Reference nvgTextBounds

Measures the specified text string. Parameter bounds should be a pointer to float[4], if the bounding box of the text should be returned. The bounds value are [xmin,ymin, xmax,ymax]. Returns the horizontal advance of the measured text (i.e. where the next character should drawn). Measured values are returned in local coordinate space

function nvgTextBounds(Ctx: PNVGcontext; X, Y: Single; Str, EndStr: PAnsiChar; Bounds: PSingle): Single; overload;

function nvgTextBounds(Ctx: PNVGcontext; X, Y: Single; const S: string; Bounds: PSingle): Single; overload;