// Copyright 2018 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#include <cinttypes>
#include <cstring>
#include "common/assert.h"
#include "core/core.h"
#include "core/core_timing.h"
#include "video_core/debug_utils/debug_utils.h"
#include "video_core/engines/maxwell_3d.h"
#include "video_core/memory_manager.h"
#include "video_core/rasterizer_interface.h"
#include "video_core/textures/texture.h"

namespace Tegra::Engines {

/// First register id that is actually a Macro call.
constexpr u32 MacroRegistersStart = 0xE00;

Maxwell3D::Maxwell3D(Core::System& system, VideoCore::RasterizerInterface& rasterizer,
                     MemoryManager& memory_manager)
    : system{system}, rasterizer{rasterizer}, memory_manager{memory_manager},
      macro_interpreter{*this}, upload_state{memory_manager, regs.upload} {
    InitDirtySettings();
    InitializeRegisterDefaults();
}

void Maxwell3D::InitializeRegisterDefaults() {
    // Initializes registers to their default values - what games expect them to be at boot. This is
    // for certain registers that may not be explicitly set by games.

    // Reset all registers to zero
    std::memset(&regs, 0, sizeof(regs));

    // Depth range near/far is not always set, but is expected to be the default 0.0f, 1.0f. This is
    // needed for ARMS.
    for (auto& viewport : regs.viewports) {
        viewport.depth_range_near = 0.0f;
        viewport.depth_range_far = 1.0f;
    }

    // Doom and Bomberman seems to use the uninitialized registers and just enable blend
    // so initialize blend registers with sane values
    regs.blend.equation_rgb = Regs::Blend::Equation::Add;
    regs.blend.factor_source_rgb = Regs::Blend::Factor::One;
    regs.blend.factor_dest_rgb = Regs::Blend::Factor::Zero;
    regs.blend.equation_a = Regs::Blend::Equation::Add;
    regs.blend.factor_source_a = Regs::Blend::Factor::One;
    regs.blend.factor_dest_a = Regs::Blend::Factor::Zero;
    for (auto& blend : regs.independent_blend) {
        blend.equation_rgb = Regs::Blend::Equation::Add;
        blend.factor_source_rgb = Regs::Blend::Factor::One;
        blend.factor_dest_rgb = Regs::Blend::Factor::Zero;
        blend.equation_a = Regs::Blend::Equation::Add;
        blend.factor_source_a = Regs::Blend::Factor::One;
        blend.factor_dest_a = Regs::Blend::Factor::Zero;
    }
    regs.stencil_front_op_fail = Regs::StencilOp::Keep;
    regs.stencil_front_op_zfail = Regs::StencilOp::Keep;
    regs.stencil_front_op_zpass = Regs::StencilOp::Keep;
    regs.stencil_front_func_func = Regs::ComparisonOp::Always;
    regs.stencil_front_func_mask = 0xFFFFFFFF;
    regs.stencil_front_mask = 0xFFFFFFFF;
    regs.stencil_two_side_enable = 1;
    regs.stencil_back_op_fail = Regs::StencilOp::Keep;
    regs.stencil_back_op_zfail = Regs::StencilOp::Keep;
    regs.stencil_back_op_zpass = Regs::StencilOp::Keep;
    regs.stencil_back_func_func = Regs::ComparisonOp::Always;
    regs.stencil_back_func_mask = 0xFFFFFFFF;
    regs.stencil_back_mask = 0xFFFFFFFF;

    regs.depth_test_func = Regs::ComparisonOp::Always;
    regs.cull.front_face = Regs::Cull::FrontFace::CounterClockWise;
    regs.cull.cull_face = Regs::Cull::CullFace::Back;

    // TODO(Rodrigo): Most games do not set a point size. I think this is a case of a
    // register carrying a default value. Assume it's OpenGL's default (1).
    regs.point_size = 1.0f;

    // TODO(bunnei): Some games do not initialize the color masks (e.g. Sonic Mania). Assuming a
    // default of enabled fixes rendering here.
    for (auto& color_mask : regs.color_mask) {
        color_mask.R.Assign(1);
        color_mask.G.Assign(1);
        color_mask.B.Assign(1);
        color_mask.A.Assign(1);
    }

