#ifdef RAPI_D3D12

#if defined(_WIN32) || defined(_WIN64)

#include <stdbool.h>
#include <string.h>
#include <math.h>

#include <map>
#include <set>
#include <vector>

#include <windows.h>
#include <wrl/client.h>

// These are needed when compiling with MinGW
#include <sal.h>
#include <specstrings.h>
#define __in_ecount_opt(size)
#define __in
#define __out
#define __REQUIRED_RPCNDR_H_VERSION__ 475
#include <rpcndr.h>
#include <initguid.h>

#include <dxgi.h>
#include <dxgi1_4.h>
#include <d3d12.h>
#include <d3dcompiler.h>

#include "dxsdk/d3dx12.h"

#ifndef _LANGUAGE_C
#define _LANGUAGE_C
#endif
#include <PR/gbi.h>

extern "C" {
#include "../cliopts.h"
#include "../configfile.h"
#include "../platform.h"
#include "../pc_main.h"
}

#include "gfx_cc.h"
#include "gfx_window_manager_api.h"
#include "gfx_rendering_api.h"
#include "gfx_direct3d_common.h"

#include "gfx_screen_config.h"

#define WINCLASS_NAME L"SUPERMARIO64"
#define GFX_API_NAME "Direct3D 12"
#define DEBUG_D3D 0

#ifdef VERSION_EU
#define FRAME_INTERVAL_US_NUMERATOR 40000
#define FRAME_INTERVAL_US_DENOMINATOR 1
#else
#define FRAME_INTERVAL_US_NUMERATOR 100000
#define FRAME_INTERVAL_US_DENOMINATOR 3
#endif

using namespace Microsoft::WRL; // For ComPtr

struct ShaderProgram {
    uint32_t shader_id;
    uint8_t num_inputs;
    bool used_textures[2];
    uint8_t num_floats;
    uint8_t num_attribs;
    
    ComPtr<ID3DBlob> vertex_shader;
    ComPtr<ID3DBlob> pixel_shader;
    ComPtr<ID3D12RootSignature> root_signature;
};

struct PipelineDesc {
    uint32_t shader_id;
    bool depth_test;
    bool depth_mask;
    bool zmode_decal;
    bool _padding;
    
    bool operator==(const PipelineDesc& o) const {
        return memcmp(this, &o, sizeof(*this)) == 0;
    }
    
    bool operator<(const PipelineDesc& o) const {
        return memcmp(this, &o, sizeof(*this)) < 0;
    }
};

struct TextureHeap {
    ComPtr<ID3D12Heap> heap;
    std::vector<uint8_t> free_list;
};

struct TextureData {
    ComPtr<ID3D12Resource> resource;
    struct TextureHeap *heap;
    uint8_t heap_offset;
    
    uint64_t last_frame_counter;
    uint32_t descriptor_index;
    int sampler_parameters;
};

static struct {
    struct ShaderProgram shader_program_pool[64];
    uint8_t shader_program_pool_size;
    
    uint32_t current_width, current_height;
    
    ComPtr<IDXGIFactory4> factory;
    ComPtr<ID3D12Device> device;
    ComPtr<ID3D12CommandQueue> command_queue;
    ComPtr<ID3D12CommandQueue> copy_command_queue;
    ComPtr<IDXGISwapChain3> swap_chain;
    ComPtr<ID3D12DescriptorHeap> rtv_heap;
    UINT rtv_descriptor_size;
    ComPtr<ID3D12Resource> render_targets[2];
    ComPtr<ID3D12CommandAllocator> command_allocator;
    ComPtr<ID3D12CommandAllocator> copy_command_allocator;
    ComPtr<ID3D12GraphicsCommandList> command_list;
    ComPtr<ID3D12GraphicsCommandList> copy_command_list;
    ComPtr<ID3D12DescriptorHeap> dsv_heap;
    ComPtr<ID3D12Resource> depth_stencil_buffer;
    ComPtr<ID3D12DescriptorHeap> srv_heap;
    UINT srv_descriptor_size;
    ComPtr<ID3D12DescriptorHeap> sampler_heap;
    UINT sampler_descriptor_size;
    
    std::map<std::pair<uint32_t, uint32_t>, std::list<struct TextureHeap>> texture_heaps;
    
    std::map<size_t, std::vector<ComPtr<ID3D12Resource>>> upload_heaps;
    std::vector<std::pair<size_t, ComPtr<ID3D12Resource>>> upload_heaps_in_flight;
    ComPtr<ID3D12Fence> copy_fence;
    uint64_t copy_fence_value;
    
    std::vector<struct TextureData> textures;
    int current_tile;
    uint32_t current_texture_ids[2];
    uint32_t srv_pos;

    int frame_index;
    ComPtr<ID3D12Fence> fence;
    HANDLE fence_event;
    HANDLE waitable_object;
    uint64_t qpc_init, qpc_freq;
    uint64_t frame_timestamp; // in units of 1/FRAME_INTERVAL_US_DENOMINATOR microseconds
    std::map<UINT, DXGI_FRAME_STATISTICS> frame_stats;
    std::set<std::pair<UINT, UINT>> pending_frame_stats;
    bool dropped_frame;
    bool sync_interval_means_frames_to_wait;
    UINT length_in_vsync_frames;
    
    uint64_t frame_counter;
    
    ComPtr<ID3D12Resource> vertex_buffer;
    void *mapped_vbuf_address;
    int vbuf_pos;
    
    std::vector<ComPtr<ID3D12Resource>> resources_to_clean_at_end_of_frame;
    std::vector<std::pair<struct TextureHeap *, uint8_t>> texture_heap_allocations_to_reclaim_at_end_of_frame;
    
    std::map<PipelineDesc, ComPtr<ID3D12PipelineState>> pipeline_states;
    bool must_reload_pipeline;
    
    // Current state:
    ID3D12PipelineState *pipeline_state;
    struct ShaderProgram *shader_program;
    bool depth_test;
    bool depth_mask;
    bool zmode_decal;
    
    CD3DX12_VIEWPORT viewport;
    CD3DX12_RECT scissor;
    
    void (*run_one_game_iter)(void);
    bool (*on_key_down)(int scancode);
    bool (*on_key_up)(int scancode);
    void (*on_all_keys_up)(void);
} d3d;

static int texture_uploads = 0;
static int max_texture_uploads;

static D3D12_CPU_DESCRIPTOR_HANDLE get_cpu_descriptor_handle(ComPtr<ID3D12DescriptorHeap>& heap) {
#if __MINGW32__
    // We would like to do this:
    // D3D12_CPU_DESCRIPTOR_HANDLE handle = heap->GetCPUDescriptorHandleForHeapStart();
    // but MinGW64 doesn't follow the calling conventions of VC++ for some reason.
    // Per MS documentation "User-defined types can be returned by value from global functions and static member functions"...
    // "Otherwise, the caller assumes the responsibility of allocating memory and passing a pointer for the return value as the first argument".
    // The method here is a non-static member function, and hence we need to pass the address to the return value as a parameter.
    // MinGW32 has the same issue.
    auto fn = heap->GetCPUDescriptorHandleForHeapStart;
    void (STDMETHODCALLTYPE ID3D12DescriptorHeap::*fun)(D3D12_CPU_DESCRIPTOR_HANDLE *out) = (void (STDMETHODCALLTYPE ID3D12DescriptorHeap::*)(D3D12_CPU_DESCRIPTOR_HANDLE *out))fn;
    D3D12_CPU_DESCRIPTOR_HANDLE handle;
    (heap.Get()->*fun)(&handle);
    return handle;
#else
    return heap->GetCPUDescriptorHandleForHeapStart();
#endif
}

static D3D12_GPU_DESCRIPTOR_HANDLE get_gpu_descriptor_handle(ComPtr<ID3D12DescriptorHeap>& heap) {
#ifdef __MINGW32__
    // See get_cpu_descriptor_handle
    auto fn = heap->GetGPUDescriptorHandleForHeapStart;
    void (STDMETHODCALLTYPE ID3D12DescriptorHeap::*fun)(D3D12_GPU_DESCRIPTOR_HANDLE *out) = (void (STDMETHODCALLTYPE ID3D12DescriptorHeap::*)(D3D12_GPU_DESCRIPTOR_HANDLE *out))fn;
    D3D12_GPU_DESCRIPTOR_HANDLE handle;
    (heap.Get()->*fun)(&handle);
    return handle;
#else
    return heap->GetGPUDescriptorHandleForHeapStart();
#endif
}

