/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "../../SDL_internal.h"

#include "SDL_render.h"
#include "SDL_system.h"

#if SDL_VIDEO_RENDER_D3D && !SDL_RENDER_DISABLED

#include "../../core/windows/SDL_windows.h"

#include "SDL_hints.h"
#include "SDL_loadso.h"
#include "SDL_syswm.h"
#include "../SDL_sysrender.h"
#include "../SDL_d3dmath.h"
#include "../../video/windows/SDL_windowsvideo.h"

#if SDL_VIDEO_RENDER_D3D
#define D3D_DEBUG_INFO
#include <d3d9.h>
#endif

#include "SDL_shaders_d3d.h"

typedef struct
{
    SDL_Rect viewport;
    SDL_bool viewport_dirty;
    SDL_Texture *texture;
    SDL_BlendMode blend;
    SDL_bool cliprect_enabled;
    SDL_bool cliprect_enabled_dirty;
    SDL_Rect cliprect;
    SDL_bool cliprect_dirty;
    LPDIRECT3DPIXELSHADER9 shader;
} D3D_DrawStateCache;


/* Direct3D renderer implementation */

typedef struct
{
    void* d3dDLL;
    IDirect3D9 *d3d;
    IDirect3DDevice9 *device;
    UINT adapter;
    D3DPRESENT_PARAMETERS pparams;
    SDL_bool updateSize;
    SDL_bool beginScene;
    SDL_bool enableSeparateAlphaBlend;
    D3DTEXTUREFILTERTYPE scaleMode[8];
    IDirect3DSurface9 *defaultRenderTarget;
    IDirect3DSurface9 *currentRenderTarget;
    void* d3dxDLL;
    LPDIRECT3DPIXELSHADER9 shaders[NUM_SHADERS];
    LPDIRECT3DVERTEXBUFFER9 vertexBuffers[8];
    size_t vertexBufferSize[8];
    int currentVertexBuffer;
    SDL_bool reportedVboProblem;
    D3D_DrawStateCache drawstate;
} D3D_RenderData;

typedef struct
{
    SDL_bool dirty;
    int w, h;
    DWORD usage;
    Uint32 format;
    D3DFORMAT d3dfmt;
    IDirect3DTexture9 *texture;
    IDirect3DTexture9 *staging;
} D3D_TextureRep;

typedef struct
{
    D3D_TextureRep texture;
    D3DTEXTUREFILTERTYPE scaleMode;

    /* YV12 texture support */
    SDL_bool yuv;
    D3D_TextureRep utexture;
    D3D_TextureRep vtexture;
    Uint8 *pixels;
    int pitch;
    SDL_Rect locked_rect;
} D3D_TextureData;

typedef struct
{
    float x, y, z;
    DWORD color;
    float u, v;
} Vertex;

static int
D3D_SetError(const char *prefix, HRESULT result)
{
    const char *error;

    switch (result) {
    case D3DERR_WRONGTEXTUREFORMAT:
        error = "WRONGTEXTUREFORMAT";
        break;
    case D3DERR_UNSUPPORTEDCOLOROPERATION:
        error = "UNSUPPORTEDCOLOROPERATION";
        break;
    case D3DERR_UNSUPPORTEDCOLORARG:
        error = "UNSUPPORTEDCOLORARG";
        break;
    case D3DERR_UNSUPPORTEDALPHAOPERATION:
        error = "UNSUPPORTEDALPHAOPERATION";
        break;
    case D3DERR_UNSUPPORTEDALPHAARG:
        error = "UNSUPPORTEDALPHAARG";
        break;
    case D3DERR_TOOMANYOPERATIONS:
        error = "TOOMANYOPERATIONS";
        break;
    case D3DERR_CONFLICTINGTEXTUREFILTER:
        error = "CONFLICTINGTEXTUREFILTER";
        break;
    case D3DERR_UNSUPPORTEDFACTORVALUE:
        error = "UNSUPPORTEDFACTORVALUE";
        break;
    case D3DERR_CONFLICTINGRENDERSTATE:
        error = "CONFLICTINGRENDERSTATE";
        break;
    case D3DERR_UNSUPPORTEDTEXTUREFILTER:
        error = "UNSUPPORTEDTEXTUREFILTER";
        break;
    case D3DERR_CONFLICTINGTEXTUREPALETTE:
        error = "CONFLICTINGTEXTUREPALETTE";
        break;
    case D3DERR_DRIVERINTERNALERROR:
        error = "DRIVERINTERNALERROR";
        break;
    case D3DERR_NOTFOUND:
        error = "NOTFOUND";
        break;
    case D3DERR_MOREDATA:
        error = "MOREDATA";
        break;
    case D3DERR_DEVICELOST:
        error = "DEVICELOST";
        break;
    case D3DERR_DEVICENOTRESET:
        error = "DEVICENOTRESET";
        break;
    case D3DERR_NOTAVAILABLE:
        error = "NOTAVAILABLE";
        break;
    case D3DERR_OUTOFVIDEOMEMORY:
        error = "OUTOFVIDEOMEMORY";
        break;
    case D3DERR_INVALIDDEVICE:
        error = "INVALIDDEVICE";
        break;
    case D3DERR_INVALIDCALL:
        error = "INVALIDCALL";
        break;
    case D3DERR_DRIVERINVALIDCALL:
        error = "DRIVERINVALIDCALL";
        break;
    case D3DERR_WASSTILLDRAWING:
        error = "WASSTILLDRAWING";
        break;
    default:
        error = "UNKNOWN";
        break;
    }
    return SDL_SetError("%s: %s", prefix, error);
}

static D3DFORMAT
PixelFormatToD3DFMT(Uint32 format)
{
    switch (format) {
    case SDL_PIXELFORMAT_RGB565:
        return D3DFMT_R5G6B5;
    case SDL_PIXELFORMAT_RGB888:
        return D3DFMT_X8R8G8B8;
    case SDL_PIXELFORMAT_ARGB8888:
        return D3DFMT_A8R8G8B8;
    case SDL_PIXELFORMAT_YV12:
    case SDL_PIXELFORMAT_IYUV:
    case SDL_PIXELFORMAT_NV12:
    case SDL_PIXELFORMAT_NV21:
        return D3DFMT_L8;
    default:
        return D3DFMT_UNKNOWN;
    }
}

static Uint32
D3DFMTToPixelFormat(D3DFORMAT format)
{
    switch (format) {
    case D3DFMT_R5G6B5:
        return SDL_PIXELFORMAT_RGB565;
    case D3DFMT_X8R8G8B8:
        return SDL_PIXELFORMAT_RGB888;
    case D3DFMT_A8R8G8B8:
        return SDL_PIXELFORMAT_ARGB8888;
    default:
        return SDL_PIXELFORMAT_UNKNOWN;
    }
}

static void
D3D_InitRenderState(D3D_RenderData *data)
{
    D3DMATRIX matrix;

    IDirect3DDevice9 *device = data->device;
    IDirect3DDevice9_SetPixelShader(device, NULL);
    IDirect3DDevice9_SetTexture(device, 0, NULL);
    IDirect3DDevice9_SetTexture(device, 1, NULL);
    IDirect3DDevice9_SetTexture(device, 2, NULL);
    IDirect3DDevice9_SetFVF(device, D3DFVF_XYZ | D3DFVF_DIFFUSE | D3DFVF_TEX1);
    IDirect3DDevice9_SetVertexShader(device, NULL);
    IDirect3DDevice9_SetRenderState(device, D3DRS_ZENABLE, D3DZB_FALSE);
    IDirect3DDevice9_SetRenderState(device, D3DRS_CULLMODE, D3DCULL_NONE);
    IDirect3DDevice9_SetRenderState(device, D3DRS_LIGHTING, FALSE);

    /* Enable color modulation by diffuse color */
    IDirect3DDevice9_SetTextureStageState(device, 0, D3DTSS_COLOROP,
                                          D3DTOP_MODULATE);
    IDirect3DDevice9_SetTextureStageState(device, 0, D3DTSS_COLORARG1,
                                          D3DTA_TEXTURE);
    IDirect3DDevice9_SetTextureStageState(device, 0, D3DTSS_COLORARG2,
                                          D3DTA_DIFFUSE);

    /* Enable alpha modulation by diffuse alpha */
    IDirect3DDevice9_SetTextureStageState(device, 0, D3DTSS_ALPHAOP,
                                          D3DTOP_MODULATE);
    IDirect3DDevice9_SetTextureStageState(device, 0, D3DTSS_ALPHAARG1,
                                          D3DTA_TEXTURE);
    IDirect3DDevice9_SetTextureStageState(device, 0, D3DTSS_ALPHAARG2,
                                          D3DTA_DIFFUSE);

