d3d1x: properly reference count the backend

[mesa.git] / src / gallium / state_trackers / d3d1x / dxgi / src / dxgi_native.cpp

/**************************************************************************
 *
 * Copyright 2010 Luca Barbieri
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial
 * portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/

#include "dxgi_private.h"
extern "C" {
#include "native.h"
#include <util/u_format.h>
#include <util/u_inlines.h>
#include <util/u_simple_shaders.h>
#include <pipe/p_shader_tokens.h>
}
#include <iostream>
#include <memory>

struct GalliumDXGIOutput;
struct GalliumDXGIAdapter;
struct GalliumDXGISwapChain;
struct GalliumDXGIFactory;

static HRESULT GalliumDXGISwapChainCreate(GalliumDXGIFactory* factory, IUnknown* device, const DXGI_SWAP_CHAIN_DESC& desc, IDXGISwapChain** ppSwapChain);
static HRESULT GalliumDXGIAdapterCreate(GalliumDXGIFactory* adapter, const struct native_platform* platform, void* dpy, IDXGIAdapter1** ppAdapter);
static HRESULT GalliumDXGIOutputCreate(GalliumDXGIAdapter* adapter, const std::string& name, const struct native_connector* connector, IDXGIOutput** ppOutput);
static void GalliumDXGISwapChainRevalidate(IDXGISwapChain* swap_chain);

template<typename Base = IDXGIObject, typename Parent = IDXGIObject>
struct GalliumDXGIObject : public GalliumPrivateDataComObject<Base>
{
        ComPtr<Parent> parent;

        GalliumDXGIObject(Parent* p_parent = 0)
        {
                this->parent = p_parent;
        }

        virtual HRESULT STDMETHODCALLTYPE GetParent(
            __in  REFIID riid,
            __out  void **ppParent)
        {
                return parent->QueryInterface(riid, ppParent);
        }
};

COM_INTERFACE(IGalliumDXGIBackend, IUnknown)

struct GalliumDXGIIdentityBackend : public GalliumComObject<IGalliumDXGIBackend>
{
        virtual void * STDMETHODCALLTYPE BeginPresent(
                HWND hwnd,
                void** window,
                RECT *rect,
                RGNDATA **rgndata,
                BOOL* preserve_aspect_ratio
        )
        {
                *window = (void*)hwnd;
                rect->left = 0;
                rect->top = 0;
                rect->right = INT_MAX;
                rect->bottom = INT_MAX;
                *rgndata = 0;

                // yes, because we like things looking good
                *preserve_aspect_ratio = TRUE;
                return 0;
        }

        virtual void STDMETHODCALLTYPE EndPresent(
                HWND hwnd,
                void* present_cookie
        )
        {}
};

struct GalliumDXGIFactory : public GalliumDXGIObject<IDXGIFactory1, IUnknown>
{
        HWND associated_window;
        const struct native_platform* platform;
        void* display;
        ComPtr<IGalliumDXGIBackend> backend;
        void* resolver_cookie;

        GalliumDXGIFactory(const struct native_platform* platform, void* display, IGalliumDXGIBackend* p_backend)
        : GalliumDXGIObject<IDXGIFactory1, IUnknown>((IUnknown*)NULL), platform(platform), display(display)
          {
                if(p_backend)
                        backend = p_backend;
                else
                        backend.reset(new GalliumDXGIIdentityBackend());
        }

        virtual HRESULT STDMETHODCALLTYPE EnumAdapters(
                UINT Adapter,
                __out  IDXGIAdapter **ppAdapter)
        {
                return EnumAdapters1(Adapter, (IDXGIAdapter1**)ppAdapter);
        }

        virtual HRESULT STDMETHODCALLTYPE EnumAdapters1(
                UINT Adapter,
                __out  IDXGIAdapter1 **ppAdapter)
        {
                *ppAdapter = 0;
                if(Adapter == 0)
                {
                        return GalliumDXGIAdapterCreate(this, platform, display, ppAdapter);
                }
#if 0
                // TODO: enable this
                if(platform == native_get_x11_platform())
                {
                        unsigned nscreens = ScreenCount((Display*)display);
                        if(Adapter < nscreens)
                        {
                                unsigned def_screen = DefaultScreen(display);
                                if(Adapter <= def_screen)
                                        --Adapter;
                                *ppAdapter = GalliumDXGIAdapterCreate(this, platform, display, Adapter);
                                return S_OK;
                        }
                }
#endif
                return DXGI_ERROR_NOT_FOUND;
        }

        /* TODO: this is a mysterious underdocumented magic API
         * Can we have multiple windows associated?
         * Can we have multiple windows associated if we use multiple factories?
         * If so, what should GetWindowAssociation return?
         * If not, does a new swapchain steal the association?
         * Does this act for existing swapchains? For new swapchains?
         */
        virtual HRESULT STDMETHODCALLTYPE MakeWindowAssociation(
                HWND WindowHandle,
                UINT Flags)
        {
                /* TODO: actually implement, for Wine, X11 and KMS*/
                associated_window = WindowHandle;
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE GetWindowAssociation(
                __out  HWND *pWindowHandle)
        {
                *pWindowHandle = associated_window;
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE CreateSwapChain(
                __in  IUnknown *pDevice,
                __in  DXGI_SWAP_CHAIN_DESC *pDesc,
                __out  IDXGISwapChain **ppSwapChain)
        {
                return GalliumDXGISwapChainCreate(this, pDevice, *pDesc, ppSwapChain);
        }

        virtual HRESULT STDMETHODCALLTYPE CreateSoftwareAdapter(
            HMODULE Module,
            __out  IDXGIAdapter **ppAdapter)
        {
                /* TODO: ignore the module, and just create a Gallium software screen */
                *ppAdapter = 0;
                return E_NOTIMPL;
        }

        /* TODO: support hotplug */
        virtual BOOL STDMETHODCALLTYPE IsCurrent( void)
        {
                return TRUE;
        }
};

struct GalliumDXGIAdapter
        : public GalliumMultiComObject<
                  GalliumDXGIObject<IDXGIAdapter1, GalliumDXGIFactory>,
                  IGalliumAdapter>
{
        struct native_display* display;
        const struct native_config** configs;
        std::unordered_multimap<unsigned, unsigned> configs_by_pipe_format;
        std::unordered_map<unsigned, unsigned> configs_by_native_visual_id;
        const struct native_connector** connectors;
        unsigned num_configs;
        DXGI_ADAPTER_DESC1 desc;
        std::vector<ComPtr<IDXGIOutput> > outputs;
        int num_outputs;
        struct native_event_handler handler;