static D3D12_RESOURCE_ALLOCATION_INFO get_resource_allocation_info(const D3D12_RESOURCE_DESC *resource_desc) {
#ifdef __MINGW32__
    // See get_cpu_descriptor_handle
    auto fn = d3d.device->GetResourceAllocationInfo;
    void (STDMETHODCALLTYPE ID3D12Device::*fun)(D3D12_RESOURCE_ALLOCATION_INFO *out, UINT visibleMask, UINT numResourceDescs, const D3D12_RESOURCE_DESC *pResourceDescs) =
    (void (STDMETHODCALLTYPE ID3D12Device::*)(D3D12_RESOURCE_ALLOCATION_INFO *out, UINT visibleMask, UINT numResourceDescs, const D3D12_RESOURCE_DESC *pResourceDescs))fn;
    D3D12_RESOURCE_ALLOCATION_INFO out;
    (d3d.device.Get()->*fun)(&out, 0, 1, resource_desc);
    return out;
#else
    return d3d.device->GetResourceAllocationInfo(0, 1, resource_desc);
#endif
}

static bool gfx_d3d12_z_is_from_0_to_1(void) {
    return true;
}

static void gfx_d3d12_unload_shader(struct ShaderProgram *old_prg) {
}

static void gfx_d3d12_load_shader(struct ShaderProgram *new_prg) {
    d3d.shader_program = new_prg;
    d3d.must_reload_pipeline = true;
}

static struct ShaderProgram *gfx_d3d12_create_and_load_new_shader(uint32_t shader_id) {
    /*static FILE *fp;
    if (!fp) {
        fp = fopen("shaders.txt", "w");
    }
    fprintf(fp, "0x%08x\n", shader_id);
    fflush(fp);*/
    
    struct ShaderProgram *prg = &d3d.shader_program_pool[d3d.shader_program_pool_size++];
    
    CCFeatures cc_features;
    get_cc_features(shader_id, &cc_features);
    
    char buf[2048];
    size_t len = 0;
    size_t num_floats = 4;
    
    append_str(buf, &len, "#define RS \"RootFlags(ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT | DENY_VERTEX_SHADER_ROOT_ACCESS)");
    if (cc_features.used_textures[0]) {
        append_str(buf, &len, ",DescriptorTable(SRV(t0), visibility = SHADER_VISIBILITY_PIXEL)");
        append_str(buf, &len, ",DescriptorTable(Sampler(s0), visibility = SHADER_VISIBILITY_PIXEL)");
    }
    if (cc_features.used_textures[1]) {
        append_str(buf, &len, ",DescriptorTable(SRV(t1), visibility = SHADER_VISIBILITY_PIXEL)");
        append_str(buf, &len, ",DescriptorTable(Sampler(s1), visibility = SHADER_VISIBILITY_PIXEL)");
    }
    append_line(buf, &len, "\"");
    
    append_line(buf, &len, "struct PSInput {");
    append_line(buf, &len, "float4 position : SV_POSITION;");
    if (cc_features.used_textures[0] || cc_features.used_textures[1]) {
        append_line(buf, &len, "float2 uv : TEXCOORD;");
        num_floats += 2;
    }
    if (cc_features.opt_fog) {
        append_line(buf, &len, "float4 fog : FOG;");
        num_floats += 4;
    }
    for (int i = 0; i < cc_features.num_inputs; i++) {
        len += sprintf(buf + len, "float%d input%d : INPUT%d;\r\n", cc_features.opt_alpha ? 4 : 3, i + 1, i);
        num_floats += cc_features.opt_alpha ? 4 : 3;
    }
    append_line(buf, &len, "};");
    
    if (cc_features.used_textures[0]) {
        append_line(buf, &len, "Texture2D g_texture0 : register(t0);");
        append_line(buf, &len, "SamplerState g_sampler0 : register(s0);");
    }
    if (cc_features.used_textures[1]) {
        append_line(buf, &len, "Texture2D g_texture1 : register(t1);");
        append_line(buf, &len, "SamplerState g_sampler1 : register(s1);");
    }
    
    // Vertex shader
    append_str(buf, &len, "PSInput VSMain(float4 position : POSITION");
    if (cc_features.used_textures[0] || cc_features.used_textures[1]) {
        append_str(buf, &len, ", float2 uv : TEXCOORD");
    }
    if (cc_features.opt_fog) {
        append_str(buf, &len, ", float4 fog : FOG");
    }
    for (int i = 0; i < cc_features.num_inputs; i++) {
        len += sprintf(buf + len, ", float%d input%d : INPUT%d", cc_features.opt_alpha ? 4 : 3, i + 1, i);
    }
    append_line(buf, &len, ") {");
    append_line(buf, &len, "PSInput result;");
    append_line(buf, &len, "result.position = position;");
    if (cc_features.used_textures[0] || cc_features.used_textures[1]) {
        append_line(buf, &len, "result.uv = uv;");
    }
    if (cc_features.opt_fog) {
        append_line(buf, &len, "result.fog = fog;");
    }
    for (int i = 0; i < cc_features.num_inputs; i++) {
        len += sprintf(buf + len, "result.input%d = input%d;\r\n", i + 1, i + 1);
    }
    append_line(buf, &len, "return result;");
    append_line(buf, &len, "}");
    
    // Pixel shader
    append_line(buf, &len, "[RootSignature(RS)]");
    append_line(buf, &len, "float4 PSMain(PSInput input) : SV_TARGET {");
    if (cc_features.used_textures[0]) {
        append_line(buf, &len, "float4 texVal0 = g_texture0.Sample(g_sampler0, input.uv);");
    }
    if (cc_features.used_textures[1]) {
        append_line(buf, &len, "float4 texVal1 = g_texture1.Sample(g_sampler1, input.uv);");
    }
    
    append_str(buf, &len, cc_features.opt_alpha ? "float4 texel = " : "float3 texel = ");
    if (!cc_features.color_alpha_same && cc_features.opt_alpha) {
        append_str(buf, &len, "float4(");
        append_formula(buf, &len, cc_features.c, cc_features.do_single[0], cc_features.do_multiply[0], cc_features.do_mix[0], false, false, true);
        append_str(buf, &len, ", ");
        append_formula(buf, &len, cc_features.c, cc_features.do_single[1], cc_features.do_multiply[1], cc_features.do_mix[1], true, true, true);
        append_str(buf, &len, ")");
    } else {
        append_formula(buf, &len, cc_features.c, cc_features.do_single[0], cc_features.do_multiply[0], cc_features.do_mix[0], cc_features.opt_alpha, false, cc_features.opt_alpha);
    }
    append_line(buf, &len, ";");
    
    if (cc_features.opt_texture_edge && cc_features.opt_alpha) {
        append_line(buf, &len, "if (texel.a > 0.3) texel.a = 1.0; else discard;");
    }
    // TODO discard if alpha is 0?
    if (cc_features.opt_fog) {
        if (cc_features.opt_alpha) {
            append_line(buf, &len, "texel = float4(lerp(texel.rgb, input.fog.rgb, input.fog.a), texel.a);");
        } else {
            append_line(buf, &len, "texel = lerp(texel, input.fog.rgb, input.fog.a);");
        }
    }
    
    if (cc_features.opt_alpha) {
        append_line(buf, &len, "return texel;");
    } else {
        append_line(buf, &len, "return float4(texel, 1.0);");
    }
    append_line(buf, &len, "}");
    
    //fwrite(buf, 1, len, stdout);
    
    ThrowIfFailed(D3DCompile(buf, len, nullptr, nullptr, nullptr, "VSMain", "vs_5_1", /*D3DCOMPILE_OPTIMIZATION_LEVEL3*/0, 0, &prg->vertex_shader, nullptr));
    ThrowIfFailed(D3DCompile(buf, len, nullptr, nullptr, nullptr, "PSMain", "ps_5_1", /*D3DCOMPILE_OPTIMIZATION_LEVEL3*/0, 0, &prg->pixel_shader, nullptr));
    
