Rsvg.Handle.render_cairo

### Method

# Rsvg Handlerender_cairo

deprecated: 2.52. since: 2.14

#### Declaration [src]

    gboolean
    rsvg_handle_render_cairo (
      RsvgHandle* handle,
      cairo_t* cr
    )

#### Description [src]

Draws a loaded SVG handle to a Cairo context. Please try to use `rsvg_handle_render_document()` instead, which allows you to pick the size at which the document will be rendered.

Historically this function has picked a size by itself, based on the following rules:

- If the SVG document has both `width` and `height` attributes with physical units (px, in, cm, mm, pt, pc) or font-based units (em, ex), the function computes the size directly based on the dots-per-inch (DPI) you have configured with `rsvg_handle_set_dpi()`. This is the same approach as `rsvg_handle_get_intrinsic_size_in_pixels()`.

- Otherwise, if there is a `viewBox` attribute and both `width` and `height` are set to `100%` (or if they don’t exist at all and thus default to 100%), the function uses the width and height of the `viewBox` as a pixel size. This produces a rendered document with the correct aspect ratio.

- Otherwise, this function computes the extents of every graphical object in the SVG document to find the total extents. This is moderately expensive, but no more expensive than rendering the whole document, for example.

- This function cannot deal with percentage-based units for `width` and `height` because there is no viewport against which they could be resolved; that is why it will compute the extents of objects in that case. This is why we recommend that you use `rsvg_handle_render_document()` instead, which takes in a viewport and follows the sizing policy from the web platform.

Drawing will occur with respect to the `cr`‘s current transformation: for example, if the `cr` has a rotated current transformation matrix, the whole SVG will be rotated in the rendered version.

This function depends on the `RsvgHandle`‘s DPI to compute dimensions in pixels, so you should call `rsvg_handle_set_dpi()` beforehand.

Note that `cr` must be a Cairo context that is not in an error state, that is, `cairo_status()` must return `CAIRO_STATUS_SUCCESS` for it. Cairo can set a context to be in an error state in various situations, for example, if it was passed an invalid matrix or if it was created for an invalid surface.

Available since: 2.14

Deprecated since: 2.52.

Please use `rsvg_handle_render_document()` instead; that function lets you pass a viewport and obtain a good error message.

#### Parameters

`cr`

  Type: `cairo_t`

  A Cairo context.

  The data is owned by the caller of the method.

#### Return value

Type: `gboolean`

`TRUE` if drawing succeeded; `FALSE` otherwise. This function will emit a `g_warning()` if a rendering error occurs.