cuda/field.cu
/*******************************************************
* 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 <cuda_runtime.h>
#define USE_FORGE_CUDA_COPY_HELPERS
#include <ComputeCopy.h>
#define PI 3.14159265359
const unsigned DIMX = 640;
const unsigned DIMY = 480;
const float MINIMUM = 1.0f;
const float MAXIMUM = 20.f;
const float STEP = 2.0f;
const float NELEMS = (MAXIMUM-MINIMUM+1)/STEP;
const unsigned DPOINTS[] = {5, 5, 5, 15, 15, 5, 15, 15};
void generatePoints(float* points, float* dirs);
inline int divup(int a, int b)
{
return (a+b-1)/b;
}
int main(void)
{
unsigned* dpoints;
float* points;
float* dirs;
/*
* 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, "Vector Field Demo");
wnd.makeCurrent();
forge::Chart chart(FG_CHART_2D);
chart.setAxesLimits(MINIMUM-1.0f, MAXIMUM, MINIMUM-1.0f, MAXIMUM);
chart.setAxesTitles("x-axis", "y-axis");
forge::Plot divPoints = chart.plot(4, forge::u32, FG_PLOT_SCATTER, FG_MARKER_CIRCLE);
divPoints.setColor(0.9f, 0.9f, 0.0f, 1.f);
divPoints.setLegend("Convergence Points");
divPoints.setMarkerSize(24);
size_t npoints = NELEMS*NELEMS;
forge::VectorField field = chart.vectorField(npoints, forge::f32);
field.setColor(0.f, 0.6f, 0.3f, 1.f);
FORGE_CUDA_CHECK(cudaMalloc((void**)&dpoints, 8*sizeof(unsigned)));
FORGE_CUDA_CHECK(cudaMalloc((void**)&points, 2*npoints*sizeof(float)));
FORGE_CUDA_CHECK(cudaMalloc((void**)&dirs, 2*npoints*sizeof(float)));
GfxHandle* handles[3];
createGLBuffer(&handles[0], divPoints.vertices(), FORGE_VERTEX_BUFFER);
createGLBuffer(&handles[1], field.vertices(), FORGE_VERTEX_BUFFER);
createGLBuffer(&handles[2], field.directions(), FORGE_VERTEX_BUFFER);
FORGE_CUDA_CHECK(cudaMemcpy(dpoints, DPOINTS, 8*sizeof(unsigned), cudaMemcpyHostToDevice));
generatePoints(points, dirs);
copyToGLBuffer(handles[0], (ComputeResourceHandle)dpoints, divPoints.verticesSize());
copyToGLBuffer(handles[1], (ComputeResourceHandle)points, field.verticesSize());
copyToGLBuffer(handles[2], (ComputeResourceHandle)dirs, field.directionsSize());
do {
wnd.draw(chart);
} while(!wnd.close());
// destroy GL-CUDA interop buffers
releaseGLBuffer(handles[0]);
releaseGLBuffer(handles[1]);
releaseGLBuffer(handles[2]);
// destroy CUDA handles
FORGE_CUDA_CHECK(cudaFree(dpoints));
FORGE_CUDA_CHECK(cudaFree(points));
FORGE_CUDA_CHECK(cudaFree(dirs));
return 0;
}
__global__
void pointGenKernel(float* points, float* dirs, int nelems, float minimum, float step)
{
int i = blockDim.x * blockIdx.x + threadIdx.x;
int j = blockDim.y * blockIdx.y + threadIdx.y;
if (i<nelems && j<nelems) {
int id = i + j * nelems;
float x = minimum + i*step;
float y = minimum + j*step;
points[2*id+0] = x;
points[2*id+1] = y;
dirs[2*id+0] = sinf(2.0f*PI*x/10.f);
dirs[2*id+1] = sinf(2.0f*PI*y/10.f);
}
}
void generatePoints(float* points, float* dirs)
{
static dim3 threads(8, 8);
dim3 blocks(divup(NELEMS, threads.x),
divup(NELEMS, threads.y));
pointGenKernel<<<blocks, threads>>>(points, dirs, NELEMS, MINIMUM, STEP);
}