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
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/* GDK - The GIMP Drawing Kit
* Copyright (C) 2014 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "gdkcairo.h"
#include "gdkglcontextprivate.h"
#include "gdksurfaceprivate.h"
#include <epoxy/gl.h>
#include <math.h>
#include <string.h>
/* x,y,width,height describes a rectangle in the gl render buffer
coordinate space, and its top left corner is drawn at the current
position according to the cairo translation. */
/**
* gdk_cairo_draw_from_gl:
* @cr: a cairo context
* @surface: The surface we're rendering for (not necessarily into)
* @source: The GL ID of the source buffer
* @source_type: The type of the @source
* @buffer_scale: The scale-factor that the @source buffer is allocated for
* @x: The source x position in @source to start copying from in GL coordinates
* @y: The source y position in @source to start copying from in GL coordinates
* @width: The width of the region to draw
* @height: The height of the region to draw
*
* The main way to not 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 @surface 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 surface 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.
*
* Deprecated: 4.6: The function is overly complex and produces broken output
* in various combinations of arguments. If you want to draw with GL textures
* in GTK, use [ctor@Gdk.GLTexture.new]; if you want to use that texture in
* Cairo, use [method@Gdk.Texture.download] to download the data into a Cairo
* image surface.
*/
void
gdk_cairo_draw_from_gl (cairo_t *cr,
GdkSurface *surface,
int source,
int source_type,
int buffer_scale,
int x,
int y,
int width,
int height)
{
GdkGLContext *paint_context;
cairo_surface_t *image;
guint framebuffer;
int alpha_size = 0;
int major, minor, version;
gboolean es_use_bgra = FALSE;
paint_context = gdk_surface_get_paint_gl_context (surface, NULL);
if (paint_context == NULL)
{
g_warning ("gdk_cairo_draw_gl_render_buffer failed - no paint context");
return;
}
es_use_bgra = gdk_gl_context_use_es_bgra (paint_context);
gdk_gl_context_make_current (paint_context);
glGenFramebuffers (1, &framebuffer);
if (source_type == GL_RENDERBUFFER)
{
glBindRenderbuffer (GL_RENDERBUFFER, source);
glGetRenderbufferParameteriv (GL_RENDERBUFFER, GL_RENDERBUFFER_ALPHA_SIZE, &alpha_size);
}
else if (source_type == GL_TEXTURE)
{
glBindTexture (GL_TEXTURE_2D, source);
if (gdk_gl_context_get_use_es (paint_context))
alpha_size = 1;
else
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_ALPHA_SIZE, &alpha_size);
}
else
{
g_warning ("Unsupported gl source type %d\n", source_type);
return;
}
gdk_gl_context_get_version (paint_context, &major, &minor);
version = major * 100 + minor;
/* TODO: Use glTexSubImage2D() and do a row-by-row copy to replace
* the GL_UNPACK_ROW_LENGTH support
*/
if (gdk_gl_context_get_use_es (paint_context) &&
!(version >= 300 || gdk_gl_context_has_unpack_subimage (paint_context)))
return;
/* TODO: avoid reading back non-required data due to dest clip */
image = cairo_surface_create_similar_image (cairo_get_target (cr),
(alpha_size == 0) ? CAIRO_FORMAT_RGB24 : CAIRO_FORMAT_ARGB32,
width, height);
cairo_surface_set_device_scale (image, buffer_scale, buffer_scale);
glBindFramebuffer (GL_FRAMEBUFFER, framebuffer);
if (source_type == GL_RENDERBUFFER)
{
/* Create a framebuffer with the source renderbuffer and
make it the current target for reads */
glFramebufferRenderbuffer (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_RENDERBUFFER, source);
}
else
{
glFramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_TEXTURE_2D, source, 0);
}
glPixelStorei (GL_PACK_ALIGNMENT, 4);
glPixelStorei (GL_PACK_ROW_LENGTH, cairo_image_surface_get_stride (image) / 4);
/* The implicit format conversion is going to make this path slower */
if (!gdk_gl_context_get_use_es (paint_context))
glReadPixels (x, y, width, height, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV,
cairo_image_surface_get_data (image));
else
glReadPixels (x, y, width, height, es_use_bgra ? GL_BGRA : GL_RGBA, GL_UNSIGNED_BYTE,
cairo_image_surface_get_data (image));
glPixelStorei (GL_PACK_ROW_LENGTH, 0);
glBindFramebuffer (GL_FRAMEBUFFER, 0);
glDeleteFramebuffers (1, &framebuffer);
cairo_surface_mark_dirty (image);
cairo_set_source_surface (cr, image, 0, 0);
cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
cairo_paint (cr);
cairo_surface_destroy (image);
}
|
