FCanvasTileItem TileItem(FVector2D(0.0f, 0.0f), TextureResource, FVector2D(LongLatDimensions.X, LongLatDimensions.Y), FLinearColor::White);
TileItem.BatchedElementParameters = BatchedElementParameters;
TileItem.BlendMode = SE_BLEND_Opaque;
Canvas->DrawItem(TileItem);
Canvas->Flush();
FlushRenderingCommands();
Canvas->SetRenderTarget(NULL);
FlushRenderingCommands();
ENQUEUE_UNIQUE_RENDER_COMMAND(
LongLatUnwrapEndSceneCommand,
{
RHIEndScene();
});
int32 ImageBytes = CalculateImageBytes(LongLatDimensions.X, LongLatDimensions.Y, 0, TargetPixelFormat);
BitsOUT.AddUninitialized(ImageBytes);
bool bReadSuccess = false;
switch (TargetPixelFormat)
{
case PF_B8G8R8A8:
bReadSuccess = RenderTarget->ReadPixelsPtr((FColor*)BitsOUT.GetTypedData());
break;
case PF_FloatRGBA:
{
TArray<FFloat16Color> FloatColors;
bReadSuccess = RenderTarget->ReadFloat16Pixels(FloatColors);
FMemory::Memcpy(BitsOUT.GetTypedData(), FloatColors.GetTypedData(), ImageBytes);
}
/**
* Helper function to create an unwrapped 2D image of the cube map ( longitude/latitude )
* This version takes explicitly passed properties of the source object, as the sources have different APIs.
* @param TextureResource Source FTextureResource object.
* @param AxisDimenion axis length of the cube.
* @param SourcePixelFormat pixel format of the source.
* @param BitsOUT Raw bits of the 2D image bitmap.
* @param SizeXOUT Filled with the X dimension of the output bitmap.
* @param SizeYOUT Filled with the Y dimension of the output bitmap.
* @return true on success.
* @param FormatOUT Filled with the pixel format of the output bitmap.
*/
bool GenerateLongLatUnwrap(const FTextureResource* TextureResource, const uint32 AxisDimenion, const EPixelFormat SourcePixelFormat, TArray<uint8>& BitsOUT, FIntPoint& SizeOUT, EPixelFormat& FormatOUT)
{
TRefCountPtr<FBatchedElementParameters> BatchedElementParameters;
BatchedElementParameters = new FMipLevelBatchedElementParameters((float)0, true);
const FIntPoint LongLatDimensions(AxisDimenion * 2, AxisDimenion);
// If the source format is 8 bit per channel or less then select a LDR target format.
const EPixelFormat TargetPixelFormat = CalculateImageBytes(1, 1, 0, SourcePixelFormat) <= 4 ? PF_B8G8R8A8 : PF_FloatRGBA;
UTextureRenderTarget2D* RenderTargetLongLat = NewObject<UTextureRenderTarget2D>();
check(RenderTargetLongLat);
RenderTargetLongLat->AddToRoot();
RenderTargetLongLat->ClearColor = FLinearColor(0.0f, 0.0f, 0.0f, 0.0f);
RenderTargetLongLat->InitCustomFormat(LongLatDimensions.X, LongLatDimensions.Y, TargetPixelFormat, false);
RenderTargetLongLat->TargetGamma = 0;
FRenderTarget* RenderTarget = RenderTargetLongLat->GameThread_GetRenderTargetResource();
FCanvas* Canvas = new FCanvas(RenderTarget, NULL, 0, 0, 0, GMaxRHIFeatureLevel);
Canvas->SetRenderTarget_GameThread(RenderTarget);
// Clear the render target to black
Canvas->Clear(FLinearColor(0, 0, 0, 0));
FCanvasTileItem TileItem(FVector2D(0.0f, 0.0f), TextureResource, FVector2D(LongLatDimensions.X, LongLatDimensions.Y), FLinearColor::White);
TileItem.BatchedElementParameters = BatchedElementParameters;
TileItem.BlendMode = SE_BLEND_Opaque;
Canvas->DrawItem(TileItem);
Canvas->Flush_GameThread();
FlushRenderingCommands();
Canvas->SetRenderTarget_GameThread(NULL);
FlushRenderingCommands();
int32 ImageBytes = CalculateImageBytes(LongLatDimensions.X, LongLatDimensions.Y, 0, TargetPixelFormat);
BitsOUT.AddUninitialized(ImageBytes);
bool bReadSuccess = false;
switch (TargetPixelFormat)
{
case PF_B8G8R8A8:
bReadSuccess = RenderTarget->ReadPixelsPtr((FColor*)BitsOUT.GetData());
break;
case PF_FloatRGBA:
{
TArray<FFloat16Color> FloatColors;
bReadSuccess = RenderTarget->ReadFloat16Pixels(FloatColors);
FMemory::Memcpy(BitsOUT.GetData(), FloatColors.GetData(), ImageBytes);
}
break;
}
// Clean up.
RenderTargetLongLat->RemoveFromRoot();
RenderTargetLongLat = NULL;
delete Canvas;
SizeOUT = LongLatDimensions;
FormatOUT = TargetPixelFormat;
if (bReadSuccess == false)
{
// Reading has failed clear output buffer.
BitsOUT.Empty();
}
return bReadSuccess;
}
