void EnqueueTasks(const vector<Task *> &tasks) {
if (PbrtOptions.nCores == 1) {
for (unsigned int i = 0; i < tasks.size(); ++i)
tasks[i]->Run();
return;
}
#ifdef PBRT_USE_GRAND_CENTRAL_DISPATCH
for (uint32_t i = 0; i < tasks.size(); ++i)
dispatch_group_async_f(gcdGroup, gcdQueue, tasks[i], lRunTask);
#else
if (!threads)
TasksInit();
{ MutexLock lock(*taskQueueMutex);
for (unsigned int i = 0; i < tasks.size(); ++i)
taskQueue.push_back(tasks[i]);
}
tasksRunningCondition.Lock();
numUnfinishedTasks += tasks.size();
tasksRunningCondition.Unlock();
workerSemaphore.Post(tasks.size());
#endif
}
void EnqueueTasks(const vector<Task *> &tasks) {
#ifdef PBRT_USE_GRAND_CENTRAL_DISPATCH
static bool oneThread = (getenv("PBRT_NTHREADS") &&
atoi(getenv("PBRT_NTHREADS")) == 1);
for (u_int i = 0; i < tasks.size(); ++i)
if (oneThread)
dispatch_sync_f(gcdQueue, tasks[i], lRunTask);
else
dispatch_group_async_f(gcdGroup, gcdQueue, tasks[i], lRunTask);
#else
if (!threads)
TasksInit();
{ MutexLock lock(*taskQueueMutex);
for (unsigned int i = 0; i < tasks.size(); ++i)
taskQueue.push_back(tasks[i]);
}
tasksRunningCondition.Lock();
numUnfinishedTasks += tasks.size();
tasksRunningCondition.Unlock();
workerSemaphore.Post(tasks.size());
#endif
}
int main(int argc, char *argv[]) {
if (argc != 2) {
fprintf(stderr, "usage: mbrast [grid_file.out]\n");
return 1;
}
// Read grids from grid dump file
std::vector<ShadedGrid> grids;
if (!ReadGrids(argv[1], &grids))
return 1;
InitSamples();
// Extract the name of the scene in case a full pathname was provided
// on the command line
char *sceneName = rindex(argv[1], '/');
if (sceneName != NULL)
++sceneName;
else
sceneName = argv[1];
// Remove trailing ".grids" from scene name
char *end = rindex(sceneName, '.');
assert(end);
*end = '\0';
printf("Rendering scene \"%s\"\n", sceneName);
// Change this call to switch to creating an instance of your 3D
// rasterizer once you start implementing it.
#if MBRAST_MODE == NAIVE_RAST_2D || MBRAST_MODE == SMART_RAST_2D
Rasterizer *rast = Create2DRasterizer();
#elif MBRAST_MODE == BASIC_RAST_3D || MBRAST_MODE == INTER_RAST_3D
Rasterizer *rast = Create3DRasterizer();
#elif MBRAST_MODE == BASIC_RAST_5D
Rasterizer *rast = Create5DRasterizer();
#endif
// Initialize task system for multithreading if the rasterizer
// indicates that it's thread safe.
bool useTasks = rast->IsThreadSafe();
int nThreads = NumSystemCores();
assert(nThreads < MAX_CORES);
if (useTasks) {
printf("Using %d threads!\n", nThreads);
TasksInit();
}
// Render the scene multiple times, with each of the pixelSamples
// sample counts. The sample counts must all be powers of two.
