我很困惑为什么我得到128字节的扫描行/ rowpitch而不是我指定的8字节。有问题的BMP是4像素，左上角是红色，右上角是绿色，左下是蓝色，右下是黄色。
代码如下：
ID3D11Resource *g_pOverlay_Staging = nullptr;
IWICImagingFactory* WICFactory = nullptr;
IWICBitmapDecoder * WICBitmapDecoder = nullptr;
IWICBitmapFrameDecode * WICBitmapFrame = nullptr;
WICPixelFormatGUID pixelFormat;
HR(CoCreateInstance(CLSID_WICImagingFactory, nullptr, CLSCTX_INPROC_SERVER, __uuidof(IWICImagingFactory), (LPVOID*)&WICFactory));
HR(WICFactory->CreateDecoderFromFilename(L"province_map.bmp", nullptr, GENERIC_READ, WICDecodeMetadataCacheOnDemand, &WICBitmapDecoder));
HR(WICBitmapDecoder->GetFrame(0,&WICBitmapFrame));
HR(WICBitmapFrame->GetPixelFormat(&pixelFormat));
DXGI_FORMAT format;
if (pixelFormat == GUID_WICPixelFormat24bppBGR){
std::wostringstream outs2;
outs2 << "pixelformat = GUID_WICPixelFormat24bppBGR" << std::endl;
OutputDebugString(outs2.str().c_str());
format = DXGI_FORMAT_R8G8B8A8_UNORM;
}
IWICFormatConverter * FC = nullptr;
WICFactory->CreateFormatConverter(&FC);
HR(FC->Initialize(WICBitmapFrame, GUID_WICPixelFormat32bppRGBA, WICBitmapDitherTypeErrorDiffusion, 0, 0, WICBitmapPaletteTypeCustom));
std::unique_ptr<uint8_t[]> temp(new uint8_t[16]);
HR(FC->CopyPixels(0, 8, 16, temp.get()));
D3D11_TEXTURE2D_DESC desc;
desc.Width = 2;
desc.Height = 2;
desc.MipLevels = 1;
desc.ArraySize = 1;
desc.Format = format;
desc.SampleDesc.Count = 1;
desc.SampleDesc.Quality = 0;
desc.Usage = D3D11_USAGE_STAGING;
desc.BindFlags = 0;
desc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE | D3D11_CPU_ACCESS_READ;
desc.MiscFlags = 0;
D3D11_SUBRESOURCE_DATA initData;
initData.pSysMem = temp.get();
initData.SysMemPitch = 8;
initData.SysMemSlicePitch = 16;
ID3D11Texture2D* tex = nullptr;
HR(d3d11DeviceInterface->CreateTexture2D(&desc, &initData, &tex));
g_pOverlay_Staging = tex;
D3D11_MAPPED_SUBRESOURCE mapped_subresource;
HR(d3d11DeviceContextInterface->Map(g_pOverlay_Staging, 0, D3D11_MAP_READ_WRITE, 0, &mapped_subresource));
uint8_t * v = reinterpret_cast<uint8_t*>(mapped_subresource.pData);
unsigned int x = 0;
while (x < 256 ) {
std::bitset<8> one(v[x]);
std::bitset<8> two(v[x+1]);
std::bitset<8> three(v[x+2]);
std::bitset<8> four(v[x + 3]);
std::wostringstream outs1;
outs1 << "x[" << x << "] = " << one << " x[" << x + 1 << "] = " << two << " x[" << x + 2 << "] = " << three << " x[" << x + 3 << "] = " << four << std::endl;
OutputDebugString(outs1.str().c_str());
x += 4;
}
输出是：
pixelformat = GUID_WICPixelFormat24bppBGR
x[0] = 11111111 x[1] = 00000000 x[2] = 00000000 x[3] = 11111111
x[4] = 00000000 x[5] = 11111111 x[6] = 00000000 x[7] = 11111111
x[8] = 00000000 x[9] = 00000000 x[10] = 00000000 x[11] = 00000000
x[12] = 00000000 x[13] = 00000000 x[14] = 00000000 x[15] = 00000000
x[16] = 00000000 x[17] = 00000000 x[18] = 00000000 x[19] = 00000000
x[20] = 00000000 x[21] = 00000000 x[22] = 00000000 x[23] = 00000000
x[24] = 00000000 x[25] = 00000000 x[26] = 00000000 x[27] = 00000000
x[28] = 00000000 x[29] = 00000000 x[30] = 00000000 x[31] = 00000000
x[32] = 00000000 x[33] = 00000000 x[34] = 00000000 x[35] = 00000000
x[36] = 00000000 x[37] = 00000000 x[38] = 00000000 x[39] = 00000000
x[40] = 00000000 x[41] = 00000000 x[42] = 00000000 x[43] = 00000000
x[44] = 00000000 x[45] = 00000000 x[46] = 00000000 x[47] = 00000000
x[48] = 00000000 x[49] = 00000000 x[50] = 00000000 x[51] = 00000000
x[52] = 00000000 x[53] = 00000000 x[54] = 00000000 x[55] = 00000000
x[56] = 00000000 x[57] = 00000000 x[58] = 00000000 x[59] = 00000000
x[60] = 00000000 x[61] = 00000000 x[62] = 00000000 x[63] = 00000000
