[unity] Fixed shader compile error with Unity 2019.4 and Urp 7.4.1. Closes #1700. Shader cleanup, removal of unused instancing vars and separate alpha texture variable.

spine-unity/Assets/Spine/Runtime/spine-unity/Shaders/Outline/Sprite/SpritesPixelLit-Outline.shader

@@ -11,8 +11,6 @@ Shader "Spine/Outline/Sprite/Pixel Lit"
 		_BumpMap ("Normal Map", 2D) = "bump" {}
 
 		[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
-		[PerRendererData] _AlphaTex ("External Alpha", 2D) = "white" {}
-		[PerRendererData] _EnableExternalAlpha ("Enable External Alpha", Float) = 0
 
 		_EmissionColor("Color", Color) = (0,0,0,0)
 		_EmissionMap("Emission", 2D) = "white" {}

spine-unity/Assets/Spine/Runtime/spine-unity/Shaders/Outline/Sprite/SpritesUnlit-Outline.shader

@@ -8,8 +8,6 @@ Shader "Spine/Outline/Sprite/Unlit"
 		_Color ("Color", Color) = (1,1,1,1)
 
 		[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
-		[PerRendererData] _AlphaTex ("External Alpha", 2D) = "white" {}
-		[PerRendererData] _EnableExternalAlpha ("Enable External Alpha", Float) = 0
 
 		_ZWrite ("Depth Write", Float) = 0.0
 		_Cutoff ("Depth alpha cutoff", Range(0,1)) = 0.0

spine-unity/Assets/Spine/Runtime/spine-unity/Shaders/Outline/Sprite/SpritesVertexLit-Outline.shader

@@ -11,8 +11,6 @@ Shader "Spine/Outline/Sprite/Vertex Lit"
 		_BumpMap ("Normal Map", 2D) = "bump" {}
 
 		[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
-		[PerRendererData] _AlphaTex ("External Alpha", 2D) = "white" {}
-		[PerRendererData] _EnableExternalAlpha ("Enable External Alpha", Float) = 0
 
 		_EmissionColor("Color", Color) = (0,0,0,0)
 		_EmissionMap("Emission", 2D) = "white" {}

spine-unity/Assets/Spine/Runtime/spine-unity/Shaders/Sprite/CGIncludes/ShaderShared.cginc

@@ -1,7 +1,5 @@
 // Upgrade NOTE: upgraded instancing buffer 'PerDrawSprite' to new syntax.
 
-// Upgrade NOTE: upgraded instancing buffer 'PerDrawSprite' to new syntax.
-
 #ifndef SHADER_SHARED_INCLUDED
 #define SHADER_SHARED_INCLUDED
 
@@ -13,28 +11,6 @@
 #include "UnityCG.cginc"
 #endif
 
-#ifdef UNITY_INSTANCING_ENABLED
-
-    UNITY_INSTANCING_BUFFER_START(PerDrawSprite)
-        // SpriteRenderer.Color while Non-Batched/Instanced.
-        fixed4 unity_SpriteRendererColorArray[UNITY_INSTANCED_ARRAY_SIZE];
-        // this could be smaller but that's how bit each entry is regardless of type
-        float4 unity_SpriteFlipArray[UNITY_INSTANCED_ARRAY_SIZE];
-    UNITY_INSTANCING_BUFFER_END(PerDrawSprite)
-
-    #define _RendererColor unity_SpriteRendererColorArray[unity_InstanceID]
-    #define _Flip unity_SpriteFlipArray[unity_InstanceID]
-
-#endif // instancing
-
-CBUFFER_START(UnityPerDrawSprite)
-#ifndef UNITY_INSTANCING_ENABLED
-    fixed4 _RendererColor;
-    float4 _Flip;
-#endif
-    float _EnableExternalAlpha;
-CBUFFER_END
-
 ////////////////////////////////////////
 // Space functions
 //
@@ -376,11 +352,6 @@ inline fixed4 applyFog(fixed4 pixel, float fogCoordOrFactorAtLWRP)
 
 uniform sampler2D _MainTex;
 
-#if ETC1_EXTERNAL_ALPHA
-//External alpha texture for ETC1 compression
-uniform sampler2D _AlphaTex;
-#endif //ETC1_EXTERNAL_ALPHA
-
 #if _TEXTURE_BLEND
 uniform sampler2D _BlendTex;
 uniform float _BlendAmount;
@@ -401,11 +372,6 @@ inline fixed4 calculateTexturePixel(float2 texcoord)
 	pixel = tex2D(_MainTex, texcoord);
 #endif // !_TEXTURE_BLEND
 
