/pygame-text

Convenience functions for drawing using the pygame.font module.

Primary LanguagePythonOtherNOASSERTION

pygame-text

This module simplifies drawing text with the pygame.font module. Specifically, the ptext module:

  • handles the pygame.font.Font objects.
  • handles the separate step of generating a pygame.Surface and then blitting it.
  • caches commonly-used Surfaces.
  • handles word wrap.
  • provides more fine-grained text positioning options.
  • provides a few special effects: outlines, drop shadows, gradient fill, and transparency.

Quick usage examples

ptext.draw("Text color", (50, 30), color="orange")
ptext.draw("Font name and size", (20, 100), fontname="fonts/Boogaloo.ttf", fontsize=60)
ptext.draw("Positioned text", topright=(840, 20))
ptext.draw("Allow me to demonstrate wrapped text.", (90, 210), width=180, lineheight=1.5)
ptext.draw("Outlined text", (400, 70), owidth=1.5, ocolor=(255,255,0), color=(0,0,0))
ptext.draw("Drop shadow", (640, 110), shadow=(2,2), scolor="#202020")
ptext.draw("Color gradient", (540, 170), color="red", gcolor="purple")
ptext.draw("Transparency", (700, 240), alpha=0.1)
ptext.draw("Vertical text", midleft=(40, 440), angle=90)
ptext.draw("All together now:\nCombining the above options",
	midbottom=(427,460), width=360, fontname="fonts/Boogaloo.ttf", fontsize=48,
	color="#AAFF00", gcolor="#66AA00", owidth=1.5, ocolor="black", alpha=0.8)

To install

Download ptext.py and put it in your source directory. To install from command line:

curl https://raw.githubusercontent.com/cosmologicon/pygame-text/master/ptext.py > my-source-directory/ptext.py

Detailed usage

ptext.draw requires the string you want to draw, and the position. You can either do this by passing coordinates as the second argument (which is the top left of where the text will appear), or use the positioning keyword arguments (described later).

ptext.draw("hello world", (20, 100))

ptext.draw takes the following optional keyword arguments:

fontname fontsize antialias
color background
top left bottom right
topleft bottomleft topright bottomright
midtop midleft midbottom midright
center centerx centery
width widthem lineheight
align
owidth ocolor
shadow scolor
gcolor
alpha
anchor
angle
surf
cache

The ptext module also has module-level globals that control the default behavior. These can be set to your desired values:

DEFAULT_FONT_NAME DEFAULT_FONT_SIZE FONT_NAME_TEMPLATE
DEFAULT_COLOR DEFAULT_BACKGROUND
DEFAULT_TEXT_ALIGN
DEFAULT_OUTLINE_COLOR OUTLINE_UNIT
DEFAULT_SHADOW_COLOR SHADOW_UNIT
ALPHA_RESOLUTION
DEFAULT_ANCHOR
ANGLE_RESOLUTION_DEGREES
AUTO_CLEAN MEMORY_LIMIT_MB MEMORY_REDUCTION_FACTOR

The ptext.draw keyword arguments and the ptext module-level global variables are described in detail in the following sections.

Font name and size

ptext.draw("hello world", (100, 100), fontname="fonts/Viga.ttf", fontsize=32)

Keyword arguments:

  • fontname: filename of the font to draw. Defaults to ptext.DEFAULT_FONT_NAME, which is set to None by default.
  • fontsize: size of the font to use, in pixels. Defaults to ptext.DEFAULT_FONT_SIZE, which is set to 24 by default.
  • antialias: whether to render with antialiasing. Defaults to True.

If you don't want to specify the whole filename for the fonts every time, it can be useful to set ptext.FONT_NAME_TEMPLATE. For instance, if your fonts are in a subdirectory called fonts and all have the extension .ttf:

ptext.FONT_NAME_TEMPLATE = "fonts/%s.ttf"
ptext.draw("hello world", (100, 100), fontname="Viga")  # Will look for fonts/Viga.ttf

fontname=None always refers to the system font.

Color and background color

ptext.draw("hello world", (100, 100), color=(200, 200, 200), background="gray")

Keyword arguments:

  • color: foreground color to use. Defaults to ptext.DEFAULT_COLOR, which is set to "white" by default.
  • background: background color to use. Defaults to ptext.DEFAULT_BACKGROUND, which is set to None by default.

color (as well as background, ocolor, scolor, and gcolor) can be an (r, g, b) sequence such as (255,127,0), a pygame.Color object, a color name such as "orange", an HTML hex color string such as "#FF7F00", or a string representing a hex color number such as "0xFF7F00".

background can also be None, in which case the background is transparent. Unlike pygame.font.Font.render, it's generally not more efficient to set a background color when calling ptext.draw. So only specify a background color if you actually want one.

