gdk_window_create_similar_surface ()

cairo_surface_t *
gdk_window_create_similar_surface (GdkWindow *window,
                                   cairo_content_t content,
                                   int width,
                                   int height);

Create a new surface that is as compatible as possible with the given window . For example the new surface will have the same fallback resolution and font options as window . Generally, the new surface will also use the same backend as window , unless that is not possible for some reason. The type of the returned surface may be examined with cairo_surface_get_type().

Initially the surface contents are all 0 (transparent if contents have transparency, black otherwise.)

Since: 2.22

gdk_window_create_similar_image_surface ()

cairo_surface_t *
gdk_window_create_similar_image_surface
                               (GdkWindow *window,
                                cairo_format_t format,
                                int width,
                                int height,
                                int scale);

Create a new image surface that is efficient to draw on the given window .

Initially the surface contents are all 0 (transparent if contents have transparency, black otherwise.)

The width and height of the new surface are not affected by the scaling factor of the window , or by the scale argument; they are the size of the surface in device pixels. If you wish to create an image surface capable of holding the contents of window you can use:

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int scale = gdk_window_get_scale_factor (window);
int width = gdk_window_get_width (window) * scale;
int height = gdk_window_get_height (window) * scale;

// format is set elsewhere
cairo_surface_t *surface =
  gdk_window_create_similar_image_surface (window,
                                           format,
                                           width, height,
                                           scale);

Note that unlike cairo_surface_create_similar_image(), the new surface's device scale is set to scale , or to the scale factor of window if scale is 0.

Since: 3.10

gdk_cairo_create ()

cairo_t *
gdk_cairo_create (GdkWindow *window);

Creates a Cairo context for drawing to window .

Note that calling cairo_reset_clip() on the resulting cairo_t will produce undefined results, so avoid it at all costs.

Typically, this function is used to draw on a GdkWindow out of the paint cycle of the toolkit; this should be avoided, as it breaks various assumptions and optimizations.

If you are drawing on a native GdkWindow in response to a GDK_EXPOSE event you should use gdk_window_begin_draw_frame() and gdk_drawing_context_get_cairo_context() instead. GTK will automatically do this for you when drawing a widget.

Since: 2.8

gdk_cairo_get_clip_rectangle ()

gboolean
gdk_cairo_get_clip_rectangle (cairo_t *cr,
                              GdkRectangle *rect);

This is a convenience function around cairo_clip_extents(). It rounds the clip extents to integer coordinates and returns a boolean indicating if a clip area exists.

gdk_cairo_get_drawing_context ()

GdkDrawingContext *
gdk_cairo_get_drawing_context (cairo_t *cr);

Retrieves the GdkDrawingContext that created the Cairo context cr .

Since: 3.22

gdk_cairo_set_source_color ()

void
gdk_cairo_set_source_color (cairo_t *cr,
                            const GdkColor *color);

Sets the specified GdkColor as the source color of cr .

Since: 2.8

gdk_cairo_set_source_rgba ()

void
gdk_cairo_set_source_rgba (cairo_t *cr,
                           const GdkRGBA *rgba);

Sets the specified GdkRGBA as the source color of cr .

Since: 3.0

gdk_cairo_set_source_pixbuf ()

void
gdk_cairo_set_source_pixbuf (cairo_t *cr,
                             const GdkPixbuf *pixbuf,
                             gdouble pixbuf_x,
                             gdouble pixbuf_y);

Sets the given pixbuf as the source pattern for cr .

The pattern has an extend mode of CAIRO_EXTEND_NONE and is aligned so that the origin of pixbuf is pixbuf_x , pixbuf_y .

Since: 2.8

gdk_cairo_set_source_window ()

void
gdk_cairo_set_source_window (cairo_t *cr,
                             GdkWindow *window,
                             gdouble x,
                             gdouble y);

Sets the given window as the source pattern for cr .

The pattern has an extend mode of CAIRO_EXTEND_NONE and is aligned so that the origin of window is x , y . The window contains all its subwindows when rendering.

Note that the contents of window are undefined outside of the visible part of window , so use this function with care.

Since: 2.24

gdk_cairo_rectangle ()

void
gdk_cairo_rectangle (cairo_t *cr,
                     const GdkRectangle *rectangle);

Adds the given rectangle to the current path of cr .

Since: 2.8

gdk_cairo_region ()

void
gdk_cairo_region (cairo_t *cr,
                  const cairo_region_t *region);

Adds the given region to the current path of cr .

Since: 2.8

gdk_cairo_region_create_from_surface ()

cairo_region_t *
gdk_cairo_region_create_from_surface (cairo_surface_t *surface);

Creates region that describes covers the area where the given surface is more than 50% opaque.

This function takes into account device offsets that might be set with cairo_surface_set_device_offset().

gdk_cairo_surface_create_from_pixbuf ()

cairo_surface_t *
gdk_cairo_surface_create_from_pixbuf (const GdkPixbuf *pixbuf,
                                      int scale,
                                      GdkWindow *for_window);

Creates an image surface with the same contents as the pixbuf.

Since: 3.10

gdk_cairo_draw_from_gl ()

void
gdk_cairo_draw_from_gl (cairo_t *cr,
                        GdkWindow *window,
                        int source,
                        int source_type,
                        int buffer_scale,
                        int x,
                        int y,
                        int width,
                        int height);

This is the main way to draw GL content in GTK+. It takes a render buffer ID (source_type == GL_RENDERBUFFER) or a texture id (source_type == GL_TEXTURE) and draws it onto cr with an OVER operation, respecting the current clip. The top left corner of the rectangle specified by x , y , width and height will be drawn at the current (0,0) position of the cairo_t.

This will work for *all* cairo_t, as long as window is realized, but the fallback implementation that reads back the pixels from the buffer may be used in the general case. In the case of direct drawing to a window with no special effects applied to cr it will however use a more efficient approach.

For GL_RENDERBUFFER the code will always fall back to software for buffers with alpha components, so make sure you use GL_TEXTURE if using alpha.

Calling this may change the current GL context.

Since: 3.16