add clouds in bg

3 files changed, 162 insertions, 10 deletions

diff --git a/main.go b/main.go
index 500d82a..a05d2ec 100644
--- a/main.go
+++ b/main.go
@@ -44,6 +44,9 @@ var (
 	//go:embed shaders/vcr.kage
 	vcrShader_src []byte
 
+	//go:embed shaders/clouds.kage
+	cloudShader_src []byte
+
 	//go:embed assets/tiles.png
 	tilesPng_src []byte
 
@@ -146,6 +149,7 @@ func (g * Game)ReplayPoint() {
         obj.vy = point.vy
         obj.alpha = point.alpha
     }
+    g.time -=1
 }
 
 func (g * Game)ResetPlayerAi() {
@@ -205,7 +209,7 @@ func (g * Game) ResetAll() {
 
 func (g *Game) Init() {
     g.surface = ebiten.NewImage(screenWidth, screenHeight)
-    g.shaderName = "none"
+    g.shaderName = "sky"
 
     g.player = NewPlayer(g, 4 * tileSize, 9 * tileSize)
     g.objects = append(g.objects, g.player)
@@ -281,6 +285,7 @@ func (g *Game) Update() error {
     }
 
     if g.state == REVERSING {
+        g.time -= 1
         for x := 0; x < rewindSpeed; x++ {
             g.ReplayPoint()
         }
@@ -364,9 +369,18 @@ func (g *Game) PlaceObject(cx, cy int) {
 
 }
 
+func DrawBackground(screen *ebiten.Image, time int)  {
+	shop := &ebiten.DrawRectShaderOptions{}
+	shop.Uniforms = map[string]any{
+        "Time":   float32(time) / 60,
+	}
+	screen.DrawRectShader(screenWidth, screenHeight, shaders["sky"], shop)
+}
+
 func (g *Game) Draw(screen *ebiten.Image) {
 
     g.surface.Fill(color.Alpha16{0x9ccf})
+    DrawBackground(g.surface, g.time)
 
     op := &ebiten.DrawImageOptions{}
     op.GeoM.Translate(float64(g.offsetX), float64(g.offsetY))
@@ -406,7 +420,7 @@ func (g *Game) Draw(screen *ebiten.Image) {
 	shop.Images[3] = g.surface
 	screen.DrawRectShader(screenWidth, screenHeight, shaders[g.shaderName], shop)
 
-    //ebitenutil.DebugPrint(screen, fmt.Sprintf("TPS: %0.2f", ebiten.ActualTPS()))
+    ebitenutil.DebugPrint(screen, fmt.Sprintf("shader: %s", g.shaderName))
     //screen.DrawImage(surface, &ebiten.DrawImageOptions{})
 }
 
@@ -430,6 +444,10 @@ func LoadShaders() error {
         return err
     }
 
+    shaders["sky"], err = ebiten.NewShader([]byte(cloudShader_src))
+    if err != nil {
+        return err
+    }
     return nil
 }
 func (g *Game) KillPlayer() {
@@ -563,8 +581,10 @@ func (g *Game) LoadImages() {
 }
 
