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/* Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of NVIDIA CORPORATION nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/*
* Paint a 3D texture with a gradient in X (blue) and Z (green), and have every
* other Z slice have full red.
*/
__global__ void cuda_kernel_texture_volume(unsigned char *surface, int width,
int height, int depth, size_t pitch,
size_t pitchSlice) {
int x = blockIdx.x * blockDim.x + threadIdx.x;
int y = blockIdx.y * blockDim.y + threadIdx.y;
// in the case where, due to quantization into grids, we have
// more threads than pixels, skip the threads which don't
// correspond to valid pixels
if (x >= width || y >= height) return;
// walk across the Z slices of this texture. it should be noted that
// this is far from optimal data access.
for (int z = 0; z < depth; ++z) {
// get a pointer to this pixel
unsigned char *pixel = surface + z * pitchSlice + y * pitch + 4 * x;
pixel[0] = 255 * x / (width - 1); // blue
pixel[1] = 255 * z / (depth - 1); // green
pixel[2] = 255 * (z % 2); // red
pixel[3] = 255; // alpha
}
}
extern "C" void cuda_texture_volume(void *surface, int width, int height,
int depth, size_t pitch, size_t pitchSlice,
float t) {
cudaError_t error = cudaSuccess;
dim3 Db = dim3(16, 16); // block dimensions are fixed to be 256 threads
dim3 Dg = dim3((width + Db.x - 1) / Db.x, (height + Db.y - 1) / Db.y);
cuda_kernel_texture_volume<<<Dg, Db>>>((unsigned char *)surface, width,
height, depth, pitch, pitchSlice);
error = cudaGetLastError();
if (error != cudaSuccess) {
printf("cuda_kernel_texture_volume() failed to launch error = %d\n", error);
}
}
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