ftp://netsw.org/x11/tools/desktop/xscreensaver-4.07.tar.gz

[xscreensaver] / hacks / glx / flurry-star.c

diff --git a/hacks/glx/flurry-star.c b/hacks/glx/flurry-star.c
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+/*
+
+Copyright (c) 2002, Calum Robinson
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of the author nor the names of its contributors may be used
+  to endorse or promote products derived from this software without specific
+  prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+/* Star.c: implementation of the Star class. */
+
+#include "flurry.h"
+
+/* Construction/Destruction */
+
+void InitStar(Star *s)
+{
+    int i;
+    for (i=0;i<3;i++) {
+        s->position[i] = RandFlt(-10000.0, 10000.0);
+    }
+    s->rotSpeed = RandFlt(0.4, 0.9);
+    s->mystery = RandFlt(0.0, 10.0);
+}
+
+#define BIGMYSTERY 1800.0
+#define MAXANGLES 16384
+
+void UpdateStar(global_info_t *global, flurry_info_t *flurry, Star *s)
+{
+    float rotationsPerSecond = (float) (2.0*PI*12.0/MAXANGLES) * s->rotSpeed /* speed control */;
+    double thisPointInRadians;
+    double thisAngle = flurry->fTime*rotationsPerSecond;
+    float cf;
+    double tmpX1,tmpY1,tmpZ1;
+    double tmpX2,tmpY2,tmpZ2;
+    double tmpX3,tmpY3,tmpZ3;
+    double tmpX4,tmpY4,tmpZ4;
+    double rotation;
+    double cr;
+    double sr;
+
+    s->ate = 0;
+    
+    cf = ((float) (cos(7.0*((flurry->fTime)*rotationsPerSecond))+cos(3.0*((flurry->fTime)*rotationsPerSecond))+cos(13.0*((flurry->fTime)*rotationsPerSecond))));
+    cf /= 6.0f;
+    cf += 0.75f; 
+    thisPointInRadians = 2.0 * PI * (double) s->mystery / (double) BIGMYSTERY;
+    
+    s->position[0] = 250.0f * cf * (float) cos(11.0 * (thisPointInRadians + (3.0*thisAngle)));
+    s->position[1] = 250.0f * cf * (float) sin(12.0 * (thisPointInRadians + (4.0*thisAngle)));
+    s->position[2] = 250.0f * (float) cos((23.0 * (thisPointInRadians + (12.0*thisAngle))));
+    
+    rotation = thisAngle*0.501 + 5.01 * (double) s->mystery / (double) BIGMYSTERY;
+    cr = cos(rotation);
+    sr = sin(rotation);
+    tmpX1 = s->position[0] * cr - s->position[1] * sr;
+    tmpY1 = s->position[1] * cr + s->position[0] * sr;
+    tmpZ1 = s->position[2];
+    
+    tmpX2 = tmpX1 * cr - tmpZ1 * sr;
+    tmpY2 = tmpY1;
+    tmpZ2 = tmpZ1 * cr + tmpX1 * sr;
+    
+    tmpX3 = tmpX2;
+    tmpY3 = tmpY2 * cr - tmpZ2 * sr;
+    tmpZ3 = tmpZ2 * cr + tmpY2 * sr + seraphDistance;
+    
+    rotation = thisAngle*2.501 + 85.01 * (double) s->mystery / (double) BIGMYSTERY;
+    cr = cos(rotation);
+    sr = sin(rotation);
+    tmpX4 = tmpX3 * cr - tmpY3 * sr;
+    tmpY4 = tmpY3 * cr + tmpX3 * sr;
+    tmpZ4 = tmpZ3;
+    
+    s->position[0] = (float) tmpX4;
+    s->position[1] = (float) tmpY4;
+    s->position[2] = (float) tmpZ4;
+}