CUDA Texture纹理存储器 示例程序

原文链接

 /*
 * Copyright 徐洪志(西北农林科技大学.信息工程学院).  All rights reserved.
 * Data: 2012-4-20
 */
 //
 // 此程序是演示了1D和2D纹理存储器的使用
 #include <stdio.h>
 #include <cutil_inline.h>
 #include <iostream>
 using namespace std;

 texture<float> texRef1D;     // 1D texture
 texture<float, > texRef2D;  // 2D texture

 // 1D 纹理操作函数
 __global__ void Texture1D(float *dst, int w, int h)
 {
     int x = threadIdx.x + blockIdx.x * blockDim.x;
     int y = threadIdx.y + blockIdx.y * blockDim.y;
     int offset = x + y * blockDim.x * gridDim.x;

     if(x<w && y<h)
         dst[offset] = tex1Dfetch(texRef1D, offset);
 }
 // 2D 纹理操作函数
 __global__ void Texture2D(float *dst, int w, int h)
 {
     int x = threadIdx.x + blockIdx.x * blockDim.x;
     int y = threadIdx.y + blockIdx.y * blockDim.y;
     int offset = x + y * blockDim.x * gridDim.x;

     dst[offset] = tex2D(texRef2D, x, y);
 }
 int main(int argc, char **argv)
 {
     CUT_DEVICE_INIT(argc, argv);  // 启动 CUDA
     /// 1D 纹理内存
     cout << "1D texture" << endl;
     float *host1D = (float*)calloc(, sizeof(float)); // 内存原数据
     float *hostRet1D = (float*)calloc(, sizeof(float));// 内存保存返回数据

     float *dev1D, *devRet1D; // 显存数据
     int i;
     cout << " host1D:" << endl;
     for(i = ; i < ; ++i)  // 初始化内存原数据
     {
         host1D[i] = i * ;
         cout << "  " << host1D[i] << " ";
     }
     cutilSafeCall( cudaMalloc((void**)&dev1D, sizeof(float)*));  // 申请显存空间
     cutilSafeCall( cudaMalloc((void**)&devRet1D, sizeof(float)*));
     cutilSafeCall( cudaMemcpy(dev1D, host1D, sizeof(float)*, cudaMemcpyHostToDevice)); // 将内存数据拷贝入显存
     cutilSafeCall( cudaBindTexture(NULL, texRef1D, dev1D, sizeof(float)*));  // 将显存数据和纹理绑定

     Texture1D<<<, >>>(devRet1D, , );  // 运行1D纹理操作函数

     cutilSafeCall( cudaMemcpy(hostRet1D, devRet1D, sizeof(float)*, cudaMemcpyDeviceToHost)); // 将显存数据拷贝入内存
     // 打印内存数据
     cout << endl << " hostRet1D:" << endl;
     for(i = ; i < ; ++i)
         cout << "  " << hostRet1D[i] << " ";

     cutilSafeCall( cudaUnbindTexture(texRef1D));  // 解绑定
     cutilSafeCall( cudaFree(dev1D));  // 释放显存空间
     cutilSafeCall( cudaFree(devRet1D));
     free(host1D);  // 释放内存空间
     free(hostRet1D);

     /// 2D 纹理内存
     cout << endl << "2D texture" << endl;
     int width = , height = ;
     float *host2D = (float*)calloc(width*height, sizeof(float));    // 内存原数据
     float *hostRet2D = (float*)calloc(width*height, sizeof(float)); // 内存返回数据 

     cudaArray *cuArray;  // CUDA数组
     float *devRet2D;     // 显存数据
     int row, col;
     cout << " host2D:" << endl;
     for(row = ; row < height; ++row)  // 初始化内存原数据
     {
         for(col = ; col < width; ++col)
         {
             host2D[row*width + col] = row + col;
             cout << "  " << host2D[row*width + col] << " ";
         }
         cout << endl;
     }
     cudaChannelFormatDesc channelDesc = cudaCreateChannelDesc<float>();
     cutilSafeCall( cudaMallocArray(&cuArray, &channelDesc, width, height));  // 申请显存空间
     cutilSafeCall( cudaMalloc((void**) &devRet2D, sizeof(float)*width*height));
     cutilSafeCall( cudaBindTextureToArray(texRef2D, cuArray)); // 将显存数据和纹理绑定
     cutilSafeCall( cudaMemcpyToArray(cuArray, , , host2D, sizeof(float)*width*height, cudaMemcpyHostToDevice)); // 将内存数据拷贝入CUDA数组

     dim3 threads(width, height);
     Texture2D<<<, threads>>>(devRet2D, width, height);  // 运行2D纹理操作函数

     cutilSafeCall( cudaMemcpy(hostRet2D, devRet2D, sizeof(float)*width*height, cudaMemcpyDeviceToHost)); // 将显存数据拷贝入内存
     // 打印内存数据
     cout << " hostRet2D:" << endl;
     for(row = ; row < height; ++row)
     {
         for(col = ; col < width; ++col)
             cout << "  " << hostRet2D[row*width + col] << " ";
         cout << endl;
     }

     cutilSafeCall( cudaUnbindTexture(texRef2D)); // 解绑定
     cutilSafeCall( cudaFreeArray(cuArray));  // 释放显存空间
     cutilSafeCall( cudaFree(devRet2D));
     free(host2D);  // 释放内存空间
     free(hostRet2D);

     CUT_EXIT(argc, argv);  // 退出CUDA
 }