﻿ Pixel Coordinates

Pixel Coordinates (original enhancement)

Pixel Coordinates are the coordinates whose origin is left-bottom end.

Supplied Functions (Original Enhancement)

Let x, y be numeric expressions below.

PIXELX(x) Pixel coordinate for problem coordinate x
PIXELY(y) Pixel coordinate for problem coordinate y

PROBLEMX(x) Problem coordinate for pixel coordinate x
PROBLEMY(y) Problem coordinate for pixel coordinate y

Example
To manipulate all pixels

```SET WINDOW left, right, bottom, top
FOR i=0 TO PIXELX(right)
FOR j=0 TO PIXELY(top)
LET x=PROBLEMX(i)
LET y=PROBLEMY(j)
…………
NEXT j
NEXT i```

[supplement]
The above functions can be defined in Full BASIC as follows.

```EXTERNAL FUNCTION PIXELX(x)
ASK WINDOW left, right, bottom, top
ASK PIXEL SIZE (left, bottom; right, top) px, py
LET PIXELX=ROUND((px-1)*(x-left)/(right-left),0)
END FUNCTION

EXTERNAL FUNCTION PIXELY(y)
ASK WINDOW left, right, bottom, top
ASK PIXEL SIZE (left, bottom; right, top) px, py
LET PIXELY=ROUND((py-1)*(y-bottom)/(top-bottom),0)
END FUNCTION

EXTERNAL FUNCTION PROBLEMX(x)
ASK WINDOW left, right, bottom, top
ASK PIXEL SIZE (left, bottom; right, top) px, py
LET PROBLEMX=(right-left)*x/(px-1)+left
END FUNCTION

EXTERNAL FUNCTION PROBLEMY(y)
ASK WINDOW left, right, bottom, top
ASK PIXEL SIZE (left, bottom; right, top) px, py
LET PROBLEMY=(top-bottom)*y/(py-1)+bottom
END FUNCTION```