x[64] = 00000000 x[65] = 00000000 x[66] = 00000000 x[67] = 00000000
x[68] = 00000000 x[69] = 00000000 x[70] = 00000000 x[71] = 00000000
x[72] = 00000000 x[73] = 00000000 x[74] = 00000000 x[75] = 00000000
x[76] = 00000000 x[77] = 00000000 x[78] = 00000000 x[79] = 00000000
x[80] = 00000000 x[81] = 00000000 x[82] = 00000000 x[83] = 00000000
x[84] = 00000000 x[85] = 00000000 x[86] = 00000000 x[87] = 00000000
x[88] = 00000000 x[89] = 00000000 x[90] = 00000000 x[91] = 00000000
x[92] = 00000000 x[93] = 00000000 x[94] = 00000000 x[95] = 00000000
x[96] = 00000000 x[97] = 00000000 x[98] = 00000000 x[99] = 00000000
x[100] = 00000000 x[101] = 00000000 x[102] = 00000000 x[103] = 00000000
x[104] = 00000000 x[105] = 00000000 x[106] = 00000000 x[107] = 00000000
x[108] = 00000000 x[109] = 00000000 x[110] = 00000000 x[111] = 00000000
x[112] = 00000000 x[113] = 00000000 x[114] = 00000000 x[115] = 00000000
x[116] = 00000000 x[117] = 00000000 x[118] = 00000000 x[119] = 00000000
x[120] = 00000000 x[121] = 00000000 x[122] = 00000000 x[123] = 00000000
x[124] = 00000000 x[125] = 00000000 x[126] = 00000000 x[127] = 00000000
x[128] = 00000000 x[129] = 00000000 x[130] = 11111111 x[131] = 11111111
x[132] = 11111111 x[133] = 11111111 x[134] = 00000000 x[135] = 11111111
x[136] = 00000000 x[137] = 00000000 x[138] = 00000000 x[139] = 00000000
x[140] = 00000000 x[141] = 00000000 x[142] = 00000000 x[143] = 00000000
x[144] = 00000000 x[145] = 00000000 x[146] = 00000000 x[147] = 00000000
x[148] = 00000000 x[149] = 00000000 x[150] = 00000000 x[151] = 00000000
x[152] = 00000000 x[153] = 00000000 x[154] = 00000000 x[155] = 00000000
x[156] = 00000000 x[157] = 00000000 x[158] = 00000000 x[159] = 00000000
x[160] = 00000000 x[161] = 00000000 x[162] = 00000000 x[163] = 00000000
x[164] = 00000000 x[165] = 00000000 x[166] = 00000000 x[167] = 00000000
x[168] = 00000000 x[169] = 00000000 x[170] = 00000000 x[171] = 00000000
x[172] = 00000000 x[173] = 00000000 x[174] = 00000000 x[175] = 00000000
x[176] = 00000000 x[177] = 00000000 x[178] = 00000000 x[179] = 00000000
x[180] = 00000000 x[181] = 00000000 x[182] = 00000000 x[183] = 00000000
x[184] = 00000000 x[185] = 00000000 x[186] = 00000000 x[187] = 00000000
x[188] = 00000000 x[189] = 00000000 x[190] = 00000000 x[191] = 00000000
x[192] = 00000000 x[193] = 00000000 x[194] = 00000000 x[195] = 00000000
x[196] = 00000000 x[197] = 00000000 x[198] = 00000000 x[199] = 00000000
x[200] = 00000000 x[201] = 00000000 x[202] = 00000000 x[203] = 00000000
x[204] = 00000000 x[205] = 00000000 x[206] = 00000000 x[207] = 00000000
x[208] = 00000000 x[209] = 00000000 x[210] = 00000000 x[211] = 00000000
x[212] = 00000000 x[213] = 00000000 x[214] = 00000000 x[215] = 00000000
x[216] = 00000000 x[217] = 00000000 x[218] = 00000000 x[219] = 00000000
x[220] = 00000000 x[221] = 00000000 x[222] = 00000000 x[223] = 00000000
x[224] = 00000000 x[225] = 00000000 x[226] = 00000000 x[227] = 00000000
x[228] = 00000000 x[229] = 00000000 x[230] = 00000000 x[231] = 00000000
x[232] = 00000000 x[233] = 00000000 x[234] = 00000000 x[235] = 00000000
x[236] = 00000000 x[237] = 00000000 x[238] = 00000000 x[239] = 00000000
x[240] = 00000000 x[241] = 00000000 x[242] = 00000000 x[243] = 00000000
x[244] = 00000000 x[245] = 00000000 x[246] = 00000000 x[247] = 00000000
x[248] = 00000000 x[249] = 00000000 x[250] = 00000000 x[251] = 00000000
x[252] = 00000000 x[253] = 00000000 x[254] = 00000000 x[255] = 00000000
答案 0 :(得分：1)
这是预期的。在您将纹理内存上传到GPU后，如果您Map将其恢复读取，则无法保证它会以您上传的相同音高返回。这是因为在上传时，驱动程序以最适合渲染的方式重新布局内存。当您将其带回CPU时，驱动程序会有效地将其转换回线性格式，通常以反映纹理缓存或页面大小的各种属性的方式。