// -*-c++-*-
// SPDX-License-Identifier: LGPL-2.1-only
// Copyright (C) 2022 James Hogan <james@albanarts.com>

#ifndef OSGXR_SubImage
#define OSGXR_SubImage 1

#include <osgXR/Swapchain>

#include <osg/ref_ptr>

namespace osgXR {

/**
 * Represents an OpenXR swapchain subimage.
 */
class SubImage
{
    public:

        /**
         * Construct a subimage representing entire swapchain image.
         * @param swapchain The swapchain (optional).
         */
        SubImage(Swapchain *swapchain = nullptr) :
            _swapchain(swapchain),
            _x(0),
            _y(0),
            _width(0),
            _height(0),
            _arrayIndex(0)
        {
        }

        /**
         * Construct a subimage representing part of a swapchain image.
         * @param swapchain The swapchain.
         * @param x         X offset in pixels.
         * @param y         Y offset in pixels.
         * @param width     Width in pixels.
         * @param height    Height in pixels.
         */
        SubImage(Swapchain *swapchain,
                 int32_t x, int32_t y,
                 uint32_t width, uint32_t height) :
            _swapchain(swapchain),
            _x(x),
            _y(y),
            _width(width),
            _height(height),
            _arrayIndex(0)
        {
        }

        // Accessors

        /// Get swapchain pointer.
        Swapchain *getSwapchain() const
        {
            return _swapchain;
        }

        /// Set offset coordinates in pixels.
        void setOffset(int32_t x, int32_t y)
        {
            _x = x;
            _y = y;
        }
        /// Get X offset in pixels.
        int32_t getX() const
        {
            return _x;
        }
        /// Get Y offset in pixels.
        int32_t getY() const
        {
            return _y;
        }

        /// Set extent in pixels (0 means the whole image).
        void setExtent(uint32_t width, uint32_t height)
        {
            _width = width;
            _height = height;
        }
        /// Get width in pixels (0 means the whole image).
        uint32_t getWidth() const
        {
            return _width;
        }
        /// Get height in pixels (0 means the whole image).
        uint32_t getHeight() const
        {
            return _height;
        }

    protected:

        /// The swapchain this subimage refers to.
        osg::ref_ptr<Swapchain> _swapchain;

        /// Offset into swapchain images in pixels.
        int32_t _x;
        int32_t _y;

        /// Size in pixels (0 means the whole image).
        uint32_t _width;
        uint32_t _height;

        /// Image array index (must be 0 for now).
        uint32_t _arrayIndex;
};

}

#endif