    /* Enable separate alpha blend function, if possible */
    if (data->enableSeparateAlphaBlend) {
        IDirect3DDevice9_SetRenderState(device, D3DRS_SEPARATEALPHABLENDENABLE, TRUE);
    }

    /* Disable second texture stage, since we're done */
    IDirect3DDevice9_SetTextureStageState(device, 1, D3DTSS_COLOROP,
                                          D3DTOP_DISABLE);
    IDirect3DDevice9_SetTextureStageState(device, 1, D3DTSS_ALPHAOP,
                                          D3DTOP_DISABLE);

    /* Set an identity world and view matrix */
    SDL_zero(matrix);
    matrix.m[0][0] = 1.0f;
    matrix.m[1][1] = 1.0f;
    matrix.m[2][2] = 1.0f;
    matrix.m[3][3] = 1.0f;
    IDirect3DDevice9_SetTransform(device, D3DTS_WORLD, &matrix);
    IDirect3DDevice9_SetTransform(device, D3DTS_VIEW, &matrix);

    /* Reset our current scale mode */
    SDL_memset(data->scaleMode, 0xFF, sizeof(data->scaleMode));

    /* Start the render with beginScene */
    data->beginScene = SDL_TRUE;
}

static int D3D_Reset(SDL_Renderer * renderer);

static int
D3D_ActivateRenderer(SDL_Renderer * renderer)
{
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;
    HRESULT result;

    if (data->updateSize) {
        SDL_Window *window = renderer->window;
        int w, h;
        Uint32 window_flags = SDL_GetWindowFlags(window);

        SDL_GetWindowSize(window, &w, &h);
        data->pparams.BackBufferWidth = w;
        data->pparams.BackBufferHeight = h;
        if (window_flags & SDL_WINDOW_FULLSCREEN && (window_flags & SDL_WINDOW_FULLSCREEN_DESKTOP) != SDL_WINDOW_FULLSCREEN_DESKTOP) {
            SDL_DisplayMode fullscreen_mode;
            SDL_GetWindowDisplayMode(window, &fullscreen_mode);
            data->pparams.Windowed = FALSE;
            data->pparams.BackBufferFormat = PixelFormatToD3DFMT(fullscreen_mode.format);
            data->pparams.FullScreen_RefreshRateInHz = fullscreen_mode.refresh_rate;
        } else {
            data->pparams.Windowed = TRUE;
            data->pparams.BackBufferFormat = D3DFMT_UNKNOWN;
            data->pparams.FullScreen_RefreshRateInHz = 0;
        }
        if (D3D_Reset(renderer) < 0) {
            return -1;
        }

        data->updateSize = SDL_FALSE;
    }
    if (data->beginScene) {
        result = IDirect3DDevice9_BeginScene(data->device);
        if (result == D3DERR_DEVICELOST) {
            if (D3D_Reset(renderer) < 0) {
                return -1;
            }
            result = IDirect3DDevice9_BeginScene(data->device);
        }
        if (FAILED(result)) {
            return D3D_SetError("BeginScene()", result);
        }
        data->beginScene = SDL_FALSE;
    }
    return 0;
}

static void
D3D_WindowEvent(SDL_Renderer * renderer, const SDL_WindowEvent *event)
{
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;

    if (event->event == SDL_WINDOWEVENT_SIZE_CHANGED) {
        data->updateSize = SDL_TRUE;
    }
}

static D3DBLEND GetBlendFunc(SDL_BlendFactor factor)
{
    switch (factor) {
    case SDL_BLENDFACTOR_ZERO:
        return D3DBLEND_ZERO;
    case SDL_BLENDFACTOR_ONE:
        return D3DBLEND_ONE;
    case SDL_BLENDFACTOR_SRC_COLOR:
        return D3DBLEND_SRCCOLOR;
    case SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR:
        return D3DBLEND_INVSRCCOLOR;
    case SDL_BLENDFACTOR_SRC_ALPHA:
        return D3DBLEND_SRCALPHA;
    case SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA:
        return D3DBLEND_INVSRCALPHA;
    case SDL_BLENDFACTOR_DST_COLOR:
        return D3DBLEND_DESTCOLOR;
    case SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR:
        return D3DBLEND_INVDESTCOLOR;
    case SDL_BLENDFACTOR_DST_ALPHA:
        return D3DBLEND_DESTALPHA;
    case SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA:
        return D3DBLEND_INVDESTALPHA;
    default:
        return (D3DBLEND)0;
    }
}

static SDL_bool
D3D_SupportsBlendMode(SDL_Renderer * renderer, SDL_BlendMode blendMode)
{
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;
    SDL_BlendFactor srcColorFactor = SDL_GetBlendModeSrcColorFactor(blendMode);
    SDL_BlendFactor srcAlphaFactor = SDL_GetBlendModeSrcAlphaFactor(blendMode);
    SDL_BlendOperation colorOperation = SDL_GetBlendModeColorOperation(blendMode);
    SDL_BlendFactor dstColorFactor = SDL_GetBlendModeDstColorFactor(blendMode);
    SDL_BlendFactor dstAlphaFactor = SDL_GetBlendModeDstAlphaFactor(blendMode);
    SDL_BlendOperation alphaOperation = SDL_GetBlendModeAlphaOperation(blendMode);

    if (!GetBlendFunc(srcColorFactor) || !GetBlendFunc(srcAlphaFactor) ||
        !GetBlendFunc(dstColorFactor) || !GetBlendFunc(dstAlphaFactor)) {
        return SDL_FALSE;
    }
    if ((srcColorFactor != srcAlphaFactor || dstColorFactor != dstAlphaFactor) && !data->enableSeparateAlphaBlend) {
        return SDL_FALSE;
    }
    if (colorOperation != SDL_BLENDOPERATION_ADD || alphaOperation != SDL_BLENDOPERATION_ADD) {
        return SDL_FALSE;
    }
    return SDL_TRUE;
}

static int
D3D_CreateTextureRep(IDirect3DDevice9 *device, D3D_TextureRep *texture, DWORD usage, Uint32 format, D3DFORMAT d3dfmt, int w, int h)
{
    HRESULT result;

    texture->dirty = SDL_FALSE;
    texture->w = w;
    texture->h = h;
    texture->usage = usage;
    texture->format = format;
    texture->d3dfmt = d3dfmt;

    result = IDirect3DDevice9_CreateTexture(device, w, h, 1, usage,
        PixelFormatToD3DFMT(format),
        D3DPOOL_DEFAULT, &texture->texture, NULL);
    if (FAILED(result)) {
        return D3D_SetError("CreateTexture(D3DPOOL_DEFAULT)", result);
    }
    return 0;
}


static int
D3D_CreateStagingTexture(IDirect3DDevice9 *device, D3D_TextureRep *texture)
{
    HRESULT result;

    if (texture->staging == NULL) {
        result = IDirect3DDevice9_CreateTexture(device, texture->w, texture->h, 1, 0,
            texture->d3dfmt, D3DPOOL_SYSTEMMEM, &texture->staging, NULL);
        if (FAILED(result)) {
            return D3D_SetError("CreateTexture(D3DPOOL_SYSTEMMEM)", result);
        }
    }
    return 0;
}

static int
D3D_RecreateTextureRep(IDirect3DDevice9 *device, D3D_TextureRep *texture)
{
    if (texture->texture) {
        IDirect3DTexture9_Release(texture->texture);
        texture->texture = NULL;
    }
    if (texture->staging) {
        IDirect3DTexture9_AddDirtyRect(texture->staging, NULL);
        texture->dirty = SDL_TRUE;
    }
    return 0;
}

static int
D3D_UpdateTextureRep(IDirect3DDevice9 *device, D3D_TextureRep *texture, int x, int y, int w, int h, const void *pixels, int pitch)
{
    RECT d3drect;
    D3DLOCKED_RECT locked;
    const Uint8 *src;
    Uint8 *dst;
    int row, length;
    HRESULT result;

    if (D3D_CreateStagingTexture(device, texture) < 0) {
        return -1;
    }

    d3drect.left = x;
    d3drect.right = x + w;
    d3drect.top = y;
    d3drect.bottom = y + h;
    
    result = IDirect3DTexture9_LockRect(texture->staging, 0, &locked, &d3drect, 0);
    if (FAILED(result)) {
        return D3D_SetError("LockRect()", result);
    }

