From b773d8e92a03a3416b1ff63aacf37be22f09c9f3 Mon Sep 17 00:00:00 2001
From: valyrie97 <valerie@valnet.xyz>
Date: Mon, 26 Dec 2022 15:25:22 -0500
Subject: [PATCH] smooth pawn motion rendering

---
 .../java/xyz/valnet/engine/math/Vector2f.java    |  4 ++++
 .../xyz/valnet/hadean/gameobjects/Camera.java    |  8 ++++++++
 .../hadean/gameobjects/worldobjects/Pawn.java    |  2 +-
 .../gameobjects/worldobjects/agents/Agent.java   | 16 ++++++++++++++++
 .../java/xyz/valnet/hadean/pathfinding/Path.java |  4 ++++
 5 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/main/java/xyz/valnet/engine/math/Vector2f.java b/src/main/java/xyz/valnet/engine/math/Vector2f.java
index 4ce9caf..9220997 100644
--- a/src/main/java/xyz/valnet/engine/math/Vector2f.java
+++ b/src/main/java/xyz/valnet/engine/math/Vector2f.java
@@ -22,4 +22,8 @@ public class Vector2f {
     return x == v.x && y == v.y;
   }
 
+  public Vector2f add(Vector2f v) {
+    return new Vector2f(x + v.x, y + v.y);
+  }
+
 }
diff --git a/src/main/java/xyz/valnet/hadean/gameobjects/Camera.java b/src/main/java/xyz/valnet/hadean/gameobjects/Camera.java
index 4f4fb7d..05327df 100644
--- a/src/main/java/xyz/valnet/hadean/gameobjects/Camera.java
+++ b/src/main/java/xyz/valnet/hadean/gameobjects/Camera.java
@@ -34,6 +34,10 @@ public class Camera extends GameObject {
     return new Vector2f(x * tileWidth + screenWidth / 2 - focus.x * tileWidth, y * tileWidth + screenHeight / 2 - focus.y * tileWidth);
   }
 
+  public Vector2f world2screen(Vector2f pos) {
+    return world2screen(pos.x, pos.y);
+  }
+
   public Vector2f screen2world(float x, float y) {
     return new Vector2f((x - screenWidth / 2 + focus.x * tileWidth) / tileWidth, (y - screenHeight / 2 + focus.y * tileWidth) / tileWidth);
   }
@@ -63,6 +67,10 @@ public class Camera extends GameObject {
     draw(layer, sprite, x, y, 1, 1);
   }
 
+  public void draw(float layer, Sprite sprite, Vector2f pos) {
+    draw(layer, sprite, pos.x, pos.y, 1, 1);
+  }
+
   public void draw(float layer, Sprite sprite, float x, float y, float w, float h) {
     Vector2f screenPos = world2screen(x, y);
     Drawing.setLayer(layer + (((y + h) - minY) / (maxY - minY)));
diff --git a/src/main/java/xyz/valnet/hadean/gameobjects/worldobjects/Pawn.java b/src/main/java/xyz/valnet/hadean/gameobjects/worldobjects/Pawn.java
index 07a78bd..44cd3af 100644
--- a/src/main/java/xyz/valnet/hadean/gameobjects/worldobjects/Pawn.java
+++ b/src/main/java/xyz/valnet/hadean/gameobjects/worldobjects/Pawn.java
@@ -28,7 +28,7 @@ public class Pawn extends Agent implements IWorker {
   @Override
   public void render() {
     super.render();
-    camera.draw(Layers.PAWNS, Assets.pawn, x, y);
+    camera.draw(Layers.PAWNS, Assets.pawn, getCalculatedPosition());
   }
 
   @Override
diff --git a/src/main/java/xyz/valnet/hadean/gameobjects/worldobjects/agents/Agent.java b/src/main/java/xyz/valnet/hadean/gameobjects/worldobjects/agents/Agent.java
index 6284837..4608aaa 100644
--- a/src/main/java/xyz/valnet/hadean/gameobjects/worldobjects/agents/Agent.java
+++ b/src/main/java/xyz/valnet/hadean/gameobjects/worldobjects/agents/Agent.java
@@ -22,6 +22,7 @@ import xyz.valnet.hadean.pathfinding.Path;
 import xyz.valnet.hadean.util.Action;
 import xyz.valnet.hadean.util.Assets;
 import xyz.valnet.hadean.util.Layers;
+import static xyz.valnet.engine.util.Math.lerp;
 
 public abstract class Agent extends WorldObject implements ISelectable {
   public abstract String getName();
@@ -35,6 +36,15 @@ public abstract class Agent extends WorldObject implements ISelectable {
     return path != null && !path.isComplete();
   }
 
+  protected Vector2f getCalculatedPosition() {
+    if(path == null || path.isComplete()) return getWorldPosition();
+    Vector2f nextPos = path.peek().getPosition().asFloat();
+    return new Vector2f(
+      lerp(x, nextPos.x, frameCounter / (float)speed),
+      lerp(y, nextPos.y, frameCounter / (float)speed)
+    );
+  }
+
   @Override
   public void start() {
     super.start();
@@ -108,6 +118,7 @@ public abstract class Agent extends WorldObject implements ISelectable {
     Drawing.setLayer(Layers.GENERAL_UI);
     Assets.flat.pushColor(Vector4f.opacity(0.4f));
     if(path != null) {
+      int count = 0;
       for(Node node : path) {
         glBegin(GL_LINES);
           Vector2f u, v;
@@ -116,11 +127,16 @@ public abstract class Agent extends WorldObject implements ISelectable {
           else u = camera.world2screen(node.from.x + 0.5f, node.from.y + 0.5f);
 
           v = camera.world2screen(node.x + 0.5f, node.y + 0.5f);
+
+          if(count == path.getLength() - 1) {
+            u = camera.world2screen(getCalculatedPosition().add(new Vector2f(0.5f, 0.5f)));
+          }
           glVertexAttrib2f(SimpleShader.TEX_COORD, 0, 88 / 256f);
           glVertex3f(u.x, u.y, 3f);
           glVertexAttrib2f(SimpleShader.TEX_COORD, 0, 88 / 255f);
           glVertex3f(v.x, v.y, 3f);
         glEnd();
+        count ++;
       }
       Assets.flat.swapColor(Vector4f.opacity(0.6f));
 
diff --git a/src/main/java/xyz/valnet/hadean/pathfinding/Path.java b/src/main/java/xyz/valnet/hadean/pathfinding/Path.java
index 528b137..b324831 100644
--- a/src/main/java/xyz/valnet/hadean/pathfinding/Path.java
+++ b/src/main/java/xyz/valnet/hadean/pathfinding/Path.java
@@ -14,6 +14,10 @@ public class Path implements Iterable<Node> {
     this.dst = dst;
   }
 
+  public int getLength() {
+    return nodes.size();
+  }
+
   public Node peek() {
     return nodes.peek();
   }