1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/thebes/cairo-xlib-utils.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,119 @@
1.4 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef CAIROXLIBUTILS_H_
1.10 +#define CAIROXLIBUTILS_H_
1.11 +
1.12 +#include "cairo.h"
1.13 +#include <X11/Xlib.h>
1.14 +
1.15 +CAIRO_BEGIN_DECLS
1.16 +
1.17 +/**
1.18 + * This callback encapsulates Xlib-based rendering. We assume that the
1.19 + * execution of the callback is equivalent to compositing some RGBA image of
1.20 + * size (bounds_width, bounds_height) onto the drawable at offset (offset_x,
1.21 + * offset_y), clipped to the union of the clip_rects if num_rects is greater
1.22 + * than zero. This includes the assumption that the same RGBA image
1.23 + * is composited if you call the callback multiple times with the same closure,
1.24 + * display and visual during a single cairo_draw_with_xlib call.
1.25 + *
1.26 + * @return True on success, False on non-recoverable error
1.27 + */
1.28 +typedef cairo_bool_t (* cairo_xlib_drawing_callback)
1.29 + (void *closure,
1.30 + Screen *screen,
1.31 + Drawable drawable,
1.32 + Visual *visual,
1.33 + short offset_x, short offset_y,
1.34 + XRectangle* clip_rects, unsigned int num_rects);
1.35 +
1.36 +/**
1.37 + * This structure captures the result of the native drawing, in case the
1.38 + * caller may wish to reapply the drawing efficiently later.
1.39 + */
1.40 +typedef struct {
1.41 + cairo_surface_t *surface;
1.42 + cairo_bool_t uniform_alpha;
1.43 + cairo_bool_t uniform_color;
1.44 + double alpha; /* valid only if uniform_alpha is TRUE */
1.45 + double r, g, b; /* valid only if uniform_color is TRUE */
1.46 +} cairo_xlib_drawing_result_t;
1.47 +
1.48 +/**
1.49 + * This type specifies whether the native drawing callback draws all pixels
1.50 + * in its bounds opaquely, independent of the contents of the target drawable,
1.51 + * or whether it leaves pixels transparent/translucent or depends on the
1.52 + * existing contents of the target drawable in some way.
1.53 + */
1.54 +typedef enum _cairo_xlib_drawing_opacity {
1.55 + CAIRO_XLIB_DRAWING_OPAQUE,
1.56 + CAIRO_XLIB_DRAWING_TRANSPARENT
1.57 +} cairo_xlib_drawing_opacity_t;
1.58 +
1.59 +/**
1.60 + * This type encodes the capabilities of the native drawing callback.
1.61 + *
1.62 + * If CAIRO_XLIB_DRAWING_SUPPORTS_OFFSET is set, 'offset_x' and 'offset_y'
1.63 + * can be nonzero in the call to the callback; otherwise they will be zero.
1.64 + *
1.65 + * If CAIRO_XLIB_DRAWING_SUPPORTS_CLIP_RECT is set, then 'num_rects' can be
1.66 + * zero or one in the call to the callback. If
1.67 + * CAIRO_XLIB_DRAWING_SUPPORTS_CLIP_LIST is set, then 'num_rects' can be
1.68 + * anything in the call to the callback. Otherwise 'num_rects' will be zero.
1.69 + * Do not set both of these values.
1.70 + *
1.71 + * If CAIRO_XLIB_DRAWING_SUPPORTS_ALTERNATE_SCREEN is set, then 'screen' can
1.72 + * be any screen on any display, otherwise it will be the default screen of
1.73 + * the display passed into cairo_draw_with_xlib.
1.74 + *
1.75 + * If CAIRO_XLIB_DRAWING_SUPPORTS_NONDEFAULT_VISUAL is set, then 'visual' can be
1.76 + * any visual, otherwise it will be equal to
1.77 + * DefaultVisualOfScreen (screen).
1.78 + */
1.79 +typedef enum {
1.80 + CAIRO_XLIB_DRAWING_SUPPORTS_OFFSET = 0x01,
1.81 + CAIRO_XLIB_DRAWING_SUPPORTS_CLIP_RECT = 0x02,
1.82 + CAIRO_XLIB_DRAWING_SUPPORTS_CLIP_LIST = 0x04,
1.83 + CAIRO_XLIB_DRAWING_SUPPORTS_ALTERNATE_SCREEN = 0x08,
1.84 + CAIRO_XLIB_DRAWING_SUPPORTS_NONDEFAULT_VISUAL = 0x10
1.85 +} cairo_xlib_drawing_support_t;
1.86 +
1.87 +/**
1.88 + * Draw Xlib output into any cairo context. All cairo transforms and effects
1.89 + * are honored, including the current operator. This is equivalent to a
1.90 + * cairo_set_source_surface and then cairo_paint.
1.91 + * @param cr the context to draw into
1.92 + * @param callback the code to perform Xlib rendering
1.93 + * @param closure associated data
1.94 + * @param dpy an X display to use in case the cairo context has no associated X display
1.95 + * @param width the width of the putative image drawn by the callback
1.96 + * @param height the height of the putative image drawn by the callback
1.97 + * @param is_opaque set to CAIRO_XLIB_DRAWING_IS_OPAQUE to indicate
1.98 + * that all alpha values of the putative image will be 1.0; the pixels drawn into
1.99 + * the Drawable must not depend on the prior contents of the Drawable
1.100 + * in any way
1.101 + * @param capabilities the capabilities of the callback as described above.
1.102 + * @param result if non-NULL, we *may* fill in the struct with information about
1.103 + * the rendered image. 'surface' may be filled in with a surface representing
1.104 + * the image, similar to the target of 'cr'. If 'uniform_alpha' is True then
1.105 + * every pixel of the image has the same alpha value 'alpha'. If
1.106 + * 'uniform_color' is True then every pixel of the image has the same RGB
1.107 + * color (r, g, b). If the image has uniform color and alpha (or alpha is zero,
1.108 + * in which case the color is always uniform) then we won't bother returning
1.109 + * a surface for it.
1.110 + */
1.111 +void cairo_draw_with_xlib (cairo_t *cr,
1.112 + cairo_xlib_drawing_callback callback,
1.113 + void *closure,
1.114 + Display *dpy,
1.115 + unsigned int width, unsigned int height,
1.116 + cairo_xlib_drawing_opacity_t is_opaque,
1.117 + cairo_xlib_drawing_support_t capabilities,
1.118 + cairo_xlib_drawing_result_t *result);
1.119 +
1.120 +CAIRO_END_DECLS
1.121 +
1.122 +#endif /*CAIROXLIBUTILS_H_*/
