M Makefile → Makefile

@@ -1,5 +1,10 @@ 
 CC = gcc
-CFLAGS = -Wall -Wextra -g
+BASE_CFLAGS = -Wall -Wextra -g
+
+# fenster.h contains function bodies unless FENSTER_HEADER is defined.
+# Define it for all translation units except one, so fenster_* is defined once.
+CFLAGS = $(BASE_CFLAGS) -DFENSTER_HEADER
+FENSTER_IMPL_CFLAGS = $(BASE_CFLAGS)
 SOURCES = xyw.c xywasm.c xywrun.c devices/console.c devices/clock.c devices/display.c
 OBJS = xyw.o xywasm.o xywrun.o devices/console.o devices/clock.o devices/display.o
 
@@ -31,7 +36,7 @@ xyw.o: xyw.c xyw.h
 	$(CC) $(CFLAGS) -c xyw.c -o xyw.o
 
 xywrun.o: xywrun.c xyw.h fenster.h
-	$(CC) $(CFLAGS) -c xywrun.c -o xywrun.o
+	$(CC) $(FENSTER_IMPL_CFLAGS) -c xywrun.c -o xywrun.o
 
 xywasm.o: xywasm.c xyw.h
 	$(CC) $(CFLAGS) -c xywasm.c -o xywasm.o

M fenster.h → fenster.h

@@ -20,9 +20,9 @@ #include <stdlib.h>
 
 struct fenster
 {
-  const char *title;
-  const int width;
-  const int height;
+  char *title;
+  int width;
+  int height;
   uint32_t *buf;
   int keys[256]; /* keys are mostly ASCII, but arrows are 17..20 */
   int mod;       /* mod is 4 bits mask, ctrl=1, shift=2, alt=4, meta=8 */

M xyw.h → xyw.h

@@ -1,11 +1,16 @@ 
 #ifndef XYW_H
 #define XYW_H
 
+#include "fenster.h"
+
 #define XYW_MODE_X 0x20
 #define XYW_MODE_Y 0x40
 #define XYW_MODE_W 0x80
 #define XYW_TOTAL_INSTRUCTIONS 0x20
 #define XYW_TOTAL_DEVICES 0x10
+
+#define XYW_WIDTH 256
+#define XYW_HEIGHT 256
 
 // clang-format off
 #define XYW_PEEKW(d) (*(d) << 8 | (d)[1])
@@ -34,6 +39,7 @@ 
 extern const char xyw_instructions[][4];
 extern int xyw_debug;
 extern int xyw_zoom;
+extern struct fenster xyw_fenster;
 extern xyw_device xyw_devices[XYW_TOTAL_DEVICES];
 
 int xyw_assemble(const char *input, const char *output);

M xywrun.c → xywrun.c

@@ -1,6 +1,5 @@ 
 #include <stdio.h>
 #include <stdlib.h>
-#include "fenster.h"
 #include "xyw.h"
 
 #include "devices/console.h"
@@ -15,9 +14,6 @@ #define SYSTEM_MEMORY_START 0xfd00
 #define USER_STACK_START 0xfd00
 #define SYSTEM_STACK_START 0xfe00
 #define DEVICE_AREA_START 0xff00
-
-#define WIDTH 256
-#define HEIGHT 256
 
 /* system device */
 #define SYSTEM_STATE 0xff00
@@ -60,6 +56,9 @@ static xyw_word yw_storage = 0; // 16-bit Y register storage
 xyw_word *pc = &pc_storage;
 xyw_word *xw = &xw_storage;
 xyw_word *yw = &yw_storage;
+
+// Global window instance (declared in xyw.h)
+struct fenster xyw_fenster;
 
 //// Helpers to retrieve device number and address within the device
 static inline int get_device(xyw_word addr)
@@ -362,11 +361,14 @@ process_metadata();
     // Set direct page to device page by default
     xyw_memory[SYSTEM_PAGE] = 0xff;
     // Initialize fenster
-    uint32_t buf[WIDTH * HEIGHT * xyw_zoom * xyw_zoom];
-    struct fenster f = {.title = title, .width = WIDTH * xyw_zoom, .height = HEIGHT * xyw_zoom, .buf = buf};
-    fenster_open(&f);
+    uint32_t buf[XYW_WIDTH * XYW_HEIGHT * xyw_zoom * xyw_zoom];
+    xyw_fenster.title = title;
+    xyw_fenster.width = XYW_WIDTH * xyw_zoom;
+    xyw_fenster.height = XYW_HEIGHT * xyw_zoom;
+    xyw_fenster.buf = buf;
+    fenster_open(&xyw_fenster);
     xyw_byte paused = 0;
-    while (fenster_loop(&f) == 0 && xyw_memory[SYSTEM_STATE] && *pc < SYSTEM_MEMORY_START)
+    while (fenster_loop(&xyw_fenster) == 0 && xyw_memory[SYSTEM_STATE] && *pc < SYSTEM_MEMORY_START)
     {
         if (!paused)
         {
@@ -414,6 +416,6 @@ // At present, JCN, JMP, JSR and RTS set the pc to 1 value less than the actual address
         // because we are relying on the fact that pc will be incremented at the end of the loop
         (*pc)++;
     }
-    fenster_close(&f);
+    fenster_close(&xyw_fenster);
     return 0;
 }