Avoid drawing the whole screen on each frame

This allows supporting 386DX "just about" (there will be flickering).

1 files changed, 18 insertions, 13 deletions

diff --git a/src/entities.c b/src/entities.c
index df8fb4e..e24c119 100644
--- a/src/entities.c
+++ b/src/entities.c
@@ -8,7 +8,7 @@
 
 #include "effect.h"
 
-#define MAX_ENTITY 32
+#define MAX_ENTITY 16
 
 static Entity entities[MAX_ENTITY];
 static uint8_t last;
@@ -44,31 +44,36 @@ void entities_update()
 
     for (uint8_t i = 0; i < last; i++, e++)
         if (e->used)
+        {
+            e->ox = e->x;
+            e->oy = e->y;
             e->update(e);
+        }
 }
 
-void entities_erase()
+void entities_draw()
 {
-    Entity *e = entities + last - 1;
+    Rect dst = { 0, 0, 16, 16 };
+    Entity *e = entities;
 
-    for (uint8_t i = 0; i < last; i++, e--)
-        if (e->used)
+    for (uint8_t i = 0; i < last; i++, e++)
+        if (e->erase)
         {
-            Rect dst = { e->x, e->y + MAP_OFFS_Y, 16, 16 };
-            blit(e->bg, &dst);
+            dst.x = e->ox;
+            dst.y = e->oy + MAP_OFFS_Y;
+            blit_copy(&dst);
+            e->erase = 0;
         }
-}
 
-void entities_draw()
-{
-    Entity *e = entities;
+    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);
+            dst.x = e->x;
+            dst.y = e->y + MAP_OFFS_Y;
             blitrc(binary_sprites_start, &e->frames[e->dir * 4 + e->frame], &dst);
+            e->erase = 1;
         }
 }