view_whatdotcolor

#View.WhatDotColor

##Syntax View.W****hatDotColor ( x, y : int ) : int

##Description The View.WhatDotColor function is used to determine the color number of the specified pixel. The alternate spelling is View.WhatDotColour.

##Example This program draws a line which bounces off the edges of the screen and makes a beep when it finds a pixel that has already been colored.

    View.Set ( "graphics" )
    var x, y : int := 0
    var dx, dx : int := 1
    loop
        if View.WhatDotColor ( x, y ) not= 0 and
            View.WhatDotColor ( x, y ) not= brightred then
            Draw.FillOval (x, y, 10, 10, brightred)
        end if
        Draw.Dot ( x, y, 1 )
        x := x + dx
        y := y + dy
        if x = 0 or x = maxx then
            dx := -dx
        end if
        if y = 0 or y = maxy then
            dy := -dy
        end if
    end loop

##Example Another example illustrates the use of View.WhatDotColor to determine the color of pixels in a window painted with multi-colorblocks. The actual color number appears in the block. The colorof the dot under the mouse cursor appears in the upper-leftcorner of the window. Note that you can also place the mousecursor over the black text indicating the color number.

##Details The screen should be in a"graphics" mode. If is not set to "graphics" mode, it will automatically be set to "graphics" mode. See View.Set for details.

##Status Exported qualified.

This means that you can only call the function by calling View.WhatDotColor, not by calling WhatDotColor.

##See also draw_dot.html, which is used for setting the color of a pixel. See also maxx.html and maxy.html, which are used to determine the number of pixels on the screen.