X-Git-Url: https://jasonwoof.com/gitweb/?p=vor.git;a=blobdiff_plain;f=main.c;h=ba1c8b7bd6421c71f35543fd8da979fa5eedda50;hp=e784d3ab4f8b17e4522e135f1f8067738cb94503;hb=ae2d57cc5b1b64621a76aed51ce14f4c555c3bc8;hpb=61c9964f01a09d4b48c27aca3a33fb744eb8e0e4

diff --git a/main.c b/main.c
index e784d3a..ba1c8b7 100644
--- a/main.c
+++ b/main.c
@@ -75,7 +75,7 @@ float screendx = SCREENDXMIN, screendy = 0.0;
 float back_dist;
 
 // all movement is based on t_frame.
-float t_frame;  // length of this frame (in ticks = 1/20th second)
+float t_frame;  // length of this frame (in ticks = 1/20th second)  adjusted for gamespeed
 int ms_frame;   // length of this frame (milliseconds)
 int ms_end;     // end of this frame (milliseconds)
 
@@ -138,19 +138,20 @@ init_engine_dots() {
 void
 new_bang_dots(int xbang, int ybang, int dx, int dy, SDL_Surface *s)
 {
-	int i, x, y;
+	int i, n, x, y;
 	uint16_t *pixel, c;
 	uint32_t colorkey;
 	int row_inc;
 	double theta, r;
 
+	n = 24.0 * t_frame;
 	pixel = s->pixels;
 	row_inc = s->pitch/sizeof(uint16_t) - s->w;
 	colorkey = s->format->colorkey;
 
 	SDL_LockSurface(s);
 
-	for(i=0; i<10; i++) {
+	for(i=0; i<n; i++) {
 		pixel = s->pixels;
 		for(y=0; y<s->h; y++) {
 			for(x = 0; x<s->w; x++) {
@@ -163,14 +164,11 @@ new_bang_dots(int xbang, int ybang, int dx, int dy, SDL_Surface *s)
 					bdot[bd2].dy = 45*r*sin(theta) + dy;
 					bdot[bd2].x = x + xbang;
 					bdot[bd2].y = y + ybang;
-					bdot[bd2].c = 0;
+					bdot[bd2].c = (i < n-3) ? 0 : c;
 					bdot[bd2].life = 100;
 					bdot[bd2].decay = frnd()*3 + 1;
 					bdot[bd2].active = 1;
 
-					// Replace the last few bang dots with the pixels from the exploding object
-					if(i>6) bdot[bd2].c = c;
-
 					bd2 = (bd2+1) % MAXBANGDOTS;
 				}
 				pixel += row_inc;
@@ -182,28 +180,21 @@ new_bang_dots(int xbang, int ybang, int dx, int dy, SDL_Surface *s)
 }
 
 void
-draw_bang_dots(SDL_Surface *s)
+move_bang_dots(float ticks)
 {
 	int i;
-	int first_i, last_i;
-	uint16_t *pixels, *pixel, c;
-	int row_inc = s->pitch/sizeof(uint16_t);
 	Sprite *hit;
 
-	pixels = (uint16_t *) s->pixels;
-	first_i = -1;
-	last_i = 0;
-
 	for(i=0; i<MAXBANGDOTS; i++) {
 		if(!bdot[i].active) continue;
 
 		// decrement life and maybe kill
 		bdot[i].life -= bdot[i].decay;
-		if(bdot[i].life<0) { bdot[i].active = 0; continue; }
-
+		if(bdot[i].life < 0) { bdot[i].active = 0; continue; }
+		
 		// move and clip
-		bdot[i].x += (bdot[i].dx - screendx)*t_frame;
-		bdot[i].y += (bdot[i].dy - screendy)*t_frame;
+		bdot[i].x += (bdot[i].dx - screendx)*ticks;
+		bdot[i].y += (bdot[i].dy - screendy)*ticks;
 		if(bdot[i].x < 0 || bdot[i].x >= XSIZE || bdot[i].y < 0 || bdot[i].y >= YSIZE) {
 			bdot[i].active = 0;
 			continue;
@@ -218,6 +209,21 @@ draw_bang_dots(SDL_Surface *s)
 				continue;
 			}
 		}
+	}
+}
+
+
+void
+draw_bang_dots(SDL_Surface *s)
+{
+	int i;
+	uint16_t *pixels, *pixel, c;
+	int row_inc = s->pitch/sizeof(uint16_t);
+
+	pixels = (uint16_t *) s->pixels;
+
+	for(i=0; i<MAXBANGDOTS; i++) {
+		if(!bdot[i].active) continue;
 
 		pixel = pixels + row_inc*(int)(bdot[i].y) + (int)(bdot[i].x);
 		if(bdot[i].c) c = bdot[i].c; else c = heatcolor[(int)(bdot[i].life)*3];
@@ -227,12 +233,15 @@ draw_bang_dots(SDL_Surface *s)
 
 
 void
-new_engine_dots(int n, int dir) {
+new_engine_dots(float time_span, int dir) {
 	int i;
+	int n = time_span * ENGINE_DOTS_PER_TIC;
 	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 };
+	float time;
+	float accelh, accelv, past_ship_dx, past_ship_dy;
 
 	hx = ship.image->w / 2;
 	hy = ship.image->h / 2;
@@ -245,18 +254,40 @@ new_engine_dots(int n, int dir) {
 			dy = r * -sin(a);  // screen y is "backwards".
 