        GalliumDXGIAdapter(GalliumDXGIFactory* factory, const struct native_platform* platform, void* dpy)
        {
                this->parent = factory;

                handler.invalid_surface = handle_invalid_surface;
                handler.new_drm_screen = dxgi_loader_create_drm_screen;
                handler.new_sw_screen = dxgi_loader_create_sw_screen;
                display = platform->create_display(dpy, &handler, this);
                if(!display)
                        throw E_FAIL;
                memset(&desc, 0, sizeof(desc));
                std::string s = std::string("GalliumD3D on ") + display->screen->get_name(display->screen) + " by " + display->screen->get_vendor(display->screen);

                /* hopefully no one will decide to use UTF-8 in Gallium name/vendor strings */
                for(int i = 0; i < std::min((int)s.size(), 127); ++i)
                        desc.Description[i] = (WCHAR)s[i];

                // TODO: add an interface to get these; for now, return mid/low values
                desc.DedicatedVideoMemory = 256 << 20;
                desc.DedicatedSystemMemory = 256 << 20;
                desc.SharedSystemMemory = 1024 << 20;

                // TODO: we should actually use an unique ID instead
                *(void**)&desc.AdapterLuid = dpy;

                configs = display->get_configs(display, (int*)&num_configs);
                for(unsigned i = 0; i < num_configs; ++i)
                {
                        if(configs[i]->window_bit)
                        {
                                configs_by_pipe_format.insert(std::make_pair(configs[i]->color_format, i));
                                configs_by_native_visual_id[configs[i]->native_visual_id] = i;
                        }
                }

                connectors = 0;
                num_outputs = 0;

                if(display->modeset)
                {
                        int num_crtcs;

                        connectors = display->modeset->get_connectors(display, &num_outputs, &num_crtcs);
                        if(!connectors)
                                num_outputs = 0;
                        else if(!num_outputs)
                        {
                                free(connectors);
                                connectors = 0;
                        }
                }
                if(!num_outputs)
                        num_outputs = 1;
        }

        static void handle_invalid_surface(struct native_display *ndpy, struct native_surface *nsurf, unsigned int seq_num)
        {
                GalliumDXGISwapChainRevalidate((IDXGISwapChain*)nsurf->user_data);
        }

        ~GalliumDXGIAdapter()
        {
                display->destroy(display);
                free(configs);
                free(connectors);
        }

        virtual HRESULT STDMETHODCALLTYPE EnumOutputs(
                UINT Output,
                __out  IDXGIOutput **ppOutput)
        {
                if(Output >= (unsigned)num_outputs)
                        return DXGI_ERROR_NOT_FOUND;

                if(connectors)
                {
                        std::ostringstream ss;
                        ss << "Output #" << Output;
                        return GalliumDXGIOutputCreate(this, ss.str(), connectors[Output], ppOutput);
                }
                else
                        return GalliumDXGIOutputCreate(this, "Unique output", NULL, ppOutput);
        }

        virtual HRESULT STDMETHODCALLTYPE GetDesc(
                __out  DXGI_ADAPTER_DESC *pDesc)
        {
                memcpy(pDesc, &desc, sizeof(*pDesc));
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE GetDesc1(
                __out  DXGI_ADAPTER_DESC1 *pDesc)
        {
                memcpy(pDesc, &desc, sizeof(*pDesc));
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE CheckInterfaceSupport(
            __in  REFGUID InterfaceName,
            __out  LARGE_INTEGER *pUMDVersion)
        {
                // these number was taken from Windows 7 with Catalyst 10.8: its meaning is unclear
                if(InterfaceName == IID_ID3D11Device || InterfaceName == IID_ID3D10Device1 || InterfaceName == IID_ID3D10Device)
                {
                        pUMDVersion->QuadPart = 0x00080011000a0411ULL;
                        return S_OK;
                }
                return DXGI_ERROR_UNSUPPORTED;
        }

        pipe_screen* STDMETHODCALLTYPE GetGalliumScreen()
        {
                return display->screen;
        }

        pipe_screen* STDMETHODCALLTYPE GetGalliumReferenceSoftwareScreen()
        {
                // TODO: give a softpipe screen
                return display->screen;
        }

        pipe_screen* STDMETHODCALLTYPE GetGalliumFastSoftwareScreen()
        {
                // TODO: give an llvmpipe screen
                return display->screen;
        }
};


struct GalliumDXGIOutput : public GalliumDXGIObject<IDXGIOutput, GalliumDXGIAdapter>
{
        DXGI_OUTPUT_DESC desc;
        const struct native_mode** modes;
        DXGI_MODE_DESC* dxgi_modes;
        unsigned num_modes;
        const struct native_connector* connector;
        DXGI_GAMMA_CONTROL* gamma;

        GalliumDXGIOutput(GalliumDXGIAdapter* adapter, std::string name, const struct native_connector* connector = 0)
        : GalliumDXGIObject<IDXGIOutput, GalliumDXGIAdapter>(adapter), connector(connector)
        {
                memset(&desc, 0, sizeof(desc));
                for(unsigned i = 0; i < std::min(name.size(), sizeof(desc.DeviceName) - 1); ++i)
                        desc.DeviceName[i] = name[i];
                desc.AttachedToDesktop = TRUE;
                /* TODO: should put an HMONITOR in desc.Monitor */

                gamma = 0;
                num_modes = 0;
                modes = 0;
                if(connector)
                {
                        modes = parent->display->modeset->get_modes(parent->display, connector, (int*)&num_modes);
                        if(modes && num_modes)
                        {
                                dxgi_modes = new DXGI_MODE_DESC[num_modes];
                                for(unsigned i = 0; i < num_modes; ++i)
                                {
                                        dxgi_modes[i].Width = modes[i]->width;
                                        dxgi_modes[i].Height = modes[i]->height;
                                        dxgi_modes[i].RefreshRate.Numerator = modes[i]->refresh_rate;
                                        dxgi_modes[i].RefreshRate.Denominator = 1;
                                        dxgi_modes[i].Scaling = DXGI_MODE_SCALING_UNSPECIFIED;
                                        dxgi_modes[i].ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
                                }
                        }
                        else
                        {
                                if(modes)
                                {
                                        free(modes);
                                        modes = 0;
                                }
                                goto use_fake_mode;
                        }
                }
                else
                {
use_fake_mode:
                        dxgi_modes = new DXGI_MODE_DESC[1];
                        dxgi_modes[0].Width = 1920;
                        dxgi_modes[0].Height = 1200;
                        dxgi_modes[0].RefreshRate.Numerator = 60;
                        dxgi_modes[0].RefreshRate.Denominator = 1;
                        dxgi_modes[0].Scaling = DXGI_MODE_SCALING_UNSPECIFIED;
                        dxgi_modes[0].ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
                }
        }

