From 73d6a6712c72958d861298706aca6387dfaf6e19 Mon Sep 17 00:00:00 2001
From: thmsn <9084377+thmsndk@users.noreply.github.com>
Date: Sun, 16 Jun 2024 22:43:43 +0200
Subject: [PATCH] poc of knockback ability

---
 js/common_functions.js | 42 ++++++++++++++++++++++++++++++++++++++++
 js/game.js             | 44 ++++++++++++++++++++++++++++++++++++++++++
 node/server.js         |  8 ++++----
 3 files changed, 90 insertions(+), 4 deletions(-)

diff --git a/js/common_functions.js b/js/common_functions.js
index 05828040..f8598cca 100644
--- a/js/common_functions.js
+++ b/js/common_functions.js
@@ -1173,6 +1173,48 @@ function is_in_front(observer,entity)
 	return false;
 }
 
+function knockback(player, monster, knockbackDistance) {
+    const dx = player.x - monster.x;
+    const dy = player.y - monster.y;
+    
+    const dist = Math.sqrt(dx * dx + dy * dy);
+    
+    // Avoid division by zero
+    if (dist === 0) {
+        return [[player.x, player.y]];
+    }
+    
+    const unitDx = dx / dist;
+    const unitDy = dy / dist;
+    
+    // Check points along the path
+	// const stepSize = 15;
+    const steps = 100; // Number of steps to check along the path
+    const validPoints = [];
+	let previousPoint = player;
+    for (let i = 1; i <= steps; i++) {
+        const intermediateX = player.x + unitDx * (knockbackDistance * i / steps);
+        const intermediateY = player.y + unitDy * (knockbackDistance * i / steps);
+        const intermediatePoint = { x: intermediateX, y: intermediateY };
+        
+		if(can_move({
+			map:player.map,
+			x:previousPoint.x,
+			y:previousPoint.y,
+			going_x:intermediatePoint.x,
+			going_y:intermediatePoint.y,
+			base:player.base})) {
+        
+			validPoints.push(intermediatePoint)
+        } else {
+            break;
+        }
+		previousPoint = intermediatePoint;
+    }
+    
+    return validPoints.map(p => [p.x,p.y]);
+}
+
 function calculate_movex(map, cur_x, cur_y, target_x, target_y) {
 	if(target_x==Infinity) target_x=CINF;
 	if(target_y==Infinity) target_y=CINF;
diff --git a/js/game.js b/js/game.js
index 2a4e7548..dfe62486 100644
--- a/js/game.js
+++ b/js/game.js
@@ -2668,6 +2668,50 @@ function init_socket(args)
 					}
 				}
 			}
+			else if(data.type=="polygon"){
+				
+				// var entity=get_entity(data.name);
+				
+
+				// TODO: styles from event
+				const graphics = new PIXI.Graphics();
+				
+
+				// Set the line style (width, color, alpha)
+				graphics.lineStyle(1, 0x0000FF, 1);
+
+				// Set the fill color
+				graphics.beginFill(0xDE3249);
+
+				// Draw the polygon
+				const points = data.points.reduce((res, p) => {
+					res.push(p.x, p.y)
+					return res;
+				},[])
+
+				graphics.drawPolygon(points);
+
+				graphics.endFill();
+
+				map.addChild(graphics);
+
+				function disappear(step,sprite)
+				{
+					return function(){
+						sprite.alpha-=0.08;
+						// we render 10 steps, each step is 1000 ms
+						if(step<10) draw_timeout(disappear(step+1,sprite), 100);
+						else
+						{
+							remove_sprite(sprite);
+							try{ sprite.destroy(); }catch(e){}
+						}
+					}
+				}
+
+				draw_timeout(disappear(0, graphics), 1000);
+
+			}
 			else if(is_sdk)
 				console.log("Unhandled 'ui': "+data.type);
 		});
diff --git a/node/server.js b/node/server.js
index 3351cb4c..69c538db 100644
--- a/node/server.js
+++ b/node/server.js
@@ -11728,7 +11728,8 @@ function update_instance(instance) {
 
 					// TODO: be able to offset the polygon start point by N lenght from the monster
 					// Frontal Cone, using the monsters own angle
-					const cone = generatePolygon(monster, 100, monster.angle /* south */);
+					const cone = generatePolygon(monster, 200, monster.angle /* south */);
+					// TODO: should the polygon handle collisions as "line of sight" so it can't effect them
 
 					// is_point_inside expects an array of tubles [[x1,y1],[x2,y2]]
 					const polygon = cone.map((p) => [p.x, p.y]);
@@ -11749,11 +11750,10 @@ function update_instance(instance) {
 						setTimeout(() => {
 							// TODO: this calculation seems kinda off when lookin at the client and the server decision
 							if (is_point_inside([player.x, player.y], polygon)) {
-								// TODO: knockback alculationbbbbbbbbbb depending on angles and such
 								console.log(`${player.name} is inside the polygon!`);
-
+								const knockbackPoints = knockback(player, monster, 250);
 								// TODO: We can also supply an effect to transport?
-								transport_player_to(player, monster.map, [player.x, player.y - 150]);
+								transport_player_to(player, monster.map, knockbackPoints[knockbackPoints.length - 1]);
 								resend(player, "u+cid");
 
 								monster.moving = true;