Colors with alpha transparency are not supported (except for the special case of invisible text with outlines or drop shadows - see below). See the alpha keyword argument for transparency.

Positioning

ptext.draw("hello world", centery=50, right=300)
ptext.draw("hello world", midtop=(400, 0))

Keyword arguments:

top left bottom right
topleft bottomleft topright bottomright
midtop midleft midbottom midright
center centerx centery

Positioning keyword arguments behave like the corresponding properties of pygame.Rect. Either specify two arguments, corresponding to the horizontal and vertical positions of the box, or a single argument that specifies both.

If the position is overspecified (e.g. both left and right are given), then extra specifications will be (arbitrarily but deterministically) discarded. For constrained text, see the section on ptext.drawbox below.

Word wrap

ptext.draw("splitting\nlines", (100, 100))
ptext.draw("splitting lines", (100, 100), width=60)

Keyword arguments:

  • width: maximum width of the text to draw, in pixels. Defaults to None.
  • widthem: maximum width of the text to draw, in font-based em units. Defaults to None.
  • lineheight: vertical spacing between lines, in units of the font's default line height. Defaults to 1.0.

ptext.draw will always wrap lines at newline (\n) characters. If width or widthem is set, it will also try to wrap lines in order to keep each line shorter than the given width. The text is not guaranteed to be within the given width, because wrapping only occurs at space characters, so if a single word is too long to fit on a line, it will not be broken up. Outline and drop shadow are also not accounted for, so they may extend beyond the given width.

You can prevent wrapping on a particular space with non-breaking space characters (\u00A0).

Text alignment

ptext.draw("hello\nworld", bottomright=(500, 400), align="left")

Keyword argument:

  • align: horizontal positioning of lines with respect to each other. Defaults to None.

align determines how lines are positioned horizontally with respect to each other, when more than one line is drawn. Valid values for align are the strings "left", "center", or "right", a numerical value between 0.0 (for left alignment) and 1.0 (for right alignment), or None.

If align is None, the alignment is determined based on other arguments, in a way that should be what you want most of the time. It depends on any positioning arguments (topleft, centerx, etc.), anchor, and ptext.DEFAULT_TEXT_ALIGN, which is set to "left" by default. I suggest you generally trust the default alignment, and only specify align if something doesn't look right.

Outline

ptext.draw("hello world", (100, 100), owidth=1, ocolor="blue")

Keyword arguments:

  • owidth: outline thickness, in outline units. Defaults to None.
  • ocolor: outline color. Defaults to ptext.DEFAULT_OUTLINE_COLOR, which is set to "black" by default.

The text will be outlined if owidth is specified. The outlining is a crude manual method, and will probably look bad at large sizes. The units of owidth are chosen so that 1.0 is a good typical value for outlines. Specifically, they're the font size times ptext.OUTLINE_UNIT, which is set to 1/24 by default.

As a special case, setting color to a transparent value (e.g. (0,0,0,0)) while using outilnes will cause the text to be invisible, giving a hollow outline. (This feature is not compatible with gcolor.)

Valid values for ocolor are the same as for color.

Drop shadow

ptext.draw("hello world", (100, 100), shadow=(1.0,1.0), scolor="blue")

Keyword arguments:

  • shadow: (x,y) values representing the drop shadow offset, in shadow units. Defaults to None.
  • scolor: drop shadow color. Defaults to ptext.DEFAULT_SHADOW_COLOR, which is "black" by default.

The text will have a drop shadow if shadow is specified. It must be set to a 2-element sequence representing the x and y offsets of the drop shadow, which can be positive, negative, or 0. For example, shadow=(1.0,1.0) corresponds to a shadow down and to the right of the text. shadow=(0,-1.2) corresponds to a shadow higher than the text.

The units of shadow are chosen so that 1.0 is a good typical value for the offset. Specifically, they're the font size times ptext.SHADOW_UNIT, which is set to 1/18 by default.

As a special case, setting color to a transparent value (e.g. (0,0,0,0)) while using drop shadow will cause the text to be invisible, giving a hollow shadow. (This feature is not compatible with gcolor.)

Valid values for scolor are the same as for color.

Gradient color

ptext.draw("hello world", (100, 100), color="black", gcolor="green")

Keyword argument:

  • gcolor: Lower gradient stop color. Defaults to None.

Specify gcolor to color the text with a vertical color gradient. The text's color will be color at the top and gcolor at the bottom. Positioning of the gradient stops and orientation of the gradient are hard coded and cannot be specified.

