ENH: separate buffer for upper (status line) and lower screen

Author: MarcCote

frotz/src/dumb/dumb_frotz.h

@@ -44,6 +44,7 @@ void dumb_set_picture_cell(int row, int col, char c);
 void dumb_row_to_str(char *s);
 void dumb_clear_output(void);
 char* dumb_get_screen(void);
+char* dumb_get_lower_screen(void);
 void dumb_clear_screen(void);
 
 /* dumb-pic.c */

frotz/src/dumb/dumb_output.c

@@ -50,9 +50,13 @@ static cell make_cell(int style, char c) {return (style << 8) | (0xff & c);}
 static char cell_char(cell c) {return c & 0xff;}
 static int cell_style(cell c) {return c >> 8;}
 
+#define UPPER_SCREEN_BUFF_SIZE 256
 #define SCREEN_BUFF_SIZE 8192
-static char screen_buffer[SCREEN_BUFF_SIZE];
+static char screen_buffer[SCREEN_BUFF_SIZE];  // aka window 0 (lower screen)
+static char upper_screen_buffer[UPPER_SCREEN_BUFF_SIZE];  // aka window 1 (upper screen)
+
 char* screen_buffer_ptr = screen_buffer;
+char* upper_screen_buffer_ptr = upper_screen_buffer;
 
 /* A cell's style is REVERSE_STYLE, normal (0), or PICTURE_STYLE.
  * PICTURE_STYLE means the character is part of an ascii image outline
@@ -114,7 +118,12 @@ int os_string_width (const zchar *s)
 
 void os_set_cursor(int row, int col)
 {
-    cursor_row = row - 1; cursor_col = col - 1;
+	//printf("\n--> win:%d\trow:%d\tcol:%d MAX_COLS:%d<--\n", cwin, row, col, h_screen_cols);
+	if (cwin == 1 && row == 1) {
+		upper_screen_buffer_ptr = upper_screen_buffer + (col-1);
+	}
+
+    cursor_row = row - 1; cursor_col = col - 1;  // 0-index
     if (cursor_row >= h_screen_rows)
 	cursor_row = h_screen_rows - 1;
 }
@@ -148,9 +157,16 @@ void os_set_text_style(int x)
 /* put a character in the cell at the cursor and advance the cursor.  */
 static void dumb_display_char(char c)
 {
-  if ((screen_buffer_ptr - screen_buffer) < (SCREEN_BUFF_SIZE - 1)) {
-    *screen_buffer_ptr++ = c;
-  }
+	if (cwin == 1 && cursor_row == 0) {
+		if ((upper_screen_buffer_ptr - upper_screen_buffer) < (UPPER_SCREEN_BUFF_SIZE - 1)) {
+			*upper_screen_buffer_ptr++ = c;
+		}
+	}
+	else {
+		if ((screen_buffer_ptr - screen_buffer) < (SCREEN_BUFF_SIZE - 1)) {
+			*screen_buffer_ptr++ = c;
+		}
+	}
 }
 
 void dumb_display_user_input(char *s)
@@ -210,7 +226,7 @@ void os_display_string (const zchar *s)
     }
 }
 
-void os_erase_area (int top, int left, int bottom, int right, int UNUSED (win))
+void os_erase_area (int top, int left, int bottom, int right, int win)
 {
     int row, col;
     top--; left--; bottom--; right--;
@@ -222,9 +238,16 @@ void os_erase_area (int top, int left, int bottom, int right, int UNUSED (win))
 
 void os_scroll_area (int top, int left, int bottom, int right, int units)
 {
-  if ((screen_buffer_ptr - screen_buffer) < (SCREEN_BUFF_SIZE - 1)) {
-    *screen_buffer_ptr++ = '\n';
-  }
+	if (cwin == 1) {
+		if ((upper_screen_buffer_ptr - upper_screen_buffer) < (UPPER_SCREEN_BUFF_SIZE - 1)) {
+			*upper_screen_buffer_ptr++ = '\n';
+		}
+	}
+	else {
+		if ((screen_buffer_ptr - screen_buffer) < (SCREEN_BUFF_SIZE - 1)) {
+			*screen_buffer_ptr++ = '\n';
+		}
+	}
 }
 
 int os_font_data(int font, int *height, int *width)
@@ -557,6 +580,25 @@ void dumb_clear_screen(void) {
   screen_buffer_ptr = screen_buffer;
 }
 
