ScreenCapture.h

#pragma once

#include "XPLMDataAccess.h"
#include "XPLMGraphics.h"

#include <array>
#include <cstddef>
#include <functional>
#include <string>
#include <vector>

#if IBM
#include <windows.h>
#endif
#if LIN
#include <GL/gl.h>
#elif __GNUC__
#include <OpenGL/gl.h>
#else
#include <GL/gl.h>
#endif

namespace vr_image_client
{

struct RawFrame
{
    int width{0};
    int height{0};
    std::vector<unsigned char> rgb;
};

constexpr bool COROP_IMAGE_CAPTURE_TO_SPEED_UP = true;
constexpr bool USE_ASTC_FORMAT = false;

class ScreenCapture
{
public:
    using LogCallback = std::function<void(const std::string &)>;
    // Change this if you want to support other VR headsets
    static constexpr float kMetaQuest3H_FOV = 110.0f;
    static constexpr float kMetaQuest3V_FOV = 96.0f;
    static constexpr int kBytesPerPixel = 3;
    static constexpr int kPboCount = 3;

    explicit ScreenCapture(LogCallback log_callback);

    void InitializeDataRefs();
    void ResetSession();
    void ReleaseResources();
    void SetScreenSize(int width, int height);
    void SetCaptureWidthRatio(float ratio);
    float GetCaptureWidthRatio() const { return capture_width_ratio_; }
    bool GetCachedScreenSize(int &width, int &height) const;

    bool CaptureFrame(RawFrame &out_frame, bool &frame_ready);
    bool QueryFieldOfView(float &horizontal_fov, float &vertical_fov) const;

private:
    void LogFirstCaptureInfo(int screen_width, int screen_height, int captured_width);
    bool EnsureBuffers(int width, int height);
    bool ResolveScreenSize(int &width, int &height);
    bool TryGetCachedScreenSize(int &width, int &height) const;

    LogCallback log_callback_;
    bool logged_first_capture_info_{false};

    XPLMDataRef horizontal_fov_ref_{nullptr};
    XPLMDataRef vertical_fov_ref_{nullptr};

    GLuint pbo_ids_[kPboCount]{0};
    int pbo_index_{0};
    int map_index_{0};
    int ready_pbo_count_{0};
    std::size_t buffer_size_{0};
    int buffer_width_{0};
    int buffer_height_{0};
    bool buffers_initialized_{false};

    int cached_screen_width_{0};
    int cached_screen_height_{0};
    float capture_width_ratio_{1.0f};
};

} // namespace vr_image_client