    // Commercial games seem to assume this value is enabled and nouveau sets this value manually.
    regs.rt_separate_frag_data = 1;
}

#define DIRTY_REGS_POS(field_name) (offsetof(Maxwell3D::DirtyRegs, field_name))

void Maxwell3D::InitDirtySettings() {
    const auto set_block = [this](const u32 start, const u32 range, const u8 position) {
        const auto start_itr = dirty_pointers.begin() + start;
        const auto end_itr = start_itr + range;
        std::fill(start_itr, end_itr, position);
    };
    dirty.regs.fill(true);

    // Init Render Targets
    constexpr u32 registers_per_rt = sizeof(regs.rt[0]) / sizeof(u32);
    constexpr u32 rt_start_reg = MAXWELL3D_REG_INDEX(rt);
    constexpr u32 rt_end_reg = rt_start_reg + registers_per_rt * 8;
    u32 rt_dirty_reg = DIRTY_REGS_POS(render_target);
    for (u32 rt_reg = rt_start_reg; rt_reg < rt_end_reg; rt_reg += registers_per_rt) {
        set_block(rt_reg, registers_per_rt, rt_dirty_reg);
        rt_dirty_reg++;
    }
    constexpr u32 depth_buffer_flag = DIRTY_REGS_POS(depth_buffer);
    dirty_pointers[MAXWELL3D_REG_INDEX(zeta_enable)] = depth_buffer_flag;
    dirty_pointers[MAXWELL3D_REG_INDEX(zeta_width)] = depth_buffer_flag;
    dirty_pointers[MAXWELL3D_REG_INDEX(zeta_height)] = depth_buffer_flag;
    constexpr u32 registers_in_zeta = sizeof(regs.zeta) / sizeof(u32);
    constexpr u32 zeta_reg = MAXWELL3D_REG_INDEX(zeta);
    set_block(zeta_reg, registers_in_zeta, depth_buffer_flag);

    // Init Vertex Arrays
    constexpr u32 vertex_array_start = MAXWELL3D_REG_INDEX(vertex_array);
    constexpr u32 vertex_array_size = sizeof(regs.vertex_array[0]) / sizeof(u32);
    constexpr u32 vertex_array_end = vertex_array_start + vertex_array_size * Regs::NumVertexArrays;
    u32 va_reg = DIRTY_REGS_POS(vertex_array);
    u32 vi_reg = DIRTY_REGS_POS(vertex_instance);
    for (u32 vertex_reg = vertex_array_start; vertex_reg < vertex_array_end;
         vertex_reg += vertex_array_size) {
        set_block(vertex_reg, 3, va_reg);
        // The divisor concerns vertex array instances
        dirty_pointers[vertex_reg + 3] = vi_reg;
        va_reg++;
        vi_reg++;
    }
    constexpr u32 vertex_limit_start = MAXWELL3D_REG_INDEX(vertex_array_limit);
    constexpr u32 vertex_limit_size = sizeof(regs.vertex_array_limit[0]) / sizeof(u32);
    constexpr u32 vertex_limit_end = vertex_limit_start + vertex_limit_size * Regs::NumVertexArrays;
    va_reg = DIRTY_REGS_POS(vertex_array);
    for (u32 vertex_reg = vertex_limit_start; vertex_reg < vertex_limit_end;
         vertex_reg += vertex_limit_size) {
        set_block(vertex_reg, vertex_limit_size, va_reg);
        va_reg++;
    }
    constexpr u32 vertex_instance_start = MAXWELL3D_REG_INDEX(instanced_arrays);
    constexpr u32 vertex_instance_size =
        sizeof(regs.instanced_arrays.is_instanced[0]) / sizeof(u32);
    constexpr u32 vertex_instance_end =
        vertex_instance_start + vertex_instance_size * Regs::NumVertexArrays;
    vi_reg = DIRTY_REGS_POS(vertex_instance);
    for (u32 vertex_reg = vertex_instance_start; vertex_reg < vertex_instance_end;
         vertex_reg += vertex_instance_size) {
        set_block(vertex_reg, vertex_instance_size, vi_reg);
        vi_reg++;
    }
    set_block(MAXWELL3D_REG_INDEX(vertex_attrib_format), regs.vertex_attrib_format.size(),
              DIRTY_REGS_POS(vertex_attrib_format));

