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Friction doesn't make sense any more, dropped that.
[vor.git] / rocks.c
diff --git a/rocks.c b/rocks.c
index 1e69ce2..fc18bf3 100644 (file)
--- a/rocks.c
+++ b/rocks.c
@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "common.h"
 #include "config.h"
 #include "file.h"
 #include "globals.h"
@@ -19,23 +20,25 @@ struct rock_struct {
 
 struct rock_struct rock[MAXROCKS], *rockptr = rock;
 
-float rockrate;
-
 SDL_Surface *surf_rock[NROCKS];
 struct shape rock_shapes[NROCKS];
 
-float rockhtimer = 0;
-int nrocks = 41;
+// timers for rock generation.
+float rtimers[4];
+
+uint32_t nrocks;
+uint32_t nrocks_timer;
+uint32_t nrocks_inc_ticks = 2*60*1000/(F_ROCKS-I_ROCKS);
+
+// constants for rock generation.
+#define KH 32.0  // 32 s for a speed=1 rock to cross the screen horizontally.
+#define KV 24.0  // 24 s for a speed=1 rock to cross the screen vertically.
+#define RDX 2.5  // range for rock dx values (+/-)
+#define RDY 2.5  // range for rock dy values (+/-)
 
 float rnd(void);
 
-// used for rock generation.
-#define KH (1.0/32.0)
-#define KV (1.0/24.0)
-#define RXMIN 5.0
-#define RXMAX 10.0
-#define RYMIN (-0.5)
-#define RYMAX 0.5
+#define crnd() (2*(rnd()-0.5))
 
 
 int
@@ -59,33 +62,146 @@ reset_rocks(void)
 {
        int i;
 
-       for(i = 0; i<MAXROCKS; i++ ) rock[i].active = 0;
+       for(i = 0; i<MAXROCKS; i++) rock[i].active = 0;
+       nrocks = I_ROCKS;
+       nrocks_timer = 0;
+}
+
+enum { LEFT, RIGHT, TOP, BOTTOM };
+
+
+// compute the number of rocks/second 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) {
+               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) {
+               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;
+}
 
-       rockrate = 54.0;
+float
+weighted_rnd_range(float min, float max) {
+       return sqrt(min * min + rnd() * (max * max - min * min));
 }
 
