I am running code, and I have it run on a slight delay to make sure everything (Widget stuff) is rendered before running the code, delay works fine but I have a function that is run to update the changes at the end of the initialization process.
The orange message is run from inside of the “UpdateDynamicTexture” function, and the yellow message is, as you can see, sequentially before it. Also, the printed statements both are referencing the same variable, in this image, “DrawingWindowSize.X” and “DrawingWindowSize.Y”
The function reads all of the parameters as empty, or zero.
// Delay execution by 0.1 second to let everything load
FTimerHandle TimerHandle;
GetWorld()->GetTimerManager().SetTimer(TimerHandle, this, &UDrawingWindow::ExecuteAfterDelay, 0.1f, false);
if (GEngine)
{
FString Message = FString::Printf(TEXT("X: %f Y: %f X*Y: %f"), DrawingWindowSize.X, DrawingWindowSize.Y, DrawingWindowSize.X * DrawingWindowSize.Y);
GEngine->AddOnScreenDebugMessage(-1, 30.0f, FColor::Yellow, Message);
}
UpdateDynamicTexture(Canvas, BlankCanvas, 0, 0, DrawingWindowSize.X, DrawingWindowSize.Y);
void UDrawingWindow::NativeConstruct()
{
Super::NativeConstruct();
// Delay execution by 0.1 second to let everything load
FTimerHandle TimerHandle;
GetWorld()->GetTimerManager().SetTimer(TimerHandle, this, &UDrawingWindow::ExecuteAfterDelay, 0.1f, false);
Eraser.R = 255, Eraser.G = 255, Eraser.B = 255;
}
void UDrawingWindow::ExecuteAfterDelay()
{
AsyncTask(ENamedThreads::GameThread, [this]()
{
InitCanvas(DrawingPanel);
});
}
void UDrawingWindow::InitCanvas(UImage* ImageWidget) {
if (!DrawingWindowDimensions)
{
GetImagePositionAndSize(ImageWidget, DrawingWindowLocation, DrawingWindowSize);
DrawingWindowDimensions = true;
}
Canvas = CreateDynamicTexture(DrawingWindowSize.X, DrawingWindowSize.Y);
SetImageTexture(ImageWidget, Canvas);
uint32 NumPixels = DrawingWindowSize.X * DrawingWindowSize.Y;
//TArray<FColor> BlankCanvas;
BlankCanvas.SetNum(NumPixels);
for (uint32 i = 0; i < NumPixels; ++i) { BlankCanvas[i] = FColor(255, 0, 0, 255); }
if (GEngine)
{
FString Message = FString::Printf(TEXT("Width: %f Height: %f Width*Height: %f"), DrawingWindowSize.X, DrawingWindowSize.Y, DrawingWindowSize.X * DrawingWindowSize.Y);
GEngine->AddOnScreenDebugMessage(-1, 30.0f, FColor::Yellow, Message);
}
UpdateDynamicTexture(Canvas, BlankCanvas, 0, 0, DrawingWindowSize.X, DrawingWindowSize.Y);
}
bool UDrawingWindow::UpdateDynamicTexture(UTexture2D* Texture, TArray<FColor>& NewPixels, int32 X, int32 Y, int32 Width, int32 Height)
{
if (GEngine)
{
FString Message = FString::Printf(TEXT("Width: %f Height: %f"), Width, Height);
GEngine->AddOnScreenDebugMessage(-1, 120.0f, FColor::Orange, Message);
}
if (GEngine)
{
FString Message = FString::Printf(TEXT("%f"), NewPixels.Num());
GEngine->AddOnScreenDebugMessage(-1, 120.0f, FColor::Orange, Message);
}
if (NewPixels.Num() == 0)
{
return false;
}
if (!Texture)
{
return false;
}
// Ensure the new pixel data matches the textures resolution
if (NewPixels.Num() != Width * Height)
{
return false;
}
if (X < 0 || Y < 0 || X + Width > Texture->GetSizeX() || Y + Height > Texture->GetSizeY())
{
return false;
}
if (static_cast<int>(Width) == 0 || static_cast<int>(Texture->GetSizeX()) == 0 || static_cast<int>(Height) == 0 || static_cast<int>(Texture->GetSizeY()) == 0)
{
return false;
}
/*if (GEngine)
{
FString Message = FString::Printf(TEXT("X: %f Y: %f"), X, Y);
GEngine->AddOnScreenDebugMessage(-1, 120.0f, FColor::Blue, Message);
}*/
// Code below is commented because it crashes the client
/*if (GEngine)
{
FString Message = FString::Printf(TEXT("Texture->Blueprint_GetSizeX(): %f"), Texture->GetSizeX());
GEngine->AddOnScreenDebugMessage(-1, 120.0f, FColor::Blue, Message);
}
if (GEngine)
{
FString Message = FString::Printf(TEXT("Texture->Blueprint_GetSizeY(): %f"), Texture->GetSizeY());
GEngine->AddOnScreenDebugMessage(-1, 120.0f, FColor::Blue, Message);
}*/
/*
// Create an update region
FUpdateTextureRegion2D UpdateRegion(X, Y, 0, 0, Width, Height);
// Update the texture
Texture->UpdateTextureRegions(
0, // Mip level
1, // Number of regions
&UpdateRegion, // Pointer to the update region
Width * sizeof(FColor), // Source row pitch
sizeof(FColor), // Source depth pitch
reinterpret_cast<uint8*>(NewPixels.GetData()) // Source data
);*/
return true;
}