    // Init Shaders
    constexpr u32 shader_registers_count =
        sizeof(regs.shader_config[0]) * Regs::MaxShaderProgram / sizeof(u32);
    set_block(MAXWELL3D_REG_INDEX(shader_config[0]), shader_registers_count,
              DIRTY_REGS_POS(shaders));

    // State

    // Viewport
    constexpr u32 viewport_dirty_reg = DIRTY_REGS_POS(viewport);
    constexpr u32 viewport_start = MAXWELL3D_REG_INDEX(viewports);
    constexpr u32 viewport_size = sizeof(regs.viewports) / sizeof(u32);
    set_block(viewport_start, viewport_size, viewport_dirty_reg);
    constexpr u32 view_volume_start = MAXWELL3D_REG_INDEX(view_volume_clip_control);
    constexpr u32 view_volume_size = sizeof(regs.view_volume_clip_control) / sizeof(u32);
    set_block(view_volume_start, view_volume_size, viewport_dirty_reg);

    // Viewport transformation
    constexpr u32 viewport_trans_start = MAXWELL3D_REG_INDEX(viewport_transform);
    constexpr u32 viewport_trans_size = sizeof(regs.viewport_transform) / sizeof(u32);
    set_block(viewport_trans_start, viewport_trans_size, DIRTY_REGS_POS(viewport_transform));

    // Cullmode
    constexpr u32 cull_mode_start = MAXWELL3D_REG_INDEX(cull);
    constexpr u32 cull_mode_size = sizeof(regs.cull) / sizeof(u32);
    set_block(cull_mode_start, cull_mode_size, DIRTY_REGS_POS(cull_mode));

    // Screen y control
    dirty_pointers[MAXWELL3D_REG_INDEX(screen_y_control)] = DIRTY_REGS_POS(screen_y_control);

    // Primitive Restart
    constexpr u32 primitive_restart_start = MAXWELL3D_REG_INDEX(primitive_restart);
    constexpr u32 primitive_restart_size = sizeof(regs.primitive_restart) / sizeof(u32);
    set_block(primitive_restart_start, primitive_restart_size, DIRTY_REGS_POS(primitive_restart));

    // Depth Test
    constexpr u32 depth_test_dirty_reg = DIRTY_REGS_POS(depth_test);
    dirty_pointers[MAXWELL3D_REG_INDEX(depth_test_enable)] = depth_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(depth_write_enabled)] = depth_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(depth_test_func)] = depth_test_dirty_reg;

    // Stencil Test
    constexpr u32 stencil_test_dirty_reg = DIRTY_REGS_POS(stencil_test);
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_enable)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_front_func_func)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_front_func_ref)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_front_func_mask)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_front_op_fail)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_front_op_zfail)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_front_op_zpass)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_front_mask)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_two_side_enable)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_back_func_func)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_back_func_ref)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_back_func_mask)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_back_op_fail)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_back_op_zfail)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_back_op_zpass)] = stencil_test_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(stencil_back_mask)] = stencil_test_dirty_reg;

    // Color Mask
    constexpr u32 color_mask_dirty_reg = DIRTY_REGS_POS(color_mask);
    dirty_pointers[MAXWELL3D_REG_INDEX(color_mask_common)] = color_mask_dirty_reg;
    set_block(MAXWELL3D_REG_INDEX(color_mask), sizeof(regs.color_mask) / sizeof(u32),
              color_mask_dirty_reg);
    // Blend State
    constexpr u32 blend_state_dirty_reg = DIRTY_REGS_POS(blend_state);
    set_block(MAXWELL3D_REG_INDEX(blend_color), sizeof(regs.blend_color) / sizeof(u32),
              blend_state_dirty_reg);
    dirty_pointers[MAXWELL3D_REG_INDEX(independent_blend_enable)] = blend_state_dirty_reg;
    set_block(MAXWELL3D_REG_INDEX(blend), sizeof(regs.blend) / sizeof(u32), blend_state_dirty_reg);
    set_block(MAXWELL3D_REG_INDEX(independent_blend), sizeof(regs.independent_blend) / sizeof(u32),
              blend_state_dirty_reg);