    src = (const Uint8 *)pixels;
    dst = (Uint8 *)locked.pBits;
    length = w * SDL_BYTESPERPIXEL(texture->format);
    if (length == pitch && length == locked.Pitch) {
        SDL_memcpy(dst, src, length*h);
    } else {
        if (length > pitch) {
            length = pitch;
        }
        if (length > locked.Pitch) {
            length = locked.Pitch;
        }
        for (row = 0; row < h; ++row) {
            SDL_memcpy(dst, src, length);
            src += pitch;
            dst += locked.Pitch;
        }
    }
    result = IDirect3DTexture9_UnlockRect(texture->staging, 0);
    if (FAILED(result)) {
        return D3D_SetError("UnlockRect()", result);
    }
    texture->dirty = SDL_TRUE;

    return 0;
}

static void
D3D_DestroyTextureRep(D3D_TextureRep *texture)
{
    if (texture->texture) {
        IDirect3DTexture9_Release(texture->texture);
        texture->texture = NULL;
    }
    if (texture->staging) {
        IDirect3DTexture9_Release(texture->staging);
        texture->staging = NULL;
    }
}

static int
D3D_CreateTexture(SDL_Renderer * renderer, SDL_Texture * texture)
{
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;
    D3D_TextureData *texturedata;
    DWORD usage;

    texturedata = (D3D_TextureData *) SDL_calloc(1, sizeof(*texturedata));
    if (!texturedata) {
        return SDL_OutOfMemory();
    }
    texturedata->scaleMode = (texture->scaleMode == SDL_ScaleModeNearest) ? D3DTEXF_POINT : D3DTEXF_LINEAR;

    texture->driverdata = texturedata;

    if (texture->access == SDL_TEXTUREACCESS_TARGET) {
        usage = D3DUSAGE_RENDERTARGET;
    } else {
        usage = 0;
    }

    if (D3D_CreateTextureRep(data->device, &texturedata->texture, usage, texture->format, PixelFormatToD3DFMT(texture->format), texture->w, texture->h) < 0) {
        return -1;
    }

    if (texture->format == SDL_PIXELFORMAT_YV12 ||
        texture->format == SDL_PIXELFORMAT_IYUV) {
        texturedata->yuv = SDL_TRUE;

        if (D3D_CreateTextureRep(data->device, &texturedata->utexture, usage, texture->format, PixelFormatToD3DFMT(texture->format), (texture->w + 1) / 2, (texture->h + 1) / 2) < 0) {
            return -1;
        }

        if (D3D_CreateTextureRep(data->device, &texturedata->vtexture, usage, texture->format, PixelFormatToD3DFMT(texture->format), (texture->w + 1) / 2, (texture->h + 1) / 2) < 0) {
            return -1;
        }
    }
    return 0;
}

static int
D3D_RecreateTexture(SDL_Renderer * renderer, SDL_Texture * texture)
{
    D3D_RenderData *data = (D3D_RenderData *)renderer->driverdata;
    D3D_TextureData *texturedata = (D3D_TextureData *)texture->driverdata;

    if (!texturedata) {
        return 0;
    }

    if (D3D_RecreateTextureRep(data->device, &texturedata->texture) < 0) {
        return -1;
    }

    if (texturedata->yuv) {
        if (D3D_RecreateTextureRep(data->device, &texturedata->utexture) < 0) {
            return -1;
        }

        if (D3D_RecreateTextureRep(data->device, &texturedata->vtexture) < 0) {
            return -1;
        }
    }
    return 0;
}

static int
D3D_UpdateTexture(SDL_Renderer * renderer, SDL_Texture * texture,
                  const SDL_Rect * rect, const void *pixels, int pitch)
{
    D3D_RenderData *data = (D3D_RenderData *)renderer->driverdata;
    D3D_TextureData *texturedata = (D3D_TextureData *) texture->driverdata;

    if (!texturedata) {
        SDL_SetError("Texture is not currently available");
        return -1;
    }

    if (D3D_UpdateTextureRep(data->device, &texturedata->texture, rect->x, rect->y, rect->w, rect->h, pixels, pitch) < 0) {
        return -1;
    }

    if (texturedata->yuv) {
        /* Skip to the correct offset into the next texture */
        pixels = (const void*)((const Uint8*)pixels + rect->h * pitch);

        if (D3D_UpdateTextureRep(data->device, texture->format == SDL_PIXELFORMAT_YV12 ? &texturedata->vtexture : &texturedata->utexture, rect->x / 2, rect->y / 2, (rect->w + 1) / 2, (rect->h + 1) / 2, pixels, (pitch + 1) / 2) < 0) {
            return -1;
        }

        /* Skip to the correct offset into the next texture */
        pixels = (const void*)((const Uint8*)pixels + ((rect->h + 1) / 2) * ((pitch + 1) / 2));
        if (D3D_UpdateTextureRep(data->device, texture->format == SDL_PIXELFORMAT_YV12 ? &texturedata->utexture : &texturedata->vtexture, rect->x / 2, (rect->y + 1) / 2, (rect->w + 1) / 2, (rect->h + 1) / 2, pixels, (pitch + 1) / 2) < 0) {
            return -1;
        }
    }
    return 0;
}

#if SDL_HAVE_YUV
static int
D3D_UpdateTextureYUV(SDL_Renderer * renderer, SDL_Texture * texture,
                     const SDL_Rect * rect,
                     const Uint8 *Yplane, int Ypitch,
                     const Uint8 *Uplane, int Upitch,
                     const Uint8 *Vplane, int Vpitch)
{
    D3D_RenderData *data = (D3D_RenderData *)renderer->driverdata;
    D3D_TextureData *texturedata = (D3D_TextureData *) texture->driverdata;

    if (!texturedata) {
        SDL_SetError("Texture is not currently available");
        return -1;
    }

    if (D3D_UpdateTextureRep(data->device, &texturedata->texture, rect->x, rect->y, rect->w, rect->h, Yplane, Ypitch) < 0) {
        return -1;
    }
    if (D3D_UpdateTextureRep(data->device, &texturedata->utexture, rect->x / 2, rect->y / 2, (rect->w + 1) / 2, (rect->h + 1) / 2, Uplane, Upitch) < 0) {
        return -1;
    }
    if (D3D_UpdateTextureRep(data->device, &texturedata->vtexture, rect->x / 2, rect->y / 2, (rect->w + 1) / 2, (rect->h + 1) / 2, Vplane, Vpitch) < 0) {
        return -1;
    }
    return 0;
}
#endif

static int
D3D_LockTexture(SDL_Renderer * renderer, SDL_Texture * texture,
                const SDL_Rect * rect, void **pixels, int *pitch)
{
    D3D_RenderData *data = (D3D_RenderData *)renderer->driverdata;
    D3D_TextureData *texturedata = (D3D_TextureData *)texture->driverdata;
    IDirect3DDevice9 *device = data->device;

    if (!texturedata) {
        SDL_SetError("Texture is not currently available");
        return -1;
    }

    texturedata->locked_rect = *rect;

    if (texturedata->yuv) {
        /* It's more efficient to upload directly... */
        if (!texturedata->pixels) {
            texturedata->pitch = texture->w;
            texturedata->pixels = (Uint8 *)SDL_malloc((texture->h * texturedata->pitch * 3) / 2);
            if (!texturedata->pixels) {
                return SDL_OutOfMemory();
            }
        }
        *pixels =
            (void *) ((Uint8 *) texturedata->pixels + rect->y * texturedata->pitch +
                      rect->x * SDL_BYTESPERPIXEL(texture->format));
        *pitch = texturedata->pitch;
    } else {
        RECT d3drect;
        D3DLOCKED_RECT locked;
        HRESULT result;

        if (D3D_CreateStagingTexture(device, &texturedata->texture) < 0) {
            return -1;
        }

        d3drect.left = rect->x;
        d3drect.right = rect->x + rect->w;
        d3drect.top = rect->y;
        d3drect.bottom = rect->y + rect->h;

        result = IDirect3DTexture9_LockRect(texturedata->texture.staging, 0, &locked, &d3drect, 0);
        if (FAILED(result)) {
            return D3D_SetError("LockRect()", result);
        }
        *pixels = locked.pBits;
        *pitch = locked.Pitch;
    }
    return 0;
}

static void
D3D_UnlockTexture(SDL_Renderer * renderer, SDL_Texture * texture)
{
    D3D_RenderData *data = (D3D_RenderData *)renderer->driverdata;
    D3D_TextureData *texturedata = (D3D_TextureData *)texture->driverdata;

