Converted the three "collision" functions to four differently-named ones.

The fourth is simply a duplicate of ship_collision for bullets. A
bit redundant, but I figure it's clearer of a definition. Besides,
this opens up the door to possibly making bullets a different struct
type in the future, if that turns out to be desirable.

src/alien.cpp

@@ -1133,9 +1133,7 @@ bool alien_place(object *alien)
 	{
 		if ((aliens[i].owner != alien) && (aliens[i].shield > 0))
 		{
-			if (collision(alien->x, alien->y, alien->image[0]->w,
+			if (ship_collision(alien, &aliens[i]))
-					alien->image[0]->h, aliens[i].x, aliens[i].y,
-					aliens[i].image[0]->w, aliens[i].image[0]->h))
 				return false;
 		}
 	}
@@ -1485,7 +1483,7 @@ void alien_move(object *alien)
 				continue;
 			}
 
-			if (collision(alien, &aliens[i]))
+			if (ship_collision(alien, &aliens[i]))
 			{
 				if ((aliens[i].classDef == CD_BARRIER) &&
 					(aliens[i].owner != alien))
@@ -1503,7 +1501,7 @@ void alien_move(object *alien)
 	// Handle a collision with the player
 	if ((player.shield > 0) && (alien->shield > 0) && (checkCollisions))
 	{
-		if (collision(alien, &player))
+		if (ship_collision(alien, &player))
 		{
 			if (alien->classDef == CD_ASTEROID)
 			{

src/bullet.cpp

@@ -181,3 +181,24 @@ object *bullet_getTarget(object *bullet)
 
 	return &aliens[i];
 }
+
+bool bullet_collision(object *bullet, object *ship)
+{
+	float x0 = bullet->x;
+	float y0 = bullet->y;
+	float w0 = bullet->image[0]->w;
+	float h0 = bullet->image[0]->h;
+
+	float x2 = ship->x;
+	float y2 = ship->y;
+	float w1 = ship->image[0]->w;
+	float h1 = ship->image[0]->h;
+
+	float x1 = x0 + w0;
+	float y1 = y0 + h0;
+
+	float x3 = x2 + w1;
+	float y3 = y2 + h1;
+
+	return !(x1<x2 || x3<x0 || y1<y2 || y3<y0);
+}

src/bullet.h

@@ -22,5 +22,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 void bullet_add(object *theWeapon, object *attacker, int y, int dy);
 object *bullet_getTarget(object *bullet);
+bool bullet_collision(object *bullet, object *ship);
 
 #endif

src/collectable.cpp

@@ -206,6 +206,27 @@ void collectable_add(float x, float y, int type, int value, int life)
 	engine.collectableTail = collectable;
 }
 
+bool collectable_collision(collectables *collectable, object *ship)
+{
+	float x0 = collectable->x;
+	float y0 = collectable->y;
+	float w0 = collectable->image->w;
+	float h0 = collectable->image->h;
+
+	float x2 = ship->x;
+	float y2 = ship->y;
+	float w1 = ship->image[0]->w;
+	float h1 = ship->image[0]->h;
+
+	float x1 = x0 + w0;
+	float y1 = y0 + h0;
+
+	float x3 = x2 + w1;
+	float y3 = y2 + h1;
+
+	return !(x1<x2 || x3<x0 || y1<y2 || y3<y0);
+}
+
 void collectable_explode(collectables *collectable)
 {
 	if ((collectable->x >= 0) && (collectable->x <= screen->w) &&

src/collectable.h

@@ -21,6 +21,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define COLLECTABLE_H
 
 void collectable_add(float x, float y, int type, int value, int life);
+bool collectable_collision(collectables *collectable, object *ship);
 void collectable_explode(collectables *collectable);
 
 #endif

src/game.cpp

@@ -253,7 +253,7 @@ static void game_doCollectables()
 
 			collectable->life--;
 
-			if ((player.shield > 0) && (collision(collectable, &player)))
+			if ((player.shield > 0) && (collectable_collision(collectable, &player)))
 			{
 				switch(collectable->type)
 				{
@@ -597,7 +597,7 @@ static void game_doBullets()
 
 				if (okayToHit)
 				{
-					if ((bullet->active) && (collision(bullet, &aliens[i])))
+					if ((bullet->active) && (bullet_collision(bullet, &aliens[i])))
 					{
 						old_shield = aliens[i].shield;
 
@@ -657,7 +657,7 @@ static void game_doBullets()
 				(bullet->id == WT_LASER) || (bullet->id == WT_CHARGER))
 			{
 				if (bullet->active && (player.shield > 0) &&
-					(bullet->owner != &player) && collision(bullet, &player))
+					(bullet->owner != &player) && bullet_collision(bullet, &player))
 				{
 					old_shield = player.shield;
 