        ~GalliumDXGIOutput()
        {
                delete [] dxgi_modes;
                free(modes);
                if(gamma)
                        delete gamma;
        }

        virtual HRESULT STDMETHODCALLTYPE GetDesc(
                __out  DXGI_OUTPUT_DESC *pDesc)
        {
                *pDesc = desc;
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE GetDisplayModeList(
                DXGI_FORMAT EnumFormat,
                UINT Flags,
                __inout  UINT *pNumModes,
                __out_ecount_part_opt(*pNumModes,*pNumModes)  DXGI_MODE_DESC *pDesc)
        {
                /* TODO: should we return DXGI_ERROR_NOT_CURRENTLY_AVAILABLE when we don't
                 * support modesetting instead of fake modes?
                 */
                pipe_format format = dxgi_to_pipe_format[EnumFormat];
                if(parent->configs_by_pipe_format.count(format))
                {
                        if(!pDesc)
                        {
                                *pNumModes = num_modes;
                                return S_OK;
                        }

                        unsigned copy_modes = std::min(num_modes, *pNumModes);
                        for(unsigned i = 0; i < copy_modes; ++i)
                        {
                                pDesc[i] = dxgi_modes[i];
                                pDesc[i].Format = EnumFormat;
                        }
                        *pNumModes = num_modes;

                        if(copy_modes < num_modes)
                                return DXGI_ERROR_MORE_DATA;
                        else
                                return S_OK;
                }
                else
                {
                        *pNumModes = 0;
                        return S_OK;
                }
        }

        virtual HRESULT STDMETHODCALLTYPE FindClosestMatchingMode(
                __in  const DXGI_MODE_DESC *pModeToMatch,
                __out  DXGI_MODE_DESC *pClosestMatch,
                __in_opt  IUnknown *pConcernedDevice)
        {
                /* TODO: actually implement this */
                DXGI_FORMAT dxgi_format = pModeToMatch->Format;
                enum pipe_format format = dxgi_to_pipe_format[dxgi_format];
                init_pipe_to_dxgi_format();
                if(!parent->configs_by_pipe_format.count(format))
                {
                        if(!pConcernedDevice)
                                return E_FAIL;
                        else
                        {
                                format = parent->configs[0]->color_format;
                                dxgi_format = pipe_to_dxgi_format[format];
                        }
                }

                *pClosestMatch = dxgi_modes[0];
                pClosestMatch->Format = dxgi_format;
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE WaitForVBlank( void)
        {
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE TakeOwnership(
                __in  IUnknown *pDevice,
                BOOL Exclusive)
        {
                return S_OK;
        }

        virtual void STDMETHODCALLTYPE ReleaseOwnership( void)
        {
        }

        virtual HRESULT STDMETHODCALLTYPE GetGammaControlCapabilities(
                __out  DXGI_GAMMA_CONTROL_CAPABILITIES *pGammaCaps)
        {
                memset(pGammaCaps, 0, sizeof(*pGammaCaps));
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE SetGammaControl(
                        __in  const DXGI_GAMMA_CONTROL *pArray)
        {
                if(!gamma)
                        gamma = new DXGI_GAMMA_CONTROL;
                *gamma = *pArray;
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE GetGammaControl(
                        __out  DXGI_GAMMA_CONTROL *pArray)
        {
                if(gamma)
                        *pArray = *gamma;
                else
                {
                        pArray->Scale.Red = 1;
                        pArray->Scale.Green = 1;
                        pArray->Scale.Blue = 1;
                        pArray->Offset.Red = 0;
                        pArray->Offset.Green = 0;
                        pArray->Offset.Blue = 0;
                        for(unsigned i = 0; i <= 1024; ++i)
                                pArray->GammaCurve[i].Red = pArray->GammaCurve[i].Green = pArray->GammaCurve[i].Blue = (float)i / 1024.0;
                }
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE SetDisplaySurface(
                __in  IDXGISurface *pScanoutSurface)
        {
                return E_NOTIMPL;
        }

        virtual HRESULT STDMETHODCALLTYPE GetDisplaySurfaceData(
                __in  IDXGISurface *pDestination)
        {
                return E_NOTIMPL;
        }

        virtual HRESULT STDMETHODCALLTYPE GetFrameStatistics(
                __out  DXGI_FRAME_STATISTICS *pStats)
        {
                memset(pStats, 0, sizeof(*pStats));
#ifdef _WIN32
                QueryPerformanceCounter(&pStats->SyncQPCTime);
#endif
                return E_NOTIMPL;
        }
};

