--- /dev/null
+#include "gpu_timers.h"
+
+#include <epoxy/gl.h>
+
+using namespace std;
+
+bool enable_timing = false;
+bool detailed_timing = false;
+bool in_warmup = false;
+
+pair<GLuint, GLuint> GPUTimers::begin_timer(const string &name, int level)
+{
+ if (!enable_timing) {
+ return make_pair(0, 0);
+ }
+
+ GLuint queries[2];
+ glGenQueries(2, queries);
+ glQueryCounter(queries[0], GL_TIMESTAMP);
+
+ Timer timer;
+ timer.name = name;
+ timer.level = level;
+ timer.query.first = queries[0];
+ timer.query.second = queries[1];
+ timers.push_back(timer);
+ return timer.query;
+}
+
+GLint64 find_elapsed(pair<GLuint, GLuint> queries)
+{
+ // NOTE: This makes the CPU wait for the GPU.
+ GLuint64 time_start, time_end;
+ glGetQueryObjectui64v(queries.first, GL_QUERY_RESULT, &time_start);
+ glGetQueryObjectui64v(queries.second, GL_QUERY_RESULT, &time_end);
+ return time_end - time_start;
+}
+
+void GPUTimers::print()
+{
+ for (size_t i = 0; i < timers.size(); ++i) {
+ if (timers[i].level >= 4 && !detailed_timing) {
+ // In practice, only affects the SOR sub-timers.
+ continue;
+ }
+
+ GLint64 time_elapsed = find_elapsed(timers[i].query);
+ for (int j = 0; j < timers[i].level * 2; ++j) {
+ fprintf(stderr, " ");
+ }
+
+ if (detailed_timing) {
+ // Look for any immediate subtimers, and see if they sum to the large one.
+ size_t num_subtimers = 0;
+ GLint64 sum_subtimers = 0;
+ for (size_t j = i + 1; j < timers.size() && timers[j].level > timers[i].level; ++j) {
+ if (timers[j].level != timers[i].level + 1)
+ continue;
+ ++num_subtimers;
+ sum_subtimers += find_elapsed(timers[j].query);
+ }
+
+ if (num_subtimers > 0 && (time_elapsed - sum_subtimers) / 1e6 >= 0.01) {
+ 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);
+ } else {
+ fprintf(stderr, "%-30s %4.3f ms\n", timers[i].name.c_str(), time_elapsed / 1e6);
+ }
+ } else {
+ fprintf(stderr, "%-30s %4.1f ms\n", timers[i].name.c_str(), time_elapsed / 1e6);
+ }
+ }
+}