Sine Wave

[FellippeHeitor]

Translated and adapted from javascript/p5.js: https://p5js.org/examples/math-sine-wave.html

Contains elements from p5js.bas: bit.ly/p5jsbas

Code: QB64: [Select]

1. DIM SHARED xspacing, w, theta, amplitude, period, dx
2. xspacing = 16
3. theta = 0.0
4. amplitude = 75.0
5. period = 500.0
6.  
7. TYPE t
8.     y AS SINGLE
9.     a AS SINGLE
10. END TYPE
11.  
12. SCREEN _NEWIMAGE(710, 400, 32)
13. w = _WIDTH + 8
14. dx = (_PI(2) / period) * xspacing
15. DIM SHARED yvalues(INT(w / xspacing)) AS t
16.  
17. FOR i = 1 TO UBOUND(yvalues)
18.     yvalues(i).a = yvalues(i - 1).a + 1
19. NEXT
20.  
21. DO
22.     CLS
23.     calcWave
24.     renderWave
25.     _DISPLAY
26.     _LIMIT 60
27. LOOP
28.  
29. SUB calcWave
30.     '// Increment theta (try different values for
31.     '// 'angular velocity' here)
32.     theta = theta + 0.02
33.  
34.     '// For every x value, calculate a y value with sine function
35.     x = theta
36.     FOR i = 0 TO UBOUND(yvalues)
37.         yvalues(i).y = _HEIGHT / 2 + SIN(x) * amplitude
38.         yvalues(i).a = yvalues(i).a + .1
39.         x = x + dx
40.     NEXT
41. END SUB
42.  
43. SUB renderWave
44.     '// A simple way to draw the wave with an ellipse at each location
45.     FOR x = 0 TO UBOUND(yvalues)
46.         c~& = hsb(yvalues(x).a MOD 360, 127, 127, 127)
47.         CircleFill x * xspacing, height / 2 + yvalues(x).y, 50, c~&
48.     NEXT
49. END SUB
50.  
51. FUNCTION hsb~& (__H AS _FLOAT, __S AS _FLOAT, __B AS _FLOAT, A AS _FLOAT)
52.     DIM H AS _FLOAT, S AS _FLOAT, B AS _FLOAT
53.  
54.     H = map(__H, 0, 255, 0, 360)
55.     S = map(__S, 0, 255, 0, 1)
56.     B = map(__B, 0, 255, 0, 1)
57.  
58.     IF S = 0 THEN
59.         hsb~& = _RGBA32(B * 255, B * 255, B * 255, A)
60.         EXIT FUNCTION
61.     END IF
62.  
63.     DIM fmx AS _FLOAT, fmn AS _FLOAT
64.     DIM fmd AS _FLOAT, iSextant AS INTEGER
65.     DIM imx AS INTEGER, imd AS INTEGER, imn AS INTEGER
66.  
67.     IF B > .5 THEN
68.         fmx = B - (B * S) + S
69.         fmn = B + (B * S) - S
70.     ELSE
71.         fmx = B + (B * S)
72.         fmn = B - (B * S)
73.     END IF
74.  
75.     iSextant = INT(H / 60)
76.  
77.     IF H >= 300 THEN
78.         H = H - 360
79.     END IF
80.  
81.     H = H / 60
82.     H = H - (2 * INT(((iSextant + 1) MOD 6) / 2))
83.  
84.     IF iSextant MOD 2 = 0 THEN
85.         fmd = (H * (fmx - fmn)) + fmn
86.     ELSE
87.         fmd = fmn - (H * (fmx - fmn))
88.     END IF
89.  
90.     imx = _ROUND(fmx * 255)
91.     imd = _ROUND(fmd * 255)
92.     imn = _ROUND(fmn * 255)
93.  
94.     SELECT CASE INT(iSextant)
95.         CASE 1
96.             hsb~& = _RGBA32(imd, imx, imn, A)
97.         CASE 2
98.             hsb~& = _RGBA32(imn, imx, imd, A)
99.         CASE 3
100.             hsb~& = _RGBA32(imn, imd, imx, A)
101.         CASE 4
102.             hsb~& = _RGBA32(imd, imn, imx, A)
103.         CASE 5
104.             hsb~& = _RGBA32(imx, imn, imd, A)
105.         CASE ELSE
106.             hsb~& = _RGBA32(imx, imd, imn, A)
107.     END SELECT
108.  
109. END FUNCTION
110.  
111. FUNCTION map! (value!, minRange!, maxRange!, newMinRange!, newMaxRange!)
112.     map! = ((value! - minRange!) / (maxRange! - minRange!)) * (newMaxRange! - newMinRange!) + newMinRange!
113. END FUNCTION
114.  
115. SUB CircleFill (x AS LONG, y AS LONG, R AS LONG, C AS _UNSIGNED LONG)
116.     x0 = R
117.     y0 = 0
118.     e = 0
119.     DO WHILE y0 < x0
120.         IF e <= 0 THEN
121.             y0 = y0 + 1
122.             LINE (x - x0, y + y0)-(x + x0, y + y0), C, BF
123.             LINE (x - x0, y - y0)-(x + x0, y - y0), C, BF
124.             e = e + 2 * y0
125.         ELSE
126.             LINE (x - y0, y - x0)-(x + y0, y - x0), C, BF
127.             LINE (x - y0, y + x0)-(x + y0, y + x0), C, BF
128.             x0 = x0 - 1
129.             e = e - 2 * x0
130.         END IF
131.     LOOP
132.     LINE (x - R, y)-(x + R, y), C, BF
133. END SUB
134.