The equivalent for onmousedown on touchscreen devices is ontouchstart, and the equivalent of onmouseup is ontouchend. If you would also like to detect dragging, you could use ontouchmove which is fired every time you move your finger after touching the screen.
A ‘simple sample redesign’ per my comment follows. unit Unit4; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs; const NUM_TRIANGLES = 10; COLORS: array[0..12] of integer = (clRed, clGreen, clBlue, clYellow, clFuchsia, clLime, clGray, clSilver, clBlack, clMaroon, clNavy, clSkyBlue, clMoneyGreen); type TTriangle = record X, Y: integer; // bottom-left corner Base, Height: … Read more