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Working thread impl

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This commit is contained in:
Stephen Seo 2021-08-23 21:19:15 +09:00
parent 61e6cf17fd
commit ade12df080
1 changed files with 88 additions and 53 deletions
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39
example02_threaded_raytracing/src/rayTracer.cpp
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@ -3,6 +3,8 @@
#include <cmath>
#include <fstream>
#include <array>
#include <thread>
#include <mutex>
#include <glm/matrix.hpp>
#include <glm/gtc/matrix_transform.hpp>
@ -316,8 +318,7 @@ Ex02::RT::Image Ex02::RT::renderColorsWithSpheres(
lights[2].falloffStart = 3.0f;
lights[2].falloffEnd = 7.0f;
if(threadCount <= 1) {
for(unsigned int j = 0; j < outputHeight; ++j) {
const auto yIteration = [&spheres, &lights, &image, outputWidth, outputHeight, rayPos] (unsigned int j, std::mutex *mutex) {
float offsetY = ((float)j + 0.5f - ((float)outputHeight / 2.0f));
for(unsigned int i = 0; i < outputWidth; ++i) {
float offsetX = ((float)i + 0.5f - ((float)outputWidth / 2.0f));
@ -378,12 +379,46 @@ Ex02::RT::Image Ex02::RT::renderColorsWithSpheres(
// at this point, it is known that no spheres blocks ray
// to light
if(mutex) {
std::lock_guard<std::mutex> lock(*mutex);
light.applyLight(
std::get<0>(*closestResult),
image.getPixel(i, j));
} else {
light.applyLight(
std::get<0>(*closestResult),
image.getPixel(i, j));
}
}
}
};
if(threadCount <= 1) {
for(unsigned int j = 0; j < outputHeight; ++j) {
yIteration(j, nullptr);
}
} else {
std::vector<std::thread> threads;
std::mutex mutex;
unsigned int range = outputHeight / threadCount;
for(unsigned int threadIdx = 0; threadIdx < threadCount; ++threadIdx) {
unsigned int start = range * threadIdx;
unsigned int end = range * (threadIdx + 1);
if(threadIdx + 1 == threadCount) {
end = outputHeight;
}
threads.emplace_back(std::thread([&yIteration] (unsigned int start, unsigned int end, std::mutex *mutex) {
for(unsigned int y = start; y < end; ++y) {
yIteration(y, mutex);
}
},
start,
end,
&mutex));
}
for(std::thread &thread : threads) {
thread.join();
}
}
return image;