#include "CWorldShadowShader.hpp"

namespace urde
{

static const char* VS =
"#include <metal_stdlib>\n"
"using namespace metal;\n"
"struct VertData\n"
"{\n"
"    float4 posIn [[ attribute(0) ]];\n"
"};\n"
"\n"
"struct ColoredQuadUniform\n"
"{\n"
"    float4x4 xf;\n"
"    float4 color;\n"
"};\n"
"\n"
"struct VertToFrag\n"
"{\n"
"    float4 position [[ position ]];\n"
"    float4 color;\n"
"};\n"
"\n"
"vertex VertToFrag vmain(VertData v [[ stage_in ]], constant ColoredQuadUniform& cqu [[ buffer(2) ]])\n"
"{\n"
"    VertToFrag vtf;\n"
"    vtf.color = cqu.color;\n"
"    vtf.position = cqu.xf * float4(v.posIn.xyz, 1.0);\n"
"    return vtf;\n"
"}\n";

static const char* FS =
"#include <metal_stdlib>\n"
"using namespace metal;\n"
"struct VertToFrag\n"
"{\n"
"    float4 position [[ position ]];\n"
"    float4 color;\n"
"};\n"
"\n"
"fragment float4 fmain(VertToFrag vtf [[ stage_in ]])\n"
"{\n"
"    return vtf.color;\n"
"}\n";

URDE_DECL_SPECIALIZE_SHADER(CWorldShadowShader)

static boo::ObjToken<boo::IVertexFormat> s_VtxFmt;
static boo::ObjToken<boo::IShaderPipeline> s_Pipeline;
static boo::ObjToken<boo::IShaderPipeline> s_ZPipeline;

struct CWorldShadowShaderMetalDataBindingFactory : TShader<CWorldShadowShader>::IDataBindingFactory
{
    boo::ObjToken<boo::IShaderDataBinding> BuildShaderDataBinding(boo::IGraphicsDataFactory::Context& ctx,
                                                                  CWorldShadowShader& filter)
    {
        boo::MetalDataFactory::Context& cctx = static_cast<boo::MetalDataFactory::Context&>(ctx);

        boo::ObjToken<boo::IGraphicsBuffer> bufs[] = {filter.m_uniBuf.get()};
        filter.m_dataBind = cctx.newShaderDataBinding(s_Pipeline, s_VtxFmt,
                                                      filter.m_vbo.get(), nullptr, nullptr, 1, bufs,
                                                      nullptr, nullptr, nullptr, 0, nullptr, nullptr, nullptr);
        filter.m_zDataBind = cctx.newShaderDataBinding(s_ZPipeline, s_VtxFmt,
                                                       filter.m_vbo.get(), nullptr, nullptr, 1, bufs,
                                                       nullptr, nullptr, nullptr, 0, nullptr, nullptr, nullptr);
        return nullptr;
    }
};

TShader<CWorldShadowShader>::IDataBindingFactory*
CWorldShadowShader::Initialize(boo::MetalDataFactory::Context& ctx)
{
    const boo::VertexElementDescriptor VtxVmt[] =
    {
        {nullptr, nullptr, boo::VertexSemantic::Position4}
    };
    s_VtxFmt = ctx.newVertexFormat(1, VtxVmt);
    s_Pipeline = ctx.newShaderPipeline(VS, FS, nullptr, nullptr,
                                       s_VtxFmt, boo::BlendFactor::SrcAlpha,
                                       boo::BlendFactor::InvSrcAlpha, boo::Primitive::TriStrips,
                                       boo::ZTest::None, false, true, false, boo::CullMode::None);
    s_ZPipeline = ctx.newShaderPipeline(VS, FS, nullptr, nullptr,
                                        s_VtxFmt, boo::BlendFactor::SrcAlpha,
                                        boo::BlendFactor::InvSrcAlpha, boo::Primitive::TriStrips,
                                        boo::ZTest::LEqual, true, true, false, boo::CullMode::None);
    return new CWorldShadowShaderMetalDataBindingFactory;
}

template <>
void CWorldShadowShader::Shutdown<boo::MetalDataFactory>()
{
    s_VtxFmt.reset();
    s_Pipeline.reset();
    s_ZPipeline.reset();
}

}