+ for(i = 0; i<MAXROCKS; i++) rock[i].active = 0;
+ nrocks = I_ROCKS;
+ nrocks_timer = 0;
+ rcnt = 0; lrcnt = -1;
+ rsum = 0; rsamples = 0;
+}
+
+enum { LEFT, RIGHT, TOP, BOTTOM };
+
+
+// compute the number of rocks/seccond that should be coming from each side
+
+// compute the speed ranges of rocks coming from each side
+void
+rock_sides(float *ti, float *speed_min, float *speed_max)
+{
+ float dx0,dx1, dy0,dy1;
+ float hfactor, vfactor;
+ int i;
+
+ for(i=0; i<4; i++) ti[i] = 0;
+ for(i=0; i<4; i++) speed_min[i] = 0;
+ for(i=0; i<4; i++) speed_max[i] = 0;
+ hfactor = (float)nrocks/KH; vfactor = (float)nrocks/KV;
+
+ dx0 = -RDX - screendx; dx1 = RDX - screendx;
+ dy0 = -RDY - screendy; dy1 = RDY - screendy;
+
+ if(dx0 != 0) {
+ if(dx0 < 0) {
+ speed_max[RIGHT] = -dx0;
+ if(dx1 < 0) {
+ // Rocks moving left only. So the RIGHT side of the screen
+ speed_min[RIGHT] = -dx1;
+ ti[RIGHT] = -(dx0+dx1)/2;
+ } else {
+ // Rocks moving left and right
+ speed_max[LEFT] = dx1;
+ ti[RIGHT] = -dx0/2;
+ ti[LEFT] = dx1/2;
+ }
+ } else {
+ // Rocks moving right only. So the LEFT side of the screen
+ speed_min[LEFT] = dx0;
+ speed_max[LEFT] = dx1;
+ ti[LEFT] = (dx0+dx1)/2;
+ }
+ }
+ ti[LEFT] *= hfactor;
+ ti[RIGHT] *= hfactor;
+
+ if(dy0 != 0) {
+ if(dy0 < 0) {
+ speed_max[BOTTOM] = -dy0;
+ if(dy1 < 0) {
+ // Rocks moving up only. So the BOTTOM of the screen
+ speed_min[BOTTOM] = -dy1;
+ ti[BOTTOM] = -(dy0+dy1)/2;
+ } else {
+ // Rocks moving up and down
+ speed_max[TOP] = dy1;
+ ti[BOTTOM] = -dy0/2;
+ ti[TOP] = dy1/2;
+ }
+ } else {
+ // Rocks moving down only. so the TOP of the screen
+ speed_min[TOP] = dy0;
+ speed_max[TOP] = dy1;
+ ti[TOP] = (dy0+dy1)/2;
+ }
+ }
+ ti[TOP] *= vfactor;
+ ti[BOTTOM] *= vfactor;
+}