/* Swap chain are rather complex, and Microsoft's documentation is rather
 * lacking. As far as I know, this is the most thorough publicly available
 * description of how swap chains work, based on multiple sources and
 * experimentation.
 *
 * There are two modes (called "swap effects") that a swap chain can operate in:
 * discard and sequential.
 *
 * In discard mode, things always look as if there is a single buffer, which
 * you can get with GetBuffers(0).
 * The 2D texture returned by GetBuffers(0) and can only be
 * used as a render target view and for resource copies, since no CPU access
 * flags are set and only the D3D11_BIND_RENDER_TARGET bind flag is set.
 * On Present, it is copied to the actual display
 * surface and the contents become undefined.
 * D3D may internally use multiple buffers, but you can't observe this, except
 * by looking at the buffer contents after Present (but those are undefined).
 * If it uses multiple buffers internally, then it will normally use BufferCount buffers
 * (this has latency implications).
 * Discard mode seems to internally use a single buffer in windowed mode,
 * even if DWM is enabled, and BufferCount buffers in fullscreen mode.
 *
 * In sequential mode, the runtime alllocates BufferCount buffers.
 * You can get each with GetBuffers(n).
 * GetBuffers(0) ALWAYS points to the backbuffer to be presented and has the
 * same usage constraints as the discard mode.
 * GetBuffer(n) with n > 0 points to resources that are identical to buffer 0, but
 * are classified as "read-only resources" (due to DXGI_USAGE_READ_ONLY),
 * meaning that you can't create render target views on them, or use them as
 * a CopyResource/CopySubresourceRegion  destination.
 * It appears the only valid operation is to use them as a source for CopyResource
 * and CopySubresourceRegion as well as just waiting for them to become
 * buffer 0 again.
 * Buffer n - 1 is always displayed on screen.
 * When you call Present(), the contents of the buffers are rotated, so that buffer 0
 * goes to buffer n - 1, and is thus displayed, and buffer 1 goes to buffer 0, becomes
 * the accessible back buffer.
 * The resources themselves are NOT rotated, so that you can still render on the
 * same ID3D11Texture2D*, and views based on it, that you got before Present().
 *
 * Present seems to happen by either copying the relevant buffer into the window,
 * or alternatively making it the current one, either by programming the CRTC or
 * by sending the resource name to the DWM compositor.
 *
 * Hence, you can call GetBuffer(0) once and keep using the same ID3D11Texture2D*
 * and ID3D11RenderTargetView* (and other views if needed) you got from it.
 *
 * If the window gets resized, DXGI will then "emulate" all successive presentations,
 * by using a stretched blit automatically.
 * Thus, you should handle WM_SIZE and call ResizeBuffers to update the DXGI
 * swapchain buffers size to the new window size.
 * Doing so requires you to release all GetBuffers() results and anything referencing
 * them, including views and Direct3D11 deferred context command lists (this is
 * documented).
 *
 * How does Microsoft implement the rotation behavior?
 * It turns out that it does it by calling RotateResourceIdentitiesDXGI in the user-mode
 * DDI driver.
 * This will rotate the kernel buffer handle, or possibly rotate the GPU virtual memory
 * mappings.
 *
 * The reason this is done by driver instead of by the runtime appears to be that
 * this is necessary to support driver-provided command list support, since otherwise
 * the command list would not always target the current backbuffer, since it would
 * be done at the driver level, while only the runtime knows about the rotation.
 *
 * OK, so how do we implement this in Gallium?
 *
 * There are three strategies:
 * 1. Use a single buffer, and always copy it to a window system provided buffer, or
 *    just give the buffer to the window system if it supports that
 * 2. Rotate the buffers in the D3D1x implementation, and recreate and rebind the views.
 *     Don't support driver-provided command lists
 * 3. Add this rotation functionality to the Gallium driver, with the idea that it would rotate
 *    remap GPU virtual memory, so that virtual address are unchanged, but the physical
 *    ones are rotated (so that pushbuffers remain valid).
 *    If the driver does not support this, either fall back to (1), or have a layer doing this,
 *    putting a deferred context layer over this intermediate layer.
 *
 * (2) is not acceptable since it prevents an optimal implementation.
 *  (3) is the ideal solution, but it is complicated.
 *
 * Hence, we implement (1) for now, and will switch to (3) later.
 *
 * Note that (1) doesn't really work for DXGI_SWAP_EFFECT_SEQUENTIAL with more
 * than one buffer, so we just pretend we got asked for a single buffer in that case
 * Fortunately, no one seems to rely on that, so we'll just not implement it at first, and
 * later perform the rotation with blits.
 * Once we switch to (3), we'll just use real rotation to do it..
 *
 * DXGI_SWAP_EFFECT_SEQUENTIAL with more than one buffer is of dubious use
 * anyway, since you can only render or write to buffer 0, and other buffers can apparently
 * be used only as sources for copies.
 * I was unable to find any code using it either in DirectX SDK examples, or on the web.
 *
 * It seems the only reason you would use it is to not have to redraw from scratch, while
 * also possibly avoid a copy compared to BufferCount == 1, assuming that your
 * application is OK with having to redraw starting not from the last frame, but from
 * one/two/more frames behind it.
 *
 * A better design would forbid the user specifying BufferCount explicitly, and
 * would instead let the application give an upper bound on how old the buffer can
 * become after presentation, with "infinite" being equivalent to discard.
 * The runtime would then tell the application with frame number the buffer switched to
 * after present.
 * In addition, in a better design, the application would be allowed to specify the
 * number of buffers available, having all them usable for rendering, so that things
 * like video players could efficiently decode frames in parallel.
 * Present would in such a better design gain a way to specify the number of buffers
 * to present.
 *
 * Other miscellaneous info:
 * DXGI_PRESENT_DO_NOT_SEQUENCE causes DXGI to hold the frame for another
 * vblank interval without rotating the resource data.
 *
 * References:
 * "DXGI Overview" in MSDN
 * IDXGISwapChain documentation on MSDN
 * "RotateResourceIdentitiesDXGI" on MSDN
 * http://forums.xna.com/forums/p/42362/266016.aspx
 */

static float quad_data[] = {
        -1, -1, 0, 0,
        -1, 1, 0, 1,
        1, 1, 1, 1,
        1, -1, 1, 0,
};

struct dxgi_blitter
{
        pipe_context* pipe;
        bool normalized;
        void* fs;
        void* vs;
        void* sampler[2];
        void* elements;
        void* blend;
        void* rasterizer;
        void* zsa;
        struct pipe_clip_state clip;
        struct pipe_vertex_buffer vbuf;
        struct pipe_draw_info draw;

        dxgi_blitter(pipe_context* pipe)
        : pipe(pipe)
        {
                //normalized = !!pipe->screen->get_param(pipe, PIPE_CAP_NPOT_TEXTURES);
                // TODO: need to update buffer in unnormalized case
                normalized = true;

                struct pipe_rasterizer_state rs_state;
                memset(&rs_state, 0, sizeof(rs_state));
                rs_state.cull_face = PIPE_FACE_NONE;
                rs_state.gl_rasterization_rules = 1;
                rs_state.flatshade = 1;
                rasterizer = pipe->create_rasterizer_state(pipe, &rs_state);

                struct pipe_blend_state blendd;
                memset(&blendd, 0, sizeof(blendd));
                blendd.rt[0].colormask = PIPE_MASK_RGBA;
                blend = pipe->create_blend_state(pipe, &blendd);

                struct pipe_depth_stencil_alpha_state zsad;
                memset(&zsad, 0, sizeof(zsad));
                zsa = pipe->create_depth_stencil_alpha_state(pipe, &zsad);

