make mod run on 1.21.2

Author: Pyrofab

src/main/java/org/ladysnake/satin/mixin/client/gl/CoreShaderMixin.java

@@ -26,21 +26,32 @@
 import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.gen.Accessor;
 
+import java.util.Iterator;
 import java.util.List;
-import java.util.Map;
+import java.util.Objects;
 
 @Mixin(ShaderProgram.class)
 public abstract class CoreShaderMixin implements SamplerAccess {
-    @Shadow @Final private Map<String, ShaderProgramDefinition.Sampler> samplers;
+    @Shadow @Final private List<ShaderProgramDefinition.Sampler> samplers;
 
     @Override
     public void satin$removeSampler(String name) {
-        this.samplers.remove(name);
+        for (Iterator<ShaderProgramDefinition.Sampler> iterator = this.samplers.iterator(); iterator.hasNext(); ) {
+            ShaderProgramDefinition.Sampler sampler = iterator.next();
+            if (Objects.equals(sampler.name(), name)) {
+                iterator.remove();
+            }
+        }
     }
 
     @Override
     public boolean satin$hasSampler(String name) {
-        return this.samplers.containsKey(name);
+        for (ShaderProgramDefinition.Sampler sampler : samplers) {
+            if (sampler.name().equals(name)) {
+                return true;
+            }
+        }
+        return false;
     }
 
     @Override

src/testmod/resources/assets/satinbasictest/post_effect/blit.json

@@ -0,0 +1,27 @@
+{
+  "targets": {
+    "swap": {}
+  },
+  "passes": [
+    {
+      "program": "satinbasictest:post/blit",
+      "inputs": [
+        {
+          "sampler_name": "In",
+          "target": "minecraft:main"
+        }
+      ],
+      "output": "swap"
+    },
+    {
+      "name": "satinbasictest:post/blit",
+      "inputs": [
+        {
+          "sampler_name": "In",
+          "target": "swap"
+        }
+      ],
+      "output": "minecraft:main"
+    }
+  ]
+}

…/satinbasictest/shaders/program/blit.fsh …ets/satinbasictest/shaders/post/blit.fshsrc/testmod/resources/assets/satinbasictest/shaders/program/blit.fsh renamed to src/testmod/resources/assets/satinbasictest/shaders/post/blit.fsh src/testmod/resources/assets/satinbasictest/shaders/program/blit.fsh renamed to src/testmod/resources/assets/satinbasictest/shaders/post/blit.fsh

@@ -4,8 +4,8 @@
     "srcrgb": "srcalpha",
     "dstrgb": "1-srcalpha"
   },
-  "vertex": "satinbasictest:blit",
-  "fragment": "satinbasictest:blit",
+  "vertex": "satinbasictest:post/blit",
+  "fragment": "satinbasictest:post/blit",
   "attributes": ["Position"],
   "samplers": [{
     "name": "DiffuseSampler"