blitz-research
27 lines
2.7 KiB
HTML
27 lines
2.7 KiB
HTML
<html><head><title>Command: Sin </title><meta http-equiv='Content-Type' content='text/html; charset=iso-8859-1'><link rel='stylesheet' href='../css/commands.css' type='text/css'></head><body><span class='Command'> Sin (Number) </span></p><span class='header'>Definition:</span> <br><br><table width='100%' border='0' cellspacing='2' cellpadding='2' align='center'><tr><td>The Sin command, or Sinus, is a trigonometry function, that returns a number between -1 and 1. This value represents the "Y" coordinate of the point a</td></tr></table><span class='header'><br>Parameter Description:</span> <br><br><table width='100%' border='0' cellspacing='2' cellpadding='2' align='center'><tr><td>number=float or integer representing a value in degree</td></tr></table><p class='header'>Command Description: <br><br><table width='100%' border='0' cellspacing='2' cellpadding='2' align='center'><tr><td>This command is used for translating angle values to coordinates, but there are a few things you have to take into account when doing it. First of all the Sin() command assumes the point you want is at radius 1 (pixel), next it uses a circle where 0 degrees is due EAST and increases in a counterclockwise direction, then you've got to take into account the the Y axis on a computer screen is up-side-down compared to a normal mathematical coordinate system.<br>
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<br>
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See also <a href='ASin.htm'>ASin</a>, <a href='Cos.htm'>Cos</a>, <a href='ACos.htm'>ACos</a>, <a href='Tan.htm'>Tan</a>, <a href='Atan.htm'>Atan</a>, <a href='ATan2.htm'>ATan2</a><br></td></tr></table><p class='header'>Example: <br><br><table width='100%' border='0' cellspacing='2' cellpadding='2' align='center'><tr><td>Graphics 640,480; Change to graphics mode, nothing tricky yet.<br>
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Origin 320,240 ; Move the point of orign for all drawing commands to the middle of the screen.<br>
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<br>
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For degrees=0 To 359; Step though all the degrees in a circle (360 in all)<br>
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Delay(5); Wait 5 milli secsonds.<br>
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<br>
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; The next line calculates the Y coordinate of the point of the circle using the Sin<br>
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; command, and multiplies it by 100 (to get a larger radius, try and change it).<br>
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y=Sin(degrees)*100<br>
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<br>
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y=-y ; Invert Y coordinate to represent it properly on screen.<br>
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<br>
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; The next line calculates the X coordinate of the point of the circle using the Cos,<br>
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; command, and multiplies it by 100 (to get a larger radius, try and change it).<br>
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x=Cos(degrees)*100<br>
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<br>
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Rect x,y,1,1 ; Draw the current point on the circle.<br>
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<br>
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Next ; Give us another angle<br>
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<br>
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MouseWait ; Wait for the mouse.<br>
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End ; Terminate the program.<br>
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<br></td></tr></table><p><b><a target="_top" href="../index.htm">Index</a></b></p></body>
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</html>
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