Create Display_LVGL_Font.py

Author: TheKitty

Fruit_Jam/CircuitPython_DVI_Video/Display_LVGL_Font.py

@@ -0,0 +1,160 @@
+# SPDX-FileCopyrightText: 2025 Anne Barela for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+#
+# Display an LVGL (.bin) font on a CircuitPython board and
+# 640x480 DVI display. Unknown characters will be "."
+#
+import displayio
+import supervisor
+from adafruit_bitmap_font import bitmap_font
+from adafruit_display_text import label
+import gc
+from adafruit_fruitjam.peripherals import request_display_config
+
+# Use the easy library call to set the resolution
+request_display_config(640, 480)
+
+# Initialize display
+display = supervisor.runtime.display
+main_group = displayio.Group()
+display.root_group = main_group
+
+print(f"Initial memory: {gc.mem_free()}")
+
+# Font loading with error handling and diagnostics
+font_file = "fonts/CP437_16h.bin"
+try:
+    font = bitmap_font.load_font(font_file)
+    print(f"Font loaded: {font_file}")
+    print(f"Memory after font load: {gc.mem_free()}")
+
+    # Diagnostic: Check font properties
+    try:
+        bbox = font.get_bounding_box()
+        print(f"Font bounding box: {bbox}")
+
+        # Test a few common characters
+        test_chars = [32, 65, 97]  # space, 'A', 'a'
+        for char_code in test_chars:
+            glyph = font.get_glyph(char_code)
+            if glyph:
+                print(f"Char {char_code} ('{chr(char_code)}'): OK")
+            else:
+                print(f"Char {char_code} ('{chr(char_code)}'): Missing")
+
+    except Exception as e:
+        print(f"Error checking font properties: {e}")
+
+except Exception as e:
+    print(f"Error loading font {font_file}: {e}")
+    # Fallback to terminalio font
+    import terminalio
+    font = terminalio.FONT
+    print("Using fallback terminalio.FONT")
+
+# Get actual font dimensions
+try:
+    font_bbox = font.get_bounding_box()
+    char_width = font_bbox[0]
+    char_height = font_bbox[1]
+    print(f"Actual font size: {char_width}x{char_height}")
+except:
+    char_width = 9    # fallback
+    char_height = 16  # fallback
+    print(f"Using fallback font size: {char_width}x{char_height}")
+
+chars_per_line = 32  # Fixed at 32 characters per line
+line_number_width = 5 * char_width  # Space for "000: " (5 characters)
+
+displayed_count = 0
+skipped_count = 0
+current_x = line_number_width  # Start after line number space
+current_y = char_height
+current_line_start = 0
+
+def create_char_label(font, char, x, y):
+    """Helper function to create character labels with error handling"""
+    try:
+        return label.Label(font, text=char, color=0xFFFFFF, x=x, y=y)
+    except Exception as e:
+        print(f"Error creating label for '{char}': {e}")
+        return None
+
+# Add first line number
+text = f"{current_line_start:03d}: "
+print(f"Creating line number: '{text}'")
+
+for i, char in enumerate(text):
+    char_label = create_char_label(font, char, i * char_width, current_y)
+    if char_label:
+        main_group.append(char_label)
+
+print(f"Memory after first line number: {gc.mem_free()}")
+
+# Try all characters from 0-255 and display ones that exist
+for char_code in range(256):
+    try:
+        # Check if we need to wrap to next line
+        if (char_code > 0) and (char_code % chars_per_line == 0):
+            current_x = line_number_width  # Reset to after line number
+            current_y += char_height + 4  # Add some line spacing
+            current_line_start = char_code
+
+            # Stop if we run out of vertical space
+            if current_y + char_height > display.height:
+                print(f"Display full, stopped at character {char_code}")
+                break
+
+            # Add line number for this new line
+            text = f"{current_line_start:03d}: "
+            for i, char in enumerate(text):
+                char_label = create_char_label(font, char, i * char_width, current_y)
+                if char_label:
+                    main_group.append(char_label)
+
+        # Check if glyph exists
+        glyph = font.get_glyph(char_code)
+
+        if glyph is None:
+            # No glyph available - display a period instead
+            display_char = "."
+            skipped_count += 1
+        else:
+            # Glyph exists - display the actual character
+            display_char = chr(char_code)
+
+        # Create label for this character (or replacement)
+        char_label = create_char_label(font, display_char, current_x, current_y)
+        if char_label:
+            main_group.append(char_label)
+
+        current_x += char_width
+        displayed_count += 1
+
+    except (MemoryError, ValueError) as e:
+        print(f"Memory/Value error at character {char_code}: {e}")
+        break
+    except Exception as e:
+        print(f"Unexpected error at character {char_code}: {e}")
+        # Continue with next character
+        current_x += char_width
+        displayed_count += 1
+
+    # More frequent garbage collection
+    if char_code % 8 == 0:
+        gc.collect()
+
+    # Progress indicator for debugging
+    if char_code % 32 == 0:
+        print(f"Processed up to character {char_code}, memory: {gc.mem_free()}")
+
+print(f"\nCompleted character display:")
+print(f"Found {displayed_count - skipped_count} characters with glyphs")
+print(f"{skipped_count} missing characters displayed as periods")
+print(f"Total labels created: {len(main_group)}")
+print(f"Final free memory: {gc.mem_free()} bytes")
+
+# Keep display active
+while True:
+    pass