 func main() {
-    LoadShaders()
-
+    err := LoadShaders()
+	if err != nil {
+		log.Fatal(err)
+	}
 	ebiten.SetWindowTitle("Hello, World!")
     game := &Game{}
     game.LoadAudio()
diff --git a/shaders/clouds.kage b/shaders/clouds.kage
new file mode 100644
index 0000000..26597e5
--- /dev/null
+++ b/shaders/clouds.kage
@@ -0,0 +1,132 @@
+//go:build ignore
+
+//kage:unit pixels
+
+package main
+
+var Time float
+
+const cloudscale = 0.8
+const speed = 0.01
+const clouddark = 0.6
+const cloudlight = 0.3
+const cloudcover = 0.2
+const cloudalpha = 8.0
+const skytint = 0.5
+
+func rand(co vec2) float {
+    return fract(sin(dot(co.xy, vec2(12.9898,-78.233))) * 43758.5453)
+}
+
+func hash( p vec2  ) vec2 {
+	p = vec2(dot(p,vec2(127.1,311.7)), dot(p,vec2(269.5,183.3)))
+	return -1.0 + 2.0*fract(sin(p)*43758.5453123)
+}
+
+func noise( p vec2  ) float {
+    const K1 = 0.366025404
+    const K2 = 0.211324865
+	i := floor(p + (p.x+p.y)*K1);	
+    a := p - i + (i.x+i.y)*K2
+
+    var o vec2
+    if (a.x>a.y) {
+      o = vec2(1.0,0.0)
+    } else {
+      o = vec2(0.0,1.0)
+    }
+
+    b := a - o + K2
+	c := a - 1.0 + 2.0*K2
+    h := max(0.5-vec3(dot(a,a), dot(b,b), dot(c,c) ), 0.0)
+	n := h*h*h*h*vec3( dot(a,hash(i+0.0)), dot(b,hash(i+o)), dot(c,hash(i+1.0)))
+    return dot(n, vec3(70.0))
+}
+
+
+
+func fbm(n vec2) float {
+    v := n
+	total := 0.0
+    amplitude := 0.1
+	for i := 0; i < 7; i++ {
+		total += noise(v) * amplitude
+		v = mat2(1.6,  1.2, -1.2,  1.6)  * v
+		amplitude *= 0.4
+	}
+	return total
+}
+
+func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
+    m := mat2(1.6,  1.2, -1.2,  1.6)
+    skycolour1 := vec3(0.45, 0.57, 0.66)
+    skycolour2 := vec3(0.55, 0.77, 0.86)
+
+    p := srcPos.xy / imageSrc0Size().xy;
+	uv := p*vec2(imageSrc0Size().x/imageSrc0Size().y,1.0);    
+    time := Time * speed
+    q := fbm(uv * cloudscale * 0.5)
+
+    //ridged noise shape
+	r := 0.0
+	uv *= cloudscale
+    uv.x -= q - time
+    weight := 0.8
+    for i:=0; i<8; i++{
+		r += abs(weight*noise( uv ))
+        uv = m*uv + time
+		weight *= 0.7
+    }
+
+    //noise shape
+	f := 0.0
+	uv = p*vec2(imageSrc0Size().x/imageSrc0Size().y,1.0);    
+	uv *= cloudscale
+    uv.x -= q - time
+    weight = 0.7
+    for i:=0;i<8;i++{
+		f += weight*noise( uv )
+        uv = m*uv + time
+		weight *= 0.6
+    }
+    
+    f *= r + f
+
+    //noise colour
+    c := 0.0
+    time = Time * speed * 2.0
+    uv = p*vec2(imageSrc0Size().x/imageSrc0Size().y,1.0)
+	uv *= cloudscale*2.0
+    uv.x -= q - time
+    weight = 0.4
+    for i:=0;i<7;i++{
+		c += weight*noise( uv )
+        uv = m*uv + time
+		weight *= 0.6
+    }
+
+    //noise ridge colour
+    c1 := 0.0
+    time = Time * speed * 3.0
+    uv = p*vec2(imageSrc0Size().x/imageSrc0Size().y,1.0)
+	uv *= cloudscale*3.0
+    uv.x -= q - time
+    weight = 0.4
+    for i:=0; i<7; i++{
+		c1 += abs(weight*noise( uv ))
+        uv = m*uv + time
+		weight *= 0.6
+    }
+	
+    c += c1
+
+    skycolour := mix(skycolour2, skycolour1, p.y);
+    cloudcolour := vec3(1.1, 1.1, 0.9) * clamp((clouddark + cloudlight*c), 0.0, 1.0);
+   
+    f = cloudcover + cloudalpha*f*r;
+    
+    result := mix(skycolour, clamp(skytint * skycolour + cloudcolour, 0.0, 1.0), clamp(f + c, 0.0, 1.0));
+    
+	return vec4( result, 1.0 );
+}
+
diff --git a/shaders/vcr.kage b/shaders/vcr.kage
index fd555d8..45a543e 100644
--- a/shaders/vcr.kage
+++ b/shaders/vcr.kage
@@ -13,7 +13,7 @@ const noiseY = 100.0
 const colorOffsetIntensity = 1.2
 
 func rand(co vec2) float {
-    return fract(sin(dot(co.xy, vec2(12.9898,78.233))) * 43758.5453);
+    return fract(sin(dot(co.xy, vec2(12.9898,78.233))) * 43758.5453)
 }
 
 func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
@@ -21,7 +21,7 @@ func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
     uv := srcPos / imageSrc0Size()
 
     uv.x = uv.x + (rand(vec2(Time,srcPos.y)) - 0.5) / (noiseX); 
-    uv.y = uv.y + (rand(vec2(Time))-0.5) / (noiseY);
+    uv.y = uv.y + (rand(vec2(Time))-0.5) / (noiseY)
 
     whiteNoise := rand(vec2(floor(uv.y*80.0),floor(uv.x*50.0))+vec2(Time,0))
     off := 1.0 - mod(uv.y - NoiseOffset / 7, 1)
@@ -29,15 +29,15 @@ func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
     if (whiteNoise > 11.5-30.0*(off)) || whiteNoise < 1.5-2.0*(off) {
         // Sample the texture.
 
-        offsetR := vec2(0.006 * sin(Time), 0.0) * colorOffsetIntensity;
-        offsetG := vec2(0.0073 * (cos(Time * 0.97)), 0.0) * colorOffsetIntensity;
+        offsetR := vec2(0.006 * sin(Time), 0.0) * colorOffsetIntensity
+        offsetG := vec2(0.0073 * (cos(Time * 0.97)), 0.0) * colorOffsetIntensity
         r := imageSrc0UnsafeAt((uv+offsetR) * imageSrc0Size()).r
         g := imageSrc0UnsafeAt((uv+offsetG) * imageSrc0Size()).g
         b := imageSrc0UnsafeAt(uv * imageSrc0Size()).b
         return vec4(r, g, b, 1.0)
     } else {
-    	col = imageSrc2UnsafeAt(uv * imageSrc0Size());
-        return col + vec4(0.8);
+    	col = imageSrc2UnsafeAt(uv * imageSrc0Size())
+        return col + vec4(0.8)
     }
 
 }