                struct pipe_vertex_element velem[2];
                memset(&velem[0], 0, sizeof(velem[0]) * 2);
                velem[0].src_offset = 0;
                velem[0].src_format = PIPE_FORMAT_R32G32_FLOAT;
                velem[1].src_offset = 8;
                velem[1].src_format = PIPE_FORMAT_R32G32_FLOAT;
                elements = pipe->create_vertex_elements_state(pipe, 2, &velem[0]);

                for(unsigned stretch = 0; stretch < 2; ++stretch)
                {
                        struct pipe_sampler_state sampler_state;
                        memset(&sampler_state, 0, sizeof(sampler_state));
                        sampler_state.min_img_filter = stretch ? PIPE_TEX_FILTER_LINEAR : PIPE_TEX_FILTER_NEAREST;
                        sampler_state.mag_img_filter = stretch ? PIPE_TEX_FILTER_LINEAR : PIPE_TEX_FILTER_NEAREST;
                        sampler_state.wrap_s = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
                        sampler_state.wrap_t = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
                        sampler_state.wrap_r = PIPE_TEX_WRAP_CLAMP_TO_EDGE;
                        sampler_state.normalized_coords = normalized;

                        sampler[stretch] = pipe->create_sampler_state(pipe, &sampler_state);
                }

                fs = util_make_fragment_tex_shader(pipe, normalized ? TGSI_TEXTURE_2D : TGSI_TEXTURE_RECT, TGSI_INTERPOLATE_LINEAR);

                const unsigned semantic_names[] = { TGSI_SEMANTIC_POSITION, TGSI_SEMANTIC_GENERIC };
                const unsigned semantic_indices[] = { 0, 0 };
                vs = util_make_vertex_passthrough_shader(pipe, 2, semantic_names, semantic_indices);

                vbuf.buffer = pipe_buffer_create(pipe->screen, PIPE_BIND_VERTEX_BUFFER, sizeof(quad_data));
                vbuf.buffer_offset = 0;
                vbuf.max_index = ~0;
                vbuf.stride = 4 * sizeof(float);
                pipe_buffer_write(pipe, vbuf.buffer, 0, sizeof(quad_data), quad_data);

                memset(&clip, 0, sizeof(clip));

                memset(&draw, 0, sizeof(draw));
                draw.mode = PIPE_PRIM_QUADS;
                draw.count = 4;
                draw.instance_count = 1;
                draw.max_index = ~0;
        }

        void blit(struct pipe_surface* surf, struct pipe_sampler_view* view, unsigned x, unsigned y, unsigned w, unsigned h)
        {
                struct pipe_framebuffer_state fb;
                memset(&fb, 0, sizeof(fb));
                fb.nr_cbufs = 1;
                fb.cbufs[0] = surf;
                fb.width = surf->width;
                fb.height = surf->height;

                struct pipe_viewport_state viewport;
                float half_width = w * 0.5f;
                float half_height = h * 0.5f;
                viewport.scale[0] = half_width;
                viewport.scale[1] = half_height;
                viewport.scale[2] = 1.0f;
                viewport.scale[3] = 1.0f;
                viewport.translate[0] = x + half_width;
                viewport.translate[1] = y + half_height;
                viewport.translate[2] = 0.0f;
                viewport.translate[3] = 1.0f;

                bool stretch = view->texture->width0 != w || view->texture->height0 != h;
                if(pipe->render_condition)
                        pipe->render_condition(pipe, 0, 0);
                pipe->set_framebuffer_state(pipe, &fb);
                pipe->bind_fragment_sampler_states(pipe, 1, &sampler[stretch]);
                pipe->set_viewport_state(pipe, &viewport);
                pipe->set_clip_state(pipe, &clip);
                pipe->bind_rasterizer_state(pipe, rasterizer);
                pipe->bind_depth_stencil_alpha_state(pipe, zsa);
                pipe->bind_blend_state(pipe, blend);
                pipe->bind_vertex_elements_state(pipe, elements);
                pipe->set_vertex_buffers(pipe, 1, &vbuf);
                pipe->bind_fs_state(pipe, fs);
                pipe->bind_vs_state(pipe, vs);
                if(pipe->bind_gs_state)
                        pipe->bind_gs_state(pipe, 0);
                if(pipe->bind_stream_output_state)
                        pipe->bind_stream_output_state(pipe, 0);
                pipe->set_fragment_sampler_views(pipe, 1, &view);

                pipe->draw_vbo(pipe, &draw);
        }

        ~dxgi_blitter()
        {
                pipe->delete_blend_state(pipe, blend);
                pipe->delete_rasterizer_state(pipe, rasterizer);
                pipe->delete_depth_stencil_alpha_state(pipe, zsa);
                pipe->delete_sampler_state(pipe, sampler[0]);
                pipe->delete_sampler_state(pipe, sampler[1]);
                pipe->delete_vertex_elements_state(pipe, elements);
                pipe->delete_vs_state(pipe, vs);
                pipe->delete_fs_state(pipe, fs);
                pipe->screen->resource_destroy(pipe->screen, vbuf.buffer);
        }
};

struct GalliumDXGISwapChain : public GalliumDXGIObject<IDXGISwapChain, GalliumDXGIFactory>
{
        ComPtr<IDXGIDevice>dxgi_device;
        ComPtr<IGalliumDevice>gallium_device;
        ComPtr<GalliumDXGIAdapter> adapter;
        ComPtr<IDXGIOutput> target;

        DXGI_SWAP_CHAIN_DESC desc;

        struct native_surface* surface;
        const struct native_config* config;

        void* window;
        struct pipe_resource* resources[NUM_NATIVE_ATTACHMENTS];
        int width;
        int height;
        unsigned seq_num;
        bool ever_validated;
        bool needs_validation;
        unsigned present_count;

        ComPtr<IDXGISurface> buffer0;
        struct pipe_resource* gallium_buffer0;
        struct pipe_sampler_view* gallium_buffer0_view;

        struct pipe_context* pipe;
        bool owns_pipe;

        BOOL fullscreen;

        std::auto_ptr<dxgi_blitter> blitter;
        bool formats_compatible;

