1 //---------------------------------------------------------------------------//
2 // Copyright (c) 2013-2014 Kyle Lutz <kyle.r.lutz@gmail.com>
3 //
4 // Distributed under the Boost Software License, Version 1.0
5 // See accompanying file LICENSE_1_0.txt or copy at
6 // http://www.boost.org/LICENSE_1_0.txt
7 //
8 // See http://boostorg.github.com/compute for more information.
9 //---------------------------------------------------------------------------//
10
11 #include <iostream>
12 #include <algorithm>
13
14 #include <QtGlobal>
15 #if QT_VERSION >= 0x050000
16 #include <QtWidgets>
17 #else
18 #include <QtGui>
19 #endif
20 #include <QtOpenGL>
21
22 #ifndef Q_MOC_RUN
23 #include <boost/compute/command_queue.hpp>
24 #include <boost/compute/kernel.hpp>
25 #include <boost/compute/program.hpp>
26 #include <boost/compute/system.hpp>
27 #include <boost/compute/interop/opengl.hpp>
28 #include <boost/compute/utility/dim.hpp>
29 #include <boost/compute/utility/source.hpp>
30 #endif // Q_MOC_RUN
31
32 namespace compute = boost::compute;
33
34 // opencl source code
35 const char source[] = BOOST_COMPUTE_STRINGIZE_SOURCE(
36 // map value to color
37 float4 color(uint i)
38 {
39 uchar c = i;
40 uchar x = 35;
41 uchar y = 25;
42 uchar z = 15;
43 uchar max = 255;
44
45 if(i == 256)
46 return (float4)(0, 0, 0, 255);
47 else
48 return (float4)(max-x*i, max-y*i, max-z*i, max) / 255.f;
49 }
50
51 __kernel void mandelbrot(__write_only image2d_t image)
52 {
53 const uint x_coord = get_global_id(0);
54 const uint y_coord = get_global_id(1);
55 const uint width = get_global_size(0);
56 const uint height = get_global_size(1);
57
58 float x_origin = ((float) x_coord / width) * 3.25f - 2.0f;
59 float y_origin = ((float) y_coord / height) * 2.5f - 1.25f;
60
61 float x = 0.0f;
62 float y = 0.0f;
63
64 uint i = 0;
65 while(x*x + y*y <= 4.f && i < 256){
66 float tmp = x*x - y*y + x_origin;
67 y = 2*x*y + y_origin;
68 x = tmp;
69 i++;
70 }
71
72 int2 coord = { x_coord, y_coord };
73 write_imagef(image, coord, color(i));
74 };
75 );
76
77 class MandelbrotWidget : public QGLWidget
78 {
79 Q_OBJECT
80
81 public:
82 MandelbrotWidget(QWidget *parent = 0);
83 ~MandelbrotWidget();
84
85 void initializeGL();
86 void resizeGL(int width, int height);
87 void paintGL();
88 void keyPressEvent(QKeyEvent* event);
89
90 private:
91 compute::context context_;
92 compute::command_queue queue_;
93 compute::program program_;
94 GLuint gl_texture_;
95 compute::opengl_texture cl_texture_;
96 };
97
MandelbrotWidget(QWidget * parent)98 MandelbrotWidget::MandelbrotWidget(QWidget *parent)
99 : QGLWidget(parent)
100 {
101 gl_texture_ = 0;
102 }
103
~MandelbrotWidget()104 MandelbrotWidget::~MandelbrotWidget()
105 {
106 }
107
initializeGL()108 void MandelbrotWidget::initializeGL()
109 {
110 // setup opengl
111 glDisable(GL_LIGHTING);
112
113 // create the OpenGL/OpenCL shared context
114 context_ = compute::opengl_create_shared_context();
115
116 // get gpu device
117 compute::device gpu = context_.get_device();
118 std::cout << "device: " << gpu.name() << std::endl;
119
120 // setup command queue
121 queue_ = compute::command_queue(context_, gpu);
122
123 // build mandelbrot program
124 program_ = compute::program::create_with_source(source, context_);
125 program_.build();
126 }
127
resizeGL(int width,int height)128 void MandelbrotWidget::resizeGL(int width, int height)
129 {
130 #if QT_VERSION >= 0x050000
131 // scale height/width based on device pixel ratio
132 width /= windowHandle()->devicePixelRatio();
133 height /= windowHandle()->devicePixelRatio();
134 #endif
135
136 // resize viewport
137 glViewport(0, 0, width, height);
138
139 // delete old texture
140 if(gl_texture_){
141 glDeleteTextures(1, &gl_texture_);
142 gl_texture_ = 0;
143 }
144
145 // generate new texture
146 glGenTextures(1, &gl_texture_);
147 glBindTexture(GL_TEXTURE_2D, gl_texture_);
148 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
149 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
150 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
151 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
152 glTexImage2D(
153 GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0
154 );
155
156 // create opencl object for the texture
157 cl_texture_ = compute::opengl_texture(
158 context_, GL_TEXTURE_2D, 0, gl_texture_, CL_MEM_WRITE_ONLY
159 );
160 }
161
paintGL()162 void MandelbrotWidget::paintGL()
163 {
164 using compute::dim;
165
166 float w = width();
167 float h = height();
168
169 glMatrixMode(GL_PROJECTION);
170 glLoadIdentity();
171 glOrtho(0.0, w, 0.0, h, -1.0, 1.0);
172 glMatrixMode(GL_MODELVIEW);
173 glLoadIdentity();
174
175 // setup the mandelbrot kernel
176 compute::kernel kernel(program_, "mandelbrot");
177 kernel.set_arg(0, cl_texture_);
178
179 // acquire the opengl texture so it can be used in opencl
180 compute::opengl_enqueue_acquire_gl_objects(1, &cl_texture_.get(), queue_);
181
182 // execute the mandelbrot kernel
183 queue_.enqueue_nd_range_kernel(
184 kernel, dim(0, 0), dim(width(), height()), dim(1, 1)
185 );
186
187 // release the opengl texture so it can be used by opengl
188 compute::opengl_enqueue_release_gl_objects(1, &cl_texture_.get(), queue_);
189
190 // ensure opencl is finished before rendering in opengl
191 queue_.finish();
192
193 // draw a single quad with the mandelbrot image texture
194 glEnable(GL_TEXTURE_2D);
195 glBindTexture(GL_TEXTURE_2D, gl_texture_);
196
197 glBegin(GL_QUADS);
198 glTexCoord2f(0, 0); glVertex2f(0, 0);
199 glTexCoord2f(0, 1); glVertex2f(0, h);
200 glTexCoord2f(1, 1); glVertex2f(w, h);
201 glTexCoord2f(1, 0); glVertex2f(w, 0);
202 glEnd();
203 }
204
keyPressEvent(QKeyEvent * event)205 void MandelbrotWidget::keyPressEvent(QKeyEvent* event)
206 {
207 if(event->key() == Qt::Key_Escape) {
208 this->close();
209 }
210 }
211
212 // the mandelbrot example shows how to create a mandelbrot image in
213 // OpenCL and render the image as a texture in OpenGL
main(int argc,char * argv[])214 int main(int argc, char *argv[])
215 {
216 QApplication app(argc, argv);
217
218 MandelbrotWidget widget;
219 widget.show();
220
221 return app.exec();
222 }
223
224 #include "mandelbrot.moc"
225