@@ -712,7 +712,7 @@ static void game_doBullets()
 			{
 				if (cargo[j].active)
 				{
-					if (collision(bullet, &cargo[j]))
+					if (bullet_collision(bullet, &cargo[j]))
 					{
 						bullet->active = false;
 						explosion_add(bullet->x, bullet->y, E_SMALL_EXPLOSION);
@@ -743,7 +743,7 @@ static void game_doBullets()
 
 			if (collectable->type == P_MINE)
 			{
-				if (collision(collectable, bullet))
+				if (collectable_collision(collectable, bullet))
 				{
 					collectable->active = false;
 					
@@ -1932,6 +1932,17 @@ static bool game_checkPauseRequest()
 	return false;
 }
 
+bool game_collision(float x0, float y0, int w0, int h0, float x2, float y2, int w1, int h1)
+{
+	float x1 = x0 + w0;
+	float y1 = y0 + h0;
+
+	float x3 = x2 + w1;
+	float y3 = y2 + h1;
+
+	return !(x1<x2 || x3<x0 || y1<y2 || y3<y0);
+}
+
 int game_mainLoop()
 {
 	resetLists();

src/game.h

@@ -25,6 +25,7 @@ extern Game game;
 void game_init();
 void game_doStars();
 void game_doExplosions();
+bool game_collision(float x0, float y0, int w0, int h0, float x2, float y2, int w1, int h1);
 int game_mainLoop();
 
 #endif

src/graphics.cpp

@@ -37,59 +37,6 @@ bRect *bufferTail;
 textObject textShape[MAX_TEXTSHAPES];
 SDL_Surface *messageBox;
 
-bool collision(float x0, float y0, int w0, int h0, float x2, float y2, int w1, int h1)
-{
-	float x1 = x0 + w0;
-	float y1 = y0 + h0;
-
-	float x3 = x2 + w1;
-	float y3 = y2 + h1;
-
-	return !(x1<x2 || x3<x0 || y1<y2 || y3<y0);
-}
-
-bool collision(object *object1, object *object2)
-{
-	float x0 = object1->x;
-	float y0 = object1->y;
-	float w0 = object1->image[0]->w;
-	float h0 = object1->image[0]->h;
-
-	float x2 = object2->x;
-	float y2 = object2->y;
-	float w1 = object2->image[0]->w;
-	float h1 = object2->image[0]->h;
-
-	float x1 = x0 + w0;
-	float y1 = y0 + h0;
-
-	float x3 = x2 + w1;
-	float y3 = y2 + h1;
-
-	return !(x1<x2 || x3<x0 || y1<y2 || y3<y0);
-}
-
-bool collision(collectables *object1, object *object2)
-{
-	float x0 = object1->x;
-	float y0 = object1->y;
-	float w0 = object1->image->w;
-	float h0 = object1->image->h;
-
-	float x2 = object2->x;
-	float y2 = object2->y;
-	float w1 = object2->image[0]->w;
-	float h1 = object2->image[0]->h;
-
-	float x1 = x0 + w0;
-	float y1 = y0 + h0;
-
-	float x3 = x2 + w1;
-	float y3 = y2 + h1;
-
-	return !(x1<x2 || x3<x0 || y1<y2 || y3<y0);
-}
-
 void initGraphics()
 {
 	bufferHead = new bRect;

src/graphics.h

@@ -34,10 +34,6 @@ extern textObject textShape[MAX_TEXTSHAPES];
 extern SDL_Surface *messageBox;
 
 
-extern bool collision(float x0, float y0, int w0, int h0, float x2, float y2, int w1, int h1);
-extern bool collision(object *object1, object *object2);
-extern bool collision(collectables *object1, object *object2);
-
 extern void initGraphics();
 extern SDL_Surface *setTransparent(SDL_Surface *sprite);
 extern void addBuffer(int x, int y, int w, int h);

src/intermission.cpp

@@ -266,7 +266,7 @@ static bool intermission_showSystem(float x, float y, bool selectable)
 		blit(systemPlanet[planet].image, r.x, r.y);
 
 		if (selectable &&
-			collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6,
+			game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6,
 				r.x, r.y, systemPlanet[planet].image->w,
 				systemPlanet[planet].image->h))
 		{
@@ -454,7 +454,7 @@ static void intermission_doComms(SDL_Surface *comms)
 		{
 			for (int i = 0 ; i < 4 ; i++)
 			{
-				if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 170, 180 + (i * 60), 430, 50))
+				if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 170, 180 + (i * 60), 430, 50))
 				{
 					intermission_createMissionDetailSurface(comms, i);
 					engine.keyState[KEY_FIRE] = 0;
@@ -463,7 +463,7 @@ static void intermission_doComms(SDL_Surface *comms)
 		}
 		else
 		{
-			if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 170, 440, 160, 20))
+			if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 170, 440, 160, 20))
 			{
 				intermission_createCommsSurface(comms);
 				engine.keyState[KEY_FIRE] = 0;
@@ -518,26 +518,26 @@ static void intermission_doOptions(SDL_Surface *optionsSurface)
 {
 	if ((engine.keyState[KEY_FIRE]))
 	{
-		if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 417, 172, 45, 22))
+		if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 417, 172, 45, 22))
 			engine.useSound = true;
 
-		if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 478, 172, 45, 22))
+		if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 478, 172, 45, 22))
 			engine.useSound = false;
 