    if (!texturedata) {
        return;
    }

    if (texturedata->yuv) {
        const SDL_Rect *rect = &texturedata->locked_rect;
        void *pixels =
            (void *) ((Uint8 *) texturedata->pixels + rect->y * texturedata->pitch +
                      rect->x * SDL_BYTESPERPIXEL(texture->format));
        D3D_UpdateTexture(renderer, texture, rect, pixels, texturedata->pitch);
    } else {
        IDirect3DTexture9_UnlockRect(texturedata->texture.staging, 0);
        texturedata->texture.dirty = SDL_TRUE;
        if (data->drawstate.texture == texture) {
            data->drawstate.texture = NULL;
            data->drawstate.shader = NULL;
            IDirect3DDevice9_SetPixelShader(data->device, NULL);
            IDirect3DDevice9_SetTexture(data->device, 0, NULL);
            if (texturedata->yuv) {
                IDirect3DDevice9_SetTexture(data->device, 1, NULL);
                IDirect3DDevice9_SetTexture(data->device, 2, NULL);
            }
        }
    }
}

static void
D3D_SetTextureScaleMode(SDL_Renderer * renderer, SDL_Texture * texture, SDL_ScaleMode scaleMode)
{
    D3D_TextureData *texturedata = (D3D_TextureData *)texture->driverdata;

    if (!texturedata) {
        return;
    }

    texturedata->scaleMode = (scaleMode == SDL_ScaleModeNearest) ? D3DTEXF_POINT : D3DTEXF_LINEAR;
}

static int
D3D_SetRenderTargetInternal(SDL_Renderer * renderer, SDL_Texture * texture)
{
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;
    D3D_TextureData *texturedata;
    D3D_TextureRep *texturerep;
    HRESULT result;
    IDirect3DDevice9 *device = data->device;

    /* Release the previous render target if it wasn't the default one */
    if (data->currentRenderTarget != NULL) {
        IDirect3DSurface9_Release(data->currentRenderTarget);
        data->currentRenderTarget = NULL;
    }

    if (texture == NULL) {
        IDirect3DDevice9_SetRenderTarget(data->device, 0, data->defaultRenderTarget);
        return 0;
    }

    texturedata = (D3D_TextureData *)texture->driverdata;
    if (!texturedata) {
        SDL_SetError("Texture is not currently available");
        return -1;
    }

    /* Make sure the render target is updated if it was locked and written to */
    texturerep = &texturedata->texture;
    if (texturerep->dirty && texturerep->staging) {
        if (!texturerep->texture) {
            result = IDirect3DDevice9_CreateTexture(device, texturerep->w, texturerep->h, 1, texturerep->usage,
                PixelFormatToD3DFMT(texturerep->format), D3DPOOL_DEFAULT, &texturerep->texture, NULL);
            if (FAILED(result)) {
                return D3D_SetError("CreateTexture(D3DPOOL_DEFAULT)", result);
            }
        }

        result = IDirect3DDevice9_UpdateTexture(device, (IDirect3DBaseTexture9 *)texturerep->staging, (IDirect3DBaseTexture9 *)texturerep->texture);
        if (FAILED(result)) {
            return D3D_SetError("UpdateTexture()", result);
        }
        texturerep->dirty = SDL_FALSE;
    }

    result = IDirect3DTexture9_GetSurfaceLevel(texturedata->texture.texture, 0, &data->currentRenderTarget);
    if(FAILED(result)) {
        return D3D_SetError("GetSurfaceLevel()", result);
    }
    result = IDirect3DDevice9_SetRenderTarget(data->device, 0, data->currentRenderTarget);
    if(FAILED(result)) {
        return D3D_SetError("SetRenderTarget()", result);
    }

    return 0;
}

static int
D3D_SetRenderTarget(SDL_Renderer * renderer, SDL_Texture * texture)
{
    if (D3D_ActivateRenderer(renderer) < 0) {
        return -1;
    }

    return D3D_SetRenderTargetInternal(renderer, texture);
}


static int
D3D_QueueSetViewport(SDL_Renderer * renderer, SDL_RenderCommand *cmd)
{
    return 0;  /* nothing to do in this backend. */
}

static int
D3D_QueueDrawPoints(SDL_Renderer * renderer, SDL_RenderCommand *cmd, const SDL_FPoint * points, int count)
{
    const DWORD color = D3DCOLOR_ARGB(cmd->data.draw.a, cmd->data.draw.r, cmd->data.draw.g, cmd->data.draw.b);
    const size_t vertslen = count * sizeof (Vertex);
    Vertex *verts = (Vertex *) SDL_AllocateRenderVertices(renderer, vertslen, 0, &cmd->data.draw.first);
    int i;

    if (!verts) {
        return -1;
    }

    SDL_memset(verts, '\0', vertslen);
    cmd->data.draw.count = count;

    for (i = 0; i < count; i++, verts++, points++) {
        verts->x = points->x;
        verts->y = points->y;
        verts->color = color;
    }

    return 0;
}

static int
D3D_QueueGeometry(SDL_Renderer *renderer, SDL_RenderCommand *cmd, SDL_Texture *texture,
        const float *xy, int xy_stride, const SDL_Color *color, int color_stride, const float *uv, int uv_stride,
        int num_vertices, const void *indices, int num_indices, int size_indices,
        float scale_x, float scale_y)
{
    int i;
    int count = indices ? num_indices : num_vertices;
    Vertex *verts = (Vertex *) SDL_AllocateRenderVertices(renderer, count * sizeof (Vertex), 0, &cmd->data.draw.first);

    if (!verts) {
        return -1;
    }

    cmd->data.draw.count = count;
    size_indices = indices ? size_indices : 0;

    for (i = 0; i < count; i++) {
        int j;
        float *xy_;
        SDL_Color col_;
        if (size_indices == 4) {
            j = ((const Uint32 *)indices)[i];
        } else if (size_indices == 2) {
            j = ((const Uint16 *)indices)[i];
        } else if (size_indices == 1) {
            j = ((const Uint8 *)indices)[i];
        } else {
            j = i;
        }

        xy_ = (float *)((char*)xy + j * xy_stride);
        col_ = *(SDL_Color *)((char*)color + j * color_stride);

        verts->x = xy_[0] * scale_x - 0.5f;
        verts->y = xy_[1] * scale_y - 0.5f;
        verts->z = 0.0f;
        verts->color = D3DCOLOR_ARGB(col_.a, col_.r, col_.g, col_.b);

        if (texture) {
            float *uv_ = (float *)((char*)uv + j * uv_stride);
            verts->u = uv_[0];
            verts->v = uv_[1];
        } else {
            verts->u = 0.0f;
            verts->v = 0.0f;
        }

        verts += 1;
    }
    return 0;
}

static int
UpdateDirtyTexture(IDirect3DDevice9 *device, D3D_TextureRep *texture)
{
    if (texture->dirty && texture->staging) {
        HRESULT result;
        if (!texture->texture) {
            result = IDirect3DDevice9_CreateTexture(device, texture->w, texture->h, 1, texture->usage,
                PixelFormatToD3DFMT(texture->format), D3DPOOL_DEFAULT, &texture->texture, NULL);
            if (FAILED(result)) {
                return D3D_SetError("CreateTexture(D3DPOOL_DEFAULT)", result);
            }
        }

        result = IDirect3DDevice9_UpdateTexture(device, (IDirect3DBaseTexture9 *)texture->staging, (IDirect3DBaseTexture9 *)texture->texture);
        if (FAILED(result)) {
            return D3D_SetError("UpdateTexture()", result);
        }
        texture->dirty = SDL_FALSE;
    }
    return 0;
}

static int
BindTextureRep(IDirect3DDevice9 *device, D3D_TextureRep *texture, DWORD sampler)
{
    HRESULT result;
    UpdateDirtyTexture(device, texture);
    result = IDirect3DDevice9_SetTexture(device, sampler, (IDirect3DBaseTexture9 *)texture->texture);
    if (FAILED(result)) {
        return D3D_SetError("SetTexture()", result);
    }
    return 0;
}

static void
UpdateTextureScaleMode(D3D_RenderData *data, D3D_TextureData *texturedata, unsigned index)
{
    if (texturedata->scaleMode != data->scaleMode[index]) {
        IDirect3DDevice9_SetSamplerState(data->device, index, D3DSAMP_MINFILTER,
                                         texturedata->scaleMode);
        IDirect3DDevice9_SetSamplerState(data->device, index, D3DSAMP_MAGFILTER,
                                         texturedata->scaleMode);
        IDirect3DDevice9_SetSamplerState(data->device, index, D3DSAMP_ADDRESSU,
                                         D3DTADDRESS_CLAMP);
        IDirect3DDevice9_SetSamplerState(data->device, index, D3DSAMP_ADDRESSV,
                                         D3DTADDRESS_CLAMP);
        data->scaleMode[index] = texturedata->scaleMode;
    }
}

static int
SetupTextureState(D3D_RenderData *data, SDL_Texture * texture, LPDIRECT3DPIXELSHADER9 *shader)
{
    D3D_TextureData *texturedata = (D3D_TextureData *)texture->driverdata;

