只能看到单个白点CUDA/OpenGL互操作

Question

我试图将C++代码转换为CUDA代码，用于从外部文件读取数据并绘制3D矩阵的程序。我一次只转换一些代码片段，并且未能尝试绘制仅由红色点组成的小型3D矩阵。我只能看到一个白点，代码如下：

#define BUFFER_OFFSET(i) ((char *)NULL + (i)) 

GLuint bufferObj; 
cudaGraphicsResource *resource; 

int size=5*5*7; 
int window_dim=600; 

__global__ void kernel(float4 *ptr, int sizei) { 

    const unsigned long int blockId = blockIdx.x //1D 
    + blockIdx.y * gridDim.x //2D 
    + gridDim.x * gridDim.y * blockIdx.z; //3D 

    const unsigned long int threadId = (blockId * blockDim.x + threadIdx.x); 
    if(threadId<sizei) { 
    ptr[threadId].x=threadIdx.x+0.5f; 
    ptr[threadId+sizei].x=1.0f; 
    ptr[threadId].y=blockIdx.y+0.5f; 
    ptr[threadId+sizei].y=0.0f; 
    ptr[threadId].z=blockIdx.z+0.5f; 
    ptr[threadId+sizei].z=0.0f; 
    ptr[threadId].w=1.0f; 
    ptr[threadId+sizei].w=1.0f; 
    } 
} 

static void key_func(unsigned char key, int x, int y) { 
    switch (key) { 
    case 27: 
    HANDLE_ERROR(cudaGraphicsUnregisterResource(resource)); 
    glBindBuffer(GL_ARRAY_BUFFER, 0); 
    glDeleteBuffers(1, &bufferObj); 
    exit(0); 
    } 
} 

static void draw_func(void) { 

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
    glLoadIdentity(); 
    gluLookAt (2.5f, 2.5f, 10.0f, 2.5f, 2.5f, 3.5f, 0.0f, 1.0f, 0.0f); 
    glPushMatrix(); 
    glMatrixMode(GL_MODELVIEW); 


    glBindBuffer(GL_ARRAY_BUFFER, bufferObj); 
    glVertexPointer(4, GL_FLOAT, sizeof(float4), 0); 
    glColorPointer(4, GL_FLOAT, sizeof(float4), BUFFER_OFFSET(sizeof(float4)*size)); 
    glPointSize(3.0); 

    glDrawArrays(GL_POINTS, 0, size); 
    glFlush(); 
    glPopMatrix(); 
    glutSwapBuffers(); 
} 

static void reshape_func(int w, int h) { 
    glViewport(0, 0, (GLsizei) w, (GLsizei) h); 
    glMatrixMode (GL_PROJECTION); 
    glLoadIdentity(); 
    glFrustum (-1.0f, 1.0f, -1.0f, 1.0f, 1.0f, 100.0f); 
    glMatrixMode (GL_MODELVIEW); 
    glutPostRedisplay(); 

} 

int main(int argc, char **argv) { 
    cudaDeviceProp prop; 
    int dev; 
    float4 *g_vertex_buffer_data = new float4[size*2]; 

    memset(&prop, 0, sizeof(cudaDeviceProp)); 
    prop.major = 3; 
    prop.minor = 0; 
    HANDLE_ERROR(cudaChooseDevice(&dev, &prop)); 

    HANDLE_ERROR(cudaGLSetGLDevice(dev)); 

    glutInit(&argc, argv); 
    glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH); 
    glutInitWindowSize(window_dim, window_dim); 
    glutCreateWindow("Interop_test"); 

    glGenBuffers(1, &bufferObj); 
    glBindBuffer(GL_ARRAY_BUFFER, bufferObj); 
    glBufferData(GL_ARRAY_BUFFER, sizeof(float4)*2*size, NULL, GL_DYNAMIC_DRAW); 

    HANDLE_ERROR(cudaGraphicsGLRegisterBuffer(&resource, bufferObj, cudaGraphicsMapFlagsNone)); 
    HANDLE_ERROR(cudaGraphicsMapResources(1, &resource, NULL)); 

    float4 *devPtr; 
    size_t sizePtr; 
    HANDLE_ERROR(cudaGraphicsResourceGetMappedPointer((void**)&devPtr, &sizePtr, resource)); 

    dim3 dimBlock(5,1,1); 
    dim3 dimGrid(1,5,7); 

    kernel<<<dimGrid,dimBlock>>>(devPtr, size); 
    ////////////Don't know if this is necessary///////////////// 
    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(float4)*size, &devPtr[0].x); 
    glBufferSubData(GL_ARRAY_BUFFER, sizeof(float4)*size, 
      sizeof(float4)*size, &devPtr[size].x); 
    ///////////////////////////////////////////////////////////////// 
    HANDLE_ERROR(cudaGraphicsUnmapResources(1, &resource, NULL)); 

glEnable(GL_DEPTH_TEST); 
glutKeyboardFunc(key_func); 
glutDisplayFunc(draw_func); 
glutReshapeFunc(reshape_func); 
glutMainLoop(); 
} 

我也尝试打印出devPtr，并且我得到正确的数据。

Answer 1

我发现哪个问题。我会回答我的问题，以便每个人都可以使用它。 只需编辑draw_func这样的：

static void draw_func(void) { 

    [...] 

    glBindBuffer(GL_ARRAY_BUFFER, bufferObj); 
    glEnableClientState(GL_VERTEX_ARRAY); 
    glEnableClientState(GL_COLOR_ARRAY); 
    glVertexPointer(4, GL_FLOAT, sizeof(float4), 0); 
    glColorPointer(4, GL_FLOAT, sizeof(float4), BUFFER_OFFSET(sizeof(float4)*size)); 
    glPointSize(3.0); 

    glDrawArrays(GL_POINTS, 0, size); 
    glDisableClientState(GL_VERTEX_ARRAY); 
    glDisableClientState(GL_COLOR_ARRAY); 

    [...] 
}