Start of Grid.

makefile

@@ -1,6 +1,6 @@
 PROG = tbftss
 
-VERSION = 0.2
+VERSION = 0.3
 
 CXXFLAGS += `sdl2-config --cflags` -DVERSION=$(VERSION) -DUNIX=1
 CXXFLAGS += -DUNIX
@@ -21,7 +21,7 @@ OBJS += challenges.o cJSON.o
 OBJS += draw.o
 OBJS += effects.o entities.o
 OBJS += fighters.o fighterDefs.o
-OBJS += galacticMap.o game.o
+OBJS += galacticMap.o game.o grid.o
 OBJS += hud.o
 OBJS += init.o io.o
 OBJS += load.o lookup.o

src/battle/battle.c

@@ -372,4 +372,6 @@ void destroyBattle(void)
 		free(t);
 	}
 	battle.triggerTail = &battle.triggerHead;
+	
+	destroyGrid();
 }

src/battle/battle.h

@@ -63,6 +63,7 @@ extern void playSound(int id);
 extern void checkTrigger(char *name, int type);
 extern void resetWaypoints(void);
 extern void doPlayerSelect(void);
+extern void destroyGrid(void);
 
 extern App app;
 extern Battle battle;

src/battle/grid.c

@@ -0,0 +1,147 @@
+/*
+Copyright (C) 2015 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 "grid.h"
+
+static Entity *candidates[MAX_GRID_CANDIDATES];
+static void addCandidate(Entity *e);
+
+void addToGrid(Entity *e)
+{
+	GridCell *cell, *prev;
+	int x, y, x1, y1, x2, y2;
+	
+	x1 = e->x / GRID_CELL_WIDTH;
+	y1 = e->y / GRID_CELL_HEIGHT;
+	x2 = (e->x + e->w) / GRID_CELL_WIDTH;
+	y2 = (e->y + e->h) / GRID_CELL_HEIGHT;
+	
+	for (x = x1 ; x <= x2 ; x++)
+	{
+		for (y = y1 ; y <= y2 ; y++)
+		{
+			prev = &battle.grid[x][y];
+			
+			for (cell = battle.grid[x][y].next ; cell != NULL ; cell = cell->next)
+			{
+				prev = cell;
+			}
+			
+			cell = malloc(sizeof(GridCell));
+			memset(cell, 0, sizeof(GridCell));
+			prev->next = cell;
+			
+			cell->entity = e;
+		}
+	}
+}
+
+void removeFromGrid(Entity *e)
+{
+	GridCell *cell, *prev;
+	int x, y, x1, y1, x2, y2;
+	
+	x1 = e->x / GRID_CELL_WIDTH;
+	y1 = e->y / GRID_CELL_HEIGHT;
+	x2 = (e->x + e->w) / GRID_CELL_WIDTH;
+	y2 = (e->y + e->h) / GRID_CELL_HEIGHT;
+	
+	for (x = x1 ; x <= x2 ; x++)
+	{
+		for (y = y1 ; y <= y2 ; y++)
+		{
+			prev = &battle.grid[x][y];
+			
+			for (cell = battle.grid[x][y].next ; cell != NULL ; cell = cell->next)
+			{
+				if (cell->entity == e)
+				{
+					prev->next = cell->next;
+					free(cell);
+					cell = prev;
+				}
+				
+				prev = cell;
+			}
+		}
+	}
+}
+
+Entity **getAllEntsWithin(int x, int y, int w, int h, Entity *ignore)
+{
+	GridCell *cell;
+	int x1, y1, x2, y2;
+	
+	memset(candidates, 0, sizeof(Entity*) * MAX_GRID_CANDIDATES);
+	
+	x1 = x / GRID_CELL_WIDTH;
+	y1 = y / GRID_CELL_HEIGHT;
+	x2 = w / GRID_CELL_WIDTH;
+	y2 = h / GRID_CELL_HEIGHT;
+	
+	for (x = x1 ; x < x2 ; x++)
+	{
+		for (y = y1 ; y < y2 ; y++)
+		{
+			for (cell = battle.grid[x][y].next ; cell != NULL ; cell = cell->next)
+			{
+				addCandidate(battle.grid[x][y].entity);
+			}
+		}
+	}
+	
+	return candidates;
+}
+
+static void addCandidate(Entity *e)
+{
+	int i = 0;
+	
+	for (i = 0 ; i < MAX_GRID_CANDIDATES ; i++)
+	{
+		if (candidates[i] == NULL || candidates[i] == e)
+		{
+			candidates[i] = e;
+			return;
+		}
+	}
+	
+	printf("Out of grid candidate space!");
+	exit(1);
+}
+
+void destroyGrid(void)
+{
+	int x, y;
+	GridCell *cell;
+	
+	for (x = 0 ; x < GRID_SIZE ; x++)
+	{
+		for (y = 0 ; y < GRID_SIZE ; y++)
+		{
+			while (battle.grid[x][y].next)
+			{
+				cell = battle.grid[x][y].next;
+				battle.grid[x][y].next = cell->next;
+				free(cell);
+			}
+		}
+	}
+}

src/battle/grid.h

@@ -0,0 +1,26 @@
+/*
+Copyright (C) 2015 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 "SDL2/SDL.h"
+
+#include "../defs.h"
+#include "../structs.h"
+
+extern Battle battle;

src/defs.h

@@ -47,6 +47,11 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #define MAX_FIGHTER_GUNS		12
 #define MAX_TARGET_RANGE		65536
 
+#define GRID_CELL_WIDTH			640
+#define GRID_CELL_HEIGHT		360
+#define GRID_SIZE				25
+#define MAX_GRID_CANDIDATES 	1024
+
 #define BF_NONE				0
 #define BF_ENGINE			(2 << 0)
 #define BF_SYSTEM_DAMAGE	(2 << 1)

src/structs.h

@@ -33,6 +33,7 @@ typedef struct Pulse Pulse;
 typedef struct Widget Widget;
 typedef struct HudMessage HudMessage;
 typedef struct Trigger Trigger;
+typedef struct GridCell GridCell;
 
 typedef struct {
 	float x;
@@ -77,6 +78,8 @@ struct Entity {
 	int side;
 	float x;
 	float y;
+	int w;
+	int h;
 	float dx;
 	float dy;
 	float thrust;
@@ -218,6 +221,11 @@ struct StarSystem {
 	StarSystem *next;
 };
 
+struct GridCell {
+	Entity *entity;
+	GridCell *next;
+};
+
 typedef struct {
 	int entId;
 	SDL_Point camera;
@@ -238,6 +246,7 @@ typedef struct {
 	Objective objectiveHead, *objectiveTail;
 	Trigger triggerHead, *triggerTail;
 	unsigned int stats[STAT_MAX];
+	GridCell grid[GRID_SIZE][GRID_SIZE];
 } Battle;
 
 typedef struct {