    ThrowIfFailed(d3d.device->CreateRootSignature(0, prg->pixel_shader->GetBufferPointer(), prg->pixel_shader->GetBufferSize(), IID_ID3D12RootSignature, IID_PPV_ARGS_Helper(&prg->root_signature)));
    
    prg->shader_id = shader_id;
    prg->num_inputs = cc_features.num_inputs;
    prg->used_textures[0] = cc_features.used_textures[0];
    prg->used_textures[1] = cc_features.used_textures[1];
    prg->num_floats = num_floats;
    //prg->num_attribs = cnt;
    
    d3d.must_reload_pipeline = true;
    return d3d.shader_program = prg;
}

static struct ShaderProgram *gfx_d3d12_lookup_shader(uint32_t shader_id) {
    for (size_t i = 0; i < d3d.shader_program_pool_size; i++) {
        if (d3d.shader_program_pool[i].shader_id == shader_id) {
            return &d3d.shader_program_pool[i];
        }
    }
    return nullptr;
}

static void gfx_d3d12_shader_get_info(struct ShaderProgram *prg, uint8_t *num_inputs, bool used_textures[2]) {
    *num_inputs = prg->num_inputs;
    used_textures[0] = prg->used_textures[0];
    used_textures[1] = prg->used_textures[1];
}

static uint32_t gfx_d3d12_new_texture(void) {
    d3d.textures.resize(d3d.textures.size() + 1);
    return (uint32_t)(d3d.textures.size() - 1);
}

static void gfx_d3d12_select_texture(int tile, uint32_t texture_id) {
    d3d.current_tile = tile;
    d3d.current_texture_ids[tile] = texture_id;
}

static void gfx_d3d12_upload_texture(uint8_t *rgba32_buf, int width, int height) {
    texture_uploads++;
    
    ComPtr<ID3D12Resource> texture_resource;
    
    // Describe and create a Texture2D.
    D3D12_RESOURCE_DESC texture_desc = {};
    texture_desc.MipLevels = 1;
    texture_desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    texture_desc.Width = width;
    texture_desc.Height = height;
    texture_desc.Flags = D3D12_RESOURCE_FLAG_NONE;
    texture_desc.DepthOrArraySize = 1;
    texture_desc.SampleDesc.Count = 1;
    texture_desc.SampleDesc.Quality = 0;
    texture_desc.Dimension = D3D12_RESOURCE_DIMENSION_TEXTURE2D;
    texture_desc.Alignment = D3D12_SMALL_RESOURCE_PLACEMENT_ALIGNMENT;
    
    D3D12_RESOURCE_ALLOCATION_INFO alloc_info = get_resource_allocation_info(&texture_desc);
    
    std::list<struct TextureHeap>& heaps = d3d.texture_heaps[std::pair<uint32_t, uint32_t>(alloc_info.SizeInBytes, alloc_info.Alignment)];
    
    struct TextureHeap *found_heap = nullptr;
    for (struct TextureHeap& heap : heaps) {
        if (!heap.free_list.empty()) {
            found_heap = &heap;
        }
    }
    if (found_heap == nullptr) {
        heaps.resize(heaps.size() + 1);
        found_heap = &heaps.back();
        
        const int textures_per_heap = 64;
        
        D3D12_HEAP_DESC heap_desc = {};
        heap_desc.SizeInBytes = alloc_info.SizeInBytes * textures_per_heap;
        if (alloc_info.Alignment == D3D12_SMALL_RESOURCE_PLACEMENT_ALIGNMENT) {
            heap_desc.Alignment = D3D12_DEFAULT_RESOURCE_PLACEMENT_ALIGNMENT;
        } else {
            heap_desc.Alignment = alloc_info.Alignment;
        }
        heap_desc.Properties.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
        heap_desc.Properties.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
        heap_desc.Properties.Type = D3D12_HEAP_TYPE_DEFAULT;
        heap_desc.Flags = D3D12_HEAP_FLAG_ALLOW_ONLY_NON_RT_DS_TEXTURES;
        ThrowIfFailed(d3d.device->CreateHeap(&heap_desc, IID_ID3D12Heap, IID_PPV_ARGS_Helper(&found_heap->heap)));
        for (int i = 0; i < textures_per_heap; i++) {
            found_heap->free_list.push_back(i);
        }
    }
    
    uint8_t heap_offset = found_heap->free_list.back();
    found_heap->free_list.pop_back();
    ThrowIfFailed(d3d.device->CreatePlacedResource(found_heap->heap.Get(), heap_offset * alloc_info.SizeInBytes, &texture_desc, D3D12_RESOURCE_STATE_COPY_DEST, nullptr, IID_ID3D12Resource, IID_PPV_ARGS_Helper(&texture_resource)));
    
    D3D12_PLACED_SUBRESOURCE_FOOTPRINT layout;
    UINT num_rows;
    UINT64 row_size_in_bytes;
    UINT64 upload_buffer_size;
    d3d.device->GetCopyableFootprints(&texture_desc, 0, 1, 0, &layout, &num_rows, &row_size_in_bytes, &upload_buffer_size);
    
    std::vector<ComPtr<ID3D12Resource>>& upload_heaps = d3d.upload_heaps[upload_buffer_size];
    ComPtr<ID3D12Resource> upload_heap;
    if (upload_heaps.empty()) {
        CD3DX12_HEAP_PROPERTIES hp(D3D12_HEAP_TYPE_UPLOAD);
        CD3DX12_RESOURCE_DESC rdb = CD3DX12_RESOURCE_DESC::Buffer(upload_buffer_size);
        ThrowIfFailed(d3d.device->CreateCommittedResource(
            &hp,
            D3D12_HEAP_FLAG_NONE,
            &rdb,
            D3D12_RESOURCE_STATE_GENERIC_READ,
            nullptr,
            IID_ID3D12Resource, IID_PPV_ARGS_Helper(&upload_heap)));
    } else {
        upload_heap = upload_heaps.back();
        upload_heaps.pop_back();
    }
    
    {
        D3D12_SUBRESOURCE_DATA texture_data = {};
        texture_data.pData = rgba32_buf;
        texture_data.RowPitch = width * 4; // RGBA
        texture_data.SlicePitch = texture_data.RowPitch * height;
        
        void *data;
        upload_heap->Map(0, nullptr, &data);
        D3D12_MEMCPY_DEST dest_data = { (uint8_t *)data + layout.Offset, layout.Footprint.RowPitch, SIZE_T(layout.Footprint.RowPitch) * SIZE_T(num_rows) };
        MemcpySubresource(&dest_data, &texture_data, static_cast<SIZE_T>(row_size_in_bytes), num_rows, layout.Footprint.Depth);
        upload_heap->Unmap(0, nullptr);

        CD3DX12_TEXTURE_COPY_LOCATION dst(texture_resource.Get(), 0);
        CD3DX12_TEXTURE_COPY_LOCATION src(upload_heap.Get(), layout);
        d3d.copy_command_list->CopyTextureRegion(&dst, 0, 0, 0, &src, nullptr);
    }
    
    CD3DX12_RESOURCE_BARRIER barrier = CD3DX12_RESOURCE_BARRIER::Transition(texture_resource.Get(), D3D12_RESOURCE_STATE_COPY_DEST, D3D12_RESOURCE_STATE_PIXEL_SHADER_RESOURCE);
    d3d.command_list->ResourceBarrier(1, &barrier);
    
    d3d.upload_heaps_in_flight.push_back(std::make_pair((size_t)upload_buffer_size, std::move(upload_heap)));
    
    struct TextureData& td = d3d.textures[d3d.current_texture_ids[d3d.current_tile]];
    if (td.resource.Get() != nullptr) {
        d3d.resources_to_clean_at_end_of_frame.push_back(std::move(td.resource));
        d3d.texture_heap_allocations_to_reclaim_at_end_of_frame.push_back(std::make_pair(td.heap, td.heap_offset));
        td.last_frame_counter = 0;
    }
    td.resource = std::move(texture_resource);
    td.heap = found_heap;
    td.heap_offset = heap_offset;
}

static int gfx_cm_to_index(uint32_t val) {
    if (val & G_TX_CLAMP) {
        return 2;
    }
    return (val & G_TX_MIRROR) ? 1 : 0;
}

static void gfx_d3d12_set_sampler_parameters(int tile, bool linear_filter, uint32_t cms, uint32_t cmt) {
    d3d.textures[d3d.current_texture_ids[tile]].sampler_parameters = linear_filter * 9 + gfx_cm_to_index(cms) * 3 + gfx_cm_to_index(cmt);
}

static void gfx_d3d12_set_depth_test(bool depth_test) {
    d3d.depth_test = depth_test;
    d3d.must_reload_pipeline = true;
}

static void gfx_d3d12_set_depth_mask(bool z_upd) {
    d3d.depth_mask = z_upd;
    d3d.must_reload_pipeline = true;
}

