[−][src]Trait opencv::freetype::FreeType2

pub trait FreeType2: AlgorithmTrait {
    fn as_raw_FreeType2(&self) -> *mut c_void;

    fn load_font_data(&mut self, font_file_name: &str, id: i32) -> Result<()> { ... }

    fn set_split_number(&mut self, num: i32) -> Result<()> { ... }

    fn put_text(
        &mut self, 
        img: &mut dyn ToInputOutputArray, 
        text: &str, 
        org: Point, 
        font_height: i32, 
        color: Scalar, 
        thickness: i32, 
        line_type: i32, 
        bottom_left_origin: bool
    ) -> Result<()> { ... }

    fn get_text_size(
        &mut self, 
        text: &str, 
        font_height: i32, 
        thickness: i32, 
        base_line: &mut i32
    ) -> Result<Size> { ... }
}

Required methods

fn as_raw_FreeType2(&self) -> *mut c_void

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Provided methods

fn load_font_data(&mut self, font_file_name: &str, id: i32) -> Result<()>

Load font data.

The function loadFontData loads font data.

Parameters

  • fontFileName: FontFile Name
  • id: face_index to select a font faces in a single file.

fn set_split_number(&mut self, num: i32) -> Result<()>

Set Split Number from Bezier-curve to line

The function setSplitNumber set the number of split points from bezier-curve to line. If you want to draw large glyph, large is better. If you want to draw small glyph, small is better.

Parameters

  • num: number of split points from bezier-curve to line

fn put_text(
    &mut self,
    img: &mut dyn ToInputOutputArray,
    text: &str,
    org: Point,
    font_height: i32,
    color: Scalar,
    thickness: i32,
    line_type: i32,
    bottom_left_origin: bool
) -> Result<()>

Draws a text string.

The function putText renders the specified text string in the image. Symbols that cannot be rendered using the specified font are replaced by "Tofu" or non-drawn.

Parameters

  • img: Image.
  • text: Text string to be drawn.
  • org: Bottom-left/Top-left corner of the text string in the image.
  • fontHeight: Drawing font size by pixel unit.
  • color: Text color.
  • thickness: Thickness of the lines used to draw a text when negative, the glyph is filled. Otherwise, the glyph is drawn with this thickness.
  • line_type: Line type. See the line for details.
  • bottomLeftOrigin: When true, the image data origin is at the bottom-left corner. Otherwise, it is at the top-left corner.

fn get_text_size(
    &mut self,
    text: &str,
    font_height: i32,
    thickness: i32,
    base_line: &mut i32
) -> Result<Size>

Calculates the width and height of a text string.

The function getTextSize calculates and returns the approximate size of a box that contains the specified text. That is, the following code renders some text, the tight box surrounding it, and the baseline: :

ⓘThis example is not tested
String text = "Funny text inside the box";
int fontHeight = 60;
int thickness = -1;
int linestyle = 8;

Mat img(600, 800, CV_8UC3, Scalar::all(0));

int baseline=0;

cv::Ptr<cv::freetype::FreeType2> ft2;
ft2 = cv::freetype::createFreeType2();
ft2->loadFontData( "./mplus-1p-regular.ttf", 0 );

Size textSize = ft2->getTextSize(text,
fontHeight,
thickness,
&baseline);

if(thickness > 0){
baseline += thickness;
}

// center the text
Point textOrg((img.cols - textSize.width) / 2,
(img.rows + textSize.height) / 2);

// draw the box
rectangle(img, textOrg + Point(0, baseline),
textOrg + Point(textSize.width, -textSize.height),
Scalar(0,255,0),1,8);

// ... and the baseline first
line(img, textOrg + Point(0, thickness),
textOrg + Point(textSize.width, thickness),
Scalar(0, 0, 255),1,8);

// then put the text itself
ft2->putText(img, text, textOrg, fontHeight,
Scalar::all(255), thickness, linestyle, true );

Parameters

  • text: Input text string.
  • fontHeight: Drawing font size by pixel unit.
  • thickness: Thickness of lines used to render the text. See putText for details.
  • baseLine: [out] y-coordinate of the baseline relative to the bottom-most text point.

Returns

The size of a box that contains the specified text.

@see cv::putText

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Implementors

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