collision: layer and mask

include/entity.h

@@ -8,6 +8,7 @@ struct Entity {
 	int hb_y;
 	int hb_w;
 	int hb_h;
+	int layer;
 	color_t hb_color;
 };
 
@@ -15,8 +16,8 @@ struct Entity {
 extern struct Entity *g_entity_grid[ENTITY_GRID_SIZE];
 
 void entity_init(void *restrict entity, int x, int y, int hb_x, int hb_y,
-                 int hb_w, int hb_h, color_t hb_color);
+                 int hb_w, int hb_h, int layer, color_t hb_color);
 void entity_deinit(void *restrict entity);
 void entity_draw_hitbox(void *restrict entity);
 void entity_grid_draw_hitboxes(void);
-int entity_collide(void *restrict entity);
+struct Entity *entity_collide(void *restrict entity, int mask);

include/layers.h

@@ -0,0 +1,9 @@
+#pragma once
+
+enum Layers {
+	L_NONE = 0,
+	L_SOLID = 1 << 1,
+	L_SEMISOLID = 1 << 2,
+	L_HARMFULL = 1 << 3,
+	L_PUSHABLE = 1 << 4,
+};

src/entity/collide.c

@@ -1,32 +1,34 @@
 #include "entity.h"
 
-static int entity_collide_with(struct Entity *restrict,
-                               struct Entity *restrict);
+static int entity_collide_with(struct Entity *restrict, struct Entity *restrict,
+                               int mask);
 
-int
-entity_collide(void *restrict entity)
+struct Entity *
+entity_collide(void *restrict entity, int mask)
 {
 	struct Entity *const e = entity;
 	int i;
 
 	i = ENTITY_GRID_SIZE;
 	while (i-- > 0)
-		if (entity_collide_with(e, g_entity_grid[i]))
-			return 1;
+		if (entity_collide_with(e, g_entity_grid[i], mask))
+			return g_entity_grid[i];
 
-	return 0;
+	return NULL;
 }
 
 /* axis aligned bounding box collision checking */
 static int
-entity_collide_with(struct Entity *restrict self, struct Entity *restrict other)
+entity_collide_with(struct Entity *restrict self, struct Entity *restrict other,
+                    int mask)
 {
 	const int sx = self->x + self->hb_x;
 	const int sy = self->y + self->hb_y;
 	const int ox = other->x + other->hb_x;
 	const int oy = other->y + other->hb_y;
 
-	if (self == NULL || other == NULL || self == other)
+	if (self == NULL || other == NULL || self == other ||
+	    !(mask & other->layer))
 		return 0;
 
 	return sx < ox + other->hb_w && sx + self->hb_w > ox &&

src/entity/init.c

@@ -1,11 +1,12 @@
 #include "entity.h"
+#include "layers.h"
 #include <gint/display.h>
 
 struct Entity *g_entity_grid[ENTITY_GRID_SIZE];
 
 void
 entity_init(void *restrict entity, int x, int y, int hb_x, int hb_y, int hb_w,
-            int hb_h, color_t hb_color)
+            int hb_h, int layer, color_t hb_color)
 {
 	static int init_grid = 1;
 	struct Entity *const e = entity;
@@ -16,6 +17,7 @@ entity_init(void *restrict entity, int x, int y, int hb_x, int hb_y, int hb_w,
 	e->hb_y = hb_y;
 	e->hb_w = hb_w;
 	e->hb_h = hb_h;
+	e->layer = layer;
 	e->hb_color = hb_color;
 
 	if (init_grid) {

src/main.c

@@ -1,4 +1,5 @@
 #include "entity.h"
+#include "layers.h"
 #include "player.h"
 #include "wall.h"
 #include <gint/display.h>
@@ -8,9 +9,11 @@ void
 main(void)
 {
 	struct Player player;
+	struct Player newb;
 	struct Wall walls[5];
 
 	player_init(&player, 16, 32);
+	player_init(&newb, 64, 128);
 	wall_init(&walls[0], 16, 0, DWIDTH - 32, 16);
 	wall_init(&walls[1], 16, DHEIGHT - 16, DWIDTH - 32, 16);
 	wall_init(&walls[2], 0, 0, 16, DHEIGHT);
@@ -26,7 +29,7 @@ main(void)
 		clearevents();
 		player.x += keydown(KEY_RIGHT) - keydown(KEY_LEFT);
 		player.y += keydown(KEY_DOWN) - keydown(KEY_UP);
-		if (entity_collide(&player)) {
+		if (entity_collide(&player, L_SOLID) != NULL) {
 			player.x = previous_x;
 			player.y = previous_y;
 		}

src/player/init.c

@@ -1,10 +1,11 @@
+#include "layers.h"
 #include "player.h"
 #include <gint/display.h>
 
 void
 player_init(struct Player *restrict p, int x, int y)
 {
-	entity_init(p, x, y, 2, 2, 12, 12, C_BLUE);
+	entity_init(p, x, y, 2, 2, 12, 12, L_PUSHABLE, C_BLUE);
 	p->spd_x = 0.0;
 	p->spd_y = 0.0;
 	p->rem_x = 0.0;

src/wall/init.c

@@ -1,8 +1,9 @@
+#include "layers.h"
 #include "wall.h"
 #include <gint/display.h>
 
 void
 wall_init(struct Wall *restrict w, int x, int y, int width, int height)
 {
-	entity_init(w, x, y, 0, 0, width, height, C_DARK);
+	entity_init(w, x, y, 0, 0, width, height, L_SOLID, C_DARK);
 }