git.sesse.net Git - nageru/blob - gpu_timers.cpp

   1 #include <epoxy/gl.h>
   2
   3 #include "gpu_timers.h"
   4
   5 using namespace std;
   6
   7 pair<GLuint, GLuint> GPUTimers::begin_timer(const string &name, int level)
   8 {
   9         if (!enable_timing) {
  10                 return make_pair(0, 0);
  11         }
  12
  13         GLuint queries[2];
  14         glGenQueries(2, queries);
  15         glQueryCounter(queries[0], GL_TIMESTAMP);
  16
  17         Timer timer;
  18         timer.name = name;
  19         timer.level = level;
  20         timer.query.first = queries[0];
  21         timer.query.second = queries[1];
  22         timers.push_back(timer);
  23         return timer.query;
  24 }
  25
  26 GLint64 find_elapsed(pair<GLuint, GLuint> queries)
  27 {
  28         // NOTE: This makes the CPU wait for the GPU.
  29         GLuint64 time_start, time_end;
  30         glGetQueryObjectui64v(queries.first, GL_QUERY_RESULT, &time_start);
  31         glGetQueryObjectui64v(queries.second, GL_QUERY_RESULT, &time_end);
  32         return time_end - time_start;
  33 }
  34
  35 void GPUTimers::print()
  36 {
  37         for (size_t i = 0; i < timers.size(); ++i) {
  38                 if (timers[i].level >= 4 && !detailed_timing) {
  39                         // In practice, only affects the SOR sub-timers.
  40                         continue;
  41                 }
  42
  43                 GLint64 time_elapsed = find_elapsed(timers[i].query);
  44                 for (int j = 0; j < timers[i].level * 2; ++j) {
  45                         fprintf(stderr, " ");
  46                 }
  47
  48                 if (detailed_timing) {
  49                         // Look for any immediate subtimers, and see if they sum to the large one.
  50                         size_t num_subtimers = 0;
  51                         GLint64 sum_subtimers = 0;
  52                         for (size_t j = i + 1; j < timers.size() && timers[j].level > timers[i].level; ++j) {
  53                                 if (timers[j].level != timers[i].level + 1) continue;
  54                                 ++num_subtimers;
  55                                 sum_subtimers += find_elapsed(timers[j].query);
  56                         }
  57
  58                         if (num_subtimers > 0 && (time_elapsed - sum_subtimers) / 1e6 >= 0.01) {
  59                                 fprintf(stderr, "%-30s %4.3f ms [%4.3f ms unaccounted for]\n", timers[i].name.c_str(), time_elapsed / 1e6, (time_elapsed - sum_subtimers) / 1e6);
  60                         } else {
  61                                 fprintf(stderr, "%-30s %4.3f ms\n", timers[i].name.c_str(), time_elapsed / 1e6);
  62                         }
  63                 } else {
  64                         fprintf(stderr, "%-30s %4.1f ms\n", timers[i].name.c_str(), time_elapsed / 1e6);
  65                 }
  66         }
  67 }