Text

The Text class draws a rectangle. It inherits add, fill, stroke, fill_stroke, path, clip and other methods from Shape.

There is also a text function that draws text. Note that the text function actually paints the text (unlike other shape functions such as rectangle, that simply add the shape as a path without painting it). This is because text is almost always painted in a flat colour.

Text class methods

The Text class inherits add, fill, stroke, fill_stroke, path, clip and other methods from Shape.

It has additional methods:

• of
• font
• size
• align
• align_left
• align_center
• align_right
• align_bottom
• align_baseline
• align_middle
• align_top
• flip
• offset

of

Creates a text item.

of(text, position)

The text is placed at the position, using the alignment specified by the align functions below.

font

Selects the font face.

font(font)

Selects the font face. If it is not supplied, the currently selected font face will be used.

size

Selects the font size.

size(size)

Sets the font size. For western fonts, the font size is approximately equal to the height of the font in user units. This may vary slightly for different font faces, and non-western fonts (for example Chinese fonts). If it is not supplied, the currently selected font size will be used.

align

Sets the text alignment.

align(alignx, aligny)

alignx should be set to LEFT, CENTER, or RIGHT. This causes the left, centre, or right of the text bounding box to be aligned with the x value of the text position.

aligny should be set to BOTTOM, MIDDLE, TOP, or BASELINE. This causes the bottom, middle, top, or baseline of the text to be aligned with the y value of the text position.

The bottom, middle, and top positions are calculated from the text bounding box, but the baseline comes from the font metrics. If you need to correctly align two text strings you should use baseline rather than bottom, because the bottom depends on the string contents.

The default is LEFT and BASELINE.

align_xxx methods

align_left() sets the horizontal alignment to LEFT but leaves the vertical alignment unchanged. align_center() and align_right() set the alignment to CENTER or RIGHT.

align_bottom() sets the horizontal alignment to LEFT but leaves the vertical alignment unchanged. align_middle(), align_top(), and align_baseline() set the alignment to MIDDLE, TOP, or BASELINE.

These are alternatives to that align method, that are mainly provided for readability, particularly if you only wish to set the alignment in one direction an leave the other at the default. There is no particular advantage to using one style or the other.

offset

Sets the text alignment.

offset(x=0, y=0)

The offset moves the text in the x and y direction. The amount of offset is measured in user space.

The offset is simple added to the position of the text. So for example:

Text(ctx).of("text", p).offset(x, y).fill(color)

is equivalent to:

Text(ctx).of("text", (p[0]+x, p[1]+y)).fill(color)

It is a matter of personal preference which form you use.

text function

Paints text at a location, without the need to create a Text object

text(ctx, txt, x, y, font=None, size=None, color=None,
                   alignx=LEFT, aligny=BASELINE, flip=False)

This draws a line of text at position (x, y).

color selects the font color. If no value is supplied, the shape will be filled with whatever paint source is current for the context.

Example

Here is an example that uses the Text class to create text with various alignments:

from generativepy.drawing import make_image, setup
from generativepy.color import Color
from generativepy.geometry import Text, Circle

'''
Create text using the geometry module.
'''

def draw(ctx, width, height, frame_no, frame_count):
    setup(ctx, width, height, width=5, background=Color(0.8))

    Text(ctx).of("Left", (0.5, 0.5)).font("Times").size(0.2).align_left().align_baseline().fill(Color('blue'))
    Text(ctx).of("Aligned", (0.5, 0.7)).font("Times").size(0.2).align_left().align_baseline().fill(Color('red'))
    Text(ctx).of("Text", (0.5, 0.9)).font("Times").size(0.2).align_left().align_baseline().fill(Color('blue'))

    Text(ctx).of("Centre", (2.5, 0.5)).font("Times").size(0.2).align_center().align_baseline().fill(Color('blue'))
    Text(ctx).of("Aligned", (2.5, 0.7)).font("Times").size(0.2).align_center().align_baseline().fill(Color('red'))
    Text(ctx).of("Text", (2.5, 0.9)).font("Times").size(0.2).align_center().align_baseline().fill(Color('blue'))

    Text(ctx).of("Right", (4.5, 0.5)).font("Times").size(0.2).align_right().align_baseline().fill(Color('blue'))
    Text(ctx).of("Aligned", (4.5, 0.7)).font("Times").size(0.2).align_right().align_baseline().fill(Color('red'))
    Text(ctx).of("Text", (4.5, 0.9)).font("Times").size(0.2).align_right().align_baseline().fill(Color('blue'))

    Circle(ctx).of_center_radius((1.9, 2), 0.02).fill(Color(0, 0, 1))
    Text(ctx).of("gTop", (2, 2)).font("Times").size(0.2).align_left().align_top().fill(Color('black'))

    Circle(ctx).of_center_radius((1.9, 2.5), 0.02).fill(Color(0, 0, 1))
    Text(ctx).of("gMid", (2, 2.5)).font("Times").size(0.2).align_left().align_middle().fill(Color('black'))

    Circle(ctx).of_center_radius((1.9, 3), 0.02).fill(Color(0, 0, 1))
    Text(ctx).of("gBase", (2, 3)).font("Times").size(0.2).align_left().align_baseline().fill(Color('black'))

    Circle(ctx).of_center_radius((1.9, 3.5), 0.02).fill(Color(0, 0, 1))
    Text(ctx).of("gBottom", (2, 3.5)).font("Times").size(0.2).align_left().align_bottom().fill(Color('black'))

make_image("/tmp/geometry-text.png", draw, 500, 500)