31 lines
1.1 KiB
Metal
Executable File
31 lines
1.1 KiB
Metal
Executable File
|
|
#include <metal_stdlib>
|
|
|
|
using namespace metal;
|
|
|
|
kernel void compute(texture2d<float, access::write> output [[texture(0)]],
|
|
texture2d<float, access::sample> input [[texture(1)]],
|
|
constant float &timer [[buffer(0)]],
|
|
uint2 gid [[thread_position_in_grid]])
|
|
{
|
|
int width = input.get_width();
|
|
int height = input.get_height();
|
|
float2 uv = float2(gid) / float2(width, height);
|
|
uv = uv * 2.0 - 1.0;
|
|
uv = uv * 2;
|
|
float radius = 1;
|
|
float distance = length(uv) - radius;
|
|
constexpr sampler textureSampler(coord::normalized,
|
|
address::repeat,
|
|
min_filter::linear,
|
|
mag_filter::linear,
|
|
mip_filter::linear );
|
|
float3 norm = float3(uv, sqrt(1.0 - dot(uv, uv)));
|
|
float pi = 3.14;
|
|
float s = atan2( norm.z, norm.x ) / (2 * pi);
|
|
float t = asin( norm.y ) / (2 * pi);
|
|
t += 0.5;
|
|
float4 color = input.sample(textureSampler, float2(s + timer * 0.1, t));
|
|
output.write(distance < 0 ? color : float4(0), gid);
|
|
}
|