Setting up to have a fire attack and lightning attack.

assets/shaders.json

@@ -14,5 +14,9 @@
   "flame": {
     "file_name": "assets/shaders/flame_trash.frag",
     "type": "fragment"
+  },
+  "lightning": {
+    "file_name": "assets/shaders/lightning_attack.frag",
+    "type": "fragment"
   }
 }

assets/shaders/lightning_attack.frag

@@ -0,0 +1,77 @@
+uniform vec2 u_resolution;
+uniform float u_time;
+uniform sampler2D source;
+uniform float u_mouse;
+uniform float value = 0.2;
+
+float random (in vec2 st) {
+    return fract(sin(dot(st.xy,
+                         vec2(12.9898,78.233)))*
+        43758.5453123);
+}
+
+float noise(in vec2 st) {
+  vec2 i = floor(st);
+  vec2 f = fract(st);
+
+  float a = random(i);
+  float b = random(i + vec2(1.0, 0.0));
+  float c = random(i + vec2(0.0, 1.0));
+  float d = random(i + vec2(1.0, 1.0));
+
+  vec2 u = f * f * (3.0 - 2.0 * f);
+
+  return mix(a, b, u.x) +
+    (c - a) * u.y * (1.0 - u.x) +
+    (d - b) * u.x * u.y;
+}
+
+float fbm(in vec2 st, int octaves=8) {
+  float v = 0.0;
+  float a = 0.5;
+  vec2 shift = vec2(100.0);
+  mat2 rot = mat2(cos(0.5), sin(0.5),
+      -sin(0.5), cos(0.5));
+
+  for(int i = 0; i < octaves; i++) {
+    v += a * noise(st);
+    st = rot * st * 2.0 + shift;
+    a *= 0.5;
+  }
+
+  return v;
+}
+
+void main() {
+  vec2 st = gl_FragCoord.xy/u_resolution.xy * 3.0;
+  vec3 color = vec3(0.0);
+
+  float speed = u_time * 40.0;
+  float value = cos(u_time) * cos(u_time);
+
+  vec2 q = vec2(0.0);
+  q.x = fbm(st + 0.00 * speed);
+  q.y = fbm(st + vec2(1.0));
+
+  vec2 r = vec2(0,0);
+  r.x += fbm( st + 1.0*q + vec2(1.0, 0.0)+ 0.15* speed );
+  r.y += fbm( st + 1.0*q + vec2(-1.0, 0.0)+ 0.126* speed);
+
+  float f = fbm(st / r);
+
+  color = mix(vec3(0.122777,0.619608, 0.666667),
+                vec3(0.498039,0.666667,0.666667),
+                clamp((f*f)*4.0,0.0,1.0));
+
+  color = mix(color,
+       vec3(0.0666667, 0.122222, 0.666667),
+       clamp(length(r.x), 0.0, 1.0));
+
+  color *= (f*f*f+0.5*f*f+0.6*f) * value;
+
+  vec4 pixel = texture2D(source, gl_TexCoord[0].xy);
+
+  float mask = color.r * pixel.a;
+
+  gl_FragColor = gl_Color * vec4(color, mask) + pixel;
+}

systems.cpp

@@ -238,7 +238,7 @@ void System::combat(GameLevel &level) {
     };
 
     if(result.player_did > 0) {
-      auto effect = shaders::get("flame");
+      auto effect = shaders::get("lightning");
       world.set<SpriteEffect>(enemy.entity, {100, effect});
     }