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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
|
/*
* Copyright © 2015, 2016 Canonical Ltd.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3,
* as published by the Free Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Authored By: Kevin DuBois <kevin.dubois@canonical.com>
*/
#include "server_example_adorning_compositor.h"
#include "as_render_target.h"
#include "mir/graphics/display_buffer.h"
#include "mir/graphics/buffer.h"
#include "mir/compositor/compositor_report.h"
#include "mir/compositor/scene_element.h"
#include "mir/renderer/gl/texture_source.h"
#include "mir/renderer/gl/render_target.h"
#include <stdexcept>
#include <boost/throw_exception.hpp>
#include MIR_SERVER_GL_H
namespace me = mir::examples;
namespace mg = mir::graphics;
namespace mc = mir::compositor;
namespace mrg = mir::renderer::gl;
bool make_current(mrg::RenderTarget* render_target)
{
render_target->make_current();
return true;
}
me::AdorningDisplayBufferCompositor::Shader::Shader(GLchar const* const* src, GLuint type) :
shader(glCreateShader(type))
{
glShaderSource(shader, 1, src, 0);
glCompileShader(shader);
}
me::AdorningDisplayBufferCompositor::Shader::~Shader()
{
glDeleteShader(shader);
}
me::AdorningDisplayBufferCompositor::Program::Program(Shader& vertex, Shader& fragment) :
program(glCreateProgram())
{
glAttachShader(program, vertex.shader);
glAttachShader(program, fragment.shader);
glLinkProgram(program);
}
me::AdorningDisplayBufferCompositor::Program::~Program()
{
glDeleteProgram(program);
}
me::AdorningDisplayBufferCompositor::AdorningDisplayBufferCompositor(
mg::DisplayBuffer& display_buffer,
std::tuple<float, float, float> const& background_rgb,
std::shared_ptr<mc::CompositorReport> const& report) :
db{display_buffer},
render_target{me::as_render_target(display_buffer)},
vert_shader_src{
"attribute vec4 vPosition;"
"uniform vec2 pos;"
"uniform vec2 scale;"
"attribute vec2 uvCoord;"
"varying vec2 texcoord;"
"void main() {"
" gl_Position = vec4(vPosition.xy * scale + pos, 0.0, 1.0);"
" texcoord = uvCoord.xy;"
"}"
},
frag_shader_src{
"#ifdef GL_ES\n"
"precision mediump float;\n"
"#endif\n"
"varying vec2 texcoord;"
"uniform sampler2D tex;"
"uniform float alpha;"
"void main() {"
" gl_FragColor = texture2D(tex, texcoord) * alpha;"
"}"
},
current(make_current(render_target)),
vertex(&vert_shader_src, GL_VERTEX_SHADER),
fragment(&frag_shader_src, GL_FRAGMENT_SHADER),
program(vertex, fragment),
report(report)
{
glUseProgram(program.program);
vPositionAttr = glGetAttribLocation(program.program, "vPosition");
glVertexAttribPointer(vPositionAttr, 4, GL_FLOAT, GL_FALSE, 0, vertex_data);
uvCoord = glGetAttribLocation(program.program, "uvCoord");
glVertexAttribPointer(uvCoord, 2, GL_FLOAT, GL_FALSE, 0, uv_data);
posUniform = glGetUniformLocation(program.program, "pos");
glClearColor(std::get<0>(background_rgb), std::get<1>(background_rgb), std::get<2>(background_rgb), 1.0);
scaleUniform = glGetUniformLocation(program.program, "scale");
alphaUniform = glGetUniformLocation(program.program, "alpha");
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
}
namespace
{
bool renderable_is_occluded(
mg::Renderable const& renderable,
mir::geometry::Rectangle const& area,
std::vector<mir::geometry::Rectangle>& coverage)
{
static glm::mat4 const identity;
static mir::geometry::Rectangle const empty{};
if (renderable.transformation() != identity)
return false; // Weirdly transformed. Assume never occluded.
auto const& window = renderable.screen_position();
auto const& clipped_window = window.intersection_with(area);
if (clipped_window == empty)
return true; // Not in the area; definitely occluded.
bool occluded = false;
for (auto const& r : coverage)
{
if (r.contains(clipped_window))
{
occluded = true;
break;
}
}
if (!occluded && renderable.alpha() == 1.0f && !renderable.shaped())
coverage.push_back(clipped_window);
return occluded;
}
void remove_occlusions_from(mc::SceneElementSequence& elements, mir::geometry::Rectangle const& area)
{
std::vector<mir::geometry::Rectangle> coverage;
auto it = elements.rbegin();
while (it != elements.rend())
{
auto const renderable = (*it)->renderable();
if (renderable_is_occluded(*renderable, area, coverage))
{
(*it)->occluded();
it = mc::SceneElementSequence::reverse_iterator(elements.erase(std::prev(it.base())));
}
else
{
it++;
}
}
}
}
void me::AdorningDisplayBufferCompositor::composite(compositor::SceneElementSequence&& scene_sequence)
{
report->began_frame(this);
remove_occlusions_from(scene_sequence, db.view_area());
//note: If what should be drawn is expressible as a SceneElementSequence,
// mg::DisplayBuffer::post_renderables_if_optimizable() should be used,
// to give the the display hardware a chance at an optimized render of
// the scene. In this example though, we want some custom elements, so
// we'll always use GLES.
render_target->make_current();
auto display_width = db.view_area().size.width.as_int();
auto display_height = db.view_area().size.height.as_int();
glUseProgram(program.program);
glViewport(0, 0, display_width, display_height);
glClear( GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT );
mg::RenderableList renderable_list;
renderable_list.reserve(scene_sequence.size());
for(auto& element : scene_sequence)
{
//courteously inform the client that its rendered
//if something is not to be rendered, mc::SceneElementSequence::occluded() should be called
element->rendered();
auto const renderable = element->renderable();
renderable_list.push_back(renderable);
float width = renderable->screen_position().size.width.as_int();
float height = renderable->screen_position().size.height.as_int();
float x = renderable->screen_position().top_left.x.as_int() - db.view_area().top_left.x.as_int();
float y = renderable->screen_position().top_left.y.as_int() - db.view_area().top_left.y.as_int();
float scale[2] {
width/display_width * 2,
height/display_height * -2};
float position[2] {
(x / display_width * 2.0f) - 1.0f,
1.0f - (y / display_height * 2.0f)
};
float const plane_alpha = renderable->alpha();
if (renderable->shaped() || plane_alpha < 1.0)
glEnable(GL_BLEND);
else
glDisable(GL_BLEND);
glUniform2fv(posUniform, 1, position);
glUniform2fv(scaleUniform, 1, scale);
glUniform1fv(alphaUniform, 1, &plane_alpha);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture);
auto const texture_source =
dynamic_cast<mir::renderer::gl::TextureSource*>(
renderable->buffer()->native_buffer_base());
if (!texture_source)
BOOST_THROW_EXCEPTION(std::logic_error("Buffer does not support GL rendering"));
texture_source->gl_bind_to_texture();
glEnableVertexAttribArray(vPositionAttr);
glEnableVertexAttribArray(uvCoord);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glDisableVertexAttribArray(uvCoord);
glDisableVertexAttribArray(vPositionAttr);
}
report->renderables_in_frame(this, renderable_list);
report->rendered_frame(this);
render_target->swap_buffers();
report->finished_frame(this);
}
|