Thanks Gigatron.
I was after this conic gradient effect as shown in the attached png
Sorry about the brief reply yesterday but it was quite late.
Other programming languages seem to have a conic gradient fill, but TBgrabmp has lineargradient and radialgradient fills. I wondered whether GL has various gradient fills, especially conic gradient. Conic gradients have been used in some nice graphics and animation examples in JavaScript, Java and OpenProcessing. Wanted to experiment with conic gradient fills with Lazarus but need to find something that does it.
Thanks for helping Gigatron.