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//---------------------------------------------------------------------------//
// Copyright (c) 2013-2014 Kyle Lutz <kyle.r.lutz@gmail.com>
//
// Distributed under the Boost Software License, Version 1.0
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
//
// See http://boostorg.github.com/compute for more information.
//---------------------------------------------------------------------------//
#include <iostream>
#include <algorithm>
#include <QtGlobal>
#if QT_VERSION >= 0x050000
#include <QtWidgets>
#else
#include <QtGui>
#endif
#include <QtOpenGL>
#ifndef Q_MOC_RUN
#include <boost/compute/command_queue.hpp>
#include <boost/compute/kernel.hpp>
#include <boost/compute/program.hpp>
#include <boost/compute/system.hpp>
#include <boost/compute/interop/opengl.hpp>
#include <boost/compute/utility/dim.hpp>
#include <boost/compute/utility/source.hpp>
#endif // Q_MOC_RUN
namespace compute = boost::compute;
// opencl source code
const char source[] = BOOST_COMPUTE_STRINGIZE_SOURCE(
// map value to color
float4 color(uint i)
{
uchar c = i;
uchar x = 35;
uchar y = 25;
uchar z = 15;
uchar max = 255;
if(i == 256)
return (float4)(0, 0, 0, 255);
else
return (float4)(max-x*i, max-y*i, max-z*i, max) / 255.f;
}
__kernel void mandelbrot(__write_only image2d_t image)
{
const uint x_coord = get_global_id(0);
const uint y_coord = get_global_id(1);
const uint width = get_global_size(0);
const uint height = get_global_size(1);
float x_origin = ((float) x_coord / width) * 3.25f - 2.0f;
float y_origin = ((float) y_coord / height) * 2.5f - 1.25f;
float x = 0.0f;
float y = 0.0f;
uint i = 0;
while(x*x + y*y <= 4.f && i < 256){
float tmp = x*x - y*y + x_origin;
y = 2*x*y + y_origin;
x = tmp;
i++;
}
int2 coord = { x_coord, y_coord };
write_imagef(image, coord, color(i));
};
);
class MandelbrotWidget : public QGLWidget
{
Q_OBJECT
public:
MandelbrotWidget(QWidget *parent = 0);
~MandelbrotWidget();
void initializeGL();
void resizeGL(int width, int height);
void paintGL();
void keyPressEvent(QKeyEvent* event);
private:
compute::context context_;
compute::command_queue queue_;
compute::program program_;
GLuint gl_texture_;
compute::opengl_texture cl_texture_;
};
MandelbrotWidget::MandelbrotWidget(QWidget *parent)
: QGLWidget(parent)
{
gl_texture_ = 0;
}
MandelbrotWidget::~MandelbrotWidget()
{
}
void MandelbrotWidget::initializeGL()
{
// setup opengl
glDisable(GL_LIGHTING);
// create the OpenGL/OpenCL shared context
context_ = compute::opengl_create_shared_context();
// get gpu device
compute::device gpu = context_.get_device();
std::cout << "device: " << gpu.name() << std::endl;
// setup command queue
queue_ = compute::command_queue(context_, gpu);
// build mandelbrot program
program_ = compute::program::create_with_source(source, context_);
program_.build();
}
void MandelbrotWidget::resizeGL(int width, int height)
{
#if QT_VERSION >= 0x050000
// scale height/width based on device pixel ratio
width /= windowHandle()->devicePixelRatio();
height /= windowHandle()->devicePixelRatio();
#endif
// resize viewport
glViewport(0, 0, width, height);
// delete old texture
if(gl_texture_){
glDeleteTextures(1, &gl_texture_);
gl_texture_ = 0;
}
// generate new texture
glGenTextures(1, &gl_texture_);
glBindTexture(GL_TEXTURE_2D, gl_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_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D(
GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0
);
// create opencl object for the texture
cl_texture_ = compute::opengl_texture(
context_, GL_TEXTURE_2D, 0, gl_texture_, CL_MEM_WRITE_ONLY
);
}
void MandelbrotWidget::paintGL()
{
using compute::dim;
float w = width();
float h = height();
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0, w, 0.0, h, -1.0, 1.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
// setup the mandelbrot kernel
compute::kernel kernel(program_, "mandelbrot");
kernel.set_arg(0, cl_texture_);
// acquire the opengl texture so it can be used in opencl
compute::opengl_enqueue_acquire_gl_objects(1, &cl_texture_.get(), queue_);
// execute the mandelbrot kernel
queue_.enqueue_nd_range_kernel(
kernel, dim(0, 0), dim(width(), height()), dim(1, 1)
);
// release the opengl texture so it can be used by opengl
compute::opengl_enqueue_release_gl_objects(1, &cl_texture_.get(), queue_);
// ensure opencl is finished before rendering in opengl
queue_.finish();
// draw a single quad with the mandelbrot image texture
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, gl_texture_);
glBegin(GL_QUADS);
glTexCoord2f(0, 0); glVertex2f(0, 0);
glTexCoord2f(0, 1); glVertex2f(0, h);
glTexCoord2f(1, 1); glVertex2f(w, h);
glTexCoord2f(1, 0); glVertex2f(w, 0);
glEnd();
}
void MandelbrotWidget::keyPressEvent(QKeyEvent* event)
{
if(event->key() == Qt::Key_Escape) {
this->close();
}
}
// the mandelbrot example shows how to create a mandelbrot image in
// OpenCL and render the image as a texture in OpenGL
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
MandelbrotWidget widget;
widget.show();
return app.exec();
}
#include "mandelbrot.moc"