X-Git-Url: https://jasonwoof.com/gitweb/?p=vor.git;a=blobdiff_plain;f=rocks.c;h=e47bc44c044f71984277808ff4a412e8c153d76a;hp=ca921cf22522e6435c827acd811b23c8d06ebb7d;hb=4461dfec6f8f09b43ec9719523d14978d82bd124;hpb=d96cae8368715101e2bf3f9ff8900dc171c70b2f

diff --git a/rocks.c b/rocks.c
index ca921cf..e47bc44 100644
--- a/rocks.c
+++ b/rocks.c
@@ -24,7 +24,10 @@ struct shape rock_shapes[NROCKS];
 
 // timers for rock generation.
 float rtimers[4];
-int nrocks;
+
+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.
@@ -50,7 +53,6 @@ init_rocks(void)
 		NULLERROR(surf_rock[i] = SDL_DisplayFormat(temp));
 		get_shape(surf_rock[i], &rock_shapes[i]);
 	}
-	nrocks = 41;
 	return 0;
 }
 
@@ -60,66 +62,109 @@ reset_rocks(void)
 	int i;
 
 	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_timer_increments(float *ti)
+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;
-	hfactor = nrocks/KH; vfactor = nrocks/KV;
+	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) {
-			if(dx1 < 0) ti[RIGHT] = -(dx0+dx1)/2;
-			else {
-				ti[RIGHT] = -dx0/2;
-				ti[LEFT] = dx1/2;
-			}
-		} else ti[LEFT] = (dx0+dx1)/2;
+	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) {
-			if(dy1 < 0) ti[BOTTOM] = -(dy0+dy1)/2;
-			else {
-				ti[BOTTOM] = -dy0/2;
-				ti[TOP] = dy1/2;
-			}
-		} else ti[TOP] = (dy0+dy1)/2;
+	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;
 }
 
+float
+weighted_rnd_range(float min, float max) {
+	return sqrt(min * min + rnd() * (max * max - min * min));
+}
+
 void
 new_rocks(void)
 {
 	int i,j;
 	float ti[4];
+	float rmin[4];
+	float rmax[4];
+
+	if(nrocks < F_ROCKS) {
+		nrocks_timer += ticks_since_last;
+		if(nrocks_timer >= nrocks_inc_ticks) {
+			nrocks_timer -= nrocks_inc_ticks;
+			nrocks++;
+		}
+	}
 
-	rock_timer_increments(ti);
+	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]*gamerate/20;
-		if(rtimers[i] >= 1) {
+		while(rtimers[i] >= 1) {
+			rtimers[i] -= 1;
 			j=0;
 			while(rockptr->active && j<MAXROCKS) {
 				if(++rockptr - rock >= MAXROCKS) rockptr = rock;
 				j++;
 			}
 			if(!rockptr->active) {
-				rtimers[i] -= 1;
 				rockptr->type_number = random() % NROCKS;
 				rockptr->image = surf_rock[rockptr->type_number];
 				rockptr->shape = &rock_shapes[rockptr->type_number];
@@ -127,24 +172,33 @@ new_rocks(void)
 					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->dx = RDX*crnd();
-				rockptr->dy = RDY*crnd();
-
 				rockptr->active = 1;
 			}
 		}