static void gfx_d3d12_set_zmode_decal(bool zmode_decal) {
    d3d.zmode_decal = zmode_decal;
    d3d.must_reload_pipeline = true;
}

static void gfx_d3d12_set_viewport(int x, int y, int width, int height) {
    d3d.viewport = CD3DX12_VIEWPORT(x, d3d.current_height - y - height, width, height);
}

static void gfx_d3d12_set_scissor(int x, int y, int width, int height) {
    d3d.scissor = CD3DX12_RECT(x, d3d.current_height - y - height, x + width, d3d.current_height - y);
}

static void gfx_d3d12_set_use_alpha(bool use_alpha) {
    // Already part of the pipeline state from shader info
}

static void gfx_d3d12_draw_triangles(float buf_vbo[], size_t buf_vbo_len, size_t buf_vbo_num_tris) {
    struct ShaderProgram *prg = d3d.shader_program;
    
    if (d3d.must_reload_pipeline) {
        ComPtr<ID3D12PipelineState>& pipeline_state = d3d.pipeline_states[PipelineDesc{
            prg->shader_id,
            d3d.depth_test,
            d3d.depth_mask,
            d3d.zmode_decal,
            0
        }];
        if (pipeline_state.Get() == nullptr) {
            D3D12_INPUT_ELEMENT_DESC ied[7] = {
               {"POSITION", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 0, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 }
            };
            uint32_t ied_pos = 1;
            if (prg->used_textures[0] || prg->used_textures[1]) {
                ied[ied_pos++] = D3D12_INPUT_ELEMENT_DESC{"TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT, 0, D3D12_APPEND_ALIGNED_ELEMENT, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0};
            }
            if (prg->shader_id & SHADER_OPT_FOG) {
                ied[ied_pos++] = D3D12_INPUT_ELEMENT_DESC{"FOG", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, D3D12_APPEND_ALIGNED_ELEMENT, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0};
            }
            for (int i = 0; i < prg->num_inputs; i++) {
                DXGI_FORMAT format = (prg->shader_id & SHADER_OPT_ALPHA) ? DXGI_FORMAT_R32G32B32A32_FLOAT : DXGI_FORMAT_R32G32B32_FLOAT;
                ied[ied_pos++] = D3D12_INPUT_ELEMENT_DESC{"INPUT", (UINT)i, format, 0, D3D12_APPEND_ALIGNED_ELEMENT, D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0};
            }
            
            D3D12_GRAPHICS_PIPELINE_STATE_DESC desc = {};
            desc.InputLayout = { ied, ied_pos };
            desc.pRootSignature = prg->root_signature.Get();
            desc.VS = CD3DX12_SHADER_BYTECODE(prg->vertex_shader.Get());
            desc.PS = CD3DX12_SHADER_BYTECODE(prg->pixel_shader.Get());
            desc.RasterizerState = CD3DX12_RASTERIZER_DESC(D3D12_DEFAULT);
            if (d3d.zmode_decal) {
                desc.RasterizerState.SlopeScaledDepthBias = -2.0f;
            }
            desc.RasterizerState.CullMode = D3D12_CULL_MODE_NONE;
            if (prg->shader_id & SHADER_OPT_ALPHA) {
                D3D12_BLEND_DESC bd = {};
                bd.AlphaToCoverageEnable = FALSE;
                bd.IndependentBlendEnable = FALSE;
                static const D3D12_RENDER_TARGET_BLEND_DESC default_rtbd = {
                    TRUE, FALSE,
                    D3D12_BLEND_SRC_ALPHA, D3D12_BLEND_INV_SRC_ALPHA, D3D12_BLEND_OP_ADD,
                    D3D12_BLEND_ONE, D3D12_BLEND_INV_SRC_ALPHA, D3D12_BLEND_OP_ADD,
                    D3D12_LOGIC_OP_NOOP,
                    D3D12_COLOR_WRITE_ENABLE_ALL
                };
                for (UINT i = 0; i < D3D12_SIMULTANEOUS_RENDER_TARGET_COUNT; i++) {
                    bd.RenderTarget[i] = default_rtbd;
                }
                desc.BlendState = bd;
            } else {
                desc.BlendState = CD3DX12_BLEND_DESC(D3D12_DEFAULT);
            }
            desc.DepthStencilState.DepthEnable = d3d.depth_test;
            desc.DepthStencilState.DepthWriteMask = d3d.depth_mask ? D3D12_DEPTH_WRITE_MASK_ALL : D3D12_DEPTH_WRITE_MASK_ZERO;
            desc.DepthStencilState.DepthFunc = D3D12_COMPARISON_FUNC_LESS_EQUAL;
            desc.DSVFormat = d3d.depth_test ? DXGI_FORMAT_D32_FLOAT : DXGI_FORMAT_UNKNOWN;
            desc.SampleMask = UINT_MAX;
            desc.PrimitiveTopologyType = D3D12_PRIMITIVE_TOPOLOGY_TYPE_TRIANGLE;
            desc.NumRenderTargets = 1;
            desc.RTVFormats[0] = DXGI_FORMAT_R8G8B8A8_UNORM;
            desc.SampleDesc.Count = 1;
            ThrowIfFailed(d3d.device->CreateGraphicsPipelineState(&desc, IID_ID3D12PipelineState, IID_PPV_ARGS_Helper(&pipeline_state)));
        }
        d3d.pipeline_state = pipeline_state.Get();
        d3d.must_reload_pipeline = false;
    }
    
    d3d.command_list->SetGraphicsRootSignature(prg->root_signature.Get());
    d3d.command_list->SetPipelineState(d3d.pipeline_state);
    
    ID3D12DescriptorHeap *heaps[] = { d3d.srv_heap.Get(), d3d.sampler_heap.Get() };
    d3d.command_list->SetDescriptorHeaps(2, heaps);
    
    int texture_pos = 0;
    for (int i = 0; i < 2; i++) {
        if (prg->used_textures[i]) {
            struct TextureData& td = d3d.textures[d3d.current_texture_ids[i]];
            if (td.last_frame_counter != d3d.frame_counter) {
                td.descriptor_index = d3d.srv_pos;
                td.last_frame_counter = d3d.frame_counter;
                
                D3D12_SHADER_RESOURCE_VIEW_DESC srv_desc = {};
                srv_desc.Shader4ComponentMapping = D3D12_DEFAULT_SHADER_4_COMPONENT_MAPPING;
                srv_desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
                srv_desc.ViewDimension = D3D12_SRV_DIMENSION_TEXTURE2D;
                srv_desc.Texture2D.MipLevels = 1;
                
                CD3DX12_CPU_DESCRIPTOR_HANDLE srv_handle(get_cpu_descriptor_handle(d3d.srv_heap), d3d.srv_pos++, d3d.srv_descriptor_size);
                d3d.device->CreateShaderResourceView(td.resource.Get(), &srv_desc, srv_handle);
            }
            
            CD3DX12_GPU_DESCRIPTOR_HANDLE srv_gpu_handle(get_gpu_descriptor_handle(d3d.srv_heap), td.descriptor_index, d3d.srv_descriptor_size);
            d3d.command_list->SetGraphicsRootDescriptorTable(2 * texture_pos, srv_gpu_handle);
            
            CD3DX12_GPU_DESCRIPTOR_HANDLE sampler_gpu_handle(get_gpu_descriptor_handle(d3d.sampler_heap), td.sampler_parameters, d3d.sampler_descriptor_size);
            d3d.command_list->SetGraphicsRootDescriptorTable(2 * texture_pos + 1, sampler_gpu_handle);
            
            ++texture_pos;
        }
    }
    
    CD3DX12_CPU_DESCRIPTOR_HANDLE rtv_handle(get_cpu_descriptor_handle(d3d.rtv_heap), d3d.frame_index, d3d.rtv_descriptor_size);
    D3D12_CPU_DESCRIPTOR_HANDLE dsv_handle = get_cpu_descriptor_handle(d3d.dsv_heap);
    d3d.command_list->OMSetRenderTargets(1, &rtv_handle, FALSE, &dsv_handle);
    
    d3d.command_list->RSSetViewports(1, &d3d.viewport);
    d3d.command_list->RSSetScissorRects(1, &d3d.scissor);
    
    int current_pos = d3d.vbuf_pos;
    memcpy((uint8_t *)d3d.mapped_vbuf_address + current_pos, buf_vbo, buf_vbo_len * sizeof(float));
    d3d.vbuf_pos += buf_vbo_len * sizeof(float);
    static int maxpos;
    if (d3d.vbuf_pos > maxpos) {
        maxpos = d3d.vbuf_pos;
        //printf("NEW MAXPOS: %d\n", maxpos);
    }
    
