1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* A class hierarchy implementing various ways of streaming pixel buffers to the GPU.
* Copyright (C) 2022 PBS <pbs3141@gmail.com>
* Released under GNU GPL v2+, read the file 'COPYING' for more information.
*/
#ifndef INKSCAPE_UI_WIDGET_CANVAS_PIXELSTREAMER_H
#define INKSCAPE_UI_WIDGET_CANVAS_PIXELSTREAMER_H
#include <memory>
#include <2geom/int-point.h>
#include <cairomm/refptr.h>
#include <cairomm/surface.h>
namespace Inkscape {
namespace UI {
namespace Widget {
// A class for turning Cairo image surfaces into OpenGL textures.
class PixelStreamer
{
public:
virtual ~PixelStreamer() = default;
// Method for streaming pixels to the GPU.
enum class Method
{
Auto, // Use the best option available at runtime.
Persistent, // Persistent buffer mapping. (Best, requires OpenGL 4.4.)
Asynchronous, // Ordinary buffer mapping. (Almost as good, requires OpenGL 3.0.)
Synchronous // Synchronous texture uploads. (Worst but still tolerable, requires OpenGL 1.1.)
};
// Create a PixelStreamer using a choice of method specified at runtime, falling back if unsupported.
static std::unique_ptr<PixelStreamer> create_supported(Method method);
// Return the method in use.
virtual Method get_method() const = 0;
/**
* Request a drawing surface of the given dimensions. If nogl is true, no GL commands will be issued,
* but the request may fail. An effort is made to keep such failures to a minimum.
*
* The surface must be returned to the PixelStreamer by calling finish(), in order to deallocate
* GL resourecs.
*/
virtual Cairo::RefPtr<Cairo::ImageSurface> request(Geom::IntPoint const &dimensions, bool nogl = false) = 0;
/**
* Give back a drawing surface produced by request(), uploading the contents to the currently bound texture.
* The texture must be at least as big as the surface.
*
* If junk is true, then the surface will be junked instead, meaning nothing will be done with the contents,
* and its GL resources will simply be deallocated.
*/
virtual void finish(Cairo::RefPtr<Cairo::ImageSurface> surface, bool junk = false) = 0;
};
} // namespace Widget
} // namespace UI
} // namespace Inkscape
#endif // INKSCAPE_UI_WIDGET_CANVAS_PIXELSTREAMER_H
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
|