 			dotptr->active = 1;
-			dotptr->x = ship.x + s[dir]*hx + (frnd()-0.5)*3;
-			dotptr->y = ship.y + s[(dir+1)&3]*hy + (frnd()-0.5)*3;
+
+			// dot was created at a random time during the time span
+			time = frnd() * time_span; // this is how long ago
+
+			// calculate how fast the ship was going when this engine dot was
+			// created (as if it had a smooth acceleration). This is used in
+			// determining the velocity of the dots, but not their starting
+			// location.
+			accelh = ((ship.jets >> 2) & 1) - (ship.jets & 1);
+			accelh *= THRUSTER_STRENGTH * time;
+			past_ship_dx = ship.dx - accelh;
+			accelv = ((ship.jets >> 1) & 1) - ((ship.jets >> 3) & 1);
+			accelv *= THRUSTER_STRENGTH * time;
+			past_ship_dy = ship.dy - accelv;
+
+			// the starting position (not speed) of the dot is calculated as
+			// though the ship were traveling at a constant speed for this
+			// time_span.
+			dotptr->x = (ship.x - (ship.dx - screendx) * time) + s[dir]*hx;
+			dotptr->y = (ship.y - (ship.dy - screendy) * time) + s[(dir+1)&3]*hy;
 			if(dir&1) {
-				dotptr->dx = ship.dx + 2*dx;
-				dotptr->dy = ship.dy + 20*dy;
+				dotptr->dx = past_ship_dx + 2*dx;
+				dotptr->dy = past_ship_dy + 20*dy;
 				dotptr->life = 60 * fabs(dy);
 			} else {
-				dotptr->dx = ship.dx + 20*dx;
-				dotptr->dy = ship.dy + 2*dy;
+				dotptr->dx = past_ship_dx + 20*dx;
+				dotptr->dy = past_ship_dy + 2*dy;
 				dotptr->life = 60 * fabs(dx);
 			}
 
+			// move the dot as though it were created in the past
+			dotptr->x += (dotptr->dx - screendx) * time;
+			dotptr->y += (dotptr->dy - screendy) * time;
+
 			if(dotptr - edot < MAXENGINEDOTS-1) dotptr++;
 			else dotptr = edot;
 		}
@@ -264,25 +295,20 @@ new_engine_dots(int n, int dir) {
 }
 
 void
-draw_engine_dots(SDL_Surface *s) {
+move_engine_dots(float ticks) {
 	int i;
-	uint16_t c;
-	uint16_t *pixels = (uint16_t *) s->pixels;
-	int row_inc = s->pitch/sizeof(uint16_t);
-	int heatindex;
 	Sprite *hit;
 
 	for(i = 0; i<MAXENGINEDOTS; i++) {
 		if(!edot[i].active) continue;
-		edot[i].x += (edot[i].dx - screendx)*t_frame;
-		edot[i].y += (edot[i].dy - screendy)*t_frame;
+
+		edot[i].x += (edot[i].dx - screendx)*ticks;
+		edot[i].y += (edot[i].dy - screendy)*ticks;
 		edot[i].life -= t_frame*3;
-		if(edot[i].life < 0
-				|| edot[i].x<0 || edot[i].x >= XSIZE
-				|| edot[i].y<0 || edot[i].y >= YSIZE) {
+		if(edot[i].life < 0 || edot[i].x<0 || edot[i].x >= XSIZE || edot[i].y < 0 || edot[i].y >= YSIZE) {
 			edot[i].active = 0;
-			continue;
 		}
+
 		// check collisions
 		if((hit = pixel_collides(edot[i].x, edot[i].y))) {
 			if(hit->type != SHIP) { // they shouldn't hit the ship, but they do
@@ -292,6 +318,20 @@ draw_engine_dots(SDL_Surface *s) {
 				continue;
 			}
 		}
+	}
+}
+
+void
+draw_engine_dots(SDL_Surface *s) {
+	int i;
+	uint16_t c;
+	uint16_t *pixels = (uint16_t *) s->pixels;
+	int row_inc = s->pitch/sizeof(uint16_t);
+	int heatindex;
+
+	for(i = 0; i<MAXENGINEDOTS; i++) {
+		if(!edot[i].active) continue;
+
 		heatindex = edot[i].life * 6;
 		c = heatindex>3*W ? heatcolor[3*W-1] : heatcolor[heatindex];
 		pixels[row_inc*(int)(edot[i].y) + (int)(edot[i].x)] = c;
@@ -299,18 +339,16 @@ draw_engine_dots(SDL_Surface *s) {
 }
 
 void
-drawdots(SDL_Surface *s) {
+draw_dots(SDL_Surface *s) {
 	int m;
 
