【UE4】读写 Texture 数据

阅读原文时间：2021年10月25日阅读：1

方式一

void AActor_Assignment2::TextureFromImage_Internal( const TArray& SrcData, const bool UseAlpha)
{
const int32 SrcWidth = CanvasSize.X;
const int32 SrcHeight = CanvasSize.Y;
// Create the texture
T_Result = UTexture2D::CreateTransient(CanvasSize.X, CanvasSize.Y, PF_B8G8R8A8);

// Lock the texture so it can be modified
uint8* MipData = static_cast<uint8*>(T_Result->PlatformData->Mips[0].BulkData.Lock(LOCK_READ_WRITE));

// Create base mip.
uint8* DestPtr = NULL;
const FColor* SrcPtr = NULL;
for (int32 y = 0; y < SrcHeight; y++)
{
    DestPtr = &MipData[(SrcHeight - 1 - y) * SrcWidth * sizeof(FColor)];
    SrcPtr = const_cast<FColor*>(&SrcData[(SrcHeight - 1 - y) * SrcWidth]);
    for (int32 x = 0; x < SrcWidth; x++)
    {
        *DestPtr++ = SrcPtr->B;
        *DestPtr++ = SrcPtr->G;
        *DestPtr++ = SrcPtr->R;
        if (UseAlpha)
        {
            *DestPtr++ = SrcPtr->A;
        }
        else
        {
            *DestPtr++ = 0xFF;
        }
        SrcPtr++;
    }
}

// Unlock the texture
T_Result->PlatformData->Mips[0].BulkData.Unlock();
T_Result->UpdateResource();

}

方式二

void AActor_Assignment3::BeginPlay()
{
Super::BeginPlay();

VideoTextureColor = UTexture2D::CreateTransient(640, 480, PF_B8G8R8A8);
VideoTextureColor->UpdateResource();
FUpdateTextureRegion2D* RegionColor = new FUpdateTextureRegion2D(0, 0, 0, 0, 640, 480);
//FUpdateTextureRegionData* ColorRegionData = new FUpdateTextureRegionsData;

// Populate the texture with blue color
TArray<FColor> PixelDepthData;
PixelDepthData.Init(FColor(255, 255, 0, 255), 640 * 480);

VideoTextureColor->UpdateTextureRegions(
    (int32)0,
    (uint32)1,
    RegionColor,
    (uint32)(4 * 640),
    (uint32)4,
    (uint8*)PixelDepthData.GetData()
);
 VideoTextureColor->LODGroup = TEXTUREGROUP_Pixels2D;

}

方式一

VideoTextureColor->CompressionSettings = TextureCompressionSettings::TC_VectorDisplacementmap;
VideoTextureColor->MipGenSettings = TextureMipGenSettings::TMGS_NoMipmaps;
VideoTextureColor->SRGB = false;  //确保这些设置，否则颜色容易丢失
//VideoTextureColor->LODGroup = TEXTUREGROUP_Pixels2D;
VideoTextureColor->UpdateResource();

FTexture2DMipMap& Mip = VideoTextureColor->PlatformData->Mips[0];
uint8* Data = (uint8*)Mip.BulkData.Lock(LOCK_READ_ONLY);
// read here in low level:
//let's say I want pixel x = 300, y = 23
//basic formula, data[channels * (width * y + x)];
FColor pixelColor = FColor(0, 0, 0, 255);
int x = 200, y = 2;
pixelColor.B = Data[4 * (640 * y + x) + 0];
pixelColor.G = Data[4 * (640 * y + x) + 1];
pixelColor.R = Data[4 * (640 * y + x) + 2];
pixelColor.A = 255;

Mip.BulkData.Unlock();
VideoTextureColor->UpdateResource();
UKismetSystemLibrary::PrintString(GetWorld(), TEXT("font color"), true, true, pixelColor);