// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include "shader_recompiler/backend/spirv/emit_spirv_instructions.h"
#include "shader_recompiler/backend/spirv/spirv_emit_context.h"

namespace Shader::Backend::SPIRV {

void EmitPrologue(EmitContext& ctx) {
    ctx.DefineBufferOffsets();
}

void ConvertDepthMode(EmitContext& ctx) {
    const Id type{ctx.F32[1]};
    const Id position{ctx.OpLoad(ctx.F32[4], ctx.output_position)};
    const Id z{ctx.OpCompositeExtract(type, position, 2u)};
    const Id w{ctx.OpCompositeExtract(type, position, 3u)};
    const Id screen_depth{ctx.OpFMul(type, ctx.OpFAdd(type, z, w), ctx.Constant(type, 0.5f))};
    const Id vector{ctx.OpCompositeInsert(ctx.F32[4], screen_depth, position, 2u)};
    ctx.OpStore(ctx.output_position, vector);
}

void EmitEpilogue(EmitContext& ctx) {
    if (ctx.stage == Stage::Vertex && ctx.runtime_info.vs_info.emulate_depth_negative_one_to_one) {
        ConvertDepthMode(ctx);
    }
}

void EmitDiscard(EmitContext& ctx) {
    ctx.OpDemoteToHelperInvocationEXT();
}

void EmitDiscardCond(EmitContext& ctx, Id condition) {
    const Id kill_label{ctx.OpLabel()};
    const Id merge_label{ctx.OpLabel()};
    ctx.OpSelectionMerge(merge_label, spv::SelectionControlMask::MaskNone);
    ctx.OpBranchConditional(condition, kill_label, merge_label);
    ctx.AddLabel(kill_label);
    ctx.OpDemoteToHelperInvocationEXT();
    ctx.OpBranch(merge_label);
    ctx.AddLabel(merge_label);
}

void EmitEmitVertex(EmitContext& ctx, const IR::Value& stream) {
    throw NotImplementedException("Geometry streams");
}

void EmitEndPrimitive(EmitContext& ctx, const IR::Value& stream) {
    throw NotImplementedException("Geometry streams");
}

} // namespace Shader::Backend::SPIRV