-#if ETC1_EXTERNAL_ALPHA
-    fixed4 alpha = tex2D (_AlphaTex, texcoord);
-    pixel.a = lerp (pixel.a, alpha.r, _EnableExternalAlpha);
-#endif
-
 #if defined(_COLOR_ADJUST)
 	pixel = adjustColor(pixel);
 #endif // _COLOR_ADJUST

spine-unity/Assets/Spine/Runtime/spine-unity/Shaders/Sprite/SpritesPixelLit.shader

@@ -9,8 +9,6 @@ Shader "Spine/Sprite/Pixel Lit"
 		_BumpMap ("Normal Map", 2D) = "bump" {}
 
 		[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
-		[PerRendererData] _AlphaTex ("External Alpha", 2D) = "white" {}
-		[PerRendererData] _EnableExternalAlpha ("Enable External Alpha", Float) = 0
 
 		_EmissionColor("Color", Color) = (0,0,0,0)
 		_EmissionMap("Emission", 2D) = "white" {}

spine-unity/Assets/Spine/Runtime/spine-unity/Shaders/Sprite/SpritesUnlit.shader

@@ -6,8 +6,6 @@ Shader "Spine/Sprite/Unlit"
 		_Color ("Color", Color) = (1,1,1,1)
 
 		[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
-		[PerRendererData] _AlphaTex ("External Alpha", 2D) = "white" {}
-		[PerRendererData] _EnableExternalAlpha ("Enable External Alpha", Float) = 0
 
 		_ZWrite ("Depth Write", Float) = 0.0
 		_Cutoff ("Depth alpha cutoff", Range(0,1)) = 0.0

spine-unity/Assets/Spine/Runtime/spine-unity/Shaders/Sprite/SpritesVertexLit.shader

@@ -9,8 +9,6 @@ Shader "Spine/Sprite/Vertex Lit"
 		_BumpMap ("Normal Map", 2D) = "bump" {}
 
 		[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
-		[PerRendererData] _AlphaTex ("External Alpha", 2D) = "white" {}
-		[PerRendererData] _EnableExternalAlpha ("Enable External Alpha", Float) = 0
 
 		_EmissionColor("Color", Color) = (0,0,0,0)
 		_EmissionMap("Emission", 2D) = "white" {}

spine-unity/Modules/com.esotericsoftware.spine.lwrp-shaders/Shaders/Spine-Sprite-LW.shader

@@ -9,8 +9,6 @@ Shader "Lightweight Render Pipeline/Spine/Sprite"
 		_BumpMap("Normal Map", 2D) = "bump" {}
 
 		[MaterialToggle] PixelSnap("Pixel snap", Float) = 0
-		[PerRendererData] _AlphaTex("External Alpha", 2D) = "white" {}
-		[PerRendererData] _EnableExternalAlpha("Enable External Alpha", Float) = 0
 
 		_EmissionColor("Color", Color) = (0,0,0,0)
 		_EmissionMap("Emission", 2D) = "white" {}

spine-unity/Modules/com.esotericsoftware.spine.urp-shaders/Shaders/2D/Spine-Sprite-URP-2D.shader

@@ -10,8 +10,6 @@ Shader "Universal Render Pipeline/2D/Spine/Sprite"
 		_BumpMap("Normal Map", 2D) = "bump" {}
 
 		[MaterialToggle] PixelSnap("Pixel snap", Float) = 0
-		[PerRendererData] _AlphaTex("External Alpha", 2D) = "white" {}
-		[PerRendererData] _EnableExternalAlpha("Enable External Alpha", Float) = 0
 
 		_EmissionColor("Color", Color) = (0,0,0,0)
 		_EmissionMap("Emission", 2D) = "white" {}

spine-unity/Modules/com.esotericsoftware.spine.urp-shaders/Shaders/Spine-Sprite-URP.shader

@@ -9,8 +9,6 @@ Shader "Universal Render Pipeline/Spine/Sprite"
 		_BumpMap("Normal Map", 2D) = "bump" {}
 
 		[MaterialToggle] PixelSnap("Pixel snap", Float) = 0
-		[PerRendererData] _AlphaTex("External Alpha", 2D) = "white" {}
-		[PerRendererData] _EnableExternalAlpha("Enable External Alpha", Float) = 0
 
 		_EmissionColor("Color", Color) = (0,0,0,0)
 		_EmissionMap("Emission", 2D) = "white" {}