Implement simple hit decals

- Give super soaker custom weapon properties
- Reduce speed at which Spread and recoil recovers
- Use LIFE_TIME and FADE_TIME constants

gfx/hit_decal.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="StreamTexture"
+path="res://.import/hit_decal.png-774262fc5a2cc970463c1e1e2886a094.stex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://gfx/hit_decal.png"
+dest_files=[ "res://.import/hit_decal.png-774262fc5a2cc970463c1e1e2886a094.stex" ]
+
+[params]
+
+compress/mode=0
+compress/lossy_quality=0.7
+compress/hdr_mode=0
+compress/bptc_ldr=0
+compress/normal_map=0
+flags/repeat=0
+flags/filter=false
+flags/mipmaps=false
+flags/anisotropic=false
+flags/srgb=2
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/HDR_as_SRGB=false
+process/invert_color=false
+stream=false
+size_limit=0
+detect_3d=false
+svg/scale=1.0

scene/HitDecal.tscn

@@ -0,0 +1,182 @@
+[gd_scene load_steps=17 format=2]
+
+[ext_resource path="res://gfx/hit_decal.png" type="Texture" id=1]
+[ext_resource path="res://src/Objects/HitDecal.cs" type="Script" id=2]
+
+[sub_resource type="VisualShaderNodeInput" id=15]
+input_name = "modulate_color"
+
+[sub_resource type="VisualShaderNodeInput" id=16]
+input_name = "modulate_alpha"
+
+[sub_resource type="VisualShaderNodeScalarOp" id=17]
+operator = 2
+
+[sub_resource type="VisualShaderNodeExpression" id=18]
+size = Vector2( 512, 260 )
+expression = "vec2 tex_size = vec2(textureSize(mask, 0));
+vec2 pix_loc  = uv.xy / TEXTURE_PIXEL_SIZE;
+mask_uv = vec3((pix_loc + offset.xy) / tex_size, 0);
+outside = mask_uv.x >= 0.0 && mask_uv.x <= 1.0 &&
+          mask_uv.y >= 0.0 && mask_uv.y <= 1.0;"
+
+[sub_resource type="VisualShaderNodeInput" id=19]
+input_name = "uv"
+
+[sub_resource type="VisualShaderNodeScalarSwitch" id=20]
+
+[sub_resource type="VisualShaderNodeVectorOp" id=21]
+operator = 2
+
+[sub_resource type="VisualShaderNodeTexture" id=22]
+source = 5
+
+[sub_resource type="VisualShaderNodeInput" id=23]
+input_name = "texture"
+
+[sub_resource type="VisualShaderNodeScalarOp" id=24]
+operator = 2
+
+[sub_resource type="VisualShaderNodeVec3Uniform" id=25]
+uniform_name = "offset"
+
+[sub_resource type="VisualShaderNodeTextureUniform" id=26]
+uniform_name = "mask"
+
+[sub_resource type="VisualShader" id=27]
+code = "shader_type canvas_item;
+uniform vec3 offset;
+uniform sampler2D mask;
+
+
+
+void vertex() {
+// Output:0
+
+}
+
+void fragment() {
+// Input:10
+	vec3 n_out10p0 = MODULATE.rgb;
+
+// Input:3
+
+// Texture:2
+	vec3 n_out2p0;
+	float n_out2p1;
+	{
+		vec4 TEXTURE_tex_read = texture(TEXTURE, UV.xy);
+		n_out2p0 = TEXTURE_tex_read.rgb;
+		n_out2p1 = TEXTURE_tex_read.a;
+	}
+
+// VectorOp:18
+	vec3 n_out18p0 = n_out10p0 * n_out2p0;
+
+// Input:13
+	float n_out13p0 = MODULATE.a;
+
+// VectorUniform:7
+	vec3 n_out7p0 = offset;
+
+// Input:16
+	vec3 n_out16p0 = vec3(UV, 0.0);
+
+// Expression:15
+	vec3 n_out15p0;
+	bool n_out15p1;
+	n_out15p0 = vec3(0.0, 0.0, 0.0);
+	n_out15p1 = false;
+	{
+		vec2 tex_size = vec2(textureSize(mask, 0));
+		vec2 pix_loc  = n_out16p0.xy / TEXTURE_PIXEL_SIZE;
+		n_out15p0 = vec3((pix_loc + n_out7p0.xy) / tex_size, 0);
