// all movement is based on t_frame.
float t_frame; // length of this frame (in ticks = 1/20th second)
+float s_frame; // length of this frame (seconds)
int ms_frame; // length of this frame (milliseconds)
int ms_end; // end of this frame (milliseconds)
int nships,score;
int gameover;
-int maneuver = 0;
+int jets = 0;
float fadetimer = 0, faderate;
}
void
-create_engine_dots(int newdots) {
+new_engine_dots(int n, int dir) {
int i;
- double theta,r,dx,dy;
-
- if(!opt_tail_engine) return;
-
- if(state == GAMEPLAY) {
- for(i = 0; i<newdots*t_frame; i++) {
- if(dotptr->active == 0) {
- theta = rnd()*M_PI*2;
- r = rnd();
- dx = cos(theta)*r;
- dy = sin(theta)*r;
-
- dotptr->active = 1;
- dotptr->x = shipx + surf_ship->w/2-14;
- dotptr->y = shipy + surf_ship->h/2 + (rnd()-0.5)*5-1;
- dotptr->dx = 10*(dx-1.5) + shipdx;
- dotptr->dy = 1*dy + shipdy;
- dotptr->life = 45 + rnd(1)*5;
-
- dotptr++;
- if(dotptr-edot >= MAXENGINEDOTS) {
- dotptr = edot;
- }
- }
- }
- }
-}
+ float a, r; // angle, random length
+ float dx, dy;
+ float hx, hy; // half ship width/height.
+ static const int s[4] = { 2, 1, 0, 1 };
-void
-create_engine_dots2(int newdots, int m) {
- int i;
- double theta, theta2, dx, dy, adx, ady;
+ hx = surf_ship->w / 2;
+ hy = surf_ship->h / 2;
- // Don't create fresh engine dots when
- // the game is not being played and a demo is not beng shown
- if(state != GAMEPLAY) return;
-
- for(i = 0; i<newdots; i++) {
+ for(i = 0; i<n; i++) {
if(dotptr->active == 0) {
- theta = rnd()*M_PI*2;
- theta2 = rnd()*M_PI*2;
-
- dx = cos(theta) * fabs(cos(theta2));
- dy = sin(theta) * fabs(cos(theta2));
- adx = fabs(dx);
- ady = fabs(dy);
-
+ a = rnd()*M_PI + (dir-1)*M_PI_2;
+ r = sin(rnd()*M_PI);
+ dx = r * cos(a);
+ dy = r * -sin(a); // screen y is "backwards".
dotptr->active = 1;
- dotptr->x = shipx + surf_ship->w/2 + (rnd()-0.5)*3;
- dotptr->y = shipy + surf_ship->h/2 + (rnd()-0.5)*3;
-
- switch(m) {
- case 0:
- dotptr->x -= 14;
- dotptr->dx = -20*adx + shipdx;
- dotptr->dy = 2*dy + shipdy;
- dotptr->life = 60 * adx;
- break;
- case 1:
- dotptr->dx = 2*dx + shipdx;
- dotptr->dy = -20*ady + shipdy;
- dotptr->life = 60 * ady;
- break;
- case 2:
- dotptr->x += 14;
- dotptr->dx = 20*adx + shipdx;
- dotptr->dy = 2*dy + shipdy;
- dotptr->life = 60 * adx;
- break;
- case 3:
- dotptr->dx = 2*dx + shipdx;
- dotptr->dy = 20*ady + shipdy;
- dotptr->life = 60 * ady;
- break;
+ dotptr->x = shipx + s[dir]*hx + (rnd()-0.5)*3;
+ dotptr->y = shipy + s[(dir+1)&3]*hy + (rnd()-0.5)*3;
+ if(dir&1) {
+ dotptr->dx = shipdx + 2*dx;
+ dotptr->dy = shipdy + 20*dy;
+ dotptr->life = 60 * fabs(dy);
+ } else {
+ dotptr->dx = shipdx + 20*dx;
+ dotptr->dy = shipdy + 2*dy;
+ dotptr->life = 60 * fabs(dx);
}
+
dotptr++;
if(dotptr-edot >= MAXENGINEDOTS) {
dotptr = edot;
drawdots(SDL_Surface *s) {
int m;
- // Create more engine dots comin' out da back
- if(!gameover) create_engine_dots(200);
-
// Create engine dots out the side we're moving from
for(m = 0; m<4; m++) {
- if(maneuver & 1<<m) { // 'maneuver' is a bit field
- create_engine_dots2(80,m);
+ if(jets & 1<<m) { // 'jets' is a bit field
+ new_engine_dots(80,m);
}
}
ms_end += ms_frame;
if(ms_frame>200 || ms_frame<0) {
// We won't run at all below 5 frames per second.
- t_frame = 0;
+ // This also happens if we were paused, grr.
+ s_frame = 0;
+ ms_frame = 0;
} else {
- t_frame = opt_gamespeed*ms_frame/50.0;
- if(state == GAMEPLAY) {
- score += ms_frame;
- }
+ s_frame = opt_gamespeed * ms_frame / 1000;
+ if(state == GAMEPLAY) score += ms_frame;
}
+ t_frame = s_frame * 20;
// Update the surface
SDL_Flip(surf_screen);
new_rocks();
- // FRICTION?
- if(opt_friction) {
- shipdx *= pow((double)0.9,(double)t_frame);
- shipdy *= pow((double)0.9,(double)t_frame);
- }
-
// INERTIA
shipx += shipdx*t_frame;
shipy += shipdy*t_frame;
shipdx = screendx; shipdy = screendy;
}
- maneuver = 0;
+ jets = 0;
} else {
SDL_PumpEvents();
keystate = SDL_GetKeyState(NULL);
if(!gameover) {
if(!paused) {
- if(keystate[SDLK_UP] | keystate[SDLK_c]) { shipdy -= 1.5*t_frame; maneuver |= 1<<3;}
- if(keystate[SDLK_DOWN] | keystate[SDLK_t]) { shipdy += 1.5*t_frame; maneuver |= 1<<1;}
- if(keystate[SDLK_LEFT] | keystate[SDLK_h]) { shipdx -= 1.5*t_frame; maneuver |= 1<<2;}
- if(keystate[SDLK_RIGHT] | keystate[SDLK_n]) { shipdx += 1.5*t_frame; maneuver |= 1;}
+ if(keystate[SDLK_LEFT] | keystate[SDLK_h]) { shipdx -= 1.5*t_frame; jets |= 1<<0;}
+ if(keystate[SDLK_DOWN] | keystate[SDLK_t]) { shipdy += 1.5*t_frame; jets |= 1<<1;}
+ if(keystate[SDLK_RIGHT] | keystate[SDLK_n]) { shipdx += 1.5*t_frame; jets |= 1<<2;}
+ if(keystate[SDLK_UP] | keystate[SDLK_c]) { shipdy -= 1.5*t_frame; jets |= 1<<3;}
if(keystate[SDLK_3]) { SDL_SaveBMP(surf_screen, "snapshot.bmp"); }
}
Got questions, comments, patches, etc.? Contact Jason Woofenden