// The bucketSize array, which must be the same size as
// pixelSamples[], gives the length of the side of the bucket we'll
// decompose the image into for the corresponding sample count.
int pixelSamples[] = { 1, 4, 32 };
int bucketSize[] = { 64, 32, 8 };
assert(sizeof(pixelSamples) == sizeof(bucketSize));
int samplesSize = sizeof(pixelSamples) / sizeof(pixelSamples[0]);
int failures = 0;
for (int samplesIndex = 0; samplesIndex < samplesSize; ++samplesIndex) {
assert(pixelSamples[samplesIndex] <= MAX_SAMPLES_PER_PIXEL);
int nPixelSamples = pixelSamples[samplesIndex];
int bucketExtent = bucketSize[samplesIndex];
printf("Rendering with %d samples per pixel\n", nPixelSamples);
// 720p resolution. (This can't be easily changed, as it's baked
// into the xy coordinates of the micropolygons. So changing this
// here would require a corresponding adjustment to those
// coordinate values when the grids are read in....)
int xRes = 1280, yRes = 720;
// Allow the rasterizer to preprocess the grids
ResetAndStartTimer();
rast->PreprocessGrids(grids, bucketExtent, xRes, yRes);
double preprocessCycles = GetElapsedMCycles() / 1024.;
printf(" Spent %.3f billion cycles on grid preprocessing.\n",
preprocessCycles);
// Allocate final output image as well as one Bucket structure for
// each rasterization task thread we're running; this way the
// rasterizer can update the framebuffer in its Bucket directly
// without needing to coordinate with any other rasterizer threads.
uint8_t *image = new uint8_t[xRes * yRes * 3];
Bucket *buckets[MAX_CORES];
int nBuckets = useTasks ? nThreads : 1;
for (int i = 0; i < nBuckets; ++i)
buckets[i] = new Bucket(bucketExtent, nPixelSamples);
// Render with intervals set from 1 to the number of pixel samples
// in multiples of two.
for (int logIntervals = 0; (1 << logIntervals) <= nPixelSamples;
++logIntervals) {
int nIntervals = (1 << logIntervals);
printf(" Rendering with %d intervals: ", nIntervals);
fflush(stdout);
if (useTasks) {
// Create a RastTask instance for each of the buckets of
// the image; do this outside of the timer so as not to
// penalize for the unnecessary dynamic allocation overhead
// in the implementation here.
std::vector<Task *> rastTasks;
for (int y = 0; y < yRes; y += bucketExtent) {
for (int x = 0; x < xRes; x += bucketExtent) {
int x1 = std::min(x + bucketExtent, xRes);
int y1 = std::min(y + bucketExtent, yRes);
RastTask *rt = new RastTask(rast, &buckets[0], x, y,
x1, y1, nIntervals, grids,
image, xRes, yRes);
rastTasks.push_back(rt);
}
}
ResetAndStartTimer();
EnqueueTasks(rastTasks);
WaitForAllTasks();
}
else {
// If not using tasks, just loop over all of the buckets
// and rasterize.
ResetAndStartTimer();
for (int y = 0; y < yRes; y += bucketExtent) {
for (int x = 0; x < xRes; x += bucketExtent) {
buckets[0]->Start(x, y, std::min(x + bucketExtent, xRes),
std::min(y + bucketExtent, yRes));
rast->Rasterize(grids, nIntervals, buckets[0]);
buckets[0]->Resolve(image, xRes, yRes);
}
}
}
// Report total time for rasterization
double rastGCycles = GetElapsedMCycles() / 1024.;
printf(" %.3f billion cycles\n", rastGCycles);
// Write the image
char outName[256];
sprintf(outName, "%s_int%d_samp%d.ppm", sceneName, nIntervals,
nPixelSamples);
WritePPM(image, xRes, yRes, outName);
printf(" Wrote output image \"%s\"\n", outName);
// Compare to the "golden" image for correctness
char goldenName[256];
sprintf(goldenName, "golden/%s_%d.ppm", sceneName,
nPixelSamples);
if (!CompareToGolden(image, xRes, yRes, goldenName, outName))
++failures;
}
printf("\n");
for (int i = 0; i < nBuckets; ++i)
delete buckets[i];
delete[] image;
}
if (useTasks)
TasksCleanup();
delete rast;
return failures;
}