    D3D12_VERTEX_BUFFER_VIEW vertex_buffer_view;
    vertex_buffer_view.BufferLocation = d3d.vertex_buffer->GetGPUVirtualAddress() + current_pos;
    vertex_buffer_view.StrideInBytes = buf_vbo_len / (3 * buf_vbo_num_tris) * sizeof(float);
    vertex_buffer_view.SizeInBytes = buf_vbo_len * sizeof(float);
    
    d3d.command_list->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
    d3d.command_list->IASetVertexBuffers(0, 1, &vertex_buffer_view);
    d3d.command_list->DrawInstanced(3 * buf_vbo_num_tris, 1, 0, 0);
}

static void gfx_d3d12_init(void) { }

static void gfx_d3d12_shutdown(void) { }

static void gfx_d3d12_start_frame(void) {
    ++d3d.frame_counter;
    d3d.srv_pos = 0;
    texture_uploads = 0;
    ThrowIfFailed(d3d.command_allocator->Reset());
    ThrowIfFailed(d3d.command_list->Reset(d3d.command_allocator.Get(), nullptr));
    
    CD3DX12_RESOURCE_BARRIER barrier = CD3DX12_RESOURCE_BARRIER::Transition(
        d3d.render_targets[d3d.frame_index].Get(),
        D3D12_RESOURCE_STATE_PRESENT,
        D3D12_RESOURCE_STATE_RENDER_TARGET);
    d3d.command_list->ResourceBarrier(1, &barrier);
    
    CD3DX12_CPU_DESCRIPTOR_HANDLE rtv_handle(get_cpu_descriptor_handle(d3d.rtv_heap), d3d.frame_index, d3d.rtv_descriptor_size);
    D3D12_CPU_DESCRIPTOR_HANDLE dsv_handle = get_cpu_descriptor_handle(d3d.dsv_heap);
    d3d.command_list->OMSetRenderTargets(1, &rtv_handle, FALSE, &dsv_handle);
    
    static unsigned char c;
    const float clear_color[] = { 0.0f, 0.0f, 0.0f, 1.0f };
    d3d.command_list->ClearRenderTargetView(rtv_handle, clear_color, 0, nullptr);
    d3d.command_list->ClearDepthStencilView(dsv_handle, D3D12_CLEAR_FLAG_DEPTH, 1.0f, 0, 0, nullptr);
    
    d3d.vbuf_pos = 0;
}

static void create_render_target_views(void) {
    D3D12_CPU_DESCRIPTOR_HANDLE rtv_handle = get_cpu_descriptor_handle(d3d.rtv_heap);
    for (UINT i = 0; i < 2; i++) {
        ThrowIfFailed(d3d.swap_chain->GetBuffer(i, IID_ID3D12Resource, (void **)&d3d.render_targets[i]));
        d3d.device->CreateRenderTargetView(d3d.render_targets[i].Get(), nullptr, rtv_handle);
        rtv_handle.ptr += d3d.rtv_descriptor_size;
    }
}

static void create_depth_buffer(void) {
    DXGI_SWAP_CHAIN_DESC1 desc1;
    ThrowIfFailed(d3d.swap_chain->GetDesc1(&desc1));
    UINT width = desc1.Width;
    UINT height = desc1.Height;
    
    d3d.current_width = width;
    d3d.current_height = height;
    
    D3D12_DEPTH_STENCIL_VIEW_DESC dsv_desc = {};
    dsv_desc.Format = DXGI_FORMAT_D32_FLOAT;
    dsv_desc.ViewDimension = D3D12_DSV_DIMENSION_TEXTURE2D;
    dsv_desc.Flags = D3D12_DSV_FLAG_NONE;

    D3D12_CLEAR_VALUE depth_optimized_cv = {};
    depth_optimized_cv.Format = DXGI_FORMAT_D32_FLOAT;
    depth_optimized_cv.DepthStencil.Depth = 1.0f;

    D3D12_HEAP_PROPERTIES hp = {};
    hp.Type = D3D12_HEAP_TYPE_DEFAULT;
    hp.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
    hp.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
    hp.CreationNodeMask = 1;
    hp.VisibleNodeMask = 1;

    D3D12_RESOURCE_DESC rd = {};
    rd.Dimension = D3D12_RESOURCE_DIMENSION_TEXTURE2D;
    rd.Alignment = 0;
    rd.Width = width;
    rd.Height = height;
    rd.DepthOrArraySize = 1;
    rd.MipLevels = 0;
    rd.Format = DXGI_FORMAT_D32_FLOAT;
    rd.SampleDesc.Count = 1;
    rd.SampleDesc.Quality = 0;
    rd.Flags = D3D12_RESOURCE_FLAG_ALLOW_DEPTH_STENCIL;
    rd.Layout = D3D12_TEXTURE_LAYOUT_UNKNOWN;
    ThrowIfFailed(d3d.device->CreateCommittedResource(&hp, D3D12_HEAP_FLAG_NONE, &rd, D3D12_RESOURCE_STATE_DEPTH_WRITE, &depth_optimized_cv, IID_ID3D12Resource, IID_PPV_ARGS_Helper(&d3d.depth_stencil_buffer)));
    
    d3d.device->CreateDepthStencilView(d3d.depth_stencil_buffer.Get(), &dsv_desc, get_cpu_descriptor_handle(d3d.dsv_heap));
}

static void gfx_d3d12_dxgi_on_resize(void) {
    if (d3d.render_targets[0].Get() != nullptr) {
        d3d.render_targets[0].Reset();
        d3d.render_targets[1].Reset();
        ThrowIfFailed(d3d.swap_chain->ResizeBuffers(0, 0, 0, DXGI_FORMAT_UNKNOWN, DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT));
        d3d.frame_index = d3d.swap_chain->GetCurrentBackBufferIndex();
        create_render_target_views();
        create_depth_buffer();
    }
}

static void onkeydown(WPARAM w_param, LPARAM l_param) {
    int key = ((l_param >> 16) & 0x1ff);
    if (d3d.on_key_down != nullptr) {
        d3d.on_key_down(key);
    }
}
static void onkeyup(WPARAM w_param, LPARAM l_param) {
    int key = ((l_param >> 16) & 0x1ff);
    if (d3d.on_key_up != nullptr) {
        d3d.on_key_up(key);
    }
}

LRESULT CALLBACK gfx_d3d12_dxgi_wnd_proc(HWND h_wnd, UINT message, WPARAM w_param, LPARAM l_param) {
    switch (message) {
        case WM_MOVE: {
            const int x = (short)LOWORD(l_param);
            const int y = (short)HIWORD(l_param);
            configWindow.x = (x < 0) ? 0 : x;
            configWindow.y = (y < 0) ? 0 : y;
            break;
        }
        case WM_SIZE:
            gfx_d3d12_dxgi_on_resize();
            break;
        case WM_DESTROY:
            game_exit();
            break;
        case WM_PAINT:
            if (d3d.run_one_game_iter != nullptr)
                d3d.run_one_game_iter();
            break;
        case WM_ACTIVATEAPP:
            if (d3d.on_all_keys_up != nullptr)
                d3d.on_all_keys_up();
            break;
        case WM_KEYDOWN:
            onkeydown(w_param, l_param);
            break;
        case WM_KEYUP:
            onkeyup(w_param, l_param);
            break;
        default:
            return DefWindowProcW(h_wnd, message, w_param, l_param);
    }
    return 0;
}

static void gfx_d3d12_dxgi_init(const char *window_title) {
    LARGE_INTEGER qpc_init, qpc_freq;
    QueryPerformanceCounter(&qpc_init);
    QueryPerformanceFrequency(&qpc_freq);
    d3d.qpc_init = qpc_init.QuadPart;
    d3d.qpc_freq = qpc_freq.QuadPart;

    // Prepare window title

    wchar_t w_title[512];
    mbstowcs(w_title, window_title, strlen(window_title) + 1);

    // Create window
    WNDCLASSEXW wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);

    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = gfx_d3d12_dxgi_wnd_proc;
    wcex.cbClsExtra     = 0;
    wcex.cbWndExtra     = 0;
    wcex.hInstance      = nullptr;
    wcex.hIcon          = nullptr;
    wcex.hCursor        = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName   = nullptr;
    wcex.lpszClassName  = WINCLASS_NAME;
    wcex.hIconSm        = nullptr;

