Start of combat-related code.

common.mk

@@ -2,7 +2,7 @@ VERSION = 0.1
 REVISION = $(shell git rev-list HEAD 2>/dev/null | wc -l)
 LOCALE_MO = $(patsubst %.po,%.mo,$(wildcard locale/*.po))
 
-SEARCHPATH += src src/game src/system src/util src/widgets src/world
+SEARCHPATH += src src/combat src/game src/system src/util src/widgets src/world
 vpath %.c $(SEARCHPATH)
 vpath %.h $(SEARCHPATH)
 
@@ -10,6 +10,7 @@ DEPS += defs.h structs.h
 
 OBJS += camera.o
 OBJS += draw.o
+OBJS += combat.o
 OBJS += entities.o
 OBJS += game.o
 OBJS += hud.o

src/combat/combat.c

@@ -0,0 +1,120 @@
+/*
+Copyright (C) 2018 Parallel Realities
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+#include "combat.h"
+
+static int isBlockedByMap(Entity *src, Entity *dest);
+static int isBlockedByEntities(Entity *src, Entity *dest);
+
+void preFire(Entity *e)
+{
+	if (e->flags & EF_WEIGHTLESS)
+	{
+		if (world.bob->y < e->y && e->isOnGround && (int) (rand() * 4) == 0)
+		{
+			e->dy = JUMP_POWER;
+		}
+	}
+
+	e->facing = (world.bob->x < e->x) ? FACING_LEFT : FACING_RIGHT;
+
+	if (e->reload > 0)
+	{
+		return;
+	}
+
+	e->attack();
+
+	e->shotsToFire--;
+
+	if (e->shotsToFire == 0)
+	{
+		e->walk();
+	}
+}
+
+int hasLineOfSight(Entity *src, Entity *dest)
+{
+	return (!isBlockedByMap(src, dest) && !isBlockedByEntities(src, dest));
+}
+
+static int isBlockedByMap(Entity *src, Entity *dest)
+{
+	SDL_Rect mapBlock;
+	int x, y, x1, y1, x2, y2, mx, my;
+	
+	x1 = (int) MIN(src->x, dest->x);
+	y1 = (int) MIN(src->y, dest->y);
+	x2 = (int) MAX(src->x, dest->x);
+	y2 = (int) MAX(src->y, dest->y);
+
+	for (x = x1; x <= x2; x++)
+	{
+		for (y = y1; y <= y2; y++)
+		{
+			mx = x / MAP_TILE_SIZE;
+			my = y / MAP_TILE_SIZE;
+
+			if (isSolid(mx, my))
+			{
+				mapBlock.x = x;
+				mapBlock.y = y;
+				mapBlock.w = MAP_TILE_SIZE;
+				mapBlock.h = MAP_TILE_SIZE;
+
+				if (lineIntersectsRect(mapBlock, src->x, src->y, dest->x, dest->y))
+				{
+					return 1;
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int isBlockedByEntities(Entity *src, Entity *dest)
+{
+	Entity **candidates, *e;
+	SDL_Rect losBounds;
+	int i;
+	
+	losBounds.x = (int) MIN(src->x, dest->x);
+	losBounds.y = (int) MIN(src->y, dest->y);
+	losBounds.w = (int) (MAX(src->x, dest->x) - losBounds.x);
+	losBounds.h = (int) (MAX(src->y, dest->y) - losBounds.y);
+	
+	candidates = getAllEntsWithin(losBounds.x, losBounds.y, losBounds.w, losBounds.h, NULL);
+
+	for (i = 0, e = candidates[i] ; e != NULL ; e = candidates[++i])
+	{
+		if (e == src || e == dest || !e->isSolid)
+		{
+			continue;
+		}
+		
+		if (lineIntersectsRect(e->bounds, src->x, src->y, dest->x, dest->y))
+		{
+			return 1;
+		}
+	}
+	
+	return 0;
+}

src/combat/combat.h

@@ -0,0 +1,27 @@
+/*
+Copyright (C) 2018 Parallel Realities
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+#include "../common.h"
+
+extern int isSolid(int x, int y);
+extern int lineIntersectsRect(SDL_Rect r, int x1, int y1, int x2, int y2);
+extern Entity **getAllEntsWithin(int x, int y, int w, int h, Entity *ignore);
+
+extern World world;

src/defs.h

@@ -74,12 +74,21 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #define MAP_TILE_OUTSIDE			255
 #define MAP_TILE_MAX				256
 
+#define JUMP_POWER					1
+
 #define ET_ENEMY					0
 #define ET_KEY						1
 #define ET_MIA						2
 
 #define EF_NONE						0
 #define EF_HEART_CELL				(2 << 0)
+#define EF_WEIGHTLESS				(2 << 1)
+
+enum
+{
+	FACING_RIGHT,
+	FACING_LEFT
+};
 
 enum
 {

src/structs.h

@@ -82,7 +82,17 @@ struct Entity {
 	int w;
 	int h;
 	int alive;
+	float dx;
+	float dy;
+	int reload;
+	int isOnGround;
+	int facing;
+	int shotsToFire;
+	int isSolid;
 	long flags;
+	SDL_Rect bounds;
+	void (*walk)(void);
+	void (*attack)(void);
 	Entity *next;
 };
 

src/util/maths.c

@@ -77,6 +77,11 @@ void getSlope(int x1, int y1, int x2, int y2, float *dx, float *dy)
 	*dy /= steps;
 }
 
+int lineIntersectsRect(SDL_Rect r, int x1, int y1, int x2, int y2)
+{
+	return 0;
+}
+
 unsigned long hashcode(const char *str)
 {
     unsigned long hash = 5381;

src/util/maths.h

@@ -19,4 +19,3 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
 
 #include "../common.h"
-