xpgl Text

To use:

from XPPython3 import xpgl

We directly support three types of fonts and provide the same interface for all.

  • X-Plane bitmap fonts: These are “built-in” fonts and each are provided in only one size.

  • OpenGL GLUT bitmap fonts: These are “built-in” OpenGL fonts with a few more options.

    • “Helvetica”: 10pt, 12pt, 18pt

    • “Times_Roman”: 10pt, 24pt

  • TrueType scalable fonts: These are loaded from font files and scaled on request. X-Planes includes a number of font files, you can also provide additional fonts with your plugin. For example, check out the fonts under <X-Plane>/Resources/fonts.

loadFont(fontName, size=0) → Font:
Parameters

  • fontName – Name of font (string or int, see below)

  • size (int) – point size of font (there are restrictions)

Returns

Font instance

You must load a font before using it. For scalable fonts, there is some preprocessing performed. For bitmap fonts, this merely sets up some data-structures.

fontName is:

  • File path to a scalable font. Paths may be absolute, or relative to <X-Plane> root

  • Literal string “Helvetica” or “Times_Roman”, indicating the preference to use a GLUT bitmap font

  • Integer enumeration Font_Proportional or Font_Basic, indicating the preference to use a built-in X-Plane bitmap font.

size is an integer:

  • Any positive value for scalable fonts.

  • Only 10, 12, or 18 for “Helvetica” GLUT font; only 10 or 24 for “Times_Roman” GLUT font

  • Ignored for X-Plane bitmap fonts

Bitmap fonts do not scale as the window changes size or shape. Scalable fonts will change size (and aspect ratio) as the underinglying window changes size / shape.

You should load all your desired fonts early in your plugin and keep a refernce to them handle for your draw routines:

f1 = xpgl.loadFont(xp.Font_Proportional)
f2 = xpgl.loadFont("Helvetica", 12)
f3 = xpgl.loadFont("Resources/fonts/Roboto-Bold.ttf", 26)

If you want multiple sizes for the same typeface, make separate calls to loadFont().

measureText(fontID, text) → float
Parameters

  • fontID (Font) – fontID must be something returned by loadFont()

  • text (str) – Text string to be measured (horizontally)

Returns

Width of string using the given font

This can be called outside of a draw routine, if useful:

>>> f2 = xpgl.loadFont("Helvetica", 12)
>>> xpgl.measureText(f2, "Hello World")
65
drawText(fontID, x, y, text, alignment='L', color=Colors['white']) → float
Parameters

  • fontID (Font) – fontID must be something returned by loadFont()

  • x (int) –

  • y (int) – (x, y) location of text to be drawn (depends on alignment)

  • text (str) – Text string to be drawn

  • alignment (str) – Either ‘L’, ‘C’, or ‘R’ for left-, center- or right-aligned text

  • color (RGBColor) – Color of the text to be drawn. Background of text is always transparent.

Returns

Width of string being drawn (same as measureText())

Draw the string using font and color, at the (x, y) position.

../../_images/xpgl_drawTextFont.png

Note that as the window changes shape, scaled fonts also change their aspect ratio. Bitmap fonts (e.g., GLUT_Helvetica in this example) do not.

../../_images/xpgl_drawTextFontsStretched.png

Alignment value is case-insensitive:

xpgl.drawLine(320, 0, 320, 480)
xpgl.drawText(Fonts['Inconsolata.ttf'], 320, 260, "Left-Aligned")
xpgl.drawText(Fonts['Inconsolata.ttf'], 320, 240, "Center-Aligned", alignment="C")
xpgl.drawText(Fonts['Inconsolata.ttf'], 320, 220, "Right-Aligned", alignment='right')
../../_images/xpgl_drawTextFontAligned.png

Non-printable characters, such as newlines (\n) are ignored.

Caution

GLUT is not fully installed on Windows and will not work for your windows-based users without considerable effort on their part. I do not recommend using GLUT bitmap fonts.