    SDL_assert(*shader == NULL);

    if (!texturedata) {
        SDL_SetError("Texture is not currently available");
        return -1;
    }

    UpdateTextureScaleMode(data, texturedata, 0);

    if (BindTextureRep(data->device, &texturedata->texture, 0) < 0) {
        return -1;
    }

    if (texturedata->yuv) {
        switch (SDL_GetYUVConversionModeForResolution(texture->w, texture->h)) {
        case SDL_YUV_CONVERSION_JPEG:
            *shader = data->shaders[SHADER_YUV_JPEG];
            break;
        case SDL_YUV_CONVERSION_BT601:
            *shader = data->shaders[SHADER_YUV_BT601];
            break;
        case SDL_YUV_CONVERSION_BT709:
            *shader = data->shaders[SHADER_YUV_BT709];
            break;
        default:
            return SDL_SetError("Unsupported YUV conversion mode");
        }

        UpdateTextureScaleMode(data, texturedata, 1);
        UpdateTextureScaleMode(data, texturedata, 2);

        if (BindTextureRep(data->device, &texturedata->utexture, 1) < 0) {
            return -1;
        }
        if (BindTextureRep(data->device, &texturedata->vtexture, 2) < 0) {
            return -1;
        }
    }
    return 0;
}

static int
SetDrawState(D3D_RenderData *data, const SDL_RenderCommand *cmd)
{
    SDL_Texture *texture = cmd->data.draw.texture;
    const SDL_BlendMode blend = cmd->data.draw.blend;

    if (texture != data->drawstate.texture) {
        D3D_TextureData *oldtexturedata = data->drawstate.texture ? (D3D_TextureData *) data->drawstate.texture->driverdata : NULL;
        D3D_TextureData *newtexturedata = texture ? (D3D_TextureData *) texture->driverdata : NULL;
        LPDIRECT3DPIXELSHADER9 shader = NULL;

        /* disable any enabled textures we aren't going to use, let SetupTextureState() do the rest. */
        if (texture == NULL) {
            IDirect3DDevice9_SetTexture(data->device, 0, NULL);
        }
        if ((!newtexturedata || !newtexturedata->yuv) && (oldtexturedata && oldtexturedata->yuv)) {
            IDirect3DDevice9_SetTexture(data->device, 1, NULL);
            IDirect3DDevice9_SetTexture(data->device, 2, NULL);
        }
        if (texture && SetupTextureState(data, texture, &shader) < 0) {
            return -1;
        }

        if (shader != data->drawstate.shader) {
            const HRESULT result = IDirect3DDevice9_SetPixelShader(data->device, shader);
            if (FAILED(result)) {
                return D3D_SetError("IDirect3DDevice9_SetPixelShader()", result);
            }
            data->drawstate.shader = shader;
        }

        data->drawstate.texture = texture;
    } else if (texture) {
        D3D_TextureData *texturedata = (D3D_TextureData *) texture->driverdata;
        UpdateDirtyTexture(data->device, &texturedata->texture);
        if (texturedata->yuv) {
            UpdateDirtyTexture(data->device, &texturedata->utexture);
            UpdateDirtyTexture(data->device, &texturedata->vtexture);
        }
    }

    if (blend != data->drawstate.blend) {
        if (blend == SDL_BLENDMODE_NONE) {
            IDirect3DDevice9_SetRenderState(data->device, D3DRS_ALPHABLENDENABLE, FALSE);
        } else {
            IDirect3DDevice9_SetRenderState(data->device, D3DRS_ALPHABLENDENABLE, TRUE);
            IDirect3DDevice9_SetRenderState(data->device, D3DRS_SRCBLEND,
                                            GetBlendFunc(SDL_GetBlendModeSrcColorFactor(blend)));
            IDirect3DDevice9_SetRenderState(data->device, D3DRS_DESTBLEND,
                                            GetBlendFunc(SDL_GetBlendModeDstColorFactor(blend)));
            if (data->enableSeparateAlphaBlend) {
                IDirect3DDevice9_SetRenderState(data->device, D3DRS_SRCBLENDALPHA,
                                                GetBlendFunc(SDL_GetBlendModeSrcAlphaFactor(blend)));
                IDirect3DDevice9_SetRenderState(data->device, D3DRS_DESTBLENDALPHA,
                                                GetBlendFunc(SDL_GetBlendModeDstAlphaFactor(blend)));
            }
        }

        data->drawstate.blend = blend;
    }

    if (data->drawstate.viewport_dirty) {
        const SDL_Rect *viewport = &data->drawstate.viewport;
        const D3DVIEWPORT9 d3dviewport = { viewport->x, viewport->y, viewport->w, viewport->h, 0.0f, 1.0f };
        IDirect3DDevice9_SetViewport(data->device, &d3dviewport);

        /* Set an orthographic projection matrix */
        if (viewport->w && viewport->h) {
            D3DMATRIX d3dmatrix;
            SDL_zero(d3dmatrix);
            d3dmatrix.m[0][0] = 2.0f / viewport->w;
            d3dmatrix.m[1][1] = -2.0f / viewport->h;
            d3dmatrix.m[2][2] = 1.0f;
            d3dmatrix.m[3][0] = -1.0f;
            d3dmatrix.m[3][1] = 1.0f;
            d3dmatrix.m[3][3] = 1.0f;
            IDirect3DDevice9_SetTransform(data->device, D3DTS_PROJECTION, &d3dmatrix);
        }

        data->drawstate.viewport_dirty = SDL_FALSE;
    }

    if (data->drawstate.cliprect_enabled_dirty) {
        IDirect3DDevice9_SetRenderState(data->device, D3DRS_SCISSORTESTENABLE, data->drawstate.cliprect_enabled ? TRUE : FALSE);
        data->drawstate.cliprect_enabled_dirty = SDL_FALSE;
    }

    if (data->drawstate.cliprect_dirty) {
        const SDL_Rect *viewport = &data->drawstate.viewport;
        const SDL_Rect *rect = &data->drawstate.cliprect;
        const RECT d3drect = { viewport->x + rect->x, viewport->y + rect->y, viewport->x + rect->x + rect->w, viewport->y + rect->y + rect->h };
        IDirect3DDevice9_SetScissorRect(data->device, &d3drect);
        data->drawstate.cliprect_dirty = SDL_FALSE;
    }

    return 0;
}

static int
D3D_RunCommandQueue(SDL_Renderer * renderer, SDL_RenderCommand *cmd, void *vertices, size_t vertsize)
{
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;
    const int vboidx = data->currentVertexBuffer;
    IDirect3DVertexBuffer9 *vbo = NULL;
    const SDL_bool istarget = renderer->target != NULL;

    if (D3D_ActivateRenderer(renderer) < 0) {
        return -1;
    }

    if (vertices) {
        /* upload the new VBO data for this set of commands. */
        vbo = data->vertexBuffers[vboidx];
        if (data->vertexBufferSize[vboidx] < vertsize) {
            const DWORD usage = D3DUSAGE_DYNAMIC | D3DUSAGE_WRITEONLY;
            const DWORD fvf = D3DFVF_XYZ | D3DFVF_DIFFUSE | D3DFVF_TEX1;
            if (vbo) {
                IDirect3DVertexBuffer9_Release(vbo);
            }

            if (FAILED(IDirect3DDevice9_CreateVertexBuffer(data->device, (UINT) vertsize, usage, fvf, D3DPOOL_DEFAULT, &vbo, NULL))) {
                vbo = NULL;
            }
            data->vertexBuffers[vboidx] = vbo;
            data->vertexBufferSize[vboidx] = vbo ? vertsize : 0;
        }

        if (vbo) {
            void *ptr;
            if (FAILED(IDirect3DVertexBuffer9_Lock(vbo, 0, (UINT) vertsize, &ptr, D3DLOCK_DISCARD))) {
                vbo = NULL;  /* oh well, we'll do immediate mode drawing.  :(  */
            } else {
                SDL_memcpy(ptr, vertices, vertsize);
                if (FAILED(IDirect3DVertexBuffer9_Unlock(vbo))) {
                    vbo = NULL;  /* oh well, we'll do immediate mode drawing.  :(  */
                }
            }
        }