    ATOM winclass = RegisterClassExW(&wcex);

    RECT wr = {0, 0, DESIRED_SCREEN_WIDTH, DESIRED_SCREEN_HEIGHT};
    AdjustWindowRect(&wr, WS_OVERLAPPEDWINDOW, FALSE);

    HWND h_wnd = CreateWindowW(WINCLASS_NAME, w_title, WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, 0, wr.right - wr.left, wr.bottom - wr.top, nullptr, nullptr, nullptr, nullptr);

    // Create device
    {
        UINT debug_flags = 0;
#if DEBUG_D3D
        ComPtr<ID3D12Debug> debug_controller;
        if (SUCCEEDED(D3D12GetDebugInterface(IID_ID3D12Debug, IID_PPV_ARGS_Helper(&debug_controller)))) {
            debug_controller->EnableDebugLayer();
            debug_flags |= DXGI_CREATE_FACTORY_DEBUG;
        }
#endif
        
        ThrowIfFailed(CreateDXGIFactory2(debug_flags, IID_IDXGIFactory4, &d3d.factory));
        ComPtr<IDXGIAdapter1> hw_adapter;
        for (UINT i = 0; d3d.factory->EnumAdapters1(i, &hw_adapter) != DXGI_ERROR_NOT_FOUND; i++) {
            DXGI_ADAPTER_DESC1 desc;
            hw_adapter->GetDesc1(&desc);
            if (desc.Flags & DXGI_ADAPTER_FLAG_SOFTWARE) {
                continue;
            }
            if (SUCCEEDED(D3D12CreateDevice(hw_adapter.Get(), D3D_FEATURE_LEVEL_11_0, IID_ID3D12Device, nullptr))) {
                break;
            }
        }
        ThrowIfFailed(D3D12CreateDevice(hw_adapter.Get(), D3D_FEATURE_LEVEL_11_0, IID_ID3D12Device, IID_PPV_ARGS_Helper(&d3d.device)));
    }
    
    // Create command queues
    {
        D3D12_COMMAND_QUEUE_DESC queue_desc = {};
        queue_desc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
        queue_desc.Type = D3D12_COMMAND_LIST_TYPE_DIRECT;
        ThrowIfFailed(d3d.device->CreateCommandQueue(&queue_desc, IID_ID3D12CommandQueue, IID_PPV_ARGS_Helper(&d3d.command_queue)));
    }
    {
        D3D12_COMMAND_QUEUE_DESC queue_desc = {};
        queue_desc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
        queue_desc.Type = D3D12_COMMAND_LIST_TYPE_COPY;
        ThrowIfFailed(d3d.device->CreateCommandQueue(&queue_desc, IID_ID3D12CommandQueue, IID_PPV_ARGS_Helper(&d3d.copy_command_queue)));
    }
    
    // Create swap chain
    {
        DXGI_SWAP_CHAIN_DESC1 swap_chain_desc = {};
        swap_chain_desc.BufferCount = 2;
        swap_chain_desc.Width = DESIRED_SCREEN_WIDTH;
        swap_chain_desc.Height = DESIRED_SCREEN_HEIGHT;
        swap_chain_desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
        swap_chain_desc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
        swap_chain_desc.Scaling = DXGI_SCALING_NONE;
        swap_chain_desc.SwapEffect = DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL;
        swap_chain_desc.Flags = DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT;
        swap_chain_desc.SampleDesc.Count = 1;

        ComPtr<IDXGISwapChain1> swap_chain1;
        ThrowIfFailed(d3d.factory->CreateSwapChainForHwnd(d3d.command_queue.Get(), h_wnd, &swap_chain_desc, nullptr, nullptr, &swap_chain1));
        //ThrowIfFailed(factory->MakeWindowAssociation(h_wnd, DXGI_MWA_NO_ALT_ENTER));
        ThrowIfFailed(swap_chain1->QueryInterface(IID_IDXGISwapChain3, &d3d.swap_chain));
        d3d.frame_index = d3d.swap_chain->GetCurrentBackBufferIndex();
        ThrowIfFailed(d3d.swap_chain->SetMaximumFrameLatency(1));
        d3d.waitable_object = d3d.swap_chain->GetFrameLatencyWaitableObject();
        WaitForSingleObject(d3d.waitable_object, INFINITE);
    }
    
    // Create render target views
    {
        D3D12_DESCRIPTOR_HEAP_DESC rtv_heap_desc = {};
        rtv_heap_desc.NumDescriptors = 2;
        rtv_heap_desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_RTV;
        rtv_heap_desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
        ThrowIfFailed(d3d.device->CreateDescriptorHeap(&rtv_heap_desc, IID_ID3D12DescriptorHeap, IID_PPV_ARGS_Helper(&d3d.rtv_heap)));
        d3d.rtv_descriptor_size = d3d.device->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_RTV);

        create_render_target_views();
    }
    
    // Create Z-buffer
    {
        D3D12_DESCRIPTOR_HEAP_DESC dsv_heap_desc = {};
        dsv_heap_desc.NumDescriptors = 1;
        dsv_heap_desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_DSV;
        dsv_heap_desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
        ThrowIfFailed(d3d.device->CreateDescriptorHeap(&dsv_heap_desc, IID_ID3D12DescriptorHeap, IID_PPV_ARGS_Helper(&d3d.dsv_heap)));

        create_depth_buffer();
    }
    
    // Create SRV heap for texture descriptors
    {
        D3D12_DESCRIPTOR_HEAP_DESC srv_heap_desc = {};
        srv_heap_desc.NumDescriptors = 1024; // Max unique textures per frame
        srv_heap_desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV;
        srv_heap_desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE;
        ThrowIfFailed(d3d.device->CreateDescriptorHeap(&srv_heap_desc, IID_ID3D12DescriptorHeap, IID_PPV_ARGS_Helper(&d3d.srv_heap)));
        d3d.srv_descriptor_size = d3d.device->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV);
    }
    
    // Create sampler heap and descriptors
    {
        D3D12_DESCRIPTOR_HEAP_DESC sampler_heap_desc = {};
        sampler_heap_desc.NumDescriptors = 18;
        sampler_heap_desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_SAMPLER;
        sampler_heap_desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE;
        ThrowIfFailed(d3d.device->CreateDescriptorHeap(&sampler_heap_desc, IID_ID3D12DescriptorHeap, IID_PPV_ARGS_Helper(&d3d.sampler_heap)));
        d3d.sampler_descriptor_size = d3d.device->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_SAMPLER);
        
        static const D3D12_TEXTURE_ADDRESS_MODE address_modes[] = {
            D3D12_TEXTURE_ADDRESS_MODE_WRAP,
            D3D12_TEXTURE_ADDRESS_MODE_MIRROR,
            D3D12_TEXTURE_ADDRESS_MODE_CLAMP
        };
        
        D3D12_CPU_DESCRIPTOR_HANDLE sampler_handle = get_cpu_descriptor_handle(d3d.sampler_heap);
        int pos = 0;
        for (int linear_filter = 0; linear_filter < 2; linear_filter++) {
            for (int cms = 0; cms < 3; cms++) {
                for (int cmt = 0; cmt < 3; cmt++) {
                    D3D12_SAMPLER_DESC sampler_desc = {};
                    sampler_desc.Filter = linear_filter ? D3D12_FILTER_MIN_MAG_MIP_LINEAR : D3D12_FILTER_MIN_MAG_MIP_POINT;
                    sampler_desc.AddressU = address_modes[cms];
                    sampler_desc.AddressV = address_modes[cmt];
                    sampler_desc.AddressW = D3D12_TEXTURE_ADDRESS_MODE_WRAP;
                    sampler_desc.MinLOD = 0;
                    sampler_desc.MaxLOD = D3D12_FLOAT32_MAX;
                    sampler_desc.MipLODBias = 0.0f;
                    sampler_desc.MaxAnisotropy = 1;
                    sampler_desc.ComparisonFunc = D3D12_COMPARISON_FUNC_NEVER;
                    d3d.device->CreateSampler(&sampler_desc, CD3DX12_CPU_DESCRIPTOR_HANDLE(sampler_handle, pos++, d3d.sampler_descriptor_size));
                }
            }
        }
    }
    