+		n_out15p1 = n_out15p0.x >= 0.0 && n_out15p0.x <= 1.0 &&
+		          n_out15p0.y >= 0.0 && n_out15p0.y <= 1.0;
+	}
+
+// TextureUniform:8
+	vec3 n_out8p0;
+	float n_out8p1;
+	{
+		vec4 n_tex_read = texture(mask, n_out15p0.xy);
+		n_out8p0 = n_tex_read.rgb;
+		n_out8p1 = n_tex_read.a;
+	}
+
+// ScalarSwitch:17
+	float n_in17p2 = 0.00000;
+	float n_out17p0;
+	if(n_out15p1)
+	{
+		n_out17p0 = n_out8p1;
+	}
+	else
+	{
+		n_out17p0 = n_in17p2;
+	}
+
+// ScalarOp:6
+	float n_out6p0 = n_out2p1 * n_out17p0;
+
+// ScalarOp:14
+	float n_out14p0 = n_out13p0 * n_out6p0;
+
+// Output:0
+	COLOR.rgb = n_out18p0;
+	COLOR.a = n_out14p0;
+
+}
+
+void light() {
+// Output:0
+
+}
+"
+graph_offset = Vector2( 341, -275 )
+mode = 1
+flags/light_only = false
+nodes/fragment/0/position = Vector2( 840, -100 )
+nodes/fragment/2/node = SubResource( 22 )
+nodes/fragment/2/position = Vector2( 400, -40 )
+nodes/fragment/3/node = SubResource( 23 )
+nodes/fragment/3/position = Vector2( 220, -40 )
+nodes/fragment/6/node = SubResource( 24 )
+nodes/fragment/6/position = Vector2( 640, 60 )
+nodes/fragment/7/node = SubResource( 25 )
+nodes/fragment/7/position = Vector2( -340, 60 )
+nodes/fragment/8/node = SubResource( 26 )
+nodes/fragment/8/position = Vector2( 400, 100 )
+nodes/fragment/10/node = SubResource( 15 )
+nodes/fragment/10/position = Vector2( 320, -200 )
+nodes/fragment/13/node = SubResource( 16 )
+nodes/fragment/13/position = Vector2( 320, -120 )
+nodes/fragment/14/node = SubResource( 17 )
+nodes/fragment/14/position = Vector2( 640, -60 )
+nodes/fragment/15/node = SubResource( 18 )
+nodes/fragment/15/position = Vector2( -140, 40 )
+nodes/fragment/15/size = Vector2( 512, 260 )
+nodes/fragment/15/input_ports = "0,1,offset;1,1,uv;"
+nodes/fragment/15/output_ports = "0,1,mask_uv;1,2,outside;"
+nodes/fragment/15/expression = "vec2 tex_size = vec2(textureSize(mask, 0));
+vec2 pix_loc  = uv.xy / TEXTURE_PIXEL_SIZE;
+mask_uv = vec3((pix_loc + offset.xy) / tex_size, 0);
+outside = mask_uv.x >= 0.0 && mask_uv.x <= 1.0 &&
+          mask_uv.y >= 0.0 && mask_uv.y <= 1.0;"
+nodes/fragment/16/node = SubResource( 19 )
+nodes/fragment/16/position = Vector2( -340, 140 )
+nodes/fragment/17/node = SubResource( 20 )
+nodes/fragment/17/position = Vector2( 620, 180 )
+nodes/fragment/18/node = SubResource( 21 )
+nodes/fragment/18/position = Vector2( 640, -180 )
+nodes/fragment/connections = PoolIntArray( 3, 0, 2, 2, 2, 1, 6, 0, 6, 0, 14, 1, 13, 0, 14, 0, 14, 0, 0, 1, 7, 0, 15, 0, 16, 0, 15, 1, 15, 0, 8, 0, 15, 1, 17, 0, 8, 1, 17, 1, 17, 0, 6, 1, 10, 0, 18, 0, 2, 0, 18, 1, 18, 0, 0, 0 )
+
+[sub_resource type="ShaderMaterial" id=14]
+shader = SubResource( 27 )
+shader_param/offset = Vector3( 0, 0, 0 )
+
+[node name="HitDecal" type="Sprite"]
+material = SubResource( 14 )
+texture = ExtResource( 1 )
+centered = false
+script = ExtResource( 2 )

scene/Player.tscn

@@ -157,6 +157,15 @@ texture = ExtResource( 10 )
 offset = Vector2( 8, 0 )
 script = ExtResource( 8 )
 Automatic = true
+RateOfFire = 120
+Capacity = 4
+ReloadTime = 2.0
+Knockback = 60.0
+Spread = 3.0
+SpreadIncrease = 10.0
+BulletVelocity = 640
+BulletsPerShot = 16
+BulletOpacity = 0.06
 
