/*

 Copyright (C) 2015 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Metal skybox shader

 */

#include <metal_graphics>

#include <metal_matrix>

#include <metal_geometric>

#include <metal_math>

#include <metal_texture>

#include <metal_stdlib>

#include "AAPLSharedTypes.h"

using namespace metal;

struct CubeVertexOutput

{

    float4 position [[position]];

    float3 texCoords;

};

vertex CubeVertexOutput skyboxVertex(constant float4 *pos_data [[ buffer(SKYBOX_VERTEX_BUFFER) ]],

                                     constant float4 *texcoord [[ buffer(SKYBOX_TEXCOORD_BUFFER) ]],

                                     constant AAPL::uniforms_t& uniforms [[ buffer(SKYBOX_CONSTANT_BUFFER) ]],

                                     uint vid [[vertex_id]])

{

    CubeVertexOutput out;

    out.position = uniforms.skybox_modelview_projection_matrix * pos_data[vid];

    out.texCoords = texcoord[vid].xyz;

    return out;

}

fragment half4 skyboxFragment(CubeVertexOutput in [[stage_in]],

                               texturecube<half> skybox_texture [[texture(SKYBOX_IMAGE_TEXTURE)]])

{

    constexpr sampler s_cube(filter::linear, mip_filter::linear);

    return skybox_texture.sample(s_cube, in.texCoords);

}