Requries pygame.surfarray module, which uses numpy or Numeric library.

Alpha transparency

ptext.draw("hello world", (100, 100), alpha=0.5)

Keyword argument:

  • alpha: alpha transparency value, between 0 and 1. Defaults to 1.0.

In order to maximize reuse of cached transparent surfaces, the value of alpha is rounded. ptext.ALPHA_RESOLUTION, which is set to 16 by default, specifies the number of different values alpha may take internally. Set it higher (up to 255) for more fine-grained control over transparency values.

Requries pygame.surfarray module, which uses numpy or Numeric library.

Anchored positioning

ptext.draw("hello world", (100, 100), anchor=(0.3,0.7))

Keyword argument:

  • anchor: a length-2 sequence of horizontal and vertical anchor fractions. Defaults to ptext.DEFAULT_ANCHOR, which is set to (0.0, 0.0) by default.

anchor specifies how the text is anchored to the given position, when no positioning keyword arguments are passed. The two values in anchor can take arbitrary values between 0.0 and 1.0. An anchor value of (0,0), the default, means that the given position is the top left of the text. A value of (1,1) means the given position is the bottom right of the text.

Rotation

ptext.draw("hello world", (100, 100), angle=10)

Keyword argument:

  • angle: counterclockwise rotation angle in degrees. Defaults to 0.

Positioning of rotated surfaces is tricky. When drawing rotated text with ptext, the anchor point, the position you actually specify, remains fixed, and the text rotates around it. For instance, if you specify the top left of the text to be at (100, 100) with an angle of 90, then the Surface will actually be drawn so that its bottom left is at (100, 100).

If you find that confusing, try specifying the center. If you anchor the text at the center, then the center will remain fixed, no matter how you rotate it.

In order to maximize reuse of cached rotated surfaces, the value of angle is rounded to the nearest multiple of ptext.ANGLE_RESOLUTION_DEGREES, which is set to 3 by default. Set it lower for more fine-grained control over rotation. It's recommended you set it only to values that divide evenly into 90 in floating-point representation. Such values include:

0.25 0.5 0.75 1 1.25 1.5 2 2.25 2.5 3 3.75 4.5 5 6 7.5 9 10 15 18 30

Destination surface

mysurface = pygame.Surface((400, 400)).convert_alpha()
ptext.draw("hello world", (100, 100), surf=mysurface)

Keyword arugment:

  • surf: destination pygame.Surface object. Defaults to the display Surface.

Specify surf if you don't want to draw directly to the display Surface (pygame.display.get_surface()).

Text Surface caching

ptext.draw("hello world", (100, 100), cache=False)
ptext.AUTO_CLEAN = False
ptext.clean()

Keyword argument:

  • cache: whether to cache Surfaces generated while rendering text during this call. Defaults to True.

ptext caches pygame.Surface objects, so they don't have to rendered with subsequent calls. You should be able to not worry about this part.

In order to keep memory from getting arbitrarily large, ptext will free previously cached Surface objects, starting with the least recently used objects. In theory, this could cause noticeable skips in gameplay. I haven't noticed it, but if you want to control this behavior, set ptext.AUTO_CLEAN to False, and call ptext.clean yourself at times when framerate is not cruical (e.g. menu screens).

ptext.MEMORY_LIMIT_MB is the approximate size of the cache in megabytes before a cleanup occurs. It's set to 64 by default. As long as the cache stays below this size, ptext.clean is a no-op. ptext.MEMORY_REDUCTION_FACTOR controls how much is deleted in this process. Valid values range from 0.0 (everything is deleted) to 1.0 (just enough is deleted to drop below the limit). It's set to 0.5 by default.

ptext.drawbox: Constrained text

ptext.drawbox("hello world", (100, 100, 200, 50))

ptext.drawbox requires two arguments: the text to be drawn, and a pygame.Rect or a Rect-like object to stay within. The font size will be chosen to be as large as possible while staying within the box. Other than fontsize and positional arguments, you can pass all the same keyword arguments to ptext.drawbox as to ptext.draw.

Other public methods

These methods are used internally, but you can use them if you want. They should work fine.

ptext.getfont(fontname, fontsize)

ptext.getfont returns the corresponding pygame.font.Font object.

ptext.wrap(text, fontname, fontsize, width=None, widthem=None)

ptext.wrap returns a list of substrings of text, one for each line in the word wrapped text.

ptext.getsurf(text, **kwargs)

ptext.getsurf takes the same keyword arguments that ptext.draw takes (except for arguments related to positioning), and returns the pygame.Surface containing the text to be drawn.