 void
 new_rocks(void)
 {
-       int i = 0;
-       float hfactor = KH*nrocks*7.5;
-
-       rockhtimer += hfactor*gamerate/20;
-       if(rockhtimer >= 1) {
-               while(rockptr->active && i<MAXROCKS) {
-                       if(++rockptr - rock >= MAXROCKS) rockptr = rock;
-                       i++;
+       int i,j;
+       float ti[4];
+       float rmin[4];
+       float rmax[4];
+
+       if(nrocks < F_ROCKS) {
+               nrocks_timer += ms_frame;
+               if(nrocks_timer >= nrocks_inc_ticks) {
+                       nrocks_timer -= nrocks_inc_ticks;
+                       nrocks++;
                }
-               if(!rockptr->active) {
-                       rockhtimer -= 1;
-                       rockptr->dx = -5.0*(1.0 + rnd());
-                       rockptr->dy = rnd()-0.5;
-                       rockptr->type_number = random() % NROCKS;
-                       rockptr->image = surf_rock[rockptr->type_number];
-                       rockptr->shape = &rock_shapes[rockptr->type_number];
-                       rockptr->x = (float)XSIZE;
-                       rockptr->y = rnd()*(YSIZE + rockptr->image->h);
-                       rockptr->active = 1;
+       }
+
+       rock_sides(ti, rmin, rmax);
+
+       // loop through the four sides of the screen
+       for(i=0; i<4; i++) {
+               // see if we generate a rock for this side this frame
+               rtimers[i] += ti[i]*s_frame;
+               while(rtimers[i] >= 1) {
+                       rtimers[i] -= 1;
+                       j=0;
+                       while(rockptr->active && j<MAXROCKS) {
+                               if(++rockptr - rock >= MAXROCKS) rockptr = rock;
+                               j++;
+                       }
+                       if(!rockptr->active) {
+                               rockptr->type_number = random() % NROCKS;
+                               rockptr->image = surf_rock[rockptr->type_number];
+                               rockptr->shape = &rock_shapes[rockptr->type_number];
+                               switch(i) {
+                                       case RIGHT:
+                                               rockptr->x = XSIZE;
+                                               rockptr->y = rnd()*(YSIZE + rockptr->image->h);
+
+                                               rockptr->dx = -weighted_rnd_range(rmin[i], rmax[i]) + screendx;
+                                               rockptr->dy = RDY*crnd();
+                                               break;
+                                       case LEFT:
+                                               rockptr->x = -rockptr->image->w;
+                                               rockptr->y = rnd()*(YSIZE + rockptr->image->h);
+
+                                               rockptr->dx = weighted_rnd_range(rmin[i], rmax[i]) + screendx;
+                                               rockptr->dy = RDY*crnd();
+                                               break;
+                                       case BOTTOM:
+                                               rockptr->x = rnd()*(XSIZE + rockptr->image->w);
+                                               rockptr->y = YSIZE;
+
+                                               rockptr->dx = RDX*crnd();
+                                               rockptr->dy = -weighted_rnd_range(rmin[i], rmax[i]) + screendy;
+                                               break;
+                                       case TOP:
+                                               rockptr->x = rnd()*(XSIZE + rockptr->image->w);
+                                               rockptr->y = -rockptr->image->h;
+
+                                               rockptr->dx = RDX*crnd();
+                                               rockptr->dy = weighted_rnd_range(rmin[i], rmax[i]) + screendy;
+                                               break;
+                               }
+
+                               rockptr->active = 1;
+                       }
                }
        }
 }
@@ -99,15 +215,13 @@ move_rocks(void)
        for(i = 0; i < MAXROCKS; i++) {
                if(rock[i].active) {
                        // move
-                       rock[i].x += rock[i].dx*gamerate;
-                       rock[i].y += rock[i].dy*gamerate + yscroll;
+                       rock[i].x += (rock[i].dx-screendx)*t_frame;
+                       rock[i].y += (rock[i].dy-screendy)*t_frame;
                        // clip
-                       if(rock[i].y < -rock[i].image->h || rock[i].y > YSIZE) {
-                               // rock[i].active = 0;
-                               rock[i].y = (YSIZE - rock[i].image->h) - rock[i].y;
-                               rock[i].y += (rock[i].dy*gamerate + yscroll) * 1.01;
+                       if(rock[i].x < -rock[i].image->w || rock[i].x >= XSIZE
+                                       || rock[i].y < -rock[i].image->h || rock[i].y >= YSIZE) {
+                               rock[i].active = 0;
                        }
-                       if(rock[i].x < -rock[i].image->w || rock[i].x > XSIZE) rock[i].active = 0;
                }
        }
 }
@@ -156,22 +270,24 @@ blast_rocks(float x, float y, float radius, int onlyslow)
        int i;
        float dx, dy, n;
 
+       if(onlyslow) return;
+
        for(i = 0; i<MAXROCKS; i++ ) {
                if(rock[i].x <= 0) continue;
 
                // This makes it so your explosion from dying magically doesn't leave
                // any rocks that aren't moving much on the x axis. If onlyslow is set,
                // only rocks that are barely moving will be pushed.
-               if(onlyslow && (rock[i].dx < -4 || rock[i].dx > 3)) continue;
+               if(onlyslow && (rock[i].dx-screendx < -4 || rock[i].dx-screendx > 3)) continue;
 
                dx = rock[i].x - x;
                dy = rock[i].y - y;
 
                n = sqrt(dx*dx + dy*dy);
                if(n < radius) {
-                       n *= 20;
-                       rock[i].dx += rockrate*(dx+30)/n;
-                       rock[i].dy += rockrate*dy/n;
+                       n *= 15;
+                       rock[i].dx += 54.0*dx/n;
+                       rock[i].dy += 54.0*dy/n;
                }
        }
 }