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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>
#define PI 3.1415926536f
/*
* Paint a 2D texture with a moving red/green hatch pattern on a
* strobing blue background. Note that this kernel reads to and
* writes from the texture, hence why this texture was not mapped
* as WriteDiscard.
*/
__global__ void cuda_kernel_texture_2d(unsigned char *surface, int width,
int height, size_t pitch, float t) {
int x = blockIdx.x * blockDim.x + threadIdx.x;
int y = blockIdx.y * blockDim.y + threadIdx.y;
float *pixel;
// 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;
// get a pointer to the pixel at (x,y)
pixel = (float *)(surface + y * pitch) + 4 * x;
// populate it
float value_x = 0.5f + 0.5f * cos(t + 10.0f * ((2.0f * x) / width - 1.0f));
float value_y = 0.5f + 0.5f * cos(t + 10.0f * ((2.0f * y) / height - 1.0f));
pixel[0] = 0.5 * pixel[0] + 0.5 * pow(value_x, 3.0f); // red
pixel[1] = 0.5 * pixel[1] + 0.5 * pow(value_y, 3.0f); // green
pixel[2] = 0.5f + 0.5f * cos(t); // blue
pixel[3] = 1; // alpha
}
extern "C" void cuda_texture_2d(void *surface, int width, int height,
size_t pitch, 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_2d<<<Dg, Db>>>((unsigned char *)surface, width, height,
pitch, t);
error = cudaGetLastError();
if (error != cudaSuccess) {
printf("cuda_kernel_texture_2d() failed to launch error = %d\n", error);
}
}
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