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Display LCD digits in a canvas.

Tcl, 72 lines
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72``` ```# The shapes of individual elements of a digit. They were worked out # with a piece of paper, a calculator and a good deal of head-scratching. array set lcdshape { a {3.0 5 5.2 3 7.0 5 6.0 15 3.8 17 2.0 15} b {6.3 2 8.5 0 18.5 0 20.3 2 18.1 4 8.1 4} c {19.0 5 21.2 3 23.0 5 22.0 15 19.8 17 18.0 15} d {17.4 21 19.6 19 21.4 21 20.4 31 18.2 33 16.4 31} e {3.1 34 5.3 32 15.3 32 17.1 34 14.9 36 4.9 36} f {1.4 21 3.6 19 5.4 21 4.4 31 2.2 33 0.4 31} g {4.7 18 6.9 16 16.9 16 18.7 18 16.5 20 6.5 20} } # Which elements are turned on for a given digit? Note that this is only # decimal digits, though adding hex digits should be easy enough. array set llcd { 0 {a b c d e f} 1 {c d} 2 {b c e f g} 3 {b c d e g} 4 {a c d g} 5 {a b d e g} 6 {a b d e f g} 7 {b c d} 8 {a b c d e f g} 9 {a b c d e g} - {g} { } {} } # Which elements are turned off for a given digit? Note that you should make # sure that this is the complement of the digits set in the llcd array... array set ulcd { 0 {g} 1 {a b e f g} 2 {a d} 3 {a f} 4 {b e f} 5 {c f} 6 {c} 7 {a e f g} 8 {} 9 {f} - {a b c d e f} { } {a b c d e f g} } # Displays a decimal number using LCD digits in the top-left of the canvas proc showLCD { canvas number {width 5} {colours {#ff8080 #ff0000 #404040 #303030}} } { global llcd ulcd lcdshape set lcdoffset 0 # Remove previous LCD number \$canvas delete lcd # Get colours to draw with foreach {onRim onFill offRim offFill} \$colours {break} # For each digit in the (space-padded) number... foreach glyph [split [format %\${width}d \$number] {}] { # ... draw its "on" elements... foreach symbol \$llcd(\$glyph) { # ... by drawing a polygon and shifting it... \$canvas move [eval \$canvas create polygon \$lcdshape(\$symbol) -tags lcd -outline \$onRim -fill \$onFill] \$lcdoffset 0 } # ... and then doing the same thing for the "off" elements foreach symbol \$ulcd(\$glyph) { \$canvas move [eval \$canvas create polygon \$lcdshape(\$symbol) -tags lcd -outline \$offRim -fill \$offFill] \$lcdoffset 0 } # And now we increase our offset too... incr lcdoffset 22 } } ```

Sometimes it is really useful to be able to display numbers that look like LCD digits (especially for things like games.) This code, which was originally developed as part of a maze-exploration game makes it trivial...

http://www.cs.man.ac.uk/~fellowsd/tcl/#games/maze

Note that the code as it stands only supports one LCD number at a time in the canvas (particularly since it deletes any old LCD number first) but that should not be a difficult problem to circumvent, and it does mean that for people that only want one number, all management of that number can be done by just feeding the value to the procedure (perhaps with the aid of a trace on a variable.) The other thing that this code does not do is support putting the number anywhere other than the top-left of the canvas, but yet again that should be easy enough to add in.

 Created by Donal Fellows on Mon, 10 Sep 2001 (MIT)

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