AND 9, 54 animation 4l ellipse 43 instant plotting 53 memory requirement 41 palette changes 7,42,43, 47, 51, 53 redrawing 41 rotating objects 43 rotation and reflection 42
scrolling l0, 87, 89
successive views 60 tumbling box 55 vertical sync 43 ball of wool 18 beach balls 51 box 55 C-curve 77 carpet 19 character definition 36 circle drawing iterative method 13 polar-coordinate method 14, 16 quadratic solution method 14 circles (pattern) 72 circles (squashed) 30, 94, 102 clouds 90 colours 6 logical and physical 6 intensity of colour 35 commands 4,5 condor 57 coordinates 3 cubes advancing cubes 31 perspective view 31 tumbling box 55 cursor graphics 4, 9 text 9 diamonds (recursive) 67 dragon curve 80 DRAW commands 5 drawing 4, 23, 56 ellipse 14,43,52,53 Exclusive-OR (EOR) 9,19 fan 48 field 87 flag 22, 96 functions 4 SIN and COS 18 GCOL 8, 19 graphics commands 4 graphics cursor 4 grass 99 high resolution 3 horse 96 INKEY 24 instant plotting 53,55 interlace 9 introduction 1 island 100 ,102 kaleidoscope 41 Koch flake 75 Lissajoux figures 15-17 Lissajoux pattern 17 local variables 65 memory 3, 41, 66 merry-go-round 93 MODE 3,4 4-colour 6 l6-colour 6 Moire pattern 20 mountains 27 obscured objects 26 OR 8, 53, 54 origin, moving the 9,20 over-plotting 27 palette 6 changes 7 (see also 'animation') palm tree 103 parameters 10,11 actual 11 formal 11 intelligent 71 pattern 21 perspective 29££ view of fan 48 view of base 94 pixel 3 ,4 planets 35££ PLOT commands 5 polo 25 procedures rainbow 97 random dots random walk rapid drawing 36 rapid filling 27 rectangular fill recursion 63££ asymmetric £33 depth of 65, 83 intelligent parameters 71 recursive calls 66, 74 diamonds 67 patterns 63 procedures 64 squares 69 redrawing 41 reflection 19,42 replacement pattern 66,76 replacement rule 63 resolution 1, 3 rotating objects beach balls 51 fan 48 spiral 43, 46 squares 45 rotation 42 scrolling sideways 10 vertical 87,89 sea 101 sine waves sketch pad sky 100 sphere 33 spiral 43, 46 squares 45 sun 92 surf 104 symmetry 19 ,22 synchronisation 43 text cursor 9 three-dimensional 25ff converging lines 30,90,99 dot shading 35,99 hidden line removal (overplotting) 26,27 impression of depth 25,26,30,52,90,102 squashed circles 30,94,10 tree 83 ,103 triangle fill 5,81,100 tumbling box 55 variables 4 boolean 92, 96 control 74 local 65