From 0f8b314cdff0a392c994732014f8412da9b41c4e Mon Sep 17 00:00:00 2001
From: Fabien Freling <public@ffreling.com>
Date: Thu, 27 Sep 2018 15:00:23 +0200
Subject: [PATCH] Add ray in flag shader

---
 levels/Level_01.tscn |  2 +-
 scenes/Goal.tscn     | 35 +++++++++++++++++++++++++++++++----
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/levels/Level_01.tscn b/levels/Level_01.tscn
index d1d6ce5..9639573 100644
--- a/levels/Level_01.tscn
+++ b/levels/Level_01.tscn
@@ -5,7 +5,7 @@
 [ext_resource path="res://scenes/Goal.tscn" type="PackedScene" id=3]
 [ext_resource path="res://levels/Level_01_env.tres" type="Environment" id=4]
 
-[node name="Level_01" type="Node" index="0"]
+[node name="Level_01" type="Node"]
 
 [node name="GridMap" type="GridMap" parent="." index="0"]
 
diff --git a/scenes/Goal.tscn b/scenes/Goal.tscn
index bc5d2bf..713136e 100644
--- a/scenes/Goal.tscn
+++ b/scenes/Goal.tscn
@@ -18,12 +18,39 @@ void vertex() {
 	MODELVIEW_MATRIX = MODELVIEW_MATRIX * mat4(vec4(length(WORLD_MATRIX[0].xyz),0,0,0),vec4(0,1,0,0),vec4(0,0,length(WORLD_MATRIX[2].xyz),0),vec4(0,0,0,1));
 }
 
+//float atan2(vec2 coords) {
+//	float pi = 3.14;
+//	if (coords.x > 0.0) {
+//		return atan(coords.x, coords.y);
+//	} else if (coords.x < 0.0) {
+//		if (coords.y >= 0.0) {
+//			return atan(coords.x, coords.y) - pi;
+//		} else {
+//			return atan(coords.x, coords.y) + pi;
+//		}
+//	} else if (coords.y > 0.0) {
+//		return pi / 2.0;
+//	} else {
+//		return - pi / 2.0;
+//	}
+//}
+
 void fragment() {
+	ALBEDO = vec3(1.0, 1.0, 0);
+
+	vec2 center_coords = vec2(UV.x - 0.5, UV.y - 0.5);
 	float max_dist = 0.5; // maximum orthogonal distance from center in a [0,1] rectangle
 	// distance from the center, normalized on [0,1]
-	float center_dist = sqrt(pow(UV.x - 0.5, 2) + pow(UV.y - 0.5, 2)) / max_dist;
-	ALBEDO = vec3(1.0, 1.0, 0);
-	ALPHA = max(1.0 - center_dist, 0.0);
+	float center_dist = sqrt(pow(center_coords.x, 2) + pow(center_coords.y, 2)) / max_dist;
+	float angle = atan(center_coords.x, center_coords.y);
+	
+	bool on_ray = abs(angle - (sin(TIME) * 3.14)) < 0.1;// * (1.0 - center_dist);
+
+	if (on_ray) {
+		ALPHA = 1.0;
+	} else {
+		ALPHA = max(1.0 - center_dist, 0.0);		
+	}
 }
 "
 
@@ -44,7 +71,7 @@ gradient = SubResource( 4 )
 width = 2
 _sections_unfolded = [ "Resource" ]
 
-[node name="Scene Root" instance=ExtResource( 1 )]
+[node name="Scene Root" index="0" instance=ExtResource( 1 )]
 
 script = ExtResource( 2 )