metal-examples-tutorials/ch13/chapter13.playground/Resources/Shaders.metal

31 lines
1.1 KiB
Metal
Executable File

#include <metal_stdlib>
using namespace metal;
kernel void compute(texture2d<float, access::write> output [[texture(0)]],
constant float &timer [[buffer(1)]],
constant float2 &mouse [[buffer(2)]],
uint2 gid [[thread_position_in_grid]])
{
int width = output.get_width();
int height = output.get_height();
float2 uv = float2(gid) / float2(width, height);
uv = uv * 2.0 - 1.0;
float radius = 0.5;
float distance = length(uv) - radius;
// output.write(distance < 0 ? float4(1) : float4(0), gid);
float planet = float(sqrt(radius * radius - uv.x * uv.x - uv.y * uv.y));
// planet /= radius;
// output.write(distance < 0 ? float4(planet) : float4(0), gid);
float3 normal = normalize(float3(uv.x, uv.y, planet));
// output.write(distance < 0 ? float4(float3(normal), 1) : float4(0), gid);
float3 source = normalize(float3(cos(timer), sin(timer), 1));
// float3 source = normalize(float3(-1, 0, 1));
float light = dot(normal, source);
output.write(distance < 0 ? float4(float3(light), 1) : float4(0), gid);
}