    ThrowIfFailed(d3d.device->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_ID3D12CommandAllocator, IID_PPV_ARGS_Helper(&d3d.command_allocator)));
    ThrowIfFailed(d3d.device->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_COPY, IID_ID3D12CommandAllocator, IID_PPV_ARGS_Helper(&d3d.copy_command_allocator)));
    
    ThrowIfFailed(d3d.device->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, d3d.command_allocator.Get(), nullptr, IID_ID3D12GraphicsCommandList, IID_PPV_ARGS_Helper(&d3d.command_list)));
    ThrowIfFailed(d3d.device->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_COPY, d3d.copy_command_allocator.Get(), nullptr, IID_ID3D12GraphicsCommandList, IID_PPV_ARGS_Helper(&d3d.copy_command_list)));
    
    ThrowIfFailed(d3d.command_list->Close());
    
    ThrowIfFailed(d3d.device->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_ID3D12Fence, IID_PPV_ARGS_Helper(&d3d.fence)));
    d3d.fence_event = CreateEvent(nullptr, FALSE, FALSE, nullptr);
    if (d3d.fence_event == nullptr) {
        ThrowIfFailed(HRESULT_FROM_WIN32(GetLastError()));
    }
    
    ThrowIfFailed(d3d.device->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_ID3D12Fence, IID_PPV_ARGS_Helper(&d3d.copy_fence)));
    
    {
        // Create a buffer of 1 MB in size. With a 120 star speed run 192 kB seems to be max usage.
        CD3DX12_HEAP_PROPERTIES hp(D3D12_HEAP_TYPE_UPLOAD);
        CD3DX12_RESOURCE_DESC rdb = CD3DX12_RESOURCE_DESC::Buffer(256 * 1024 * sizeof(float));
        ThrowIfFailed(d3d.device->CreateCommittedResource(
            &hp,
            D3D12_HEAP_FLAG_NONE,
            &rdb,
            D3D12_RESOURCE_STATE_GENERIC_READ,
            nullptr,
            IID_ID3D12Resource,
            IID_PPV_ARGS_Helper(&d3d.vertex_buffer)));
        
        CD3DX12_RANGE read_range(0, 0); // Read not possible from CPU
        ThrowIfFailed(d3d.vertex_buffer->Map(0, &read_range, &d3d.mapped_vbuf_address));
    }
    
    ShowWindow(h_wnd, SW_SHOW);
    UpdateWindow(h_wnd);
}

static void gfx_d3d12_dxgi_shutdown(void) {
    if (d3d.render_targets[0].Get() != nullptr) {
        d3d.render_targets[0].Reset();
        d3d.render_targets[1].Reset();
    }

    // uhh
}

static void gfx_d3d12_dxgi_set_keyboard_callbacks(bool (*on_key_down)(int scancode), bool (*on_key_up)(int scancode), void (*on_all_keys_up)(void)) {
    d3d.on_key_down = on_key_down;
    d3d.on_key_up = on_key_up;
    d3d.on_all_keys_up = on_all_keys_up;
}

static void gfx_d3d12_dxgi_main_loop(void (*run_one_game_iter)(void)) {
    d3d.run_one_game_iter = run_one_game_iter;
    
    MSG msg;
    while (GetMessage(&msg, nullptr, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}

static void gfx_d3d12_dxgi_get_dimensions(uint32_t *width, uint32_t *height) {
    *width = d3d.current_width;
    *height = d3d.current_height;
}

static void gfx_d3d12_dxgi_handle_events(void) {
    /*MSG msg;
    while (PeekMessageW(&msg, nullptr, 0, 0, PM_REMOVE)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }*/
}

static uint64_t qpc_to_us(uint64_t qpc) {
    return qpc / d3d.qpc_freq * 1000000 + qpc % d3d.qpc_freq * 1000000 / d3d.qpc_freq;
}

static bool gfx_d3d12_dxgi_start_frame(void) {
    DXGI_FRAME_STATISTICS stats;
    if (d3d.swap_chain->GetFrameStatistics(&stats) == S_OK && (stats.SyncRefreshCount != 0 || stats.SyncQPCTime.QuadPart != 0ULL)) {
        {
            LARGE_INTEGER t0;
            QueryPerformanceCounter(&t0);
            //printf("Get frame stats: %llu\n", (unsigned long long)(t0.QuadPart - d3d.qpc_init));
        }
        //printf("stats: %u %u %u %u %u %.6f\n", d3d.pending_frame_stats.rbegin()->first, d3d.pending_frame_stats.rbegin()->second, stats.PresentCount, stats.PresentRefreshCount, stats.SyncRefreshCount, (double)(stats.SyncQPCTime.QuadPart - d3d.qpc_init) / d3d.qpc_freq);
        if (d3d.frame_stats.empty() || d3d.frame_stats.rbegin()->second.PresentCount != stats.PresentCount) {
            d3d.frame_stats.insert(std::make_pair(stats.PresentCount, stats));
        }
        if (d3d.frame_stats.size() > 3) {
            d3d.frame_stats.erase(d3d.frame_stats.begin());
        }
    }
    if (!d3d.frame_stats.empty()) {
        while (!d3d.pending_frame_stats.empty() && d3d.pending_frame_stats.begin()->first < d3d.frame_stats.rbegin()->first) {
            d3d.pending_frame_stats.erase(d3d.pending_frame_stats.begin());
        }
    }
    while (d3d.pending_frame_stats.size() > 15) {
        // Just make sure the list doesn't grow too large if GetFrameStatistics fails.
        d3d.pending_frame_stats.erase(d3d.pending_frame_stats.begin());
    }
    
    d3d.frame_timestamp += FRAME_INTERVAL_US_NUMERATOR;
    
    if (d3d.frame_stats.size() >= 2) {
        DXGI_FRAME_STATISTICS *first = &d3d.frame_stats.begin()->second;
        DXGI_FRAME_STATISTICS *last = &d3d.frame_stats.rbegin()->second;
        uint64_t sync_qpc_diff = last->SyncQPCTime.QuadPart - first->SyncQPCTime.QuadPart;
        UINT sync_vsync_diff = last->SyncRefreshCount - first->SyncRefreshCount;
        UINT present_vsync_diff = last->PresentRefreshCount - first->PresentRefreshCount;
        UINT present_diff = last->PresentCount - first->PresentCount;
        
        if (sync_vsync_diff == 0) {
            sync_vsync_diff = 1;
        }
        
        double estimated_vsync_interval = (double)sync_qpc_diff / (double)sync_vsync_diff;
        //printf("Estimated vsync_interval: %f\n", estimated_vsync_interval);
        uint64_t estimated_vsync_interval_us = qpc_to_us(estimated_vsync_interval);
        if (estimated_vsync_interval_us < 2 || estimated_vsync_interval_us > 1000000) {
            // Unreasonable, maybe a monitor change
            estimated_vsync_interval_us = 16666;
            estimated_vsync_interval = estimated_vsync_interval_us * d3d.qpc_freq / 1000000;
        }
        
        UINT queued_vsyncs = 0;
        bool is_first = true;
        for (const std::pair<UINT, UINT>& p : d3d.pending_frame_stats) {
            if (is_first && d3d.sync_interval_means_frames_to_wait) {
                is_first = false;
                continue;
            }
            queued_vsyncs += p.second;
        }
        
        uint64_t last_frame_present_end_qpc = (last->SyncQPCTime.QuadPart - d3d.qpc_init) + estimated_vsync_interval * queued_vsyncs;
        uint64_t last_end_us = qpc_to_us(last_frame_present_end_qpc);
        
        double vsyncs_to_wait = (double)(int64_t)(d3d.frame_timestamp / FRAME_INTERVAL_US_DENOMINATOR - last_end_us) / estimated_vsync_interval_us;
        //printf("ts: %llu, last_end_us: %llu, Init v: %f\n", d3d.frame_timestamp / 3, last_end_us, vsyncs_to_wait);
        
