CUDA 一维纹理的创建和使用测试

CUDA 复杂问题 + 细节问题 解答 见 CUDA复杂问题 + 细节问题 解答

先直接贴上总代码

#include "cuda_runtime.h"
#include "device_launch_parameters.h"
#include "cuda.h"
#include <iostream>
using std::cout;
using std::endl;
#define arrayNum 100
texture<float, cudaTextureType1D, cudaReadModeElementType>	tex1DTest;
cudaArray* gputexArray = NULL;
void Bind1DTex()
{
	tex1DTest.normalized = true;
	tex1DTest.filterMode = cudaFilterModeLinear;
	tex1DTest.addressMode[0] = cudaAddressModeClamp;

	float testArray[arrayNum];

	for (int i = 0; i < arrayNum; i++)
		testArray[i] = i;

	cudaChannelFormatDesc ChannelDesc = cudaCreateChannelDesc<float>();

	if (gputexArray == NULL)
		cudaMallocArray(&gputexArray, &ChannelDesc, arrayNum, 1);

	cudaMemcpyToArray(gputexArray, 0, 0, testArray, arrayNum * sizeof(float), cudaMemcpyHostToDevice);
	cudaBindTextureToArray(tex1DTest, gputexArray, ChannelDesc);
}
__global__ void cudaTest(float *c)
{
	int i = threadIdx.x;
	c[i] = tex1D(tex1DTest, (float)(i+0.5)/(float)arrayNum);
}
int main()
{
	float *dev_c = 0;
	float *c = 0;
	c = (float*)malloc(arrayNum * sizeof(float));
	cudaMalloc((void**)&dev_c, arrayNum * sizeof(float));
	Bind1DTex();
	cudaTest << <1, arrayNum >> >(dev_c);

	cudaMemcpy(c, dev_c, arrayNum * sizeof(float), cudaMemcpyDeviceToHost);
	for (int i = 0;i < arrayNum;i++) {
		cout << c[i] << endl;
	}

	system("pause");
    return 0;
}

有个细节需要注意一下：

c[i] = tex1D(tex1DTest, (float)(i+0.5)/(float)arrayNum);

采样纹理的时候需要加个0.5的偏置，否则我们采样到的结果就是：0 0.5 1.5 2.5 ...

而加上0.5的偏置以后，采样结果就是：0 1 2 3 4 ...了