Forge

opencl/fractal.cpp
/*******************************************************
* Copyright (c) 2015-2019, ArrayFire
* All rights reserved.
*
* This file is distributed under 3-clause BSD license.
* The complete license agreement can be obtained at:
* http://arrayfire.com/licenses/BSD-3-Clause
********************************************************/
#include <forge.h>
#include "cl_helpers.h"
#include <mutex>
#include <vector>
#include <sstream>
#include <iostream>
#include <iterator>
#include <algorithm>
using namespace cl;
using namespace std;
const unsigned DIMX = 512;
const unsigned DIMY = 512;
const unsigned IMG_SIZE = DIMX * DIMY * 4;
#define USE_FORGE_OPENCL_COPY_HELPERS
#include <ComputeCopy.h>
static const std::string fractal_ocl_kernel =
"float magnitude(float2 a)\n"
"{\n"
" return sqrt(a.s0*a.s0+a.s1*a.s1);\n"
"}\n"
"\n"
"float2 mul(float2 a, float2 b)\n"
"{\n"
" return (float2)(a.s0*b.s0-a.s1*b.s1, a.s1*b.s0+a.s0*b.s1);\n"
"}\n"
"\n"
"float2 add(float2 a, float2 b)\n"
"{\n"
" return (float2)(a.s0+b.s0, a.s1+b.s1);\n"
"}\n"
"\n"
"int pixel(int x, int y, int width, int height)\n"
"{\n"
"\n"
" const float scale = 1.5;\n"
" float jx = scale * (float)(width/2.0f - x)/(width/2.0f);\n"
" float jy = scale * (float)(height/2.0f - y)/(height/2.0f);\n"
"\n"
" float2 c = (float2)(-0.8f, 0.156f);\n"
" float2 a = (float2)(jx, jy);\n"
"\n"
" for (int i=0; i<200; i++) {\n"
" a = add(mul(a, a), c);\n"
" if (magnitude(a) > 1000.0f)\n"
" return 0;\n"
" }\n"
"\n"
" return 1;\n"
"}\n"
"\n"
"kernel\n"
"void julia(global unsigned char* out, const unsigned w, const unsigned h)\n"
"{\n"
" int x = get_group_id(0) * get_local_size(0) + get_local_id(0);\n"
" int y = get_group_id(1) * get_local_size(1) + get_local_id(1);\n"
"\n"
" if (x<w && y<h) {\n"
" int offset = x + y * w;\n"
" int juliaValue = pixel(x, y, w, h);\n"
" out[offset*4 + 1] = 255 * juliaValue;\n"
" out[offset*4 + 0] = 0;\n"
" out[offset*4 + 2] = 0;\n"
" out[offset*4 + 3] = 255;\n"
" }\n"
"}\n";
inline int divup(int a, int b)
{
return (a+b-1)/b;
}
void kernel(cl::Buffer& devOut, cl::CommandQueue& queue)
{
static std::once_flag compileFlag;
static cl::Program prog;
static cl::Kernel kern;
std::call_once(compileFlag,
[queue]() {
prog = cl::Program(queue.getInfo<CL_QUEUE_CONTEXT>(), fractal_ocl_kernel, true);
kern = cl::Kernel(prog, "julia");
});
auto juliaOp = cl::KernelFunctor<Buffer, unsigned, unsigned>(kern);
static const NDRange local(8, 8);
NDRange global(local[0] * divup(DIMX, (int)(local[0])),
local[1] * divup(DIMY, (int)(local[1])));
juliaOp(EnqueueArgs(queue, global, local), devOut, DIMX, DIMY);
}
int main(void)
{
try {
/*
* First Forge call should be a window creation call
* so that necessary OpenGL context is created for any
* other forge::* object to be created successfully
*/
forge::Window wnd(DIMX, DIMY, "Fractal Demo");
wnd.makeCurrent();
/* Create an image object which creates the necessary
* textures and pixel buffer objects to hold the image
* */
forge::Image img(DIMX, DIMY, FG_RGBA, forge::u8);
/*
* Helper function to create a CLGL interop context.
* This function checks for if the extension is available
* and creates the context on the appropriate device.
* Note: context and queue are defined in cl_helpers.h
*/
context = createCLGLContext(wnd);
Device device = context.getInfo<CL_CONTEXT_DEVICES>()[0];
queue = CommandQueue(context, device);
/* copy your data into the pixel buffer object exposed by
* forge::Image class and then proceed to rendering.
* To help the users with copying the data from compute
* memory to display memory, Forge provides copy headers
* along with the library to help with this task
*/
cl::Buffer devOut(context, CL_MEM_READ_WRITE, IMG_SIZE);
kernel(devOut, queue);
GfxHandle* handle = 0;
// create GL-CPU interop buffer
createGLBuffer(&handle, img.pixels(), FORGE_IMAGE_BUFFER);
// copy the data from compute buffer to graphics buffer
copyToGLBuffer(handle, (ComputeResourceHandle)devOut(), img.size());
do {
wnd.draw(img);
} while(!wnd.close());
// destroy GL-CPU Interop buffer
releaseGLBuffer(handle);
}catch (forge::Error err) {
std::cout << err.what() << "(" << err.err() << ")" << std::endl;
} catch (cl::Error err) {
std::cout << err.what() << "(" << err.err() << ")" << std::endl;
}
return 0;
}