    // Scissor State
    constexpr u32 scissor_test_dirty_reg = DIRTY_REGS_POS(scissor_test);
    set_block(MAXWELL3D_REG_INDEX(scissor_test), sizeof(regs.scissor_test) / sizeof(u32),
              scissor_test_dirty_reg);

    // Polygon Offset
    constexpr u32 polygon_offset_dirty_reg = DIRTY_REGS_POS(polygon_offset);
    dirty_pointers[MAXWELL3D_REG_INDEX(polygon_offset_fill_enable)] = polygon_offset_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(polygon_offset_line_enable)] = polygon_offset_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(polygon_offset_point_enable)] = polygon_offset_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(polygon_offset_units)] = polygon_offset_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(polygon_offset_factor)] = polygon_offset_dirty_reg;
    dirty_pointers[MAXWELL3D_REG_INDEX(polygon_offset_clamp)] = polygon_offset_dirty_reg;
}

void Maxwell3D::CallMacroMethod(u32 method, std::vector<u32> parameters) {
    // Reset the current macro.
    executing_macro = 0;

    // Lookup the macro offset
    const u32 entry = ((method - MacroRegistersStart) >> 1) % macro_positions.size();

    // Execute the current macro.
    macro_interpreter.Execute(macro_positions[entry], std::move(parameters));
}

void Maxwell3D::CallMethod(const GPU::MethodCall& method_call) {
    auto debug_context = system.GetGPUDebugContext();

    const u32 method = method_call.method;

    if (method == cb_data_state.current) {
        regs.reg_array[method] = method_call.argument;
        ProcessCBData(method_call.argument);
        return;
    } else if (cb_data_state.current != null_cb_data) {
        FinishCBData();
    }

    // It is an error to write to a register other than the current macro's ARG register before it
    // has finished execution.
    if (executing_macro != 0) {
        ASSERT(method == executing_macro + 1);
    }

    // Methods after 0xE00 are special, they're actually triggers for some microcode that was
    // uploaded to the GPU during initialization.
    if (method >= MacroRegistersStart) {
        // We're trying to execute a macro
        if (executing_macro == 0) {
            // A macro call must begin by writing the macro method's register, not its argument.
            ASSERT_MSG((method % 2) == 0,
                       "Can't start macro execution by writing to the ARGS register");
            executing_macro = method;
        }

        macro_params.push_back(method_call.argument);

        // Call the macro when there are no more parameters in the command buffer
        if (method_call.IsLastCall()) {
            CallMacroMethod(executing_macro, std::move(macro_params));
        }
        return;
    }

    ASSERT_MSG(method < Regs::NUM_REGS,
               "Invalid Maxwell3D register, increase the size of the Regs structure");

    if (debug_context) {
        debug_context->OnEvent(Tegra::DebugContext::Event::MaxwellCommandLoaded, nullptr);
    }

    if (regs.reg_array[method] != method_call.argument) {
        regs.reg_array[method] = method_call.argument;
        const std::size_t dirty_reg = dirty_pointers[method];
        if (dirty_reg) {
            dirty.regs[dirty_reg] = true;
            if (dirty_reg >= DIRTY_REGS_POS(vertex_array) &&
                dirty_reg < DIRTY_REGS_POS(vertex_array_buffers)) {
                dirty.vertex_array_buffers = true;
            } else if (dirty_reg >= DIRTY_REGS_POS(vertex_instance) &&
                       dirty_reg < DIRTY_REGS_POS(vertex_instances)) {
                dirty.vertex_instances = true;
            } else if (dirty_reg >= DIRTY_REGS_POS(render_target) &&
                       dirty_reg < DIRTY_REGS_POS(render_settings)) {
                dirty.render_settings = true;
            }
        }
    }

