#include <metal_stdlib>

using namespace metal;

typedef struct {
	float4 position;
	float4 texture_coords;
} vertex_struct;

struct ToFragStruct {
    float4 position [[position]];
    float2 texture_coords;
};

// vertex shader function
vertex ToFragStruct vertex_shader(device vertex_struct* vertex_array [[ buffer(0) ]],
                                  unsigned int vid [[ vertex_id ]])
{
    ToFragStruct out;

    out.position = vertex_array[vid].position;
    out.texture_coords = vertex_array[vid].texture_coords.xy;

    return out;
}

// fragment shader function
fragment float4 fragment_shader(ToFragStruct in [[stage_in]],
                                texture2d<float> texture [[texture(0)]],
                                sampler sam [[sampler(0)]])
{
    return texture.sample(sam, in.texture_coords);
}