        GalliumDXGISwapChain(GalliumDXGIFactory* factory, IUnknown* p_device, const DXGI_SWAP_CHAIN_DESC& p_desc)
        : GalliumDXGIObject<IDXGISwapChain, GalliumDXGIFactory>(factory), desc(p_desc), surface(0)
        {
                HRESULT hr;

                hr = p_device->QueryInterface(IID_IGalliumDevice, (void**)&gallium_device);
                if(!SUCCEEDED(hr))
                        throw hr;

                hr = p_device->QueryInterface(IID_IDXGIDevice, (void**)&dxgi_device);
                if(!SUCCEEDED(hr))
                        throw hr;

                hr = dxgi_device->GetAdapter((IDXGIAdapter**)&adapter);
                if(!SUCCEEDED(hr))
                        throw hr;

                memset(resources, 0, sizeof(resources));

                if(desc.SwapEffect == DXGI_SWAP_EFFECT_SEQUENTIAL && desc.BufferCount != 1)
                {
                        std::cerr << "Gallium DXGI: if DXGI_SWAP_EFFECT_SEQUENTIAL is specified, only BufferCount == 1 is implemented, but " << desc.BufferCount  << " was specified: ignoring this" << std::endl;
                        // change the returned desc, so that the application might perhaps notice what we did and react well
                        desc.BufferCount = 1;
                }

                pipe = gallium_device->GetGalliumContext();
                owns_pipe = false;
                if(!pipe)
                {
                        pipe = adapter->display->screen->context_create(adapter->display->screen, 0);
                        owns_pipe = true;
                }

                blitter.reset(new dxgi_blitter(pipe));
                window = 0;
        }

        void init_for_window()
        {
                if(surface)
                {
                        surface->destroy(surface);
                        surface = 0;
                }

                unsigned config_num;
                if(!strcmp(parent->platform->name, "X11"))
                {
                        XWindowAttributes xwa;
                        XGetWindowAttributes((Display*)parent->display, (Window)window, &xwa);
                        config_num = adapter->configs_by_native_visual_id[xwa.visual->visualid];
                }
                else
                {
                        enum pipe_format format = dxgi_to_pipe_format[desc.BufferDesc.Format];
                        if(!adapter->configs_by_pipe_format.count(format))
                        {
                                if(adapter->configs_by_pipe_format.empty())
                                        throw E_FAIL;
                                // TODO: choose the best match
                                format = (pipe_format)adapter->configs_by_pipe_format.begin()->first;
                        }
                        // TODO: choose the best config
                        config_num = adapter->configs_by_pipe_format.find(format)->second;
                }

                config = adapter->configs[config_num];
                surface = adapter->display->create_window_surface(adapter->display, (EGLNativeWindowType)window, config);
                surface->user_data = this;

                width = 0;
                height = 0;
                seq_num = 0;
                present_count = 0;
                needs_validation = true;
                ever_validated = false;

                formats_compatible = util_is_format_compatible(
                                util_format_description(dxgi_to_pipe_format[desc.BufferDesc.Format]),
                                util_format_description(config->color_format));
        }

        ~GalliumDXGISwapChain()
        {
                if(owns_pipe)
                        pipe->destroy(pipe);
        }

        virtual HRESULT STDMETHODCALLTYPE GetDevice(
            __in  REFIID riid,
            __out  void **ppDevice)
        {
                return dxgi_device->QueryInterface(riid, ppDevice);
        }

        HRESULT create_buffer0()
        {
                HRESULT hr;
                ComPtr<IDXGISurface> new_buffer0;
                DXGI_USAGE usage = DXGI_USAGE_BACK_BUFFER | DXGI_USAGE_RENDER_TARGET_OUTPUT;
                if(desc.SwapEffect == DXGI_SWAP_EFFECT_DISCARD)
                        usage |= DXGI_USAGE_DISCARD_ON_PRESENT;
                // for our blitter
                usage |= DXGI_USAGE_SHADER_INPUT;

                DXGI_SURFACE_DESC surface_desc;
                surface_desc.Format = desc.BufferDesc.Format;
                surface_desc.Width = desc.BufferDesc.Width;
                surface_desc.Height = desc.BufferDesc.Height;
                surface_desc.SampleDesc = desc.SampleDesc;
                hr = dxgi_device->CreateSurface(&surface_desc, 1, usage, 0, &new_buffer0);
                if(!SUCCEEDED(hr))
                        return hr;

                ComPtr<IGalliumResource> gallium_resource;
                hr = new_buffer0->QueryInterface(IID_IGalliumResource, (void**)&gallium_resource);
                if(!SUCCEEDED(hr))
                        return hr;

                struct pipe_resource* new_gallium_buffer0 = gallium_resource->GetGalliumResource();
                if(!new_gallium_buffer0)
                        return E_FAIL;

                buffer0.reset(new_buffer0.steal());
                gallium_buffer0 = new_gallium_buffer0;
                struct pipe_sampler_view templat;
                memset(&templat, 0, sizeof(templat));
                templat.texture = gallium_buffer0;
                templat.swizzle_r = 0;
                templat.swizzle_g = 1;
                templat.swizzle_b = 2;
                templat.swizzle_a = 3;
                templat.format = gallium_buffer0->format;
                gallium_buffer0_view = pipe->create_sampler_view(pipe, gallium_buffer0, &templat);
                return S_OK;
        }

        bool validate()
        {
                unsigned new_seq_num;
                needs_validation = false;

                if(!surface->validate(surface, (1 << NATIVE_ATTACHMENT_BACK_LEFT) | (1 << NATIVE_ATTACHMENT_FRONT_LEFT), &new_seq_num, resources, &width, &height))
                        return false;

                if(!ever_validated || seq_num != new_seq_num)
                {
                        seq_num = new_seq_num;
                        ever_validated = true;
                }
                return true;
        }

        virtual HRESULT STDMETHODCALLTYPE Present(
                UINT SyncInterval,
                UINT Flags)
        {
                if(Flags & DXGI_PRESENT_TEST)
                        return S_OK;

                if(!buffer0)
                {
                        HRESULT hr = create_buffer0();
                        if(!SUCCEEDED(hr))
                                return hr;
                }

                void* cur_window = 0;
                RECT rect;
                RGNDATA* rgndata;
                BOOL preserve_aspect_ratio;
                unsigned dst_w, dst_h;
                bool db;
                struct pipe_resource* dst;
                struct pipe_resource* src;
                struct pipe_surface* dst_surface;

                void* present_cookie = parent->backend->BeginPresent(desc.OutputWindow, &cur_window, &rect, &rgndata, &preserve_aspect_ratio);
                if(!cur_window || rect.left >= rect.right || rect.top >= rect.bottom)
                        goto end_present;

                if(cur_window != window)
                {
                        window = cur_window;
                        init_for_window();
                }

                if(needs_validation)
                {
                        if(!validate())
                                return DXGI_ERROR_DEVICE_REMOVED;
                }

                db = !!(config->buffer_mask & NATIVE_ATTACHMENT_BACK_LEFT);
                dst = resources[db ? NATIVE_ATTACHMENT_BACK_LEFT : NATIVE_ATTACHMENT_FRONT_LEFT];
                src = gallium_buffer0;
                dst_surface = 0;