 
-		if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 417, 222, 45, 22))
+		if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 417, 222, 45, 22))
 		{
 			engine.useMusic = true;
 			audio_playMusic("music/through_space.ogg", -1);
 		}
 
-		if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 478, 222, 45, 22))
+		if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 478, 222, 45, 22))
 		{
 			engine.useMusic = false;
 			audio_haltMusic();
 		}
 
-		if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 417, 272, 45, 22))
+		if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 417, 272, 45, 22))
 		{
 			if (!engine.fullScreen)
 			{
@@ -546,7 +546,7 @@ static void intermission_doOptions(SDL_Surface *optionsSurface)
 			}
 		}
 
-		if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 478, 272, 45, 22))
+		if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 478, 272, 45, 22))
 		{
 			if (engine.fullScreen)
 			{
@@ -920,7 +920,7 @@ int intermission()
 					blit(shape[i + 1], 80 + (i * 90), 500);
 				}
 
-				if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 80 + (i * 90), 500, 32, 32))
+				if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 80 + (i * 90), 500, 32, 32))
 				{
 					if (i != 0)
 					{

src/loadSave.cpp

@@ -238,7 +238,7 @@ int showSaveSlots(SDL_Surface *savesSurface, signed char saveSlot)
 	{
 		for (int i = 1 ; i <= 5 ; i++)
 		{
-			if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6,
+			if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6,
 				r.x, r.y, r.w, r.h))
 			{
 				clickedSlot = i;
@@ -247,18 +247,18 @@ int showSaveSlots(SDL_Surface *savesSurface, signed char saveSlot)
 			r.y += 30;
 		}
 
-		if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 215,
+		if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 215,
 			365, 100, 25))
 		{
 			saveGame(saveSlot);
 			createSavesSurface(savesSurface, -10);
 		}
 
-		if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 335,
+		if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 335,
 				365, 100, 25))
 			createSavesSurface(savesSurface, -1);
 
-		if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 453,
+		if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 453,
 			365, 100, 25))
 		{
 			char filename[PATH_MAX];

src/ship.cpp

@@ -19,6 +19,27 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include "Starfighter.h"
 
+bool ship_collision(object *ship, object *otherShip)
+{
+	float x0 = ship->x;
+	float y0 = ship->y;
+	float w0 = ship->image[0]->w;
+	float h0 = ship->image[0]->h;
+
+	float x2 = otherShip->x;
+	float y2 = otherShip->y;
+	float w1 = otherShip->image[0]->w;
+	float h1 = otherShip->image[0]->h;
+
+	float x1 = x0 + w0;
+	float y1 = y0 + h0;
+
+	float x3 = x2 + w1;
+	float y3 = y2 + h1;
+
+	return !(x1<x2 || x3<x0 || y1<y2 || y3<y0);
+}
+
 /*
 Fill in later...
 */
@@ -142,7 +163,7 @@ void ship_fireRay(object *ship)
 	{
 		if (player.shield > 0)
 		{
-			if (collision(player.x, player.y, player.image[0]->w,
+			if (game_collision(player.x, player.y, player.image[0]->w,
 					player.image[0]->h, ray.x, ray.y, ray.w, ray.h) &&
 				(!engine.cheatShield))
 			{
@@ -174,7 +195,7 @@ void ship_fireRay(object *ship)
 		if ((aliens[i].shield > 0) && (ship != &aliens[i]) &&
 			(ship->classDef != aliens[i].classDef))
 		{
-			if (collision(aliens[i].x, aliens[i].y, aliens[i].image[0]->w,
+			if (game_collision(aliens[i].x, aliens[i].y, aliens[i].image[0]->w,
 					aliens[i].image[0]->h, ray.x, ray.y, ray.w, ray.h))
 			{
 				alien_hurt(&aliens[i], ship->owner, 1, false);

src/ship.h

@@ -18,6 +18,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifndef SHIP_H
 #define SHIP_H
 
+bool ship_collision(object *ship, object *otherShip);
 void ship_fireBullet(object *ship, int weaponType);
 void ship_fireRay(object *ship);
 

src/shop.cpp

@@ -1044,7 +1044,7 @@ void showShop()
 	{
 		for (int i = 0 ; i < icons ; i++)
 		{
-			if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6,
+			if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6,
 				shopItems[i].x, shopItems[i].y, 32, 25))
 			{
 				shopSelectedItem = i;
@@ -1055,14 +1055,14 @@ void showShop()
 
 		if (shopSelectedItem > -1)
 		{
-			if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 60, 350, 24, 16))
+			if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 60, 350, 24, 16))
 			{
 				buy(shopSelectedItem);
 				engine.keyState[KEY_FIRE] = 0;
 				drawShop();
 			}
 
-			if (collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 700, 350, 24, 16))
+			if (game_collision(engine.cursor_x + 13, engine.cursor_y + 13, 6, 6, 700, 350, 24, 16))
 			{
 				sell(shopSelectedItem);
 				engine.keyState[KEY_FIRE] = 0;