From 1de3217738c8930f76acd06410f3a5ce22447fcb Mon Sep 17 00:00:00 2001
From: Anuken <arnukren@gmail.com>
Date: Thu, 13 Aug 2020 10:20:29 -0400
Subject: [PATCH] GetLink instruction

---
 core/src/mindustry/logic/LExecutor.java       | 22 ++++++++++++++++
 core/src/mindustry/logic/LStatements.java     | 25 ++++++++++++++++++-
 .../world/blocks/logic/LogicBlock.java        | 13 +++++++++-
 3 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/core/src/mindustry/logic/LExecutor.java b/core/src/mindustry/logic/LExecutor.java
index 754f669798..1115904aea 100644
--- a/core/src/mindustry/logic/LExecutor.java
+++ b/core/src/mindustry/logic/LExecutor.java
@@ -29,6 +29,7 @@ public class LExecutor{
 
     public LongSeq graphicsBuffer = new LongSeq();
     public StringBuilder textBuffer = new StringBuilder();
+    public Building[] links = {};
 
     public boolean initialized(){
         return instructions != null && vars != null && instructions.length > 0;
@@ -161,6 +162,27 @@ public class LExecutor{
         }
     }
 
+    public static class GetLinkI implements LInstruction{
+        public int output, index;
+
+        public GetLinkI(int output, int index){
+            this.index = index;
+            this.output = output;
+        }
+
+        public GetLinkI(){
+        }
+
+        @Override
+        public void run(LExecutor exec){
+            int address = exec.numi(index);
+
+            if(address >= 0 && address < exec.links.length){
+                exec.setobj(output, exec.links[address]);
+            }
+        }
+    }
+
     public static class ReadI implements LInstruction{
         public int target, position, output;
 
diff --git a/core/src/mindustry/logic/LStatements.java b/core/src/mindustry/logic/LStatements.java
index 7a5d7449c4..42636cb505 100644
--- a/core/src/mindustry/logic/LStatements.java
+++ b/core/src/mindustry/logic/LStatements.java
@@ -56,6 +56,30 @@ public class LStatements{
         }
     }
 
+    @RegisterStatement("read")
+    public static class GetLinkStatement extends LStatement{
+        public String output = "result", address = "0";
+
+        @Override
+        public void build(Table table){
+            field(table, output, str -> output = str);
+
+            table.add(" = link# ");
+
+            field(table, address, str -> address = str);
+        }
+
+        @Override
+        public LCategory category(){
+            return LCategory.io;
+        }
+
+        @Override
+        public LInstruction build(LAssembler builder){
+            return new GetLinkI(builder.var(output), builder.var(address));
+        }
+    }
+
     @RegisterStatement("write")
     public static class WriteStatement extends LStatement{
         public String input = "result", target = "cell1", address = "0";
@@ -120,7 +144,6 @@ public class LStatements{
         }
     }
 
-
     @RegisterStatement("draw")
     public static class DrawStatement extends LStatement{
         public GraphicsType type = GraphicsType.clear;
diff --git a/core/src/mindustry/world/blocks/logic/LogicBlock.java b/core/src/mindustry/world/blocks/logic/LogicBlock.java
index a47d4fe229..ee1c3ef2be 100644
--- a/core/src/mindustry/world/blocks/logic/LogicBlock.java
+++ b/core/src/mindustry/world/blocks/logic/LogicBlock.java
@@ -262,11 +262,22 @@ public class LogicBlock extends Block{
 
                     //store connections
                     for(LogicLink link : links){
-                        if(link.active && validLink(world.build(link.x, link.y))){
+                        if(link.active && (link.valid = validLink(world.build(link.x, link.y)))){
                             asm.putConst(link.name, world.build(link.x, link.y));
                         }
                     }
 
+                    //store link objects
+                    executor.links = new Building[links.count(l -> l.valid && l.active)];
+                    int index = 0;
+                    for(LogicLink link : links){
+                        if(link.active && link.valid){
+                            executor.links[index ++] = world.build(link.x, link.y);
+                        }
+                    }
+
+                    asm.putConst("@links", executor.links.length);
+
                     //store any older variables
                     for(Var var : executor.vars){
                         if(!var.constant){