Actual font rendering support

lib/colors.dart

@@ -3,4 +3,6 @@ import 'package:flutter/material.dart';
 class Palette {
   static const defaultBg = Colors.black;
   static const defaultFg = Colors.white;
+
+  static const subtitle = Colors.yellow;
 }

lib/game.dart

@@ -0,0 +1,12 @@
+import 'package:dartterm/colors.dart';
+import 'package:dartterm/terminal.dart';
+
+void main() async {
+  at(0, 0).puts("Hello, bats!");
+  at(0, 2).fg(Palette.subtitle).small().puts("Beware of the bat!");
+  at(4, 4)
+      .bg(Palette.subtitle)
+      .fg(Palette.defaultBg)
+      .big()
+      .puts("BEWARE OF THE BAT!");
+}

lib/main.dart

@@ -1,9 +1,11 @@
 import 'package:dartterm/colors.dart';
-import 'package:dartterm/terminal.dart';
+import 'package:dartterm/game.dart' as game;
+import 'package:dartterm/terminal.dart' as terminal;
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 
 void main() {
+  // terminal.at(0, 0).puts("Hello, world!");
   runApp(const App());
 }
 
@@ -41,6 +43,7 @@ class _ViewerState extends State<Viewer> {
     super.initState();
     ticker = Ticker(tick);
     ticker!.start();
+    game.main();
   }
 
   @override
@@ -48,7 +51,8 @@ class _ViewerState extends State<Viewer> {
     return Scaffold(
         body: Center(
       child: AspectRatio(
-          aspectRatio: width / height, child: terminal.toWidget(context)),
+          aspectRatio: terminal.width / terminal.height,
+          child: terminal.toWidget(context)),
     ));
   }
 

lib/terminal.dart

@@ -13,32 +13,6 @@ class Terminal {
 
   Terminal() {
     tiles = [for (var i = 0; i < nTiles; i += 1) Tile.empty()];
-    for (final (x, c) in toCp437String("Hello, world!").indexed) {
-      tiles[x].content = Content(Font.normal.imageName, c % 32, 2 * (c ~/ 32));
-      tiles[x + Terminal.width].content =
-          Content(Font.normal.imageName, c % 32, 2 * (c ~/ 32) + 1);
-    }
-
-    for (final (x, c) in toCp437String("BEWARE OF THE BAT!").indexed) {
-      tiles[x + Terminal.width * 2].content =
-          Content(Font.small.imageName, c % 16, c ~/ 16);
-    }
-
-    for (final (x, c) in toCp437String("BEWARE OF THE BAT!").indexed) {
-      tiles[Terminal.width * (x + 2)].content =
-          Content(Font.small.imageName, c % 16, c ~/ 16);
-    }
-
-    for (final (x, c) in toCp437String("BEWARE OF THE BAT!").indexed) {
-      tiles[2 * x + 4 + Terminal.width * 4].content =
-          Content(Font.big.imageName, 2 * (c % 32), 2 * (c ~/ 32));
-      tiles[2 * x + 4 + Terminal.width * 5].content =
-          Content(Font.big.imageName, 2 * (c % 32), 2 * (c ~/ 32) + 1);
-      tiles[2 * x + 1 + 4 + Terminal.width * 4].content =
-          Content(Font.big.imageName, 2 * (c % 32) + 1, 2 * (c ~/ 32));
-      tiles[2 * x + 1 + 4 + Terminal.width * 5].content =
-          Content(Font.big.imageName, 2 * (c % 32) + 1, 2 * (c ~/ 32) + 1);
-    }
   }
 
   CustomPaint toWidget(BuildContext context) {
@@ -65,6 +39,92 @@ class Terminal {
   }
 }
 
+class Cursor {
+  final Terminal t;
+  int x, y;
+  Color? _bg, _fg;
+  Font font = Font.normal;
+
+  // TODO: Clip
+
+  Cursor({required this.t, required this.x, required this.y});
+
+  void clear() {
+    t.tiles = [for (var i = 0; i < nTiles; i += 1) Tile.empty()];
+  }
+
+  void putc(int c) {
+    for (var dx = 0; dx < font.cellWidth; dx += 1) {
+      for (var dy = 0; dy < font.cellHeight; dy += 1) {
+        var i = t.fromXY(x + dx, y + dy);
+
+        if (i != null) {
+          final (sourceCx, sourceCy) = (
+            (c % font.nCellsW) * font.cellWidth + dx,
+            (c ~/ font.nCellsW) * font.cellHeight + dy
+          );
+
+          t.tiles[i].content = Content(font.imageName, sourceCx, sourceCy);
+
+          final (bg, fg) = (_bg, _fg);
+          if (bg != null) {
+            t.tiles[i].bg = bg;
+          }
+          if (fg != null) {
+            t.tiles[i].fg = fg;
+          }
+        }
+      }
+    }
+  }
+
+  void puts(String s) {
+    var startX = x;
+    for (final c in toCp437String(s)) {
+      if (c == 10) {
+        // newline
+        x = startX;
+        y += font.cellHeight;
+        continue;
+      }
+      if (c == 13) {
+        // carriage return
+        x = startX;
+        continue;
+      }
+      putc(c);
+      x += font.cellWidth;
+    }
+  }
+
+  Cursor fg(Color c) {
+    _fg = c;
+    return this;
+  }
+
+  Cursor bg(Color c) {
+    _bg = c;
+    return this;
+  }
+
+  Cursor small() {
+    font = Font.small;
+    return this;
+  }
+
+  Cursor normal() {
+    font = Font.normal;
+    return this;
+  }
+
+  Cursor big() {
+    font = Font.big;
+    return this;
+  }
+}
+
+class Clip {}
+
 class Tile {
   Content? content;
 
@@ -85,11 +145,19 @@ class Content {
 }
 
 // reexports
-Terminal terminal = Terminal();
+Terminal _terminal = Terminal();
 const int width = Terminal.width;
 const int height = Terminal.height;
 const int nTiles = Terminal.nTiles;
 
 Widget toWidget(BuildContext context) {
-  return terminal.toWidget(context);
+  return _terminal.toWidget(context);
+}
+
+void clear() {
+  at(0, 0).clear();
+}
+
+Cursor at(int x, int y) {
+  return Cursor(t: _terminal, x: x, y: y);
 }

lib/terminal_painter.dart

@@ -44,7 +44,7 @@ class TerminalCustomPainter extends CustomPainter {
 
     // == Draw the background and foreground of every tile ==
     for (var i = 0; i < nTiles; i++) {
-      final (pcxDst, pcyDst) = terminal.toXY(i) ?? (0, 0);
+      final (pcxDst, pcyDst) = t.toXY(i) ?? (0, 0);
       final (pxDst, pyDst) = (pcxDst * cellW, pcyDst * cellH);
       final rectDst = Rect.fromLTWH(pxDst.toDouble(), pyDst.toDouble(),
           cellW.toDouble(), cellH.toDouble());