    switch (method) {
    case MAXWELL3D_REG_INDEX(macros.data): {
        ProcessMacroUpload(method_call.argument);
        break;
    }
    case MAXWELL3D_REG_INDEX(macros.bind): {
        ProcessMacroBind(method_call.argument);
        break;
    }
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[0]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[1]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[2]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[3]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[4]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[5]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[6]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[7]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[8]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[9]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[10]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[11]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[12]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[13]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[14]):
    case MAXWELL3D_REG_INDEX(const_buffer.cb_data[15]): {
        StartCBData(method);
        break;
    }
    case MAXWELL3D_REG_INDEX(cb_bind[0].raw_config): {
        ProcessCBBind(Regs::ShaderStage::Vertex);
        break;
    }
    case MAXWELL3D_REG_INDEX(cb_bind[1].raw_config): {
        ProcessCBBind(Regs::ShaderStage::TesselationControl);
        break;
    }
    case MAXWELL3D_REG_INDEX(cb_bind[2].raw_config): {
        ProcessCBBind(Regs::ShaderStage::TesselationEval);
        break;
    }
    case MAXWELL3D_REG_INDEX(cb_bind[3].raw_config): {
        ProcessCBBind(Regs::ShaderStage::Geometry);
        break;
    }
    case MAXWELL3D_REG_INDEX(cb_bind[4].raw_config): {
        ProcessCBBind(Regs::ShaderStage::Fragment);
        break;
    }
    case MAXWELL3D_REG_INDEX(draw.vertex_end_gl): {
        DrawArrays();
        break;
    }
    case MAXWELL3D_REG_INDEX(clear_buffers): {
        ProcessClearBuffers();
        break;
    }
    case MAXWELL3D_REG_INDEX(query.query_get): {
        ProcessQueryGet();
        break;
    }
    case MAXWELL3D_REG_INDEX(condition.mode): {
        ProcessQueryCondition();
        break;
    }
    case MAXWELL3D_REG_INDEX(sync_info): {
        ProcessSyncPoint();
        break;
    }
    case MAXWELL3D_REG_INDEX(exec_upload): {
        upload_state.ProcessExec(regs.exec_upload.linear != 0);
        break;
    }
    case MAXWELL3D_REG_INDEX(data_upload): {
        const bool is_last_call = method_call.IsLastCall();
        upload_state.ProcessData(method_call.argument, is_last_call);
        if (is_last_call) {
            dirty.OnMemoryWrite();
        }
        break;
    }
    default:
        break;
    }

    if (debug_context) {
        debug_context->OnEvent(Tegra::DebugContext::Event::MaxwellCommandProcessed, nullptr);
    }
}

void Maxwell3D::ProcessMacroUpload(u32 data) {
    ASSERT_MSG(regs.macros.upload_address < macro_memory.size(),
               "upload_address exceeded macro_memory size!");
    macro_memory[regs.macros.upload_address++] = data;
}

void Maxwell3D::ProcessMacroBind(u32 data) {
    macro_positions[regs.macros.entry++] = data;
}

void Maxwell3D::ProcessQueryGet() {
    const GPUVAddr sequence_address{regs.query.QueryAddress()};
    // Since the sequence address is given as a GPU VAddr, we have to convert it to an application
    // VAddr before writing.

    // TODO(Subv): Support the other query units.
    ASSERT_MSG(regs.query.query_get.unit == Regs::QueryUnit::Crop,
               "Units other than CROP are unimplemented");

    u64 result = 0;

    // TODO(Subv): Support the other query variables
    switch (regs.query.query_get.select) {
    case Regs::QuerySelect::Zero:
        // This seems to actually write the query sequence to the query address.
        result = regs.query.query_sequence;
        break;
    default:
        result = 1;
        UNIMPLEMENTED_MSG("Unimplemented query select type {}",
                          static_cast<u32>(regs.query.query_get.select.Value()));
    }

    // TODO(Subv): Research and implement how query sync conditions work.

