X-Git-Url: https://jasonwoof.com/gitweb/?p=vor.git;a=blobdiff_plain;f=rocks.c;h=fc18bf36bdf3a4a96b12fb9d7cafe2499b0cd817;hp=fe66c4c3ba5bdc4effced5b5859c9cb06b53defb;hb=3ef599c7104a20c4f5268dbefb6590aa3e285663;hpb=46dacbe75dac20a1c6e1b61a2eb99ca25fc971ec

diff --git a/rocks.c b/rocks.c
index fe66c4c..fc18bf3 100644
--- 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"
@@ -12,8 +13,6 @@
 struct rock_struct {
 	float x,y,dx,dy;
 	int active;
-	int dead;  // has been blown out of the way
-	           // to make room for a new ship appearing.
 	SDL_Surface *image;
 	struct shape *shape;
 	int type_number;
@@ -21,16 +20,26 @@ struct rock_struct {
 
 struct rock_struct rock[MAXROCKS], *rockptr = rock;
 
-float rockrate,rockspeed;
-
 SDL_Surface *surf_rock[NROCKS];
 struct shape rock_shapes[NROCKS];
 
-int countdown = 0;
+// 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);
 
-uint32_t area;
+#define crnd() (2*(rnd()-0.5))
+
 
 int
 init_rocks(void)
@@ -39,8 +48,6 @@ init_rocks(void)
 	char a[MAX_PATH_LEN];
 	SDL_Surface *temp;
 
-	area = 0;
-
 	for(i = 0; i<NROCKS; i++) {
 		snprintf(a,MAX_PATH_LEN,add_path("sprites/rock%02d.png"),i);
 		NULLERROR(temp = IMG_Load(a));
@@ -51,76 +58,172 @@ init_rocks(void)
 }
 
 void
-new_rocks(void)
+reset_rocks(void)
 {
-	if(--countdown <= 0 && (rnd()*100.0<(rockrate += 0.025))) {
-		// Possibly create a rock
-		rockptr++;
-		if(rockptr-rock >= MAXROCKS) {
-			rockptr = rock;
-		}
-		if(!rockptr->active) {
-			rockptr->dx = -(rockspeed)*(1 + 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;
-			area += rockptr->shape->area;
+	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_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;
 		}
-		if(gamerate>0.1) {
-			countdown = (int)(ROCKRATE/gamerate);
+	} 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 {
-			countdown = 0;
+			// 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
-move_rocks(void)
+new_rocks(void)
 {
-	int i;
+	int i,j;
+	float ti[4];
+	float rmin[4];
+	float rmax[4];
 
-	// Move all the rocks
-	for(i = 0; i < MAXROCKS; i++) {
-		if(rock[i].active) {
-			rock[i].x += rock[i].dx*gamerate;
-			rock[i].y += rock[i].dy*gamerate + yscroll;
-			if(rock[i].y > YSIZE || rock[i].y < -rock[i].image->h) {
-				if(rock[i].dead) {
-					area -= rock[i].shape->area;
-					rock[i].dead = 0;
-					rock[i].active = 0;
-				} else {
-					// wrap
-					rock[i].y = (YSIZE - rock[i].image->h) - rock[i].y;
-					rock[i].y += (rock[i].dy*gamerate + yscroll) * 1.01;
-				}
+	if(nrocks < F_ROCKS) {
+		nrocks_timer += ms_frame;
+		if(nrocks_timer >= nrocks_inc_ticks) {
+			nrocks_timer -= nrocks_inc_ticks;
+			nrocks++;
+		}
+	}
+
+	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(rock[i].x < -rock[i].image->w || rock[i].x > XSIZE) {
-				area -= rock[i].shape->area;
-				rock[i].active = 0;
-				rock[i].dead = 0;
+			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;
 			}
 		}
 	}
 }
 
 void
-reset_rocks(void)
+move_rocks(void)
 {
 	int i;
 
-	area = 0;
-	for(i = 0; i<MAXROCKS; i++ ) {
-		rock[i].active = 0;
-		rock[i].dead = 0;
+	// Move all the rocks
+	for(i = 0; i < MAXROCKS; i++) {
+		if(rock[i].active) {
+			// move
+			rock[i].x += (rock[i].dx-screendx)*t_frame;
+			rock[i].y += (rock[i].dy-screendy)*t_frame;
+			// clip
+			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;
+			}
+		}
 	}
-
-	rockrate = 54.0;
-	rockspeed = 5.0;
 }
 
 void
@@ -167,25 +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].dead || 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;
-			rock[i].dead = 1;
+			n *= 15;
+			rock[i].dx += 54.0*dx/n;
+			rock[i].dy += 54.0*dy/n;
 		}
 	}
 }