        /* cycle through a few VBOs so D3D has some time with the data before we replace it. */
        if (vbo) {
            data->currentVertexBuffer++;
            if (data->currentVertexBuffer >= SDL_arraysize(data->vertexBuffers)) {
                data->currentVertexBuffer = 0;
            }
        } else if (!data->reportedVboProblem) {
            SDL_LogError(SDL_LOG_CATEGORY_RENDER, "SDL failed to get a vertex buffer for this Direct3D 9 rendering batch!");
            SDL_LogError(SDL_LOG_CATEGORY_RENDER, "Dropping back to a slower method.");
            SDL_LogError(SDL_LOG_CATEGORY_RENDER, "This might be a brief hiccup, but if performance is bad, this is probably why.");
            SDL_LogError(SDL_LOG_CATEGORY_RENDER, "This error will not be logged again for this renderer.");
            data->reportedVboProblem = SDL_TRUE;
        }
    }

    IDirect3DDevice9_SetStreamSource(data->device, 0, vbo, 0, sizeof (Vertex));

    while (cmd) {
        switch (cmd->command) {
            case SDL_RENDERCMD_SETDRAWCOLOR: {
                /* currently this is sent with each vertex, but if we move to
                   shaders, we can put this in a uniform here and reduce vertex
                   buffer bandwidth */
                break;
            }

            case SDL_RENDERCMD_SETVIEWPORT: {
                SDL_Rect *viewport = &data->drawstate.viewport;
                if (SDL_memcmp(viewport, &cmd->data.viewport.rect, sizeof (SDL_Rect)) != 0) {
                    SDL_memcpy(viewport, &cmd->data.viewport.rect, sizeof (SDL_Rect));
                    data->drawstate.viewport_dirty = SDL_TRUE;
                }
                break;
            }

            case SDL_RENDERCMD_SETCLIPRECT: {
                const SDL_Rect *rect = &cmd->data.cliprect.rect;
                if (data->drawstate.cliprect_enabled != cmd->data.cliprect.enabled) {
                    data->drawstate.cliprect_enabled = cmd->data.cliprect.enabled;
                    data->drawstate.cliprect_enabled_dirty = SDL_TRUE;
                }

                if (SDL_memcmp(&data->drawstate.cliprect, rect, sizeof (SDL_Rect)) != 0) {
                    SDL_memcpy(&data->drawstate.cliprect, rect, sizeof (SDL_Rect));
                    data->drawstate.cliprect_dirty = SDL_TRUE;
                }
                break;
            }

            case SDL_RENDERCMD_CLEAR: {
                const DWORD color = D3DCOLOR_ARGB(cmd->data.color.a, cmd->data.color.r, cmd->data.color.g, cmd->data.color.b);
                const SDL_Rect *viewport = &data->drawstate.viewport;
                const int backw = istarget ? renderer->target->w : data->pparams.BackBufferWidth;
                const int backh = istarget ? renderer->target->h : data->pparams.BackBufferHeight;
                const SDL_bool viewport_equal = ((viewport->x == 0) && (viewport->y == 0) && (viewport->w == backw) && (viewport->h == backh)) ? SDL_TRUE : SDL_FALSE;

                if (data->drawstate.cliprect_enabled || data->drawstate.cliprect_enabled_dirty) {
                    IDirect3DDevice9_SetRenderState(data->device, D3DRS_SCISSORTESTENABLE, FALSE);
                    data->drawstate.cliprect_enabled_dirty = data->drawstate.cliprect_enabled;
                }

                /* Don't reset the viewport if we don't have to! */
                if (!data->drawstate.viewport_dirty && viewport_equal) {
                    IDirect3DDevice9_Clear(data->device, 0, NULL, D3DCLEAR_TARGET, color, 0.0f, 0);
                } else {
                    /* Clear is defined to clear the entire render target */
                    const D3DVIEWPORT9 wholeviewport = { 0, 0, backw, backh, 0.0f, 1.0f };
                    IDirect3DDevice9_SetViewport(data->device, &wholeviewport);
                    data->drawstate.viewport_dirty = SDL_TRUE;  /* we still need to (re)set orthographic projection, so always mark it dirty. */
                    IDirect3DDevice9_Clear(data->device, 0, NULL, D3DCLEAR_TARGET, color, 0.0f, 0);
                }

                break;
            }

            case SDL_RENDERCMD_DRAW_POINTS: {
                const size_t count = cmd->data.draw.count;
                const size_t first = cmd->data.draw.first;
                SetDrawState(data, cmd);
                if (vbo) {
                    IDirect3DDevice9_DrawPrimitive(data->device, D3DPT_POINTLIST, (UINT) (first / sizeof (Vertex)), (UINT) count);
                } else {
                    const Vertex *verts = (Vertex *) (((Uint8 *) vertices) + first);
                    IDirect3DDevice9_DrawPrimitiveUP(data->device, D3DPT_POINTLIST, (UINT) count, verts, sizeof (Vertex));
                }
                break;
            }

            case SDL_RENDERCMD_DRAW_LINES: {
                const size_t count = cmd->data.draw.count;
                const size_t first = cmd->data.draw.first;
                const Vertex *verts = (Vertex *) (((Uint8 *) vertices) + first);

                /* DirectX 9 has the same line rasterization semantics as GDI,
                   so we need to close the endpoint of the line with a second draw call. */
                const SDL_bool close_endpoint = ((count == 2) || (verts[0].x != verts[count-1].x) || (verts[0].y != verts[count-1].y));

                SetDrawState(data, cmd);

                if (vbo) {
                    IDirect3DDevice9_DrawPrimitive(data->device, D3DPT_LINESTRIP, (UINT) (first / sizeof (Vertex)), (UINT) (count - 1));
                    if (close_endpoint) {
                        IDirect3DDevice9_DrawPrimitive(data->device, D3DPT_POINTLIST, (UINT) ((first / sizeof (Vertex)) + (count - 1)), 1);
                    }
                } else {
                    IDirect3DDevice9_DrawPrimitiveUP(data->device, D3DPT_LINESTRIP, (UINT) (count - 1), verts, sizeof (Vertex));
                    if (close_endpoint) {
                        IDirect3DDevice9_DrawPrimitiveUP(data->device, D3DPT_POINTLIST, 1, &verts[count-1], sizeof (Vertex));
                    }
                }
                break;
            }

            case SDL_RENDERCMD_FILL_RECTS: /* unused */
                break;

            case SDL_RENDERCMD_COPY: /* unused */
                break;

            case SDL_RENDERCMD_COPY_EX: /* unused */
                break;

            case SDL_RENDERCMD_GEOMETRY: {
                const size_t count = cmd->data.draw.count;
                const size_t first = cmd->data.draw.first;
                SetDrawState(data, cmd);
                if (vbo) {
                    IDirect3DDevice9_DrawPrimitive(data->device, D3DPT_TRIANGLELIST, (UINT) (first / sizeof (Vertex)), (UINT) count / 3);
                } else {
                    const Vertex* verts = (Vertex*)(((Uint8*)vertices) + first);
                    IDirect3DDevice9_DrawPrimitiveUP(data->device, D3DPT_TRIANGLELIST, (UINT) count / 3, verts, sizeof(Vertex));
                }
                break;
            }

            case SDL_RENDERCMD_NO_OP:
                break;
        }

        cmd = cmd->next;
    }

    return 0;
}


static int
D3D_RenderReadPixels(SDL_Renderer * renderer, const SDL_Rect * rect,
                     Uint32 format, void * pixels, int pitch)
{
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;
    D3DSURFACE_DESC desc;
    LPDIRECT3DSURFACE9 backBuffer;
    LPDIRECT3DSURFACE9 surface;
    RECT d3drect;
    D3DLOCKED_RECT locked;
    HRESULT result;

    if (data->currentRenderTarget) {
        backBuffer = data->currentRenderTarget;
    } else {
        backBuffer = data->defaultRenderTarget;
    }

    result = IDirect3DSurface9_GetDesc(backBuffer, &desc);
    if (FAILED(result)) {
        return D3D_SetError("GetDesc()", result);
    }

    result = IDirect3DDevice9_CreateOffscreenPlainSurface(data->device, desc.Width, desc.Height, desc.Format, D3DPOOL_SYSTEMMEM, &surface, NULL);
    if (FAILED(result)) {
        return D3D_SetError("CreateOffscreenPlainSurface()", result);
    }

    result = IDirect3DDevice9_GetRenderTargetData(data->device, backBuffer, surface);
    if (FAILED(result)) {
        IDirect3DSurface9_Release(surface);
        return D3D_SetError("GetRenderTargetData()", result);
    }

    d3drect.left = rect->x;
    d3drect.right = rect->x + rect->w;
    d3drect.top = rect->y;
    d3drect.bottom = rect->y + rect->h;

    result = IDirect3DSurface9_LockRect(surface, &locked, &d3drect, D3DLOCK_READONLY);
    if (FAILED(result)) {
        IDirect3DSurface9_Release(surface);
        return D3D_SetError("LockRect()", result);
    }

