gl3-fill-circle* ( center radius segments -- )

Vocabulary

ui.render

Inputs

center	an object
radius	an object
segments	an object

Outputs

None

Definition

USING: arrays kernel math math.constants math.functions
opengl.gl sequences ;

IN: ui.render

:: gl3-fill-circle* ( center radius segments -- )
    center first :> cx center second :> cy segments 1 + <iota> 
    [| i |
        i segments / 2 * pi *
        [ cos radius * cx + ] [ sin radius * cy + ] bi 2array
    ] map cx cy 2array prefix
    make-position-vertices upload-vertices
    GL_TRIANGLE_FAN 0 segments 2 + glDrawArrays ;