使用UWidgetBlueprintLibrary类的绘制函数，可以在UMG里绘制二维图像。
做成静态函数后就可以在蓝图中直接调用
void AAGraphics::DrawLine(FPaintContext Context, FVector2D PositionA, FVector2D PositionB, FLinearColor Tint, bool bAntiAlias) { UWidgetBlueprintLibrary::DrawLine(Context, PositionA, PositionB, Tint, bAntiAlias); } void AAGraphics::DrawTriangle(FPaintContext Context, FVector2D PositionA, FVector2D PositionB, FVector2D PositionC, FLinearColor Tint, bool bAntiAlias) { UWidgetBlueprintLibrary::DrawLine(Context, PositionA, PositionB, Tint, bAntiAlias); UWidgetBlueprintLibrary::DrawLine(Context, PositionB, PositionC, Tint, bAntiAlias); UWidgetBlueprintLibrary::DrawLine(Context, PositionC, PositionA, Tint, bAntiAlias); } void AAGraphics::DrawFullCircle(FPaintContext Context, FVector2D Center, float radius, int NumSegments, FLinearColor Tint, bool bAntiAlias) { if (NumSegments == 0) NumSegments = 360.0; float SegmentLength = 360.0 / NumSegments; for (float i = 0; i < 360; i += SegmentLength) { FVector2D PositionA(cos(i * PI / 180.0) * radius + Center.X, sin(i * PI / 180.0) * radius + Center.Y); FVector2D PositionB(cos((i + SegmentLength) * PI / 180.0) * radius + Center.X, sin((i + SegmentLength) * PI / 180.0) * radius + Center.Y); FVector2D PositionC(Center.X, Center.Y); DrawTriangle(Context, PositionA, PositionB, PositionC, Tint, bAntiAlias); } } void AAGraphics::DrawCircle(FPaintContext Context, FVector2D Center, float radius, int NumSegments, FLinearColor Tint, bool bAntiAlias) { if (NumSegments == 0) NumSegments = 360.0; float SegmentLength = 360.0 / NumSegments; for (float i = 0; i < 360.0; i += SegmentLength) { FVector2D PositionA(cos(i * PI / 180.0) * radius + Center.X, sin(i * PI / 180.0) * radius + Center.Y); FVector2D PositionB(cos((i + SegmentLength) * PI / 180.0) * radius + Center.X, sin((i + SegmentLength) * PI / 180.0) * radius + Center.Y); UWidgetBlueprintLibrary::DrawLine(Context, PositionA, PositionB, Tint, bAntiAlias); } }