Add GPU performance queries.

[ipdf/code.git] / src / screen.cpp

diff --git a/src/screen.cpp b/src/screen.cpp
index 40754b3..9687c55 100644 (file)
--- a/src/screen.cpp
+++ b/src/screen.cpp
@@ -94,6 +94,12 @@ Screen::Screen()
                Fatal("Your system does not support the ARB_explicit_attrib_location extension, which is required.");
        }
 
+       m_frame_begin_time = SDL_GetPerformanceCounter();
+       m_last_frame_time = 0;
+       m_last_frame_gpu_timer = 0;
+       glGenQueries(1, &m_frame_gpu_timer);
+       glBeginQuery(GL_TIME_ELAPSED, m_frame_gpu_timer);
+
        glDebugMessageCallback(opengl_debug_callback, 0);
 
        GLuint default_vao;
@@ -230,7 +236,24 @@ void Screen::Present()
 {
        if (m_debug_font_atlas)
                DebugFontFlush();
+       m_last_frame_time = SDL_GetPerformanceCounter() - m_frame_begin_time;
+       glEndQuery(GL_TIME_ELAPSED);
        SDL_GL_SwapWindow(m_window);
+       m_frame_begin_time = SDL_GetPerformanceCounter();
+       if (m_last_frame_gpu_timer)
+               glDeleteQueries(1, &m_last_frame_gpu_timer);
+       m_last_frame_gpu_timer = m_frame_gpu_timer;
+       glGenQueries(1, &m_frame_gpu_timer);
+       glBeginQuery(GL_TIME_ELAPSED, m_frame_gpu_timer);
+}
+
+double Screen::GetLastFrameTimeGPU() const
+{
+       if (!m_last_frame_gpu_timer)
+               return 0;
+       uint64_t frame_time_ns;
+       glGetQueryObjectui64v(m_last_frame_gpu_timer, GL_QUERY_RESULT, &frame_time_ns);
+       return frame_time_ns/1000000000.0;
 }
 
 void Screen::ScreenShot(const char * filename) const