offset>x ( n font string -- x )
Factor handbook » UI framework » Implementing new gadgets » Customizing gadget appearance » Implementing custom drawing logic » Rendering text

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Vocabulary
ui.text

Inputs

n	an integer
font	a font
string	a string

Outputs

x

a real

Generic word contract
Outputs the x coordinate of the character at the given index.

Definition

USING: ui.text.private ;

IN: ui.text

HOOK: offset>x font-renderer ( n font string -- x )

Methods

USING: accessors core-text io.encodings.string
io.encodings.utf16 math opengl sequences ui.text
ui.text.core-text ;

M:: core-text-renderer offset>x ( n font string -- x )
    font string cached-line line>> 0 n string subseq
    utf16n encode length 2 /i f CTLineGetOffsetForStringIndex
    gl-unscale ;