/*
 * Copyright (c) Contributors to the Open 3D Engine Project.
 * For complete copyright and license terms please see the LICENSE at the root of this distribution.
 *
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 */

#include <viewsrg.srgi>

ShaderResourceGroup PerDrawSrg : SRG_PerDraw
{
    row_major float4x4 m_viewProjectionOverride;
    float m_pointSize;
}

option enum class ViewProjectionMode { ViewProjection, ManualOverride } o_viewProjMode;

struct VSInput
{
    float3 m_position : POSITION;
    float4 m_color : COLOR;
};

struct VSOutput
{
    float4 m_position : SV_Position;
    float4 m_color : COLOR;
    [[vk::builtin("PointSize")]]
    float  m_pointSize  : PSIZE;
};

VSOutput MainVS(VSInput vsInput)
{
    VSOutput OUT;
    if (o_viewProjMode == ViewProjectionMode::ViewProjection)
    {
        OUT.m_position = mul(ViewSrg::m_viewProjectionMatrix, float4(vsInput.m_position.xyz, 1.0));
    }
    else if (o_viewProjMode == ViewProjectionMode::ManualOverride)
    {
        OUT.m_position = mul(PerDrawSrg::m_viewProjectionOverride, float4(vsInput.m_position.xyz, 1.0));
    }
    OUT.m_color = vsInput.m_color;

    // On Vulkan you need to specify the point size in the VS when using the point topology.
    OUT.m_pointSize = PerDrawSrg::m_pointSize;
    return OUT;
}

struct PSOutput
{
    float4 m_color : SV_Target0;
};

PSOutput MainPS(VSOutput input)
{
    PSOutput OUT;
    OUT.m_color = input.m_color;
    return OUT;
}