From 4427956569b5135130040bd49d2e8653b7921c52 Mon Sep 17 00:00:00 2001
From: Evtema3 <evtema3@gmail.com>
Date: Mon, 28 Aug 2023 16:17:14 -0400
Subject: [PATCH] Update to 1.20

Referenced compatibility fixes from https://github.com/VisiVersa/Common-Shaders/ by HalbFettKaese.

Resource pack now loads correctly by default by using alpha255 in place of an undefined alpha variable in the fragment shader. Users may adjust this to alpha100 on their own accord.
---
 .../core/rendertype_entity_translucent_cull.fsh     | 13 +++++++------
 .../core/rendertype_entity_translucent_cull.vsh     |  3 ++-
 pack.mcmeta                                         |  2 +-
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/assets/minecraft/shaders/core/rendertype_entity_translucent_cull.fsh b/assets/minecraft/shaders/core/rendertype_entity_translucent_cull.fsh
index befe170..4df88b0 100644
--- a/assets/minecraft/shaders/core/rendertype_entity_translucent_cull.fsh
+++ b/assets/minecraft/shaders/core/rendertype_entity_translucent_cull.fsh
@@ -9,8 +9,8 @@ uniform float FogStart;
 uniform float FogEnd;
 uniform vec4 FogColor;
 
-in int isGUI;
-in int isHand;
+flat in int isGUI;
+flat in int isHand;
 in float zpos;
 in float vertexDistance;
 in vec4 vertexColor;
@@ -33,12 +33,13 @@ void main() {
     if (color.a < 0.1) discard; // Snipped due to size.
 	
     // updated to 1.19.4 thanks to the der discohund
+    // updated to 1.20 thanks to HalbFettKaese + Evtema3
 
-    // Switch used parts of the texture depending on where the model is displayed
-    if (isGUI == 0 && roughly_equal(alpha, 253.0, 0.01)) discard;
+    // Switch used parts of the texture depending on where the model is displayed (using alpha255 by default)
+    if (isGUI == 0 && roughly_equal(alpha255, 253.0, 0.01)) discard;
     if (isGUI == 1) {
-             if (zpos  > 125.0 && roughly_equal(alpha, 254.0, 0.01)) discard;     // Handled as inventory slot
-        else if (zpos <= 125.0 && roughly_equal(alpha, 253.0, 0.01)) discard; // Handled as on the player doll
+             if (zpos  > 100.0 && roughly_equal(alpha255, 254.0, 0.01)) discard;     // Handled as inventory slot
+        else if (zpos <= 100.0 && roughly_equal(alpha255, 253.0, 0.01)) discard; // Handled as on the player doll
     }
 	
     fragColor = linear_fog(color, vertexDistance, FogStart, FogEnd, FogColor);
diff --git a/assets/minecraft/shaders/core/rendertype_entity_translucent_cull.vsh b/assets/minecraft/shaders/core/rendertype_entity_translucent_cull.vsh
index 2241914..d5a188f 100644
--- a/assets/minecraft/shaders/core/rendertype_entity_translucent_cull.vsh
+++ b/assets/minecraft/shaders/core/rendertype_entity_translucent_cull.vsh
@@ -33,10 +33,11 @@ out vec2 texCoord2;
 out vec4 normal;
 
 // updated to 1.19.4 thanks to the der discohund
+// updated to 1.20 thanks to HalbFettKaese + Evtema3
 
 // gui item model detection from Onnowhere
 bool isgui(mat4 ProjMat) {
-    return ProjMat[3][2] == -2.0;
+    return abs(ProjMat[3][3]) > 0.01;
 }
 // first person hand item model detection from esben
 bool ishand(float FogStart) {
diff --git a/pack.mcmeta b/pack.mcmeta
index 486fe02..755647f 100644
--- a/pack.mcmeta
+++ b/pack.mcmeta
@@ -1,6 +1,6 @@
 {
    "pack": {
-      "pack_format": 8,
+      "pack_format": 15,
       "description": "Adds a way to have different items in the hand and the GUI."
    }
 }