Stars twinkle

gecko0307 · Nov 22, 2024 · 0691ba9 · 0691ba9
1 parent 489ffe7
commit 0691ba9
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Showing 3 changed files with 21 additions and 7 deletions.
diff --git a/...ternal/shaders/StarfieldSky/Sky.frag.glsl → ...aders/StarfieldSky/StarfieldSky.frag.glsl b/...ternal/shaders/StarfieldSky/Sky.frag.glsl → ...aders/StarfieldSky/StarfieldSky.frag.glsl
@@ -38,23 +38,33 @@ float noise3d(vec3 x)
 uniform vec3 spaceColor;
 uniform float starsThreshold;
 uniform float starsBrightness;
+uniform float starsTwinkleSpeed;
 
 uniform vec3 sunDirection;
 uniform vec3 sunColor;
 
+uniform float localTime;
+
 const float sunEnergy = 100.0;
 const float sunAngularDiameterCos = 0.9999;
 
 void main()
 {
     vec3 radiance = toLinear(spaceColor);
 
-    float stars = noise3d(normalize(worldNormal));
-    float starsRadiance = (stars >= starsThreshold)? pow((stars - starsThreshold) / (1.0 - starsThreshold), starsBrightness) : 0.0;
-    vec3 starsColor = vec3(1.0, 1.0, 1.0); // Make uniform
-    radiance += toLinear(starsColor) * starsRadiance;
+    vec3 n = normalize(worldNormal);
+
+    float randomFactor = noise3d(n);
+    float starsRadiance = (randomFactor >= starsThreshold)? pow((randomFactor - starsThreshold) / (1.0 - starsThreshold), starsBrightness) : 0.0;
+    vec3 starsColor = vec3(0.9 + 0.1 * randomFactor, 0.9, 1.0 - 0.1 * randomFactor);
+
+    float twinkleRandomFactor = hash(dot(n, vec3(12.9898, 78.233, 45.164)));
+    float twinkle = 0.5 + 0.5 * sin((twinkleRandomFactor + localTime * starsTwinkleSpeed) * PI2);
+    twinkle = mix(0.1, 1.5, twinkle);
+
+    radiance += toLinear(starsColor) * starsRadiance * twinkle;
 
-    float cosTheta = clamp(dot(normalize(worldNormal), sunDirection), 0.0, 1.0);
+    float cosTheta = clamp(dot(n, sunDirection), 0.0, 1.0);
     float sunDisk = smoothstep(sunAngularDiameterCos, sunAngularDiameterCos + 0.00002, cosTheta);
     radiance += sunColor * sunDisk * sunEnergy;
 

diff --git a/...ternal/shaders/StarfieldSky/Sky.vert.glsl → ...aders/StarfieldSky/StarfieldSky.vert.glsl b/...ternal/shaders/StarfieldSky/Sky.vert.glsl → ...aders/StarfieldSky/StarfieldSky.vert.glsl
diff --git a/src/dagon/extra/starfieldsky.d b/src/dagon/extra/starfieldsky.d
@@ -47,14 +47,15 @@ class StarfieldSkyShader: Shader
     Color4f spaceColor = Color4f(0.0f, 0.0f, 0.0f, 1.0f);
     float starsThreshold = 0.995f;
     float starsBrightness = 8.0f;
+    float starsTwinkleSpeed = 1.0f;
 
     Vector3f sunDirection = Vector3f(-1.0f, -1.0f, -1.0f).normalized;
     Color4f sunColor = Color4f(1.0f, 1.0f, 1.0f, 1.0f);
 
     this(Owner owner)
     {
-        vs = Shader.load("data/__internal/shaders/Sky/Sky.vert.glsl");
-        fs = Shader.load("data/__internal/shaders/Sky/Sky.frag.glsl");
+        vs = Shader.load("data/__internal/shaders/StarfieldSky/StarfieldSky.vert.glsl");
+        fs = Shader.load("data/__internal/shaders/StarfieldSky/StarfieldSky.frag.glsl");
 
         auto myProgram = New!ShaderProgram(vs, fs, this);
         super(myProgram, owner);
@@ -81,6 +82,9 @@ class StarfieldSkyShader: Shader
         setParameter("spaceColor", spaceColor.rgb);
         setParameter("starsThreshold", starsThreshold);
         setParameter("starsBrightness", starsBrightness);
+        setParameter("starsTwinkleSpeed", starsTwinkleSpeed);
+
+        setParameter("localTime", state.localTime);
 
         if (state.material.sun)
         {