Add entity system, add new enemy (snake)

1 files changed, 72 insertions, 0 deletions

diff --git a/src/entities.c b/src/entities.c
new file mode 100644
index 0000000..be976ea
--- /dev/null
+++ b/src/entities.c
@@ -0,0 +1,72 @@
+#include <stdint.h>
+#include <string.h>
+
+#include "vga.h"
+#include "map.h"
+#include "data.h"
+
+#include "entities.h"
+
+#define MAX_ENTITY 32
+
+static Entity entities[MAX_ENTITY];
+static uint8_t last;
+
+void entities_init()
+{
+    memset(entities, 0, sizeof(Entity) * MAX_ENTITY);
+    last = 0;
+}
+
+Entity *entities_new()
+{
+    for (uint8_t i = 0; i < MAX_ENTITY; i++)
+    {
+        if (entities[i].used == 0)
+        {
+            memset(&entities[i], 0, sizeof(Entity));
+            entities[i].used = 1;
+
+            if (i >= last)
+                last = i + 1;
+
+            return &entities[i];
+        }
+    }
+
+    return NULL;
+}
+
+void entities_update()
+{
+    Entity *e = entities;
+
+    for (uint8_t i = 0; i < last; i++, e++)
+        if (e->used)
+            e->update(e);
+}
+
+void entities_erase()
+{
+    Entity *e = entities + last - 1;
+
+    for (uint8_t i = 0; i < last; i++, e--)
+        if (e->used)
+        {
+            Rect dst = { e->x, e->y + MAP_OFFS_Y, 16, 16 };
+            blit(e->bg, &dst);
+        }
+}
+
+void entities_draw()
+{
+    Entity *e = entities;
+
+    for (uint8_t i = 0; i < last; i++, e++)
+        if (e->used)
+        {
+            Rect dst = { e->x, e->y + MAP_OFFS_Y, 16, 16 };
+            read_buffer(e->bg, &dst);
+            blitrc(binary_sprites_start, &e->frames[e->dir * 4 + e->frame], &dst);
+        }
+}