+
+char* dumb_get_lower_screen(void) {
+  *screen_buffer_ptr = '\0';
+  return screen_buffer;
+}
+
+void dumb_clear_lower_screen(void) {
+  screen_buffer_ptr = screen_buffer;
+}
+
+char* dumb_get_upper_screen(void) {
+  upper_screen_buffer[UPPER_SCREEN_BUFF_SIZE-1] = '\0';
+  return upper_screen_buffer;
+}
+
+void dumb_clear_upper_screen(void) {
+  upper_screen_buffer_ptr = upper_screen_buffer;
+}
+
 void dumb_free(void) {
 	if (screen_data) {
       free(screen_data);

frotz/src/interface/frotz_interface.c

@@ -37,6 +37,10 @@ extern void dumb_set_next_action (char *a);
 extern void dumb_show_screen (int a);
 extern char* dumb_get_screen(void);
 extern void dumb_clear_screen(void);
+extern char* dumb_get_lower_screen(void);
+extern void dumb_clear_lower_screen(void);
+extern char* dumb_get_upper_screen(void);
+extern void dumb_clear_upper_screen(void);
 extern void z_save (void);
 extern void load_story(char *s);
 extern void load_story_rom(char *s, void* rom, size_t rom_size);
@@ -72,7 +76,9 @@ zbyte next_opcode;
 int last_ret_pc = -1;
 int desired_seed = 0;
 int ROM_IDX = 0;
-char world[8192] = "";
+
+char world[256 + 8192] = "";  // Upper + lower screens.
+
 int emulator_halted = 0;
 char halted_message[] = "Emulator halted due to runtime error.\n";
 // Track the addresses and values of special per-game ram locations.
@@ -1427,10 +1433,8 @@ void take_intro_actions() {
 
   char* text;
   for (int i=0; i<num_actions; ++i) {
-    text = dumb_get_screen();
-    text = clean_observation(text);
-    strcat(world, text);
-    dumb_clear_screen();
+    strcat(world, dumb_get_lower_screen());
+    dumb_clear_lower_screen();
 
     dumb_set_next_action(intro_actions[i]);
     zstep();
@@ -1533,7 +1537,7 @@ char* setup(char *story_file, int seed, void *rom, size_t rom_size) {
   run_free();
   load_rom_bindings(story_file);
 
-  world[0] = '\0';  // Clear buffer.
+  world[0] = '\0';  // Clear lower screen buffer.
   take_intro_actions();
   init_special_ram();
 
@@ -1568,11 +1572,14 @@ char* setup(char *story_file, int seed, void *rom, size_t rom_size) {
   // get_world_state_hash(last_state_hash);
   // get_world_state_hash(current_state_hash);
 
-  text = dumb_get_screen();
-  text = clean_observation(text);
-  // strcpy(world, text);
-  strcat(world, text);
-  dumb_clear_screen();
+  // Concatenate upper and lower screens.
+  strcat(world, dumb_get_lower_screen());
+  strcat(world, dumb_get_upper_screen());
+  strcpy(world, clean_observation(world));
+
+  dumb_clear_lower_screen();
+  dumb_clear_upper_screen();
+
   return world;
 }
 
@@ -1627,10 +1634,13 @@ char* step(char *next_action) {
   state_has_changed = memcmp(old_objs, new_objs, (get_num_world_objs() + 1) * sizeof(zobject)) != 0;
   // printf("%s =(%d)= %s <== %s", current_state_hash, state_has_changed, last_state_hash, next_action);
 
-  text = dumb_get_screen();
-  text = clean_observation(text);
-  strcpy(world, text);
-  dumb_clear_screen();
+  // Retrieve and concatenate upper and lower screens.
+  strcpy(world, dumb_get_lower_screen());
+  strcat(world, dumb_get_upper_screen());
+  strcpy(world, clean_observation(world));
+  dumb_clear_lower_screen();
+  dumb_clear_upper_screen();
+
   return world;
 }
 

frotz/src/interface/frotz_interface.h

@@ -53,7 +53,7 @@ extern void getRAM(unsigned char *ram);
 
 int filter_candidate_actions(char *candidate_actions, char *valid_actions, zword *diff_array);
 
-extern char world[8192];
+extern char world[256 + 8192];
 
 extern int tw_max_score;