DWrite Fonts: Cairo: A Vector Graphics Library

## DWrite Fonts

DWrite Fonts — Font support for Microsoft DirectWrite

## Functions

cairo_font_face_t * | cairo_dwrite_font_face_create_for_dwrite_fontface ()
IDWriteRenderingParams * | cairo_dwrite_font_face_get_rendering_params ()
void | cairo_dwrite_font_face_set_rendering_params ()
DWRITE_MEASURING_MODE | cairo_dwrite_font_face_get_measuring_mode ()
void | cairo_dwrite_font_face_set_measuring_mode ()

## Types and Values

#define | CAIRO_HAS_DWRITE_FONT

## Description

The Microsoft DirectWrite font backend is primarily used to render text on Microsoft Windows systems.

## Functions

### cairo_dwrite_font_face_create_for_dwrite_fontface ()

    cairo_font_face_t *
    cairo_dwrite_font_face_create_for_dwrite_fontface
                                   (IDWriteFontFace *dwrite_font_face);

Creates a new font for the DWrite font backend based on a DWrite font face. This font can then be used with `cairo_set_font_face()` or `cairo_scaled_font_create()`.

Here is an example of how this function might be used:

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    #include <cairo-dwrite.h>
    #include <dwrite.h>

    IDWriteFactory* dWriteFactory = NULL;
    HRESULT hr = DWriteCreateFactory(
        DWRITE_FACTORY_TYPE_SHARED,
        __uuidof(IDWriteFactory),
       reinterpret_cast<IUnknown**>(&dWriteFactory));

    IDWriteFontCollection *systemCollection;
    hr = dWriteFactory->GetSystemFontCollection(&systemCollection);

    UINT32 idx;
    BOOL found;
    systemCollection->FindFamilyName(L"Segoe UI Emoji", &idx, &found);

    IDWriteFontFamily *family;
    systemCollection->GetFontFamily(idx, &family);

    IDWriteFont *dwritefont;
    DWRITE_FONT_WEIGHT weight = DWRITE_FONT_WEIGHT_NORMAL;
    DWRITE_FONT_STYLE style = DWRITE_FONT_STYLE_NORMAL;
    hr = family->GetFirstMatchingFont(weight, DWRITE_FONT_STRETCH_NORMAL, style, &dwritefont);

    IDWriteFontFace *dwriteface;
    hr = dwritefont->CreateFontFace(&dwriteface);

    cairo_font_face_t *face;
    face = cairo_dwrite_font_face_create_for_dwrite_fontface(dwriteface);
    cairo_set_font_face(cr, face);
    cairo_set_font_size(cr, 70);
    cairo_move_to(cr, 100, 100);
    cairo_show_text(cr, "😃");

Note: When printing a DWrite font to a CAIRO_SURFACE_TYPE_WIN32_PRINTING surface, the printing surface will substitute each DWrite font with a Win32 font created from the same underlying font file. If the matching font file can not be found, the CAIRO_SURFACE_TYPE_WIN32_PRINTING surface will convert each glyph to a filled path. If a DWrite font was not created from a system font, it is recommended that the font used to create the DWrite font be made available to GDI to avoid the undesirable fallback to emitting paths. This can be achieved using the GDI font loading functions such as `AddFontMemResourceEx()`.

#### Parameters

dwrite_font_face | A pointer to an IDWriteFontFace specifying the DWrite font to use. |

#### Returns

a newly created cairo_font_face_t. Free with `cairo_font_face_destroy()` when you are done using it.

Since: 1.18

### cairo_dwrite_font_face_get_rendering_params ()

    IDWriteRenderingParams *
    cairo_dwrite_font_face_get_rendering_params
                                   (cairo_font_face_t *font_face);

Gets the IDWriteRenderingParams object of `font_face` .

#### Parameters

font_face | The cairo_dwrite_font_face_t object to query |

#### Returns

the IDWriteRenderingParams object or `NULL` if none.

Since: 1.18

### cairo_dwrite_font_face_set_rendering_params ()

    void
    cairo_dwrite_font_face_set_rendering_params
                                   (cairo_font_face_t *font_face,
                                    IDWriteRenderingParams *params);

Sets the IDWriteRenderingParams object to `font_face` . This IDWriteRenderingParams is used to render glyphs if default values of font options are used. If non-defalut values of font options are specified when creating a cairo_scaled_font_t, cairo creates a new IDWriteRenderingParams object for the cairo_scaled_font_t object by overwriting the corresponding parameters.

#### Parameters

font_face | The cairo_dwrite_font_face_t object to modify |
params | The IDWriteRenderingParams object |

Since: 1.18

### cairo_dwrite_font_face_get_measuring_mode ()

    DWRITE_MEASURING_MODE
    cairo_dwrite_font_face_get_measuring_mode
                                   (cairo_font_face_t *font_face);

Gets the DWRITE_MEASURING_MODE enum of `font_face` .

#### Parameters

font_face | The cairo_dwrite_font_face_t object to query |

#### Returns

The DWRITE_MEASURING_MODE enum of `font_face` .

Since: 1.18

### cairo_dwrite_font_face_set_measuring_mode ()

    void
    cairo_dwrite_font_face_set_measuring_mode
                                   (cairo_font_face_t *font_face,
                                    DWRITE_MEASURING_MODE mode);

Sets the DWRITE_MEASURING_MODE enum to `font_face` .

#### Parameters

font_face | The cairo_dwrite_font_face_t object to modify |
mode | The DWRITE_MEASURING_MODE enum. |

Since: 1.18

## Types and Values

### CAIRO_HAS_DWRITE_FONT

    #define CAIRO_HAS_DWRITE_FONT

Defined if the Microsoft DWrite font backend is available. This macro can be used to conditionally compile backend-specific code.

Since: 1.18

## See Also

cairo_font_face_t