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Copy pathlbm_chapter5_1_1d.cu
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lbm_chapter5_1_1d.cu
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#include <cuda_runtime.h>
#include <device_launch_parameters.h>
#include <iostream>
#include "cpu_anim.h"
#define m 512
#define dx 1.0f
#define alpha 0.25
#define omega (1.0 / (alpha + 0.5))
#define twall 1.0f
#define nstep 2000
struct DataBlock {
unsigned char* output_bitmap;
CPUAnimBitmap* bitmap;
float* dev_rho;
float* dev_f;
float* dev_f_old;
float frames;
};
__global__ void collision(float* f_old, float* f, float* rho) {
int x = threadIdx.x + blockIdx.x * blockDim.x;
for (int k = 0; k < 2; k++) {
f_old[x * 2 + k] = (1 - omega) * f[x * 2 + k] + omega * 0.5* rho[x];
}
}
__global__ void stream(float* f_old, float* f) {
int x = threadIdx.x + blockIdx.x * blockDim.x;
if (x < m - 1) {
f[(x+1) * 2 + 0] = f_old[x * 2 + 0];
f[x * 2 + 1] = f_old[(x + 1) * 2 + 1];
}
}
__global__ void boundary(float* f) {
f[0 * 2 + 0] = twall - f[0 * 2 + 1];
f[(m-1) * 2 + 0] = f[(m - 2) * 2 + 0];
f[(m - 1) * 2 + 1] = f[(m - 2) * 2 + 1];
}
__global__ void update(float* rho,float* f) {
int x = threadIdx.x + blockIdx.x * blockDim.x;
rho[x] = f[x *2 + 0] + f[x * 2 + 1];
}
__global__ void rho_to_bitmap(unsigned char* bitmap, float* rho) {
int x = threadIdx.x + blockIdx.x * blockDim.x;
int y = threadIdx.y + blockIdx.y * blockDim.y;
int offset = x + y * m;
if (y <= rho[x] * (m-50)) {
bitmap[offset * 4 + 0] = 255;
bitmap[offset * 4 + 1] = 0;
bitmap[offset * 4 + 2] = 0;
bitmap[offset * 4 + 3] = 255;
}
}
void anim_gpu(DataBlock* d, int ticks) {
CPUAnimBitmap* bitmap = d->bitmap;
dim3 grid(m / 16, m / 16);
dim3 threads(16, 16);
for (int i = 0; i < nstep; i++) {
collision << <m / 16, 16 >> > (d->dev_f_old, d->dev_f, d->dev_rho);
cudaDeviceSynchronize();
stream << <m / 16, 16 >> > (d->dev_f_old, d->dev_f);
cudaDeviceSynchronize();
boundary << <1, 1 >> > (d->dev_f);
cudaDeviceSynchronize();
update << <m / 16, 16 >> > (d->dev_rho, d->dev_f);
cudaDeviceSynchronize();
}
rho_to_bitmap << <grid, threads >> > (d->output_bitmap, d->dev_rho);
cudaMemcpy(bitmap->get_ptr(), d->output_bitmap, bitmap->image_size(), cudaMemcpyDeviceToHost);
++d->frames;
}
void solve(DataBlock* d) {
for (int i = 0; i < nstep; i++) {
collision << <m / 16, 16 >> > (d->dev_f_old, d->dev_f, d->dev_rho);
cudaDeviceSynchronize();
stream << <m / 16, 16 >> > (d->dev_f_old, d->dev_f);
cudaDeviceSynchronize();
boundary << <1, 1 >> > (d->dev_f);
cudaDeviceSynchronize();
update << <m / 16, 16 >> > (d->dev_rho, d->dev_f);
cudaDeviceSynchronize();
}
}
void anim_exit(DataBlock* d) {
cudaFree(d->dev_rho);
cudaFree(d->dev_f);
cudaFree(d->dev_f_old);
}
int main() {
float* rho, * f, * f_old;
DataBlock data;
CPUAnimBitmap bitmap((int)m, (int)m, (void*)&data);
data.bitmap = &bitmap;
data.frames = 0;
rho = new float[m];
f = new float[m * 2];
f_old = new float[m * 2];
for (int x = 0; x < m; x++) {
rho[x] = 0;
for (int k = 0; k < 2; k++) {
f[x * 2 + k] = 0;
f_old[x * 2 + k] = 0;
}
}
cudaMalloc((void**)&data.output_bitmap, bitmap.image_size());
cudaMalloc((void**)&data.dev_rho, sizeof(float) * m);
cudaMalloc((void**)&data.dev_f, sizeof(float) * m * 2);
cudaMalloc((void**)&data.dev_f_old, sizeof(float) * m * 2);
cudaMemcpy(data.dev_rho, rho, sizeof(float) * m, cudaMemcpyHostToDevice);
cudaMemcpy(data.dev_f, f, sizeof(float) * m * 2, cudaMemcpyHostToDevice);
cudaMemcpy(data.dev_f_old, f_old, sizeof(float) * m * 2, cudaMemcpyHostToDevice);
data.bitmap->anim_and_exit((void(*)(void*, int))anim_gpu, (void(*)(void*))anim_exit);
//solve(&data);
cudaMemcpy(rho,data.dev_rho, sizeof(float) * m , cudaMemcpyDeviceToHost);
for (int x = 0; x < m; x++) {
std::cout << rho[x] << ",";
}
std::cout << std::endl;
delete[] f;
delete[] f_old;
delete[] rho;
}