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A long time ago Family Computing had a bunch of little programs showing off tricks using a 1-pixel shapetable. You have this 1-pixel shape, and you use SCALE to change its length. You can get that one pixel to pull off a lot of little tricks for you. I find it very funny that what was done way back with this is still being done today on webpages. Nowadays people will use a 1-pixel transparent GIF as a spacer in tables to position objects on the screen by stretching the height and width of that 1-pixel image. Anyway, here are three example programs showing off how much complexity you can do with just this simple little one-pixel shape table. First I have a simple example I whipped up called "MAGIC SQUARES".... draws random overlapping grids which makes for interesting eye candy. (For novices, you don't have to type the REM statements) 5 REM Set up the shape table 10 POKE 232,0: POKE 233,3: DATA 1,0,4,0,4,0 20 FOR A = 768 TO 773: READ B: POKE A,B: NEXT 25 REM Reset graphics, and set scale to 159 30 TEXT : HOME : HGR : SCALE= 159 40 VTAB 21: PRINT "MAGIC SQUARES" 45 REM Draw from 0 to 159 with random stepping of 47 REM 4 to 34 steps. 50 FOR A = 0 TO 159 STEP INT ( RND (1) * 30) + 4 55 REM Draw a line down from along the top edge 60 ROT= 32: XDRAW 1 AT A,0 65 REM Draw a line to the right from the left edge 70 ROT= 16: XDRAW 1 AT 0,A 80 NEXT 85 REM Draw some more lines over the lines just drawn. 90 GOTO 50 (Press Control-C to quit) Here's another which draws square-spirals which erase themselves using the same code which draws them. (As before, you don't need to type in the REM statements) 5 REM Set up the shape table 10 POKE 232,0: POKE 233,3: DATA 1,0,4,0,4,0 20 FOR A = 768 TO 773: READ B: POKE A,B: NEXT 25 REM Hires page 1, full screen 30 HGR: POKE - 16302,0 35 REM Get random x,y start position 40 X = RND (1) * 279 50 Y = RND (1) * 191 55 REM Get random scale for size of spiral 60 SC = RND (1) * 90 + 10 65 REM Get random stepping for amount to reduce spiral size 70 RD = RND (1) * 5 + 1 65 REM Draw the spiral twice, once to draw, once to erase 80 FOR I = 1 TO 2: R =0 85 REM Set start location for XDRAW 90 HCOLOR= 0 : HPLOT X,Y 95 REM Start at biggest size and shrink down 100 FOR A = SC TO 1 STEP -RD 103 REM Rotate 90 degrees for each XDRAW and reduce 105 REM scale for each XDRAW. XDRAW-ing without 107 REM coordinates starts where last XDRAW ended. 110 R = R + 16 : IF R > 63 THEN R = 0 120 ROT= R: SCALE = A: XDRAW 1 130 NEXT A,C: GOTO 40 Here's my last XDRAW example, which does very complex "flowers". It's a set of scale and rotations which are randomly chosen and xdrawn repeatedly. Over time they rotate and create complex circular "flower" shapes on the screen. If you wait a little while, you'll discover it is actually drawing a "regular" shape, and it will eventually begin to overprint right from where it started, and proceed to erase everything it had drawn up to that point. Neat! Press any key to clear screen and start a new random shape. Press Control-C to exit. 5 REM Watch for Control-C for exiting.. 10 ONERR GOTO 200 15 REM Array of scale and rotations for each step 20 DIM SC%(30), RT%(30) 25 REM Shape table 30 POKE 232,0: POKE 233,3: DATA 1,0,4,0,4,0 40 FOR A = 768 TO 773: READ B: POKE A,B: NEXT 50 HOME : HGR : POKE - 16302,0 55 REM Starting point for the XDRAWs-- Make it invisible 60 HCOLOR = 0 : HPLOT RND (1) * 200+39, RND (1) * 100+45 65 REM Reset stepping variables if we're restarting 70 I = 0 : R = 0 75 REM Randomly pick number of XDRAW steps 80 CN = INT ( RND (1) * 28) + 2 85 REM Randomly pick the scale and rotation for each step 90 FOR A = 1 TO CN 100 SC%(A) = RND (1) * 10 + 4 110 RT%(A) = RND (1) * 32 120 NEXT A 125 REM Main loop. Count up to CN, then back to zero 130 I = I + 1 : IF I > CN THEN I = 1 135 REM Rotate by the amount in RT%(I). The -16 makes the 136 REM 0-32 value in RT%(I) a rotation from -16 to +16.. 140 R = R + RT%(I) - 16 143 REM Adding or subtracting from R can make it exceed 145 REM the 0-63 range. These lines "wrap the value" if 147 REM it goes too far one way or the other. 150 IF R > 63 THEN R = R - 64 160 IF R < 0 THEN R = R + 64 165 REM Scale by stored random amount, rotate by new 167 REM random amount (+/- 90 degrees) and XDRAW segment 170 SCALE= SC%(I) : ROT= R : XDRAW 1 175 REM Watch for any keypress. If none, continue drawing. 180 IF PEEK (-16368) < 128 THEN 130 185 REM IF there is a keypress, start over. 190 GOTO 50 195 REM If control-C pressed, ONERR jumps to here to exit. 200 TEXT : END (For easier debugging, remove line 10 until it is bug-free. Line 10 looks for any error and jumps to 200 if it sees one. The only 'error' if it is working right will be caused when you press Control-C.) -Mr. Boffo Email: mister_boffo@hotmail.com On Thu, 06 Jan 2000 11:04:52 GMT, mister_boffo@hotmail.com (Mr. Boffo) wrote: Darn, I found a bug while reading it over again. In program #2, change line 130... >130 NEXT A,C: GOTO 40 Should be: 130 NEXT A,I: GOTO 40 -Mr. Boffo Email: mister_boffo@hotmail.com