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Pixel

Pixel (Function)​

Format​

pixel (x_position, y_position )

returns rgb_expr

Description​

Returns the colour of the pixel at the x_position and y_position coordinate, as the same kind of number Rgb makes, alpha included. A pixel that has not been drawn on since the last Clg, or that was drawn with the colour CLEAR, is transparent and returns 0. White returns -1.

pixel reads the graphics output, or the image that SetGraph is drawing on. It sees only what was drawn: sprites float above the drawing and are left out (use GetSlice to read them too). A half-transparent colour drawn over something else is read back as the colour that results. A point outside the graphics output gives a meaningless number (12345), so keep the coordinates inside it.

The coordinates may be whole numbers or fractions. They are measured in pixels unless a Window has been set, in which case they are in the units that window defines and the nearest pixel is read.

Sample Program​

The following sample program shows how to use the binary and operation and integer division to extract the red, blue, and green values from the number returned by pixel.

color red
rect 0,0,100,100

color rgb(100,50,150)
rect 100,100,100,100

color white
rect 200,200,100,100

while true
    c = pixel(mousex, mousey)
    r = (c & 0xff0000) \ 0x10000
    g = (c & 0xff00) \ 0x100
    b = (c & 0xff)
    print r,g,b
    pause .5
end while

See Also​

GetSlice, ImagePixel, Pixel, Rgb, SetGraph, Window

History​

0.9.5mNew To Version
2.0.0.4Added example