                /* TODO: sharing the context for blitting won't work correctly if queries are active
                 * Hopefully no one is crazy enough to keep queries active while presenting, expecting
                 * sensible results.
                 * We could alternatively force using another context, but that might cause inefficiency issues
                 */

                if((unsigned)rect.right > dst->width0)
                        rect.right = dst->width0;
                if((unsigned)rect.bottom > dst->height0)
                        rect.bottom = dst->height0;
                if(rect.left > rect.right)
                        rect.left = rect.right;
                if(rect.top > rect.bottom)
                        rect.top = rect.bottom;

                if(rect.left >= rect.right && rect.top >= rect.bottom)
                        goto end_present;

                dst_w = rect.right - rect.left;
                dst_h = rect.bottom - rect.top;

                // TODO: add support for rgndata
//              if(preserve_aspect_ratio || !rgndata)
                if(1)
                {
                        unsigned blit_x, blit_y, blit_w, blit_h;
                        float black[4] = {0, 0, 0, 0};

                        if(!formats_compatible || src->width0 != dst_w || src->height0 != dst_h)
                                dst_surface = pipe->screen->get_tex_surface(pipe->screen, dst, 0, 0, 0, PIPE_BIND_RENDER_TARGET);

                        if(preserve_aspect_ratio)
                        {
                                int delta = src->width0 * dst_h - dst_w * src->height0;
                                if(delta > 0)
                                {
                                        blit_w = dst_w;
                                        blit_h = dst_w * src->height0 / src->width0;
                                }
                                else if(delta < 0)
                                {
                                        blit_w = dst_h * src->width0 / src->height0;
                                        blit_h = dst_h;
                                }
                                else
                                {
                                        blit_w = dst_w;
                                        blit_h = dst_h;
                                }

                                blit_x = (dst_w - blit_w) >> 1;
                                blit_y = (dst_h - blit_h) >> 1;
                        }
                        else
                        {
                                blit_x = 0;
                                blit_y = 0;
                                blit_w = dst_w;
                                blit_h = dst_h;
                        }

                        if(blit_x)
                                pipe->clear_render_target(pipe, dst_surface, black, rect.left, rect.top, blit_x, dst_h);
                        if(blit_y)
                                pipe->clear_render_target(pipe, dst_surface, black, rect.left, rect.top, dst_w, blit_y);

                        if(formats_compatible && blit_w == src->width0 && blit_h == src->height0)
                        {
                                pipe_subresource sr;
                                sr.face = 0;
                                sr.level = 0;
                                pipe->resource_copy_region(pipe, dst, sr, rect.left, rect.top, 0, src, sr, 0, 0, 0, blit_w, blit_h);
                        }
                        else
                        {
                                blitter->blit(dst_surface, gallium_buffer0_view, rect.left + blit_x, rect.top + blit_y, blit_w, blit_h);
                                if(!owns_pipe)
                                        gallium_device->RestoreGalliumState();
                        }

                        if(blit_w != dst_w)
                                pipe->clear_render_target(pipe, dst_surface, black, rect.left + blit_x + blit_w, rect.top, dst_w - blit_x - blit_w, dst_h);
                        if(blit_h != dst_h)
                                pipe->clear_render_target(pipe, dst_surface, black, rect.left, rect.top + blit_y + blit_h, dst_w, dst_h - blit_y - blit_h);
                }

                if(dst_surface)
                        pipe->screen->tex_surface_destroy(dst_surface);

                if(db)
                {
                        if(!surface->swap_buffers(surface))
                                return DXGI_ERROR_DEVICE_REMOVED;
                }
                else
                {
                        if(!surface->flush_frontbuffer(surface))
                                return DXGI_ERROR_DEVICE_REMOVED;
                }

end_present:
                parent->backend->EndPresent(desc.OutputWindow, present_cookie);

                ++present_count;
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE GetBuffer(
                    UINT Buffer,
                    __in  REFIID riid,
                    __out  void **ppSurface)
        {
                if(Buffer > 0)
                {
                        if(desc.SwapEffect == DXGI_SWAP_EFFECT_SEQUENTIAL)
                                std::cerr << "DXGI unimplemented: GetBuffer(n) with n > 0 not supported, returning buffer 0 instead!" << std::endl;
                        else
                                std::cerr << "DXGI error: in GetBuffer(n), n must be 0 for DXGI_SWAP_EFFECT_DISCARD\n" << std::endl;
                }

                if(!buffer0)
                {
                        HRESULT hr = create_buffer0();
                        if(!SUCCEEDED(hr))
                                return hr;
                }
                return buffer0->QueryInterface(riid, ppSurface);
        }

        /* TODO: implement somehow */
        virtual HRESULT STDMETHODCALLTYPE SetFullscreenState(
                BOOL Fullscreen,
                __in_opt  IDXGIOutput *pTarget)
        {
                fullscreen = Fullscreen;
                target = pTarget;
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE GetFullscreenState(
                __out  BOOL *pFullscreen,
                __out  IDXGIOutput **ppTarget)
        {
                if(pFullscreen)
                        *pFullscreen = fullscreen;
                if(ppTarget)
                        *ppTarget = target.ref();
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE GetDesc(
                __out  DXGI_SWAP_CHAIN_DESC *pDesc)
        {
                *pDesc = desc;
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE ResizeBuffers(
                UINT BufferCount,
                UINT Width,
                UINT Height,
                DXGI_FORMAT NewFormat,
                UINT SwapChainFlags)
        {
                if(buffer0)
                {
                        buffer0.p->AddRef();
                        ULONG v = buffer0.p->Release();
                        // we must fail if there are any references to buffer0 other than ours
                        if(v > 1)
                                return E_FAIL;
                        pipe_sampler_view_reference(&gallium_buffer0_view, 0);
                        buffer0 = (IUnknown*)NULL;
                        gallium_buffer0 = 0;
                }

