Merge branch 'Mario/random_spawns'

[xonotic/xonotic-data.pk3dir.git] / qcsrc / common / explosion_equation.qc

diff --git a/qcsrc/common/explosion_equation.qc b/qcsrc/common/explosion_equation.qc
index 4d5eb5a7ee65798c8b89fba13d19075b5a32167a..3fddd70d23187131d433c72d00bbe87691bc5887 100644 (file)
--- a/qcsrc/common/explosion_equation.qc
+++ b/qcsrc/common/explosion_equation.qc
@@ -1,54 +1,62 @@
-vector explosion_calcpush_nomultiplier(vector explosion_v, vector target_v)
+float explosion_calcpush_getmultiplier(vector explosion_v, vector target_v)
 {
-       // solution of the equations:
-       //    v'                = v + alpha vp             // central hit
-       //    m*v'   + mp*vp'   = m*v + mp*vp              // conservation of momentum
-       //    m*v'^2 + mp*vp'^2 = m*v^2 + mp*vp^2          // conservation of energy (ELASTIC hit)
-       // -> alpha = 0                                    // case 1: did not hit
-       // -> alpha = 2*mp*(vp^2 - vp.v) / ((m+mp) * vp^2) // case 2: did hit
-       //                                                 // non-elastic hits are somewhere between these two
-
-       float alpha;
-       alpha  = explosion_v * (explosion_v - target_v);
+       float a;
+       a  = explosion_v * (explosion_v - target_v);
 
-       if(alpha <= 0)
+       if(a <= 0)
                // target is too fast to be hittable by this
-               return '0 0 0';
+               return 0;
+
+       a /= (explosion_v * explosion_v);
+               // we know we can divide by this, or above a would be == 0
 
-       alpha /= (explosion_v * explosion_v);
-               // now alpha is a multiplier
-               // we know we can divide by this, or above alpha would be == 0
-       
-       return
-               explosion_v * alpha;
+       return a;
 }
 
 #if 0
 vector explosion_calcpush(vector explosion_v, float explosion_m, vector target_v, float target_m, float elasticity)
 {
        // solution of the equations:
-       //    v'                = v + alpha vp             // central hit
-       //    m*v'   + mp*vp'   = m*v + mp*vp              // conservation of momentum
-       //    m*v'^2 + mp*vp'^2 = m*v^2 + mp*vp^2          // conservation of energy (ELASTIC hit)
-       // -> alpha = 0                                    // case 1: did not hit
-       // -> alpha = 2*mp*(vp^2 - vp.v) / ((m+mp) * vp^2) // case 2: did hit
-       //                                                 // non-elastic hits are somewhere between these two
+       //    v'                = v + a vp             // central hit
+       //    m*v'   + mp*vp'   = m*v + mp*vp          // conservation of momentum
+       //    m*v'^2 + mp*vp'^2 = m*v^2 + mp*vp^2      // conservation of energy (ELASTIC hit)
+       // -> a = 0                                    // case 1: did not hit
+       // -> a = 2*mp*(vp^2 - vp.v) / ((m+mp) * vp^2) // case 2: did hit
+       //                                             // non-elastic hits are somewhere between these two
 
        // this would be physically correct, but we don't do that
-       return explosion_calcpush_nomultiplier(explosion_v, target_v, 
+       return explosion_v * explosion_calcpush_getmultiplier(explosion_v, target_v) * (
                (1 + elasticity) * (
                        explosion_m
                ) / (
                        target_m + explosion_m
                )
-       );
+       ); // note: this factor is at least 0, at most 2
 }
 #endif
 
 // simplified formula, tuned so that if the target has velocity 0, we get exactly the original force
 vector damage_explosion_calcpush(vector explosion_f, vector target_v, float speedfactor)
 {
-       if(speedfactor == 0)
+       // if below 1, the formulas make no sense (and would cause superjumps)
+       if(speedfactor < 1)
                return explosion_f;
-       return explosion_calcpush_nomultiplier(explosion_f * speedfactor, target_v) * (1.0 / speedfactor);
+
+#if 0
+       float m;
+       // find m so that
+       //   speedfactor * (1 + e) * m / (1 + m) == 1
+       m = 1 / ((1 + 0) * speedfactor - 1);
+       vector v;
+       v = explosion_calcpush(explosion_f * speedfactor, m, target_v, 1, 0);
+       // the factor we then get is:
+       //   1
+       printf("MASS: %f\nv: %v -> %v\nENERGY BEFORE == %f + %f = %f\nENERGY AFTER >= %f\n",
+               m,
+               target_v, target_v + v,
+               target_v * target_v, m * explosion_f * speedfactor * explosion_f * speedfactor, target_v * target_v + m * explosion_f * speedfactor * explosion_f * speedfactor,
+               (target_v + v) * (target_v + v));
+       return v;
+#endif
+       return explosion_f * explosion_calcpush_getmultiplier(explosion_f * speedfactor, target_v);
 }