Create Display_BDF_PCF_Font.py

For Guide

Author: TheKitty

Fruit_Jam/CircuitPython_DVI_Video/Display_BDF_PCF_Font.py

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+# SPDX-FileCopyrightText: 2025 Anne Barela for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+#
+# Take a BDF or PCF font file and display it on a CircuitPython
+# HDMI/DVI display in 320x200 resolution. "." is used for unknown characters
+
+import gc
+import terminalio
+import displayio
+import supervisor
+from adafruit_bitmap_font import bitmap_font
+from adafruit_display_text import label
+from adafruit_fruitjam.peripherals import request_display_config
+
+# Use the easy library call to set the resolution
+request_display_config(320, 240)
+
+# Initialize display
+display = supervisor.runtime.display
+main_group = displayio.Group()
+display.root_group = main_group
+
+# Use Labels to display characters that exist in font
+font_file = "fonts/cp437-8x12a.pcf"
+font = bitmap_font.load_font(font_file)  # Use font = terminalio.FONT for built-in
+char_width = 8    # font character width
+char_height = 12  # font character height
+chars_per_line = 32  # Fixed at 32 characters per line
+line_number_width = 35  # Space for line numbers like "000: "
+
+displayed_count = 0
+skipped_count = 0
+
+current_x = line_number_width  # Start after line number space
+current_y = char_height
+current_line_start = 0
+
+# Add first line number
+line_label = label.Label(
+    font,
+    text=f"{current_line_start:03d}: ",
+    color=0xFFFFFF,
+    x=0,
+    y=current_y
+)
+main_group.append(line_label)
+
+# 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 + 2  # 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 {char_code}")
+                break
+
+            # Add line number for this new line
+            line_label = label.Label(
+                font,
+                text=f"{current_line_start:03d}: ",
+                color=0xFFFFFF,
+                x=0,
+                y=current_y
+            )
+            main_group.append(line_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 = label.Label(
+            font,
+            text=display_char,
+            color=0xFFFFFF,
+            x=current_x,
+            y=current_y
+        )
+
+        main_group.append(char_label)
+        current_x += char_width
+        displayed_count += 1
+
+    except (MemoryError, ValueError) as e:
+        print(f"Memory limit reached at char {char_code}")
+        break
+
+    # Garbage collection every 16 characters
+    if char_code % 16 == 0:
+        gc.collect()
+
+print(f"Found {displayed_count - skipped_count} chars with glyphs")
+print(f"{skipped_count} missing chars -> periods")
+print(f"Free memory: {gc.mem_free()} bytes")
+
+# Keep display active
+while True:
+    pass