mirror of
https://github.com/libretro/RetroArch
synced 2025-01-17 19:14:56 +00:00
90 lines
2.1 KiB
C
90 lines
2.1 KiB
C
|
|
#define SRC(...) #__VA_ARGS__
|
|
SRC(
|
|
struct UBO
|
|
{
|
|
float4x4 modelViewProj;
|
|
float2 OutputSize;
|
|
float time;
|
|
};
|
|
uniform UBO global;
|
|
|
|
struct PSInput
|
|
{
|
|
float4 position : SV_POSITION;
|
|
float2 texcoord : TEXCOORD0;
|
|
};
|
|
|
|
PSInput VSMain(float4 position : POSITION, float2 texcoord : TEXCOORD0)
|
|
{
|
|
PSInput result;
|
|
result.position = mul(global.modelViewProj, position);
|
|
result.texcoord = texcoord;
|
|
return result;
|
|
}
|
|
|
|
static const float baseScale = 1.25; // [1.0 .. 10.0]
|
|
static const float density = 0.5; // [0.01 .. 1.0]
|
|
static const float speed = 0.15; // [0.1 .. 1.0]
|
|
|
|
float rand(float2 co)
|
|
{
|
|
return frac(sin(dot(co.xy, float2(12.9898, 78.233))) * 43758.5453);
|
|
}
|
|
|
|
float dist_func(float2 distv)
|
|
{
|
|
float dist = sqrt((distv.x * distv.x) + (distv.y * distv.y)) * (40.0 / baseScale);
|
|
dist = clamp(dist, 0.0, 1.0);
|
|
return cos(dist * (3.14159265358 * 0.5)) * 0.5;
|
|
}
|
|
|
|
float random_dots(float2 co)
|
|
{
|
|
float part = 1.0 / 20.0;
|
|
float2 cd = floor(co / part);
|
|
float p = rand(cd);
|
|
|
|
if (p > 0.005 * (density * 40.0))
|
|
return 0.0;
|
|
|
|
float2 dpos = (float2(frac(p * 2.0) , p) + float2(2.0, 2.0)) * 0.25;
|
|
|
|
float2 cellpos = frac(co / part);
|
|
float2 distv = (cellpos - dpos);
|
|
|
|
return dist_func(distv);
|
|
}
|
|
|
|
float snow(float2 pos, float time, float scale)
|
|
{
|
|
// add wobble
|
|
pos.x += cos(pos.y * 1.2 + time * 3.14159 * 2.0 + 1.0 / scale) / (8.0 / scale) * 4.0;
|
|
// add gravity
|
|
pos += time * scale * float2(-0.5, 1.0) * 4.0;
|
|
return random_dots(pos / scale) * (scale * 0.5 + 0.5);
|
|
}
|
|
|
|
|
|
float4 PSMain(PSInput input) : SV_TARGET
|
|
{
|
|
float tim = global.time * 0.4 * speed;
|
|
float2 pos = input.position.xy / global.OutputSize.xx;
|
|
pos.y = 1.0 - pos.y; // Flip Y
|
|
float a = 0.0;
|
|
// Each of these is a layer of snow
|
|
// Remove some for better performance
|
|
// Changing the scale (3rd value) will mess with the looping
|
|
a += snow(pos, tim, 1.0);
|
|
a += snow(pos, tim, 0.7);
|
|
a += snow(pos, tim, 0.6);
|
|
a += snow(pos, tim, 0.5);
|
|
a += snow(pos, tim, 0.4);
|
|
a += snow(pos, tim, 0.3);
|
|
a += snow(pos, tim, 0.25);
|
|
a += snow(pos, tim, 0.125);
|
|
a = a * min(pos.y * 4.0, 1.0);
|
|
return float4(1.0, 1.0, 1.0, a);
|
|
};
|
|
)
|