OGLDrawTimer.h

//
//  OpenGLDrawTimer.h
//  avara3d
//
//  Created by Morgan Davis on 12/24/25.
//  Copyright © 2026 Morgan K Davis. All rights reserved.
//
 
#ifndef AVARA3D_PROFILING_OPENGLDRAWTIMER_H
#define AVARA3D_PROFILING_OPENGLDRAWTIMER_H
 
#include <chrono>
#include <cstdint>
#include <vector>
 
#include "a3d/render/backend/opengl/GLTypes.h"
 
namespace a3d {
 
    class OGLDrawTimer {
 
    public:
        // [Internal Lifecycle Functions]
 
        explicit OGLDrawTimer(unsigned bufferedFrames);
 
        OGLDrawTimer(const OGLDrawTimer&)            = delete;
        OGLDrawTimer& operator=(const OGLDrawTimer&) = delete;
 
        OGLDrawTimer(OGLDrawTimer&& other)            = delete;
        OGLDrawTimer& operator=(OGLDrawTimer&& other) = delete;
 
        ~OGLDrawTimer();
 
        // [Internal Member Functions]
 
        bool                     initialize();
        void                     begin();
        std::chrono::nanoseconds end();
 
    private:
        // [Private Types]
 
        enum class Mode {
            Disabled,
            DesktopTimeElapsed,
            WebDisjointTimerQuery,
            WebDisjointTimerQueryExt
        };
 
        // [Private Member Functions]
 
        bool                     resolveQuery(size_t index);
        void                     resolveIssuedQueries(size_t skipIndex);
 
        // [Private Member Variables]
 
        Mode                     _mode;
        gl::enum_t               _queryTarget;
        unsigned                 _bufferSize;
        std::vector<unsigned>    _glQueries;
        size_t                   _frame;
        std::chrono::nanoseconds _lastTime;
        std::vector<uint8_t>     _issued;
        bool                     _active      = false;
        bool                     _initialized = false;
    };
 
}
 
#endif // AVARA3D_PROFILING_OPENGLDRAWTIMER_H