Font System

Font Size:          18px
Cell Size:          18px × 18px
Chars Per Row:      13
Total Characters:   95 (space through ~)
Image Dimensions:   234px × 144px (13 cols × 8 rows)
Rows Needed:        ?95 / 13? = 8 rows

The 20px grid provides optimal spacing for the Roboto font at 12pt size, ensuring characters have adequate padding and maintain readability at typical screen resolutions. The fixed width of 15px creates a pleasant monospace-like appearance for UI elements.

 !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~

The charset MUST start with a space character. If you omit the leading space, all character lookups will be off by one position, causing '%' to render as 'g', '>' to render as '?', and other visual glitches. This was a common bug that has been fixed - see Docs/CHARSET_FIX_SUMMARY.md for details.

# Configuration in generate_font.py
FONT_SIZE = 18          # Font size to render (affects quality)
CHAR_WIDTH = 18         # Width of each grid cell
CHAR_HEIGHT = 18        # Height of each grid cell
CHARS_PER_ROW = 13      # Number of characters per row
BG_COLOR = (0, 0, 0, 0) # Transparent background (RGBA)
FG_COLOR = (255, 255, 255, 255) # White text (RGBA)

# Generate with default name (defaultfont.png)
python Scripts/generate_font.py

# Generate with custom name
python Scripts/generate_font.py myfont_18px.png

# Windows
copy defaultfont.png Ramdisk\Fonts\

# Linux/Mac
cp defaultfont.png Ramdisk/Fonts/

# Windows
ForceRebuildISO.bat

# Linux/Mac
./rebuild.sh

# Edit generate_font.py - change these values:
FONT_SIZE = 12
CHAR_WIDTH = 12
CHAR_HEIGHT = 12

# Run generator
python Scripts/generate_font.py roboto_12px.png

# Repeat for 16px
FONT_SIZE = 16
CHAR_WIDTH = 16
CHAR_HEIGHT = 16
python Scripts/generate_font.py roboto_16px.png

# Repeat for 20px
FONT_SIZE = 20
CHAR_WIDTH = 20
CHAR_HEIGHT = 20
python Scripts/generate_font.py roboto_20px.png

# Copy all to Ramdisk
copy *.png Ramdisk\Fonts\

For 12pt fonts: Use 18-20px grid
For 14pt fonts: Use 20-22px grid
For 16pt fonts: Use 22-24px grid
For 18pt fonts: Use 24-28px grid
The grid should be slightly larger than the font size to provide adequate spacing.

<code>// Load font PNG
PNG fontImage = new PNG(File.ReadAllBytes("Fonts/roboto_12pt_regular.png"));

// Define charset (MUST match generation script)
string charset = " !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";

// Create font instance
IFont font = new IFont(
    fontImage,      // PNG image
    charset,        // Character order
    20,             // Grid cell size (FontSize)
    true,           // Use fixed width mode?
    15,             // Fixed character width (if fixed mode)
    -5              // Padding adjustment
);</code>

// Draw a single character
int advanceWidth = font.DrawChar(graphics, x, y, 'A');
x += advanceWidth; // Move cursor forward

// Draw a string
font.DrawString(x, y, "Hello, World!");

// Draw string with clipping
font.DrawString(x, y, "Long text...", maxWidth, maxHeight);

Variable Width (proportional):

• fixedWidth = false
• Each character's width is calculated by trimming empty columns
• Space character uses FontSize / 2
• More natural appearance for body text
• Example: "i" is narrower than "W"

Fixed Width (monospace):

• fixedWidth = true
• All characters use CharWidth
• Space character uses CharWidth / 2
• Useful for UI elements, tables, code display
• Example: All characters have identical width

// Load different style variants
IFont normalFont = new IFont(normalPNG, charset, 20);
IFont boldFont = new IFont(boldPNG, charset, 20);
IFont italicFont = new IFont(italicPNG, charset, 20);
IFont boldItalicFont = new IFont(boldItalicPNG, charset, 20);

// Set variants on the normal font
normalFont.SetVariants(boldFont, italicFont, boldItalicFont);

// Get a specific variant
IFont variant = normalFont.GetVariant(FontStyle.Bold);

// Measure string width (if MeasureString method exists)
int width = font.MeasureString("Hello");

// Manually calculate character width
int index = charset.IndexOf('A');
// Use font.CharWidth or calculate based on mode

<code>public static IFont LoadCustomFont(string path, int size) {
    try {
        byte[] data = File.ReadAllBytes(path);
        var img = new PNG(data);
        
        string charset = " !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";
        
        return new IFont(img, charset, size, false, 0, 0);
    } catch {
        Console.WriteLine("Failed to load font: " + path);
        return null;
    }
}</code>

Symptom:

"CPU 50%" shows as "CPUg50%" or characters are shifted by one position

Cause:

Charset mismatch between Python script and C# code. Most commonly, the leading space is missing.

Solution:

1. Verify charset in generate_font.py starts with a space
2. Verify charset in C# code starts with a space
3. Regenerate font PNG with corrected charset
4. Rebuild guideXOS ISO

Possible Causes:

• Font PNG is corrupted or not a valid PNG file
• Font file path is incorrect
• Grid dimensions don't match FontSize parameter
• Not enough rows in the font image for all characters

Solutions:

• Verify PNG file opens correctly in an image viewer
• Check file path in File.ReadAllBytes() call
• Recalculate image dimensions: width = chars_per_row × size, height = rows × size
• Regenerate font with correct parameters

Check these items:

• Font PNG exists in Ramdisk/Fonts/ directory
• File name matches exactly (case-sensitive on some systems)
• PNG has correct format (RGBA, not indexed color)
• ISO was rebuilt after adding the font file
• Check console output for error messages

Solution:

Generate a new font file with different FONT_SIZE, CHAR_WIDTH, and CHAR_HEIGHT parameters. Remember that each size requires a separate font file.

Cause:

TrueType font rendering quality in the Python script, or PNG doesn't have proper alpha channel

Solutions:

• Increase FONT_SIZE in generate_font.py for better quality
• Try different TrueType font source
• Ensure PNG uses RGBA format with alpha channel
• Use a higher-quality system font as the source

Enable diagnostic output in WindowManager.cs by uncommenting font.DiagnoseFont(); to see character mapping information in the console.