实时加载本地图片和音效

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前言

从本地路径加载图片和音效数据, 得到UTexture2D和USoundWave

UE4Editor_dmHYzjuVWx

图片

从文件加载UTexture2D

一切尽在注释中

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//加载ImageWrapper模块，同时创建一个针对格式操作的辅助对象
static TSharedPtr<IImageWrapper> GetImageWrapperByExtention(const FString InImagePath)
{
	IImageWrapperModule& ImageWrapperModule = FModuleManager::GetModuleChecked<IImageWrapperModule>(FName("ImageWrapper"));



	if (InImagePath.EndsWith(".png"))
	{
		return ImageWrapperModule.CreateImageWrapper(EImageFormat::PNG);
	}
	else if (InImagePath.EndsWith(".jpg") || InImagePath.EndsWith(".jpeg"))
	{
		return ImageWrapperModule.CreateImageWrapper(EImageFormat::JPEG);
	}
	else if (InImagePath.EndsWith(".bmp"))
	{
		return ImageWrapperModule.CreateImageWrapper(EImageFormat::BMP);
	}
	else if (InImagePath.EndsWith(".ico"))
	{
		return ImageWrapperModule.CreateImageWrapper(EImageFormat::ICO);
	}
	else if (InImagePath.EndsWith(".exr"))
	{
		return ImageWrapperModule.CreateImageWrapper(EImageFormat::EXR);
	}
	else if (InImagePath.EndsWith(".icns"))
	{
		return ImageWrapperModule.CreateImageWrapper(EImageFormat::ICNS);
	}
	return nullptr;
}

UTexture2D* UFlib_IO::LoadTexture2DFromFile(const FString& FilePath, bool& IsValid, int32& Width, int32& Height)
{

	IsValid = false;
	UTexture2D* LoadedT2D = NULL;


	TSharedPtr<IImageWrapper> ImageWrapper = GetImageWrapperByExtention(FilePath);
//得到解压后的源数据
	TArray<uint8> RawFileData;
	if (!FFileHelper::LoadFileToArray(RawFileData, *FilePath, 0)) return NULL;

	if (ImageWrapper.IsValid() && ImageWrapper->SetCompressed(RawFileData.GetData(), RawFileData.Num()))
	{
		TArray<uint8> UncompressedBGRA;
        //设置格式并获取未压缩的数据
		if (ImageWrapper->GetRaw(ERGBFormat::BGRA, 8, UncompressedBGRA))
		{
			//创建UTexture2D*
			LoadedT2D = UTexture2D::CreateTransient(ImageWrapper->GetWidth(), ImageWrapper->GetHeight(), PF_B8G8R8A8);

			if (!LoadedT2D) return NULL;
			//得到高度和宽度
			Width = ImageWrapper->GetWidth();
			Height = ImageWrapper->GetHeight();
 			// 锁住他的数据  
			void* TextureData = LoadedT2D->PlatformData->Mips[0].BulkData.Lock(LOCK_READ_WRITE);
            //获取纹理数据
			FMemory::Memcpy(TextureData, UncompressedBGRA.GetData(), UncompressedBGRA.Num());
            //解锁
			LoadedT2D->PlatformData->Mips[0].BulkData.Unlock();

			LoadedT2D->UpdateResource();
		}
	}

	IsValid = true;
	return LoadedT2D;
}

RenderTarget2D导出成本地图片

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bool UFlib_IO::ExportTextureRenderTarget2D2PNG(UTextureRenderTarget2D* TextureRenderTarget, const FString& FilePath)
{

	FTextureRenderTargetResource* rtResource = TextureRenderTarget->GameThread_GetRenderTargetResource();
	FReadSurfaceDataFlags readPixelFlags(RCM_UNorm);

	TArray<FColor> outBMP;

	for (FColor& color : outBMP)
	{
		color.A = 255;
	}
	outBMP.AddUninitialized(TextureRenderTarget->GetSurfaceWidth() * TextureRenderTarget->GetSurfaceHeight());
	rtResource->ReadPixels(outBMP, readPixelFlags);

	FIntPoint destSize(TextureRenderTarget->GetSurfaceWidth(), TextureRenderTarget->GetSurfaceHeight());
	TArray<uint8> CompressedBitmap;
	FImageUtils::CompressImageArray(destSize.X, destSize.Y, outBMP, CompressedBitmap);
	bool imageSavedOk = FFileHelper::SaveArrayToFile(CompressedBitmap, *FilePath);

	return imageSavedOk;
}

音效

从本地文件加载USoundWave

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class USoundWave* UFlib_IO::LoadWaveDataFromFile(const FString& FilePath)
{
	USoundWave* sw = NewObject<USoundWave>(USoundWave::StaticClass());

	if (!sw)
		return nullptr;


	TArray < uint8 > rawFile;

	FFileHelper::LoadFileToArray(rawFile, FilePath.GetCharArray().GetData());
	FWaveModInfo WaveInfo;

	if (WaveInfo.ReadWaveInfo(rawFile.GetData(), rawFile.Num()))
	{
		sw->InvalidateCompressedData();

		sw->RawData.Lock(LOCK_READ_WRITE);
		void* LockedData = sw->RawData.Realloc(rawFile.Num());
		FMemory::Memcpy(LockedData, rawFile.GetData(), rawFile.Num());
		sw->RawData.Unlock();

		int32 DurationDiv = *WaveInfo.pChannels * *WaveInfo.pBitsPerSample * *WaveInfo.pSamplesPerSec;
		if (DurationDiv)
		{
			sw->Duration = *WaveInfo.pWaveDataSize * 8.0f / DurationDiv;
		}
		else
		{
			sw->Duration = 0.0f;
		}

		sw->SetSampleRate(*WaveInfo.pSamplesPerSec);
		sw->NumChannels = *WaveInfo.pChannels;
		sw->RawPCMDataSize = WaveInfo.SampleDataSize;
		sw->SoundGroup = ESoundGroup::SOUNDGROUP_Default;
	}
	else {
		return nullptr;
	}

	return sw;
}