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https://github.com/scp-fs2open/fs2open.github.com.git
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portej05
719825f80d
I've tested this through compiling and through hand checking. Normalises line endings in ALL files to \n.
135 lines
2.8 KiB
C++
135 lines
2.8 KiB
C++
/*
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* Copyright (C) Volition, Inc. 1999. All rights reserved.
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*
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* All source code herein is the property of Volition, Inc. You may not sell
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* or otherwise commercially exploit the source or things you created based on the
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* source.
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*
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*/
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#include "globalincs/pstypes.h"
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#include "math/staticrand.h"
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#include "math/vecmat.h"
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int Semirand_inited = 0;
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int Semirand[SEMIRAND_MAX];
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// Initialize Semirand array.
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void init_semirand()
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{
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int i;
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Semirand_inited = 1;
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for (i=0; i<SEMIRAND_MAX; i++)
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Semirand[i] = (myrand() << 15) + myrand();
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}
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// Return a fairly random 32 bit value given a reasonably small number.
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int static_rand(int num)
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{
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int a, b, c;
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if (!Semirand_inited)
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init_semirand();
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a = num & (SEMIRAND_MAX - 1);
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b = (num >> SEMIRAND_MAX_LOG) & (SEMIRAND_MAX - 1);
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c = (num >> (2 * SEMIRAND_MAX_LOG)) & (SEMIRAND_MAX - 1);
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return Semirand[a] ^ Semirand[b] ^ Semirand[c];
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}
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// Return a random value in 0.0f .. 1.0f- (ie, it will never return 1.0f).
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float static_randf(int num)
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{
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int a;
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a = static_rand(num);
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return (a & 0xffff) / 65536.0f;
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}
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float static_randf_range(int num, float min, float max)
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{
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float rval;
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rval = static_randf(num);
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rval = rval * (max - min) + min;
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return rval;
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}
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void static_randvec(int num, vec3d *vp)
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{
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vp->xyz.x = static_randf(num) - 0.5f;
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vp->xyz.y = static_randf(num+1) - 0.5f;
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vp->xyz.z = static_randf(num+2) - 0.5f;
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vm_vec_normalize_quick(vp);
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}
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// randomly perturb a vector around a given (normalized vector) or optional orientation matrix
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void static_rand_cone(int num, vec3d *out, vec3d *in, float max_angle, matrix *orient)
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{
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vec3d t1, t2;
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matrix *rot;
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matrix m;
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// get an orientation matrix
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if(orient != NULL){
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rot = orient;
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} else {
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vm_vector_2_matrix(&m, in, NULL, NULL);
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rot = &m;
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}
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// axis 1
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vm_rot_point_around_line(&t1, in, fl_radian(static_randf_range(num,-max_angle, max_angle)), &vmd_zero_vector, &rot->vec.fvec);
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// axis 2
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vm_rot_point_around_line(&t2, &t1, fl_radian(static_randf_range(num+1,-max_angle, max_angle)), &vmd_zero_vector, &rot->vec.rvec);
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// axis 3
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vm_rot_point_around_line(out, &t2, fl_radian(static_randf_range(num+2,-max_angle, max_angle)), &vmd_zero_vector, &rot->vec.uvec);
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}
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/////////////////////////////////////////////////////////////////////
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// Alternate random number generator, that doesn't affect rand() sequence
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/////////////////////////////////////////////////////////////////////
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#define RND_MASK 0x6000
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#define RND_MAX 0x7fff
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int Rnd_seed = 1;
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// Seed the random number generator. Doesn't have to be called.
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void srand_alt(int seed)
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{
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Rnd_seed = seed;
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}
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// Get a random integer between 1 and RND_MAX
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int rand_alt()
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{
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static int x=Rnd_seed;
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int old_x;
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old_x = x;
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x >>= 1;
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if ( old_x & 1 ) {
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x ^= RND_MASK;
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}
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return x;
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}
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// Get a random float between 0 and 1.0
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float frand_alt()
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{
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int r = rand_alt();
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return i2fl(r)/RND_MAX;
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}
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