rocks.c

   1 #include <SDL_image.h>
   2 #include <math.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5
   6 #include "config.h"
   7 #include "file.h"
   8 #include "globals.h"
   9 #include "rocks.h"
  10 #include "shape.h"
  11
  12 struct rock_struct {
  13         float x,y,dx,dy;
  14         int active;
  15         SDL_Surface *image;
  16         struct shape *shape;
  17         int type_number;
  18 };
  19
  20 struct rock_struct rock[MAXROCKS], *rockptr = rock;
  21
  22 float rockrate;
  23
  24 SDL_Surface *surf_rock[NROCKS];
  25 struct shape rock_shapes[NROCKS];
  26
  27 float rockhtimer = 0;
  28 int nrocks = 41;
  29
  30 float rnd(void);
  31
  32 // used for rock generation.
  33 #define KH (1.0/32.0)
  34 #define KV (1.0/24.0)
  35 #define RXMIN 5.0
  36 #define RXMAX 10.0
  37 #define RYMIN (-0.5)
  38 #define RYMAX 0.5
  39
  40
  41 int
  42 init_rocks(void)
  43 {
  44         int i;
  45         char a[MAX_PATH_LEN];
  46         SDL_Surface *temp;
  47
  48         for(i = 0; i<NROCKS; i++) {
  49                 snprintf(a,MAX_PATH_LEN,add_path("sprites/rock%02d.png"),i);
  50                 NULLERROR(temp = IMG_Load(a));
  51                 NULLERROR(surf_rock[i] = SDL_DisplayFormat(temp));
  52                 get_shape(surf_rock[i], &rock_shapes[i]);
  53         }
  54         return 0;
  55 }
  56
  57 void
  58 reset_rocks(void)
  59 {
  60         int i;
  61
  62         for(i = 0; i<MAXROCKS; i++ ) rock[i].active = 0;
  63
  64         rockrate = 54.0;
  65 }
  66
  67 void
  68 new_rocks(void)
  69 {
  70         int i = 0;
  71         float hfactor = KH*nrocks*7.5;
  72
  73         rockhtimer += hfactor*gamerate/20;
  74         if(rockhtimer >= 1) {
  75                 while(rockptr->active && i<MAXROCKS) {
  76                         if(++rockptr - rock >= MAXROCKS) rockptr = rock;
  77                         i++;
  78                 }
  79                 if(!rockptr->active) {
  80                         rockhtimer -= 1;
  81                         rockptr->dx = -5.0*(1.0 + rnd());
  82                         rockptr->dy = rnd()-0.5;
  83                         rockptr->type_number = random() % NROCKS;
  84                         rockptr->image = surf_rock[rockptr->type_number];
  85                         rockptr->shape = &rock_shapes[rockptr->type_number];
  86                         rockptr->x = (float)XSIZE;
  87                         rockptr->y = rnd()*(YSIZE + rockptr->image->h);
  88                         rockptr->active = 1;
  89                 }
  90         }
  91 }
  92
  93 void
  94 move_rocks(void)
  95 {
  96         int i;
  97
  98         // Move all the rocks
  99         for(i = 0; i < MAXROCKS; i++) {
 100                 if(rock[i].active) {
 101                         // move
 102                         rock[i].x += rock[i].dx*gamerate;
 103                         rock[i].y += rock[i].dy*gamerate + yscroll;
 104                         // clip
 105                         if(rock[i].y < -rock[i].image->h || rock[i].y > YSIZE) {
 106                                 // rock[i].active = 0;
 107                                 rock[i].y = (YSIZE - rock[i].image->h) - rock[i].y;
 108                                 rock[i].y += (rock[i].dy*gamerate + yscroll) * 1.01;
 109                         }
 110                         if(rock[i].x < -rock[i].image->w || rock[i].x > XSIZE) rock[i].active = 0;
 111                 }
 112         }
 113 }
 114
 115 void
 116 draw_rocks(void)
 117 {
 118         int i;
 119         SDL_Rect src, dest;
 120
 121         src.x = 0; src.y = 0;
 122
 123         for(i = 0; i<MAXROCKS; i++) {
 124                 if(rock[i].active) {
 125                         src.w = rock[i].image->w;
 126                         src.h = rock[i].image->h;
 127
 128                         dest.w = src.w;
 129                         dest.h = src.h;
 130                         dest.x = (int) rock[i].x;
 131                         dest.y = (int) rock[i].y;
 132
 133                         SDL_BlitSurface(rock[i].image,&src,surf_screen,&dest);
 134
 135                 }
 136         }
 137 }
 138
 139 int
 140 hit_rocks(float x, float y, struct shape *shape)
 141 {
 142         int i;
 143
 144         for(i=0; i<MAXROCKS; i++) {
 145                 if(rock[i].active) {
 146                         if(collide(x-rock[i].x, y-rock[i].y, rock[i].shape, shape))
 147                                 return 1;
 148                 }
 149         }
 150         return 0;
 151 }
 152
 153 void
 154 blast_rocks(float x, float y, float radius, int onlyslow)
 155 {
 156         int i;
 157         float dx, dy, n;
 158
 159         for(i = 0; i<MAXROCKS; i++ ) {
 160                 if(rock[i].x <= 0) continue;
 161
 162                 // This makes it so your explosion from dying magically doesn't leave
 163                 // any rocks that aren't moving much on the x axis. If onlyslow is set,
 164                 // only rocks that are barely moving will be pushed.
 165                 if(onlyslow && (rock[i].dx < -4 || rock[i].dx > 3)) continue;
 166
 167                 dx = rock[i].x - x;
 168                 dy = rock[i].y - y;
 169
 170                 n = sqrt(dx*dx + dy*dy);
 171                 if(n < radius) {
 172                         n *= 20;
 173                         rock[i].dx += rockrate*(dx+30)/n;
 174                         rock[i].dy += rockrate*dy/n;
 175                 }
 176         }
 177 }