirisame
+   (C)2012-2022 Marisa Kirisame
 */
 vec3 rgb2hsv( vec3 c )
 {
-	vec4 K = vec4(0.0,-1.0/3.0,2.0/3.0,-1.0);
+	vec4 K = vec4(0.,-1./3.,2./3.,-1.);
 	vec4 p = (c.g<c.b)?vec4(c.bg,K.wz):vec4(c.gb,K.xy);
 	vec4 q = (c.r<p.x)?vec4(p.xyw,c.r):vec4(c.r,p.yzx);
 	float d = q.x-min(q.w,q.y);
-	float e = 1.0e-10;
-	return vec3(abs(q.z+(q.w-q.y)/(6.0*d+e)),d/(q.x+e),q.x);
+	float e = 1.e-10;
+	return vec3(abs(q.z+(q.w-q.y)/(6.*d+e)),d/(q.x+e),q.x);
 }
 vec3 hsv2rgb( vec3 c )
 {
-	vec4 K = vec4(1.0,2.0/3.0,1.0/3.0,3.0);
-	vec3 p = abs(fract(c.xxx+K.xyz)*6.0-K.www);
-	return c.z*mix(K.xxx,clamp(p-K.xxx,0.0,1.0),c.y);
+	vec4 K = vec4(1.,2./3.,1./3.,3.);
+	vec3 p = abs(fract(c.xxx+K.xyz)*6.-K.www);
+	return c.z*mix(K.xxx,clamp(p-K.xxx,0.,1.),c.y);
 }
 
 void main()
 {
-	#define d(x) x/64.0
-	float dither8[64] = float[]
-	(
-		d( 0),d(48),d(12),d(60),d( 3),d(51),d(15),d(63),
-		d(32),d(16),d(44),d(28),d(35),d(19),d(47),d(31),
-		d( 8),d(56),d( 4),d(52),d(11),d(59),d( 7),d(55),
-		d(40),d(24),d(36),d(20),d(43),d(27),d(39),d(23),
-		d( 2),d(50),d(14),d(62),d( 1),d(49),d(13),d(61),
-		d(34),d(18),d(46),d(30),d(33),d(17),d(45),d(29),
-		d(10),d(58),d( 6),d(54),d( 9),d(57),d( 5),d(53),
-		d(42),d(26),d(38),d(22),d(41),d(25),d(37),d(21)
-	);
-	#undef d
 	vec2 coord = TexCoord;
 	vec4 res = texture(InputTexture,coord);
 	vec3 hsv = rgb2hsv(res.rgb);
 	hsv.y = clamp(hsv.y*palsat,0.,1.);
 	hsv.z = pow(max(hsv.z,0.),palpow);
 	res.rgb = hsv2rgb(hsv);
-	if ( res.r <= 0.0 ) res.r -= paldither;
-	if ( res.g <= 0.0 ) res.g -= paldither;
-	if ( res.b <= 0.0 ) res.b -= paldither;
-	if ( res.r >= 1.0 ) res.r += paldither;
-	if ( res.g >= 1.0 ) res.g += paldither;
-	if ( res.b >= 1.0 ) res.b += paldither;
-	res.rgb += paldither*dither8[int(coord.x*sfact.x)%8+int(coord.y*sfact.y)%8*8]-0.5*paldither;
+	ivec2 dcoord = ivec2(int(coord.x*sfact.x)%8,int(coord.y*sfact.y)%8);
+	res.rgb += paldither*texelFetch(DitherTexture,dcoord,0).x-.5*paldither;
 	vec3 lc = clamp(floor(res.rgb*64),0,63);
 	ivec2 lcoord = ivec2(lc.r,lc.g+lc.b*64);
 	lcoord.x += 64*palnum;
diff --git a/textures/mfxdither.png b/textures/mfxdither.png
new file mode 100644
index 0000000000000000000000000000000000000000..6b32e3e6de807257f6cfd6a2a4ee1e790cf3627f
GIT binary patch
literal 140
zcmeAS@N?(olHy`uVBq!ia0y~yVBi2@5W(;;<zYAj14FQ<i(?4Kbw&?{?f)4V_Upgr
zK5hM*vHn280ht2@2N>k<^Pks#Eq$AD{sDsnF$W9|Ft8st|IU2a_%mbsfr0}(AT{dG
p#jh(r7QW25{D8p$p92O57RoC+ZHja_z`(%3;OXk;vd$@?2>`hvF(&{3

literal 0
HcmV?d00001

diff --git a/zscript/mfx_menu.zsc b/zscript/mfx_menu.zsc
index e80e3cd..69c1263 100644
--- a/zscript/mfx_menu.zsc
+++ b/zscript/mfx_menu.zsc
@@ -159,11 +159,22 @@ Class OptionMenuItemMFXSlider : OptionMenuItemSlider
 // passes shift/alt presses to MFXSliders
 Class MFXOptionMenu : OptionMenu
 {
+	private void UpdatePresetNames()
+	{
+		for ( int i=0; i<mDesc.mItems.size(); i++ )
+		{
+			if ( !(mDesc.mItems[i] is 'OptionMenuItemMFXPresetList') )
+				continue;
+			OptionMenuItemMFXPresetList(mDesc.mItems[i]).UpdateNames();
+		}
+	}
+
 	override void Init( Menu parent, OptionMenuDescriptor desc )
 	{
 		Super.init(parent,desc);
 		DontDim = true;
 		DontBlur = true;
+		UpdatePresetNames();
 	}
 
 	override bool OnUIEvent( UIEvent ev )
@@ -181,11 +192,6 @@ Class MFXOptionMenu : OptionMenu
 	override void OnReturn()
 	{
 		Super.OnReturn();
-		for ( int i=0; i<mDesc.mItems.size(); i++ )
-		{
-			if ( !(mDesc.mItems[i] is 'OptionMenuItemMFXPresetList') )
-				continue;
-			OptionMenuItemMFXPresetList(mDesc.mItems[i]).UpdateNames();
-		}
+		UpdatePresetNames();
 	}
 }