Add shader loading functionality

[no changelog]

src/main/java/moe/nea/firmament/mixins/InjectCustomShaderPrograms.java

@@ -0,0 +1,31 @@
+package moe.nea.firmament.mixins;
+
+import com.llamalad7.mixinextras.injector.wrapoperation.WrapOperation;
+import com.llamalad7.mixinextras.sugar.Local;
+import com.mojang.datafixers.util.Pair;
+import moe.nea.firmament.events.RegisterCustomShadersEvent;
+import net.minecraft.client.gl.ShaderProgram;
+import net.minecraft.client.render.GameRenderer;
+import net.minecraft.resource.ResourceFactory;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.List;
+import java.util.function.Consumer;
+
+@Mixin(GameRenderer.class)
+public class InjectCustomShaderPrograms {
+
+    @Inject(method = "loadPrograms",
+        at = @At(value = "INVOKE", target = "Lnet/minecraft/client/render/GameRenderer;loadBlurPostProcessor(Lnet/minecraft/resource/ResourceFactory;)V",
+            shift = At.Shift.AFTER))
+    void addFirmamentShaders(
+        ResourceFactory resourceFactory, CallbackInfo ci,
+        @Local(index = 3) List<Pair<ShaderProgram, Consumer<ShaderProgram>>> list
+    ) {
+        var event = new RegisterCustomShadersEvent(list, resourceFactory);
+        RegisterCustomShadersEvent.Companion.publish(event);
+    }
+}