src/add-ons/screen_savers/flurry/Star.cpp

   1 /*
   2
   3 Copyright (c) 2002, Calum Robinson
   4 All rights reserved.
   5
   6 Redistribution and use in source and binary forms, with or without
   7 modification, are permitted provided that the following conditions are met:
   8
   9 * Redistributions of source code must retain the above copyright notice, this
  10   list of conditions and the following disclaimer.
  11
  12 * Redistributions in binary form must reproduce the above copyright notice,
  13   this list of conditions and the following disclaimer in the documentation
  14   and/or other materials provided with the distribution.
  15
  16 * Neither the name of the author nor the names of its contributors may be used
  17   to endorse or promote products derived from this software without specific
  18   prior written permission.
  19
  20 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  21 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  22 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  23 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
  24 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  25 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  27 ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  29 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30
  31 */
  32
  33
  34 #include "Star.h"
  35 #include "Shared.h"
  36
  37
  38 #define BIGMYSTERY 1800.0
  39 #define MAXANGLES 16384
  40
  41
  42 // Construction/Destruction
  43 void
  44 InitStar(Star* s)
  45 {
  46         for (int i=0; i < 3; i++)
  47                 s->position[i] = RandFlt(-10000.0, 10000.0);
  48
  49         s->rotSpeed = RandFlt(0.4, 0.9);
  50         s->mystery = RandFlt(0.0, 10.0);
  51 }
  52
  53
  54 void
  55 UpdateStar(flurry_info_t* info, Star* s)
  56 {
  57          /* speed control */
  58         float rotationsPerSecond = (float)(2.0 * M_PI * 12.0 / MAXANGLES)
  59                 * s->rotSpeed;
  60         double thisPointInRadians;
  61         double thisAngle = info->fTime * rotationsPerSecond;
  62         float cf;
  63         double tmpX1;
  64         double tmpY1;
  65         double tmpZ1;
  66         double tmpX2;
  67         double tmpY2;
  68         double tmpZ2;
  69         double tmpX3;
  70         double tmpY3;
  71         double tmpZ3;
  72         double tmpX4;
  73         double tmpY4;
  74         double tmpZ4;
  75         double rotation;
  76         double cr;
  77         double sr;
  78
  79         s->ate = 0;
  80
  81         cf = ((float)(cos(7.0 * ((info->fTime) * rotationsPerSecond))
  82                 + cos(3.0 * ((info->fTime) * rotationsPerSecond))
  83                 + cos(13.0 * ((info->fTime) * rotationsPerSecond))));
  84         cf /= 6.0f;
  85         cf += 0.75f;
  86         thisPointInRadians = 2.0 * M_PI * (double) s->mystery / (double) BIGMYSTERY;
  87
  88         s->position[0] = 250.0f * cf * (float)cos(11.0 * (thisPointInRadians
  89                 + (3.0 * thisAngle)));
  90         s->position[1] = 250.0f * cf * (float)sin(12.0 * (thisPointInRadians
  91                 + (4.0 * thisAngle)));
  92         s->position[2] = 250.0f * (float)cos((23.0 * (thisPointInRadians
  93                 + (12.0 * thisAngle))));
  94
  95         rotation = thisAngle * 0.501 + 5.01 * (double)s->mystery
  96                 / (double)BIGMYSTERY;
  97         cr = cos(rotation);
  98         sr = sin(rotation);
  99         tmpX1 = s->position[0] * cr - s->position[1] * sr;
 100         tmpY1 = s->position[1] * cr + s->position[0] * sr;
 101         tmpZ1 = s->position[2];
 102
 103         tmpX2 = tmpX1 * cr - tmpZ1 * sr;
 104         tmpY2 = tmpY1;
 105         tmpZ2 = tmpZ1 * cr + tmpX1 * sr;
 106
 107         tmpX3 = tmpX2;
 108         tmpY3 = tmpY2 * cr - tmpZ2 * sr;
 109         tmpZ3 = tmpZ2 * cr + tmpY2 * sr + seraphDistance;
 110
 111         rotation = thisAngle * 2.501 + 85.01 * (double)s->mystery
 112                 / (double) BIGMYSTERY;
 113         cr = cos(rotation);
 114         sr = sin(rotation);
 115         tmpX4 = tmpX3 * cr - tmpY3 * sr;
 116         tmpY4 = tmpY3 * cr + tmpX3 * sr;
 117         tmpZ4 = tmpZ3;
 118
 119         s->position[0] = (float)tmpX4;
 120         s->position[1] = (float)tmpY4;
 121         s->position[2] = (float)tmpZ4;
 122 }