                if(desc.SwapEffect != DXGI_SWAP_EFFECT_SEQUENTIAL)
                        desc.BufferCount = BufferCount;
                desc.BufferDesc.Format = NewFormat;
                desc.BufferDesc.Width = Width;
                desc.BufferDesc.Height = Height;
                desc.Flags = SwapChainFlags;
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE ResizeTarget(
                const DXGI_MODE_DESC *pNewTargetParameters)
        {
                /* TODO: implement */
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE GetContainingOutput(
                        __out  IDXGIOutput **ppOutput)
        {
                *ppOutput = adapter->outputs[0].ref();
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE GetFrameStatistics(
                        __out  DXGI_FRAME_STATISTICS *pStats)
        {
                memset(pStats, 0, sizeof(*pStats));
#ifdef _WIN32
                QueryPerformanceCounter(&pStats->SyncQPCTime);
#endif
                pStats->PresentCount = present_count;
                pStats->PresentRefreshCount = present_count;
                pStats->SyncRefreshCount = present_count;
                return S_OK;
        }

        virtual HRESULT STDMETHODCALLTYPE GetLastPresentCount(
                __out  UINT *pLastPresentCount)
        {
                *pLastPresentCount = present_count;
                return S_OK;
        }
};

static void GalliumDXGISwapChainRevalidate(IDXGISwapChain* swap_chain)
{
        ((GalliumDXGISwapChain*)swap_chain)->needs_validation = true;
}

static HRESULT GalliumDXGIAdapterCreate(GalliumDXGIFactory* factory, const struct native_platform* platform, void* dpy, IDXGIAdapter1** pAdapter)
{
        try
        {
                *pAdapter = new GalliumDXGIAdapter(factory, platform, dpy);
                return S_OK;
        }
        catch(HRESULT hr)
        {
                return hr;
        }
}

static HRESULT GalliumDXGIOutputCreate(GalliumDXGIAdapter* adapter, const std::string& name, const struct native_connector* connector, IDXGIOutput** pOutput)
{
        try
        {
                *pOutput = new GalliumDXGIOutput(adapter, name, connector);
                return S_OK;
        }
        catch(HRESULT hr)
        {
                return hr;
        }
}

static HRESULT GalliumDXGISwapChainCreate(GalliumDXGIFactory* factory, IUnknown* device, const DXGI_SWAP_CHAIN_DESC& desc, IDXGISwapChain** pSwapChain)
{
        try
        {
                *pSwapChain = new GalliumDXGISwapChain(factory, device, desc);
                return S_OK;
        }
        catch(HRESULT hr)
        {
                return hr;
        }
}

struct dxgi_binding
{
        const struct native_platform* platform;
        void* display;
        IGalliumDXGIBackend* backend;
};

static dxgi_binding dxgi_default_binding;
static __thread dxgi_binding dxgi_thread_binding;

void STDMETHODCALLTYPE GalliumDXGIUseNothing()
{
        dxgi_thread_binding.platform = 0;
        dxgi_thread_binding.display = 0;
        if(dxgi_thread_binding.backend)
                dxgi_thread_binding.backend->Release();
        dxgi_thread_binding.backend = 0;
}

#ifdef GALLIUM_DXGI_USE_X11
void STDMETHODCALLTYPE GalliumDXGIUseX11Display(Display* dpy, IGalliumDXGIBackend* backend)
{
        GalliumDXGIUseNothing();
        dxgi_thread_binding.platform = native_get_x11_platform();
        dxgi_thread_binding.display = dpy;

        if(backend)
        {
                dxgi_thread_binding.backend = backend;
                backend->AddRef();
        }
}
#endif

/*
#ifdef GALLIUM_DXGI_USE_DRM
void STDMETHODCALLTYPE GalliumDXGIUseDRMCard(int fd)
{
        GalliumDXGIUseNothing();
        dxgi_thread_binding.platform = native_get_drm_platform();
        dxgi_thread_binding.display = (void*)fd;
        dxgi_thread_binding.backend = 0;
}
#endif

#ifdef GALLIUM_DXGI_USE_FBDEV
void STDMETHODCALLTYPE GalliumDXGIUseFBDev(int fd)
{
        GalliumDXGIUseNothing();
        dxgi_thread_binding.platform = native_get_fbdev_platform();
        dxgi_thread_binding.display = (void*)fd;
        dxgi_thread_binding.backend = 0;
}
#endif

#ifdef GALLIUM_DXGI_USE_GDI
void STDMETHODCALLTYPE GalliumDXGIUseHDC(HDC hdc, PFNHWNDRESOLVER resolver, void* resolver_cookie)
{
        GalliumDXGIUseNothing();
        dxgi_thread_binding.platform = native_get_gdi_platform();
        dxgi_thread_binding.display = (void*)hdc;
        dxgi_thread_binding.backend = 0;
}
#endif
*/
void STDMETHODCALLTYPE GalliumDXGIMakeDefault()
{
        if(dxgi_default_binding.backend)
                dxgi_default_binding.backend->Release();
        dxgi_default_binding = dxgi_thread_binding;
        if(dxgi_default_binding.backend)
                dxgi_default_binding.backend->AddRef();
}

 /* TODO: why did Microsoft add this? should we do something different for DXGI 1.0 and 1.1?
  * Or perhaps what they actually mean is "only create a single factory in your application"?
  * TODO: should we use a singleton here, so we never have multiple DXGI objects for the same thing? */
 HRESULT STDMETHODCALLTYPE  CreateDXGIFactory1(
                __in   REFIID riid,
                __out  void **ppFactory
)
 {
         GalliumDXGIFactory* factory;
         *ppFactory = 0;
         if(dxgi_thread_binding.platform)
                 factory = new GalliumDXGIFactory(dxgi_thread_binding.platform, dxgi_thread_binding.display, dxgi_thread_binding.backend);
         else if(dxgi_default_binding.platform)
                 factory = new GalliumDXGIFactory(dxgi_default_binding.platform, dxgi_default_binding.display, dxgi_default_binding.backend);
         else
                 factory = new GalliumDXGIFactory(native_get_x11_platform(), NULL, NULL);
         HRESULT hres = factory->QueryInterface(riid, ppFactory);
         factory->Release();
         return hres;
 }

 HRESULT STDMETHODCALLTYPE  CreateDXGIFactory(
                 __in   REFIID riid,
                 __out  void **ppFactory
)
 {
         return CreateDXGIFactory1(riid, ppFactory);
 }