３次スプライン関数

  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
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
-
|
|
|
!
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

#include "d3m.hsp"
#module
 
;【スプライン補間関数】
; data   : データ点 data(num) の配列
; cft    : 求めた係数を代入する変数 cft(num, 4) の配列
; num    : データの数
 
#deffunc sp_calc array data, array cft, int num
    n=num-2
    // 2次
    // 3重対角行列を解く
    cft(0, 2)=0.0
    cft(num-1, 2)=0.0
    repeat n
        cft(cnt+1, 2)=3.0*(data(cnt)-2.0*data(cnt+1)+data(cnt+2))
    loop
    repeat n, 1
        cft(cnt, 2)=(cft(cnt, 2)-cft(cnt-1, 2))/4.0
    loop
    repeat n, 1
        cft(cnt, 2)-=cft(cnt+1, 2)/4.0
    loop
 
    // 0次
    repeat num
        cft(cnt, 0)=data(cnt)
    loop
 
    // 1次, 3次
    n++
    cft(n, 1)=0.0
    cft(n, 3)=0.0
    repeat n
        cft(cnt, 3)=(cft(cnt+1, 2)-cft(cnt, 2))/3.0
        cft(cnt, 1)=data(cnt+1)-data(cnt)-cft(cnt, 2)-cft(cnt, 3)
    loop
return
 
#defcfunc sp_retXY array cft
    i = int(t)
    d = t - i
return cft(i, 0) + (cft(i, 1) + (cft(i, 2) + cft(i, 3) * d) * d) * d
 
#deffunc sp_Draw array x, array y, int num
    t = 0.0
    d3initlineto
    while t < num
        d3lineto sp_retXY(x), 0, sp_retXY(y)
        t += 0.01
    wend
return
#global
; ----------------------------------------------------------------
#const CAM_DISTANCE 500.0
#const GRID_SPAN    50
#const ANG_SPEED    0.05
    ; 頂点の数
    n = 3
    ddim x, n : ddim y, n
    ddim cX, n, 4 : ddim cY, n, 4
 
    ; x , y
    x = -200.0,   0.0, 200.0
    y = -200.0, 200.0,   0.0
 
    sp_calc x, cX, n
    sp_calc y, cY, n
 
    theta = 1.0
    title "カーソルキー左右でカメラの回転"
    gosub *set_camera
    need_to_redraw = 1
 
// メインループ
    repeat
        stick keys, 15
        gosub *move_camera
        gosub *draw
        wait 1
    loop
 
*move_camera
    if keys & 0b101 {
        theta += ANG_SPEED * ((keys >> 2 & 1) - (keys & 1))
        gosub *set_camera
        need_to_redraw = 1
    }
    return
 
*set_camera
    d3setcam cos(theta)*CAM_DISTANCE, sin(theta)*CAM_DISTANCE, 0, 0, 0, 0
    return
 
*draw
    if need_to_redraw == 0 : return
 
    redraw 0
    color 255, 255, 255 : boxf
    color 192,192,192
    repeat 11, -5
        d3line -GRID_SPAN * 5,   0,  GRID_SPAN * cnt, GRID_SPAN * 5,   0, GRID_SPAN * cnt
        d3line  GRID_SPAN * cnt, 0, -GRID_SPAN * 5,   GRID_SPAN * cnt, 0, GRID_SPAN * 5
    loop
    color : sp_Draw cX, cY, n
    color ,255
    repeat n
        d3circle x(cnt), 0, y(cnt), 10
    loop
    d3pos x(0), 0, y(0) : mes "始点"
    d3pos x(1), 0, y(1) : mes "オンカーブ点"
    d3pos x(2), 0, y(2) : mes "終点"
    redraw
    need_to_redraw = 0
    return