        if (vsyncs_to_wait <= 0) {
            // Too late
            
            if ((int64_t)(d3d.frame_timestamp / FRAME_INTERVAL_US_DENOMINATOR - last_end_us) < -66666) {
                // The application must have been paused or similar
                vsyncs_to_wait = round(((double)FRAME_INTERVAL_US_NUMERATOR / FRAME_INTERVAL_US_DENOMINATOR) / estimated_vsync_interval_us);
                if (vsyncs_to_wait < 1) {
                    vsyncs_to_wait = 1;
                }
                d3d.frame_timestamp = FRAME_INTERVAL_US_DENOMINATOR * (last_end_us + vsyncs_to_wait * estimated_vsync_interval_us);
            } else {
                // Drop frame
                //printf("Dropping frame\n");
                d3d.dropped_frame = true;
                return false;
            }
        }
        if (floor(vsyncs_to_wait) != vsyncs_to_wait) {
            uint64_t left = last_end_us + floor(vsyncs_to_wait) * estimated_vsync_interval_us;
            uint64_t right = last_end_us + ceil(vsyncs_to_wait) * estimated_vsync_interval_us;
            uint64_t adjusted_desired_time = d3d.frame_timestamp / FRAME_INTERVAL_US_DENOMINATOR + (last_end_us + (FRAME_INTERVAL_US_NUMERATOR / FRAME_INTERVAL_US_DENOMINATOR) > d3d.frame_timestamp / FRAME_INTERVAL_US_DENOMINATOR ? 2000 : -2000);
            int64_t diff_left = adjusted_desired_time - left;
            int64_t diff_right = right - adjusted_desired_time;
            if (diff_left < 0) {
                diff_left = -diff_left;
            }
            if (diff_right < 0) {
                diff_right = -diff_right;
            }
            if (diff_left < diff_right) {
                vsyncs_to_wait = floor(vsyncs_to_wait);
            } else {
                vsyncs_to_wait = ceil(vsyncs_to_wait);
            }
            if (vsyncs_to_wait == 0) {
                //printf("vsyncs_to_wait became 0 so dropping frame\n");
                d3d.dropped_frame = true;
                return false;
            }
        }
        //printf("v: %d\n", (int)vsyncs_to_wait);
        if (vsyncs_to_wait > 4) {
            // Invalid, so change to 4
            vsyncs_to_wait = 4;
        }
        d3d.length_in_vsync_frames = vsyncs_to_wait;
    } else {
        d3d.length_in_vsync_frames = 2;
    }
    
    return true;
}

static void gfx_d3d12_dxgi_swap_buffers_begin(void) {
    if (max_texture_uploads < texture_uploads && texture_uploads != 38 && texture_uploads != 34 && texture_uploads != 29) {
        max_texture_uploads = texture_uploads;
    }
    //printf("Texture uploads: %d %d\n", max_texture_uploads, texture_uploads);
    texture_uploads = 0;
    
    ThrowIfFailed(d3d.copy_command_list->Close());
    {
        ID3D12CommandList *lists[] = { d3d.copy_command_list.Get() };
        d3d.copy_command_queue->ExecuteCommandLists(1, lists);
        d3d.copy_command_queue->Signal(d3d.copy_fence.Get(), ++d3d.copy_fence_value);
    }
    
    CD3DX12_RESOURCE_BARRIER barrier = CD3DX12_RESOURCE_BARRIER::Transition(
        d3d.render_targets[d3d.frame_index].Get(),
        D3D12_RESOURCE_STATE_RENDER_TARGET,
        D3D12_RESOURCE_STATE_PRESENT);
    d3d.command_list->ResourceBarrier(1, &barrier);
    
    d3d.command_queue->Wait(d3d.copy_fence.Get(), d3d.copy_fence_value);
    
    ThrowIfFailed(d3d.command_list->Close());
    
    {
        ID3D12CommandList *lists[] = { d3d.command_list.Get() };
        d3d.command_queue->ExecuteCommandLists(1, lists);
    }
    
    {
        LARGE_INTEGER t0;
        QueryPerformanceCounter(&t0);
        //printf("Present: %llu %u\n", (unsigned long long)(t0.QuadPart - d3d.qpc_init), d3d.length_in_vsync_frames);
    }
    
    //d3d.length_in_vsync_frames = 1;
    ThrowIfFailed(d3d.swap_chain->Present(d3d.length_in_vsync_frames, 0));
    UINT this_present_id;
    if (d3d.swap_chain->GetLastPresentCount(&this_present_id) == S_OK) {
        d3d.pending_frame_stats.insert(std::make_pair(this_present_id, d3d.length_in_vsync_frames));
    }
    d3d.dropped_frame = false;
}

static void gfx_d3d12_dxgi_swap_buffers_end(void) {
    LARGE_INTEGER t0, t1, t2;
    QueryPerformanceCounter(&t0);
    
    static UINT64 fence_value;
    ThrowIfFailed(d3d.command_queue->Signal(d3d.fence.Get(), ++fence_value));
    if (d3d.fence->GetCompletedValue() < fence_value) {
        ThrowIfFailed(d3d.fence->SetEventOnCompletion(fence_value, d3d.fence_event));
        WaitForSingleObject(d3d.fence_event, INFINITE);
    }
    QueryPerformanceCounter(&t1);
    
    d3d.resources_to_clean_at_end_of_frame.clear();
    for (std::pair<size_t, ComPtr<ID3D12Resource>>& heap : d3d.upload_heaps_in_flight) {
        d3d.upload_heaps[heap.first].push_back(std::move(heap.second));
    }
    d3d.upload_heaps_in_flight.clear();
    for (std::pair<struct TextureHeap *, uint8_t>& item : d3d.texture_heap_allocations_to_reclaim_at_end_of_frame) {
        item.first->free_list.push_back(item.second);
    }
    d3d.texture_heap_allocations_to_reclaim_at_end_of_frame.clear();
    
    if (!d3d.dropped_frame) {
        WaitForSingleObject(d3d.waitable_object, INFINITE);
    }
    
    DXGI_FRAME_STATISTICS stats;
    d3d.swap_chain->GetFrameStatistics(&stats);
    
    QueryPerformanceCounter(&t2);
    
    d3d.frame_index = d3d.swap_chain->GetCurrentBackBufferIndex();
    
    ThrowIfFailed(d3d.copy_command_allocator->Reset());
    ThrowIfFailed(d3d.copy_command_list->Reset(d3d.copy_command_allocator.Get(), nullptr));
    
    d3d.sync_interval_means_frames_to_wait = d3d.pending_frame_stats.rbegin()->first == stats.PresentCount;
    
    //printf("done %llu gpu:%d wait:%d freed:%llu frame:%u %u monitor:%u t:%llu\n", (unsigned long long)(t0.QuadPart - d3d.qpc_init), (int)(t1.QuadPart - t0.QuadPart), (int)(t2.QuadPart - t0.QuadPart), (unsigned long long)(t2.QuadPart - d3d.qpc_init), d3d.pending_frame_stats.rbegin()->first, stats.PresentCount, stats.SyncRefreshCount, (unsigned long long)(stats.SyncQPCTime.QuadPart - d3d.qpc_init));
}

double gfx_d3d12_dxgi_get_time(void) {
    LARGE_INTEGER t;
    QueryPerformanceCounter(&t);
    return (double)(t.QuadPart - d3d.qpc_init) / d3d.qpc_freq;
}

struct GfxRenderingAPI gfx_d3d12_api = {
    gfx_d3d12_z_is_from_0_to_1,
    gfx_d3d12_unload_shader,
    gfx_d3d12_load_shader,
    gfx_d3d12_create_and_load_new_shader,
    gfx_d3d12_lookup_shader,
    gfx_d3d12_shader_get_info,
    gfx_d3d12_new_texture,
    gfx_d3d12_select_texture,
    gfx_d3d12_upload_texture,
    gfx_d3d12_set_sampler_parameters,
    gfx_d3d12_set_depth_test,
    gfx_d3d12_set_depth_mask,
    gfx_d3d12_set_zmode_decal,
    gfx_d3d12_set_viewport,
    gfx_d3d12_set_scissor,
    gfx_d3d12_set_use_alpha,
    gfx_d3d12_draw_triangles,
    gfx_d3d12_init,
    gfx_d3d12_start_frame,
    gfx_d3d12_shutdown,
};

struct GfxWindowManagerAPI gfx_dxgi = {
    gfx_d3d12_dxgi_init,
    gfx_d3d12_dxgi_set_keyboard_callbacks,
    gfx_d3d12_dxgi_main_loop,
    gfx_d3d12_dxgi_get_dimensions,
    gfx_d3d12_dxgi_handle_events,
    gfx_d3d12_dxgi_start_frame,
    gfx_d3d12_dxgi_swap_buffers_begin,
    gfx_d3d12_dxgi_swap_buffers_end,
    gfx_d3d12_dxgi_get_time,
    gfx_d3d12_dxgi_shutdown,
};

#else

#error "D3D12 is only supported on Windows"

#endif // _WIN32

#endif // RAPI_D3D12