| 1 | /********************************************************************** <BR>
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| 2 | This file is part of Crack dot Com's free source code release of
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| 3 | Golgotha. <a href="http://www.crack.com/golgotha_release"> <BR> for
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| 4 | information about compiling & licensing issues visit this URL</a>
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| 5 | <PRE> If that doesn't help, contact Jonathan Clark at
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| 6 | golgotha_source@usa.net (Subject should have "GOLG" in it)
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| 7 | ***********************************************************************/
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| 8 |
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| 9 | #ifndef I4_ANGLE_HH
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| 10 | #define I4_ANGLE_HH
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| 11 |
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| 12 | #include "math/num_type.hh"
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| 13 | #include "math/pi.hh"
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| 14 |
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| 15 | // returns the absolute difference between two angles
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| 16 | // this will always be between 0 and 180 degrees
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| 17 | inline i4_angle i4_angle_diff(i4_angle angle1, i4_angle angle2)
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| 18 | {
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| 19 | i4_angle d;
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| 20 | if (angle1>angle2)
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| 21 | d=angle1-angle2;
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| 22 | else
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| 23 | d=angle2-angle1;
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| 24 | if (d>i4_pi())
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| 25 | return 2*i4_pi()-d;
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| 26 | else
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| 27 | return d;
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| 28 | }
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| 29 |
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| 30 | // returns the clockwise distance from angle2 to angle1, this may be over 180 degrees
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| 31 | inline i4_angle i4_angle_minus(i4_angle angle1, i4_angle angle2)
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| 32 | {
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| 33 | if (angle1>angle2)
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| 34 | return angle1-angle2;
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| 35 | else
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| 36 | return angle1+2*i4_pi()-angle2;
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| 37 | }
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| 38 |
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| 39 | inline i4_angle i4_interpolate_angle(i4_angle from, i4_angle to, i4_float fraction)
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| 40 | {
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| 41 | i4_angle diff=i4_angle_diff(from, to) * fraction;
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| 42 | if (i4_angle_minus(to, from)>=i4_pi())
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| 43 | return from-diff;
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| 44 | else
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| 45 | return from+diff;
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| 46 | }
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| 47 |
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| 48 | inline void i4_normalize_angle(i4_float &angle)
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| 49 | {
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| 50 | while (angle<0) angle += (i4_2pi());
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| 51 | while (angle>=i4_2pi()) angle -= (i4_2pi());
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| 52 | }
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| 53 |
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| 54 | inline i4_float i4_rotate_to(i4_float &from, i4_float to, i4_float speed)
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| 55 | {
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| 56 | i4_float dangle;
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| 57 | sw8 rot_dir = 0;
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| 58 |
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| 59 | dangle = (to-from);
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| 60 | if (dangle>i4_pi())
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| 61 | dangle -= 2*i4_pi();
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| 62 | else if (dangle<-i4_pi())
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| 63 | dangle += 2*i4_pi();
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| 64 |
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| 65 | if (dangle>speed) dangle = speed;
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| 66 | else if (dangle<-speed) dangle = -speed;
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| 67 |
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| 68 | from += dangle;
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| 69 | i4_normalize_angle(from);
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| 70 |
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| 71 | return dangle;
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| 72 | }
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| 73 |
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| 74 |
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| 75 | #endif
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