    struct LongQueryResult {
        u64_le value;
        u64_le timestamp;
    };
    static_assert(sizeof(LongQueryResult) == 16, "LongQueryResult has wrong size");

    switch (regs.query.query_get.mode) {
    case Regs::QueryMode::Write:
    case Regs::QueryMode::Write2: {
        u32 sequence = regs.query.query_sequence;
        if (regs.query.query_get.short_query) {
            // Write the current query sequence to the sequence address.
            // TODO(Subv): Find out what happens if you use a long query type but mark it as a short
            // query.
            memory_manager.Write<u32>(sequence_address, sequence);
        } else {
            // Write the 128-bit result structure in long mode. Note: We emulate an infinitely fast
            // GPU, this command may actually take a while to complete in real hardware due to GPU
            // wait queues.
            LongQueryResult query_result{};
            query_result.value = result;
            // TODO(Subv): Generate a real GPU timestamp and write it here instead of CoreTiming
            query_result.timestamp = system.CoreTiming().GetTicks();
            memory_manager.WriteBlock(sequence_address, &query_result, sizeof(query_result));
        }
        break;
    }
    default:
        UNIMPLEMENTED_MSG("Query mode {} not implemented",
                          static_cast<u32>(regs.query.query_get.mode.Value()));
    }
}

void Maxwell3D::ProcessQueryCondition() {
    const GPUVAddr condition_address{regs.condition.Address()};
    switch (regs.condition.mode) {
    case Regs::ConditionMode::Always: {
        execute_on = true;
        break;
    }
    case Regs::ConditionMode::Never: {
        execute_on = false;
        break;
    }
    case Regs::ConditionMode::ResNonZero: {
        Regs::QueryCompare cmp;
        memory_manager.ReadBlockUnsafe(condition_address, &cmp, sizeof(cmp));
        execute_on = cmp.initial_sequence != 0U && cmp.initial_mode != 0U;
        break;
    }
    case Regs::ConditionMode::Equal: {
        Regs::QueryCompare cmp;
        memory_manager.ReadBlockUnsafe(condition_address, &cmp, sizeof(cmp));
        execute_on =
            cmp.initial_sequence == cmp.current_sequence && cmp.initial_mode == cmp.current_mode;
        break;
    }
    case Regs::ConditionMode::NotEqual: {
        Regs::QueryCompare cmp;
        memory_manager.ReadBlockUnsafe(condition_address, &cmp, sizeof(cmp));
        execute_on =
            cmp.initial_sequence != cmp.current_sequence || cmp.initial_mode != cmp.current_mode;
        break;
    }
    default: {
        UNIMPLEMENTED_MSG("Uninplemented Condition Mode!");
        execute_on = true;
        break;
    }
    }
}

void Maxwell3D::ProcessSyncPoint() {
    const u32 sync_point = regs.sync_info.sync_point.Value();
    const u32 increment = regs.sync_info.increment.Value();
    [[maybe_unused]] const u32 cache_flush = regs.sync_info.unknown.Value();
    if (increment) {
        system.GPU().IncrementSyncPoint(sync_point);
    }
}

void Maxwell3D::DrawArrays() {
    LOG_DEBUG(HW_GPU, "called, topology={}, count={}", static_cast<u32>(regs.draw.topology.Value()),
              regs.vertex_buffer.count);
    ASSERT_MSG(!(regs.index_array.count && regs.vertex_buffer.count), "Both indexed and direct?");

    auto debug_context = system.GetGPUDebugContext();

    if (debug_context) {
        debug_context->OnEvent(Tegra::DebugContext::Event::IncomingPrimitiveBatch, nullptr);
    }

    // Both instance configuration registers can not be set at the same time.
    ASSERT_MSG(!regs.draw.instance_next || !regs.draw.instance_cont,
               "Illegal combination of instancing parameters");

    if (regs.draw.instance_next) {
        // Increment the current instance *before* drawing.
        state.current_instance += 1;
    } else if (!regs.draw.instance_cont) {
        // Reset the current instance to 0.
        state.current_instance = 0;
    }

    const bool is_indexed{regs.index_array.count && !regs.vertex_buffer.count};
    rasterizer.AccelerateDrawBatch(is_indexed);

    if (debug_context) {
        debug_context->OnEvent(Tegra::DebugContext::Event::FinishedPrimitiveBatch, nullptr);
    }

