55 lines
1.5 KiB
HLSL
55 lines
1.5 KiB
HLSL
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#ifndef STARS_INCLUDED
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#define STARS_INCLUDED
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#include "JCommon.cginc"
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void CalculateStarsColor(
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float4 localPos,
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float starsStartPosition, float starsEndPosition,
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fixed4 starsColor, fixed starsOpacity,
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float starsDensity,
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float starsSize,
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fixed starsGlow,
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fixed starsTwinkle,
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out fixed4 color)
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{
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float cellCount = starsDensity*50;
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float cellSize = 1/cellCount;
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float3 cellCenter = floor(localPos.xyz/cellSize)*cellSize + 0.5*cellSize*float3(1,1,1);
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float rand = RandomValue(cellCenter.xyz) - 0.5;
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float3 starPos = cellCenter + float3(1,1,1)*cellSize*rand;
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float sqrDistance = SqrDistance(localPos.xyz, starPos);
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float sqrDistanceThreshold = 0.00001*starsSize*starsSize;
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fixed4 clear = fixed4(0,0,0,0);
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fixed4 white = fixed4(1,1,1,1);
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color = lerp(clear, white, sqrDistance <= sqrDistanceThreshold);
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color *= starsColor;
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color.a *= 2*(1 + starsGlow)*(rand + 0.5);
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float wave = TriangleWave(rand*_Time.y*starsTwinkle)*0.5 + 0.5;
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color.a *= lerp(0.5, 1, (1-wave));
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color.a *= starsOpacity;
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color = lerp(clear, color, cellCenter.y >= starsStartPosition);
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color = lerp(clear, color, cellCenter.y <= starsEndPosition);
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color = lerp(clear, color, rand <= starsDensity);
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}
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void CalculateStarsColorBaked(
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float4 localPos,
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samplerCUBE starsCubemap,
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sampler2D starsTwinkleMap,
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fixed starsOpacity,
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out fixed4 color)
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{
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float2 span = float2(1,1)*_Time.y*0.1;
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fixed twinkle = tex2D(starsTwinkleMap, localPos.xy + span).r;
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color = texCUBE(starsCubemap, localPos.xyz);
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color.a *= twinkle;
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color.a *= starsOpacity;
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}
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#endif
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