    SDL_ConvertPixels(rect->w, rect->h,
                      D3DFMTToPixelFormat(desc.Format), locked.pBits, locked.Pitch,
                      format, pixels, pitch);

    IDirect3DSurface9_UnlockRect(surface);

    IDirect3DSurface9_Release(surface);

    return 0;
}

static void
D3D_RenderPresent(SDL_Renderer * renderer)
{
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;
    HRESULT result;

    if (!data->beginScene) {
        IDirect3DDevice9_EndScene(data->device);
        data->beginScene = SDL_TRUE;
    }

    result = IDirect3DDevice9_TestCooperativeLevel(data->device);
    if (result == D3DERR_DEVICELOST) {
        /* We'll reset later */
        return;
    }
    if (result == D3DERR_DEVICENOTRESET) {
        D3D_Reset(renderer);
    }
    result = IDirect3DDevice9_Present(data->device, NULL, NULL, NULL, NULL);
    if (FAILED(result)) {
        D3D_SetError("Present()", result);
    }
}

static void
D3D_DestroyTexture(SDL_Renderer * renderer, SDL_Texture * texture)
{
    D3D_RenderData *renderdata = (D3D_RenderData *) renderer->driverdata;
    D3D_TextureData *data = (D3D_TextureData *) texture->driverdata;

    if (renderdata->drawstate.texture == texture) {
        renderdata->drawstate.texture = NULL;
        renderdata->drawstate.shader = NULL;
        IDirect3DDevice9_SetPixelShader(renderdata->device, NULL);
        IDirect3DDevice9_SetTexture(renderdata->device, 0, NULL);
        if (data->yuv) {
            IDirect3DDevice9_SetTexture(renderdata->device, 1, NULL);
            IDirect3DDevice9_SetTexture(renderdata->device, 2, NULL);
        }
    }

    if (!data) {
        return;
    }

    D3D_DestroyTextureRep(&data->texture);
    D3D_DestroyTextureRep(&data->utexture);
    D3D_DestroyTextureRep(&data->vtexture);
    SDL_free(data->pixels);
    SDL_free(data);
    texture->driverdata = NULL;
}

static void
D3D_DestroyRenderer(SDL_Renderer * renderer)
{
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;

    if (data) {
        int i;

        /* Release the render target */
        if (data->defaultRenderTarget) {
            IDirect3DSurface9_Release(data->defaultRenderTarget);
            data->defaultRenderTarget = NULL;
        }
        if (data->currentRenderTarget != NULL) {
            IDirect3DSurface9_Release(data->currentRenderTarget);
            data->currentRenderTarget = NULL;
        }
        for (i = 0; i < SDL_arraysize(data->shaders); ++i) {
            if (data->shaders[i]) {
                IDirect3DPixelShader9_Release(data->shaders[i]);
                data->shaders[i] = NULL;
            }
        }
        /* Release all vertex buffers */
        for (i = 0; i < SDL_arraysize(data->vertexBuffers); ++i) {
            if (data->vertexBuffers[i]) {
                IDirect3DVertexBuffer9_Release(data->vertexBuffers[i]);
            }
            data->vertexBuffers[i] = NULL;
        }
        if (data->device) {
            IDirect3DDevice9_Release(data->device);
            data->device = NULL;
        }
        if (data->d3d) {
            IDirect3D9_Release(data->d3d);
            SDL_UnloadObject(data->d3dDLL);
        }
        SDL_free(data);
    }
    SDL_free(renderer);
}

static int
D3D_Reset(SDL_Renderer * renderer)
{
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;
    const Float4X4 d3dmatrix = MatrixIdentity();
    HRESULT result;
    SDL_Texture *texture;
    int i;

    /* Cancel any scene that we've started */
    if (!data->beginScene) {
        IDirect3DDevice9_EndScene(data->device);
        data->beginScene = SDL_TRUE;
    }

    /* Release the default render target before reset */
    if (data->defaultRenderTarget) {
        IDirect3DSurface9_Release(data->defaultRenderTarget);
        data->defaultRenderTarget = NULL;
    }
    if (data->currentRenderTarget != NULL) {
        IDirect3DSurface9_Release(data->currentRenderTarget);
        data->currentRenderTarget = NULL;
    }

    /* Release application render targets */
    for (texture = renderer->textures; texture; texture = texture->next) {
        if (texture->access == SDL_TEXTUREACCESS_TARGET) {
            D3D_DestroyTexture(renderer, texture);
        } else {
            D3D_RecreateTexture(renderer, texture);
        }
    }

    /* Release all vertex buffers */
    for (i = 0; i < SDL_arraysize(data->vertexBuffers); ++i) {
        if (data->vertexBuffers[i]) {
            IDirect3DVertexBuffer9_Release(data->vertexBuffers[i]);
        }
        data->vertexBuffers[i] = NULL;
        data->vertexBufferSize[i] = 0;
    }

    result = IDirect3DDevice9_Reset(data->device, &data->pparams);
    if (FAILED(result)) {
        if (result == D3DERR_DEVICELOST) {
            /* Don't worry about it, we'll reset later... */
            return 0;
        } else {
            return D3D_SetError("Reset()", result);
        }
    }

    /* Allocate application render targets */
    for (texture = renderer->textures; texture; texture = texture->next) {
        if (texture->access == SDL_TEXTUREACCESS_TARGET) {
            D3D_CreateTexture(renderer, texture);
        }
    }

    IDirect3DDevice9_GetRenderTarget(data->device, 0, &data->defaultRenderTarget);
    D3D_InitRenderState(data);
    D3D_SetRenderTargetInternal(renderer, renderer->target);
    data->drawstate.viewport_dirty = SDL_TRUE;
    data->drawstate.cliprect_dirty = SDL_TRUE;
    data->drawstate.cliprect_enabled_dirty = SDL_TRUE;
    data->drawstate.texture = NULL;
    data->drawstate.shader = NULL;
    data->drawstate.blend = SDL_BLENDMODE_INVALID;
    IDirect3DDevice9_SetTransform(data->device, D3DTS_VIEW, (D3DMATRIX*)&d3dmatrix);

    /* Let the application know that render targets were reset */
    {
        SDL_Event event;
        event.type = SDL_RENDER_TARGETS_RESET;
        SDL_PushEvent(&event);
    }

    return 0;
}

static int
D3D_SetVSync(SDL_Renderer * renderer, const int vsync)
{
    D3D_RenderData *data = renderer->driverdata;
    if (vsync) {
        data->pparams.PresentationInterval = D3DPRESENT_INTERVAL_ONE;
        renderer->info.flags |= SDL_RENDERER_PRESENTVSYNC;
    } else {
        data->pparams.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;
        renderer->info.flags &= ~SDL_RENDERER_PRESENTVSYNC;
    }
    if (D3D_Reset(renderer) < 0) {
        /* D3D_Reset will call SDL_SetError() */
        return -1;
    }
    return 0;
}