    // TODO(bunnei): Below, we reset vertex count so that we can use these registers to determine if
    // the game is trying to draw indexed or direct mode. This needs to be verified on HW still -
    // it's possible that it is incorrect and that there is some other register used to specify the
    // drawing mode.
    if (is_indexed) {
        regs.index_array.count = 0;
    } else {
        regs.vertex_buffer.count = 0;
    }
}

void Maxwell3D::ProcessCBBind(Regs::ShaderStage stage) {
    // Bind the buffer currently in CB_ADDRESS to the specified index in the desired shader stage.
    auto& shader = state.shader_stages[static_cast<std::size_t>(stage)];
    auto& bind_data = regs.cb_bind[static_cast<std::size_t>(stage)];

    ASSERT(bind_data.index < Regs::MaxConstBuffers);
    auto& buffer = shader.const_buffers[bind_data.index];

    buffer.enabled = bind_data.valid.Value() != 0;
    buffer.address = regs.const_buffer.BufferAddress();
    buffer.size = regs.const_buffer.cb_size;
}

void Maxwell3D::ProcessCBData(u32 value) {
    const u32 id = cb_data_state.id;
    cb_data_state.buffer[id][cb_data_state.counter] = value;
    // Increment the current buffer position.
    regs.const_buffer.cb_pos = regs.const_buffer.cb_pos + 4;
    cb_data_state.counter++;
}

void Maxwell3D::StartCBData(u32 method) {
    constexpr u32 first_cb_data = MAXWELL3D_REG_INDEX(const_buffer.cb_data[0]);
    cb_data_state.start_pos = regs.const_buffer.cb_pos;
    cb_data_state.id = method - first_cb_data;
    cb_data_state.current = method;
    cb_data_state.counter = 0;
    ProcessCBData(regs.const_buffer.cb_data[cb_data_state.id]);
}

void Maxwell3D::FinishCBData() {
    // Write the input value to the current const buffer at the current position.
    const GPUVAddr buffer_address = regs.const_buffer.BufferAddress();
    ASSERT(buffer_address != 0);

    // Don't allow writing past the end of the buffer.
    ASSERT(regs.const_buffer.cb_pos <= regs.const_buffer.cb_size);

    const GPUVAddr address{buffer_address + cb_data_state.start_pos};
    const std::size_t size = regs.const_buffer.cb_pos - cb_data_state.start_pos;

    const u32 id = cb_data_state.id;
    memory_manager.WriteBlock(address, cb_data_state.buffer[id].data(), size);
    dirty.OnMemoryWrite();

    cb_data_state.id = null_cb_data;
    cb_data_state.current = null_cb_data;
}

Texture::TICEntry Maxwell3D::GetTICEntry(u32 tic_index) const {
    const GPUVAddr tic_address_gpu{regs.tic.TICAddress() + tic_index * sizeof(Texture::TICEntry)};

    Texture::TICEntry tic_entry;
    memory_manager.ReadBlockUnsafe(tic_address_gpu, &tic_entry, sizeof(Texture::TICEntry));

    [[maybe_unused]] const auto r_type{tic_entry.r_type.Value()};
    [[maybe_unused]] const auto g_type{tic_entry.g_type.Value()};
    [[maybe_unused]] const auto b_type{tic_entry.b_type.Value()};
    [[maybe_unused]] const auto a_type{tic_entry.a_type.Value()};

    // TODO(Subv): Different data types for separate components are not supported
    DEBUG_ASSERT(r_type == g_type && r_type == b_type && r_type == a_type);

    return tic_entry;
}

Texture::TSCEntry Maxwell3D::GetTSCEntry(u32 tsc_index) const {
    const GPUVAddr tsc_address_gpu{regs.tsc.TSCAddress() + tsc_index * sizeof(Texture::TSCEntry)};

    Texture::TSCEntry tsc_entry;
    memory_manager.ReadBlockUnsafe(tsc_address_gpu, &tsc_entry, sizeof(Texture::TSCEntry));
    return tsc_entry;
}

std::vector<Texture::FullTextureInfo> Maxwell3D::GetStageTextures(Regs::ShaderStage stage) const {
    std::vector<Texture::FullTextureInfo> textures;

    auto& fragment_shader = state.shader_stages[static_cast<std::size_t>(stage)];
    auto& tex_info_buffer = fragment_shader.const_buffers[regs.tex_cb_index];
    ASSERT(tex_info_buffer.enabled && tex_info_buffer.address != 0);