-	// Create engine dots out the side we're moving from
+	// Create engine dots
 	for(m = 0; m<4; m++) {
 		if(ship.jets & 1<<m) { // 'jets' is a bit field
-			new_engine_dots(200.0*t_frame,m);
+			new_engine_dots(t_frame,m);
 		}
 	}
 
-	move_dust();
-
 	SDL_LockSurface(s);
 	draw_dust(s);
 	draw_engine_dots(s);
@@ -510,7 +548,7 @@ void
 draw(void) {
 
 	SDL_FillRect(surf_screen,NULL,0);  // black background
-	drawdots(surf_screen);             // background dots
+	draw_dots(surf_screen);             // background dots
 	draw_sprite(SPRITE(&ship));
 	draw_rocks();
 
@@ -642,12 +680,10 @@ gameloop() {
 				}
 			}
 
-			new_rocks();
-
 			// SCROLLING
-			tmp = (ship.y+ship.dy*t_frame-YSCROLLTO)/25 + (ship.dy-screendy);
+			tmp = (ship.y+ship.h/2+ship.dy*t_frame-YSCROLLTO)/25 + (ship.dy-screendy);
 			screendy += tmp * t_frame/12;
-			tmp = (ship.x+ship.dx*t_frame-XSCROLLTO)/25 + (ship.dx-screendx);
+			tmp = (ship.x+ship.w/2+ship.dx*t_frame-XSCROLLTO)/25 + (ship.dx-screendx);
 			screendx += tmp * t_frame/12;
 			// taper off so we don't hit the barrier abruptly.
 			// (if we would hit in < 2 seconds, adjust to 2 seconds).
@@ -660,8 +696,10 @@ gameloop() {
 			bangx += (bangdx - screendx)*t_frame;
 			bangy += (bangdy - screendy)*t_frame;
 
-			move_sprites();
-
+			move_sprites(t_frame);
+			move_engine_dots(t_frame);
+			move_bang_dots(t_frame);
+			move_dust(t_frame);
 
 			// BOUNCE off left or right edge of screen
 			if(ship.x < 0 || ship.x+ship.w > XSIZE) {
@@ -675,6 +713,8 @@ gameloop() {
 				ship.dy = screendy - (ship.dy-screendy)*opt_bounciness;
 			}
 
+			new_rocks(t_frame);
+
 			draw();
 
 			if(state == GAMEPLAY && bang) {
@@ -741,10 +781,11 @@ gameloop() {
 
 		if(state == GAMEPLAY) {
 			if(!paused) {
-				if(keystate[SDLK_LEFT]  | keystate[SDLK_h]) { ship.dx -= 1.5*t_frame; ship.jets |= 1<<0;}
-				if(keystate[SDLK_DOWN]  | keystate[SDLK_t]) { ship.dy += 1.5*t_frame; ship.jets |= 1<<1;}
-				if(keystate[SDLK_RIGHT] | keystate[SDLK_n]) { ship.dx += 1.5*t_frame; ship.jets |= 1<<2;}
-				if(keystate[SDLK_UP]    | keystate[SDLK_c]) { ship.dy -= 1.5*t_frame; ship.jets |= 1<<3;}
+				// FIXME why is this at the bottom? Shouldn't it be up before the ship movement?
+				if(keystate[SDLK_LEFT]  || keystate[SDLK_h]) { ship.dx -= THRUSTER_STRENGTH*t_frame; ship.jets |= 1<<0;}
+				if(keystate[SDLK_DOWN]  || keystate[SDLK_t]) { ship.dy += THRUSTER_STRENGTH*t_frame; ship.jets |= 1<<1;}
+				if(keystate[SDLK_RIGHT] || keystate[SDLK_n]) { ship.dx += THRUSTER_STRENGTH*t_frame; ship.jets |= 1<<2;}
+				if(keystate[SDLK_UP]    || keystate[SDLK_c]) { ship.dy -= THRUSTER_STRENGTH*t_frame; ship.jets |= 1<<3;}
 				if(keystate[SDLK_3])		{ SDL_SaveBMP(surf_screen, "snapshot.bmp"); }
 			}