SDL_Renderer *
D3D_CreateRenderer(SDL_Window * window, Uint32 flags)
{
    SDL_Renderer *renderer;
    D3D_RenderData *data;
    SDL_SysWMinfo windowinfo;
    HRESULT result;
    D3DPRESENT_PARAMETERS pparams;
    IDirect3DSwapChain9 *chain;
    D3DCAPS9 caps;
    DWORD device_flags;
    Uint32 window_flags;
    int w, h;
    SDL_DisplayMode fullscreen_mode;
    int displayIndex;

    renderer = (SDL_Renderer *) SDL_calloc(1, sizeof(*renderer));
    if (!renderer) {
        SDL_OutOfMemory();
        return NULL;
    }

    data = (D3D_RenderData *) SDL_calloc(1, sizeof(*data));
    if (!data) {
        SDL_free(renderer);
        SDL_OutOfMemory();
        return NULL;
    }

    if (!D3D_LoadDLL(&data->d3dDLL, &data->d3d)) {
        SDL_free(renderer);
        SDL_free(data);
        SDL_SetError("Unable to create Direct3D interface");
        return NULL;
    }

    renderer->WindowEvent = D3D_WindowEvent;
    renderer->SupportsBlendMode = D3D_SupportsBlendMode;
    renderer->CreateTexture = D3D_CreateTexture;
    renderer->UpdateTexture = D3D_UpdateTexture;
#if SDL_HAVE_YUV
    renderer->UpdateTextureYUV = D3D_UpdateTextureYUV;
#endif
    renderer->LockTexture = D3D_LockTexture;
    renderer->UnlockTexture = D3D_UnlockTexture;
    renderer->SetTextureScaleMode = D3D_SetTextureScaleMode;
    renderer->SetRenderTarget = D3D_SetRenderTarget;
    renderer->QueueSetViewport = D3D_QueueSetViewport;
    renderer->QueueSetDrawColor = D3D_QueueSetViewport;  /* SetViewport and SetDrawColor are (currently) no-ops. */
    renderer->QueueDrawPoints = D3D_QueueDrawPoints;
    renderer->QueueDrawLines = D3D_QueueDrawPoints;  /* lines and points queue vertices the same way. */
    renderer->QueueGeometry = D3D_QueueGeometry;
    renderer->RunCommandQueue = D3D_RunCommandQueue;
    renderer->RenderReadPixels = D3D_RenderReadPixels;
    renderer->RenderPresent = D3D_RenderPresent;
    renderer->DestroyTexture = D3D_DestroyTexture;
    renderer->DestroyRenderer = D3D_DestroyRenderer;
    renderer->SetVSync = D3D_SetVSync;
    renderer->info = D3D_RenderDriver.info;
    renderer->info.flags = (SDL_RENDERER_ACCELERATED | SDL_RENDERER_TARGETTEXTURE);
    renderer->driverdata = data;

    SDL_VERSION(&windowinfo.version);
    SDL_GetWindowWMInfo(window, &windowinfo);

    window_flags = SDL_GetWindowFlags(window);
    SDL_GetWindowSize(window, &w, &h);
    SDL_GetWindowDisplayMode(window, &fullscreen_mode);

    SDL_zero(pparams);
    pparams.hDeviceWindow = windowinfo.info.win.window;
    pparams.BackBufferWidth = w;
    pparams.BackBufferHeight = h;
    pparams.BackBufferCount = 1;
    pparams.SwapEffect = D3DSWAPEFFECT_DISCARD;

    if (window_flags & SDL_WINDOW_FULLSCREEN && (window_flags & SDL_WINDOW_FULLSCREEN_DESKTOP) != SDL_WINDOW_FULLSCREEN_DESKTOP) {
        pparams.Windowed = FALSE;
        pparams.BackBufferFormat = PixelFormatToD3DFMT(fullscreen_mode.format);
        pparams.FullScreen_RefreshRateInHz = fullscreen_mode.refresh_rate;
    } else {
        pparams.Windowed = TRUE;
        pparams.BackBufferFormat = D3DFMT_UNKNOWN;
        pparams.FullScreen_RefreshRateInHz = 0;
    }
    if (flags & SDL_RENDERER_PRESENTVSYNC) {
        pparams.PresentationInterval = D3DPRESENT_INTERVAL_ONE;
    } else {
        pparams.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;
    }

    /* Get the adapter for the display that the window is on */
    displayIndex = SDL_GetWindowDisplayIndex(window);
    data->adapter = SDL_Direct3D9GetAdapterIndex(displayIndex);

    IDirect3D9_GetDeviceCaps(data->d3d, data->adapter, D3DDEVTYPE_HAL, &caps);

    device_flags = D3DCREATE_FPU_PRESERVE;
    if (caps.DevCaps & D3DDEVCAPS_HWTRANSFORMANDLIGHT) {
        device_flags |= D3DCREATE_HARDWARE_VERTEXPROCESSING;
    } else {
        device_flags |= D3DCREATE_SOFTWARE_VERTEXPROCESSING;
    }

    if (SDL_GetHintBoolean(SDL_HINT_RENDER_DIRECT3D_THREADSAFE, SDL_FALSE)) {
        device_flags |= D3DCREATE_MULTITHREADED;
    }

    result = IDirect3D9_CreateDevice(data->d3d, data->adapter,
                                     D3DDEVTYPE_HAL,
                                     pparams.hDeviceWindow,
                                     device_flags,
                                     &pparams, &data->device);
    if (FAILED(result)) {
        D3D_DestroyRenderer(renderer);
        D3D_SetError("CreateDevice()", result);
        return NULL;
    }

    /* Get presentation parameters to fill info */
    result = IDirect3DDevice9_GetSwapChain(data->device, 0, &chain);
    if (FAILED(result)) {
        D3D_DestroyRenderer(renderer);
        D3D_SetError("GetSwapChain()", result);
        return NULL;
    }
    result = IDirect3DSwapChain9_GetPresentParameters(chain, &pparams);
    if (FAILED(result)) {
        IDirect3DSwapChain9_Release(chain);
        D3D_DestroyRenderer(renderer);
        D3D_SetError("GetPresentParameters()", result);
        return NULL;
    }
    IDirect3DSwapChain9_Release(chain);
    if (pparams.PresentationInterval == D3DPRESENT_INTERVAL_ONE) {
        renderer->info.flags |= SDL_RENDERER_PRESENTVSYNC;
    }
    data->pparams = pparams;

    IDirect3DDevice9_GetDeviceCaps(data->device, &caps);
    renderer->info.max_texture_width = caps.MaxTextureWidth;
    renderer->info.max_texture_height = caps.MaxTextureHeight;

    if (caps.PrimitiveMiscCaps & D3DPMISCCAPS_SEPARATEALPHABLEND) {
        data->enableSeparateAlphaBlend = SDL_TRUE;
    }

    /* Store the default render target */
    IDirect3DDevice9_GetRenderTarget(data->device, 0, &data->defaultRenderTarget);
    data->currentRenderTarget = NULL;

    /* Set up parameters for rendering */
    D3D_InitRenderState(data);

    if (caps.MaxSimultaneousTextures >= 3) {
        int i;
        for (i = 0; i < SDL_arraysize(data->shaders); ++i) {
            result = D3D9_CreatePixelShader(data->device, (D3D9_Shader)i, &data->shaders[i]);
            if (FAILED(result)) {
                D3D_SetError("CreatePixelShader()", result);
            }
        }
        if (data->shaders[SHADER_YUV_JPEG] && data->shaders[SHADER_YUV_BT601] && data->shaders[SHADER_YUV_BT709]) {
            renderer->info.texture_formats[renderer->info.num_texture_formats++] = SDL_PIXELFORMAT_YV12;
            renderer->info.texture_formats[renderer->info.num_texture_formats++] = SDL_PIXELFORMAT_IYUV;
        }
    }

    data->drawstate.blend = SDL_BLENDMODE_INVALID;

    return renderer;
}

SDL_RenderDriver D3D_RenderDriver = {
    D3D_CreateRenderer,
    {
     "direct3d",
     (SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_TARGETTEXTURE),
     1,
     {SDL_PIXELFORMAT_ARGB8888},
     0,
     0}
};
#endif /* SDL_VIDEO_RENDER_D3D && !SDL_RENDER_DISABLED */

#ifdef __WIN32__
/* This function needs to always exist on Windows, for the Dynamic API. */
IDirect3DDevice9 *
SDL_RenderGetD3D9Device(SDL_Renderer * renderer)
{
    IDirect3DDevice9 *device = NULL;

#if SDL_VIDEO_RENDER_D3D && !SDL_RENDER_DISABLED
    D3D_RenderData *data = (D3D_RenderData *) renderer->driverdata;

    /* Make sure that this is a D3D renderer */
    if (renderer->DestroyRenderer != D3D_DestroyRenderer) {
        SDL_SetError("Renderer is not a D3D renderer");
        return NULL;
    }

    device = data->device;
    if (device) {
        IDirect3DDevice9_AddRef(device);
    }
#endif /* SDL_VIDEO_RENDER_D3D && !SDL_RENDER_DISABLED */

    return device;
}
#endif /* __WIN32__ */

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