    GPUVAddr tex_info_buffer_end = tex_info_buffer.address + tex_info_buffer.size;

    // Offset into the texture constbuffer where the texture info begins.
    static constexpr std::size_t TextureInfoOffset = 0x20;

    for (GPUVAddr current_texture = tex_info_buffer.address + TextureInfoOffset;
         current_texture < tex_info_buffer_end; current_texture += sizeof(Texture::TextureHandle)) {

        const Texture::TextureHandle tex_handle{memory_manager.Read<u32>(current_texture)};

        Texture::FullTextureInfo tex_info{};
        // TODO(Subv): Use the shader to determine which textures are actually accessed.
        tex_info.index =
            static_cast<u32>(current_texture - tex_info_buffer.address - TextureInfoOffset) /
            sizeof(Texture::TextureHandle);

        // Load the TIC data.
        auto tic_entry = GetTICEntry(tex_handle.tic_id);
        // TODO(Subv): Workaround for BitField's move constructor being deleted.
        std::memcpy(&tex_info.tic, &tic_entry, sizeof(tic_entry));

        // Load the TSC data
        auto tsc_entry = GetTSCEntry(tex_handle.tsc_id);
        // TODO(Subv): Workaround for BitField's move constructor being deleted.
        std::memcpy(&tex_info.tsc, &tsc_entry, sizeof(tsc_entry));

        textures.push_back(tex_info);
    }

    return textures;
}

Texture::FullTextureInfo Maxwell3D::GetTextureInfo(const Texture::TextureHandle tex_handle,
                                                   std::size_t offset) const {
    Texture::FullTextureInfo tex_info{};
    tex_info.index = static_cast<u32>(offset);

    // Load the TIC data.
    auto tic_entry = GetTICEntry(tex_handle.tic_id);
    // TODO(Subv): Workaround for BitField's move constructor being deleted.
    std::memcpy(&tex_info.tic, &tic_entry, sizeof(tic_entry));

    // Load the TSC data
    auto tsc_entry = GetTSCEntry(tex_handle.tsc_id);
    // TODO(Subv): Workaround for BitField's move constructor being deleted.
    std::memcpy(&tex_info.tsc, &tsc_entry, sizeof(tsc_entry));

    return tex_info;
}

Texture::FullTextureInfo Maxwell3D::GetStageTexture(Regs::ShaderStage stage,
                                                    std::size_t offset) const {
    const auto& shader = state.shader_stages[static_cast<std::size_t>(stage)];
    const auto& tex_info_buffer = shader.const_buffers[regs.tex_cb_index];
    ASSERT(tex_info_buffer.enabled && tex_info_buffer.address != 0);

    const GPUVAddr tex_info_address =
        tex_info_buffer.address + offset * sizeof(Texture::TextureHandle);

    ASSERT(tex_info_address < tex_info_buffer.address + tex_info_buffer.size);

    const Texture::TextureHandle tex_handle{memory_manager.Read<u32>(tex_info_address)};

    return GetTextureInfo(tex_handle, offset);
}

u32 Maxwell3D::GetRegisterValue(u32 method) const {
    ASSERT_MSG(method < Regs::NUM_REGS, "Invalid Maxwell3D register");
    return regs.reg_array[method];
}

void Maxwell3D::ProcessClearBuffers() {
    ASSERT(regs.clear_buffers.R == regs.clear_buffers.G &&
           regs.clear_buffers.R == regs.clear_buffers.B &&
           regs.clear_buffers.R == regs.clear_buffers.A);

    rasterizer.Clear();
}

u32 Maxwell3D::AccessConstBuffer32(Regs::ShaderStage stage, u64 const_buffer, u64 offset) const {
    const auto& shader_stage = state.shader_stages[static_cast<std::size_t>(stage)];
    const auto& buffer = shader_stage.const_buffers[const_buffer];
    u32 result;
    std::memcpy(&result, memory_manager.GetPointer(buffer.address + offset), sizeof(u32));
    return result;
}

} // namespace Tegra::Engines