 [node name="Tip" type="Node2D" parent="Items/Super Soaker"]
 position = Vector2( 17, 0.5 )

src/Items/Weapon.cs

@@ -66,8 +66,8 @@ public class Weapon : Sprite
 
     public override void _Process(float delta)
     {
-        var spreadDecrease = Mathf.Max(Mathf.Tau / 300, _currentSpreadInc * 2);
-        var recoilDecrease = Mathf.Max(Mathf.Tau / 800, _currentRecoil * 2);
+        var spreadDecrease = Mathf.Max(Mathf.Tau / 200, _currentSpreadInc * 1.5F);
+        var recoilDecrease = Mathf.Max(Mathf.Tau / 600, _currentRecoil * 1.5F);
         _currentSpreadInc = Mathf.Max(0, _currentSpreadInc - spreadDecrease * delta);
         _currentRecoil    = Mathf.Max(0, _currentRecoil    - recoilDecrease * delta);
 

src/Objects/Bullet.cs

@@ -3,7 +3,9 @@ using Godot;
 
 public class Bullet : Node2D
 {
-    private static readonly TimeSpan TRAIL_DURATION = TimeSpan.FromSeconds(0.6);
+    private static readonly TimeSpan LIFE_TIME = TimeSpan.FromSeconds(0.6);
+    private static readonly TimeSpan FADE_TIME = TimeSpan.FromSeconds(0.6);
+    private static readonly PackedScene HIT_DECAL = GD.Load<PackedScene>("res://scene/HitDecal.tscn");
 
     public Vector2 Direction { get; }
     public int EffectiveRange { get; }
@@ -12,7 +14,7 @@ public class Bullet : Node2D
     public Color Color { get; }
 
     private readonly Vector2 _startPosition;
-    private TimeSpan _age;
+    private TimeSpan _age = TimeSpan.Zero;
     private float _distance;
 
     public Bullet(Vector2 position, Vector2 direction,
@@ -26,6 +28,16 @@ public class Bullet : Node2D
         Color    = color;
     }
 
+    protected void OnCollide(CollisionObject2D obj, Vector2 hitPosition)
+    {
+        var sprite = obj.GetNodeOrNull<Sprite>("Sprite");
+        if (sprite == null) return;
+
+        var hole  = HIT_DECAL.Init<HitDecal>();
+        var color = new Color(Color, (1 + Color.a) / 2);
+        hole.Add(sprite, hitPosition, color);
+    }
+
     public override void _Ready()
         { if (this.GetGame() is Server) Visible = false; }
 
@@ -33,8 +45,8 @@ public class Bullet : Node2D
     {
         _age += TimeSpan.FromSeconds(delta);
 
-        if (_age > TRAIL_DURATION) {
-            Modulate = new Color(Modulate, Modulate.a - delta * 2);
+        if (_age > LIFE_TIME) {
+            Modulate = new Color(Modulate, Modulate.a - delta / (float)FADE_TIME.TotalSeconds);
             if (Modulate.a <= 0) this.RemoveFromParent();
         }
     }
@@ -50,6 +62,8 @@ public class Bullet : Node2D
         if (collision.Count != 0) {
             Position  = (Vector2)collision["position"];
             _distance = _startPosition.DistanceTo(Position);
+            var obj   = (CollisionObject2D)collision["collider"];
+            OnCollide(obj, Position - obj.Position);
             SetPhysicsProcess(false);
         }
 

src/Objects/HitDecal.cs

@@ -0,0 +1,38 @@
+using System;
+using Godot;
+
+// TODO: When spawned, add to multiple nearby sprites.
+public class HitDecal : Sprite
+{
+    private static readonly TimeSpan LIFE_TIME = TimeSpan.FromSeconds(5.0);
+    private static readonly TimeSpan FADE_TIME = TimeSpan.FromSeconds(5.0);
+
+    private TimeSpan _age = TimeSpan.Zero;
+    private float _fadeFactor;
+
+    public void Add(Sprite sprite, Vector2 hitVec, Color color)
+    {
+        Position   = (hitVec - Texture.GetSize() / 2).Round();
+        var offset = Position + sprite.Texture.GetSize() / 2;
+
+        ShaderMaterial material;
+        Material = material = (ShaderMaterial)Material.Duplicate();
+        material.SetShaderParam("offset", new Vector3(offset.x, offset.y, 0));
+        material.SetShaderParam("mask", sprite.Texture);
+
+        Modulate    = color;
+        _fadeFactor = color.a;
+
+        sprite.AddChild(this);
+    }
+
+    public override void _Process(float delta)
+    {
+        _age += TimeSpan.FromSeconds(delta);
+        if (_age > LIFE_TIME) {
+            var dec  = delta / (float)FADE_TIME.TotalSeconds * _fadeFactor;
+            Modulate = new Color(Modulate, Modulate.a - dec);
+            if (Modulate.a <= 0) this.RemoveFromParent();
+        }
+    }
+}