sdl_internal.h

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// Copyright 2020-2023, Collabora, Ltd.
// SPDX-License-Identifier: BSL-1.0
/*!
 * @file
 * @brief  Internal header for SDL XR system.
 * @author Jakob Bornecrantz <jakob@collabora.com>
 * @ingroup sdl_test
 */
 
#include "xrt/xrt_system.h"
#include "xrt/xrt_device.h"
#include "xrt/xrt_instance.h"
#include "xrt/xrt_tracking.h"
#include "xrt/xrt_compositor.h"
 
#include "util/u_pacing.h"
#include "util/u_logging.h"
#include "util/comp_base.h"
#include "util/comp_swapchain.h"
 
#include "SDL2/SDL.h"
 
#include "ogl/ogl_api.h"
 
 
#ifdef __cplusplus
extern "C" {
#endif
 
struct sdl_program;
 
/*!
 * Sub-class of @ref comp_swapchain, used to do OpenGL rendering.
 *
 * @ingroup sdl_test
 */
struct sdl_swapchain
{
        struct comp_swapchain base;
 
        //! Pointer back to main program.
        struct sdl_program *sp;
 
        //! Cached width and height.
        int w, h;
 
        //! Number of textures in base.base.base.image_count.
        GLuint textures[XRT_MAX_SWAPCHAIN_IMAGES];
 
        //! Same number of images as textures.
        GLuint memory[XRT_MAX_SWAPCHAIN_IMAGES];
};
 
/*!
 * Tracking frame state.
 *
 * @ingroup sdl_test
 */
struct sdl_comp_frame
{
        int64_t id;
        uint64_t predicted_display_time_ns;
        uint64_t desired_present_time_ns;
        uint64_t present_slop_ns;
};
 
/*!
 * Split out for convenience.
 *
 * This ultimately implements @ref xrt_compositor_native but does so by
 * extending @ref comp_base, similar to how @ref comp_compositor works.
 *
 * @extends comp_base
 * @ingroup sdl_test
 */
struct sdl_compositor
{
        //! Base native compositor.
        struct comp_base base;
 
        //! Pacing helper to drive us forward.
        struct u_pacing_compositor *upc;
 
        struct
        {
                //! Frame interval that we are using.
                uint64_t frame_interval_ns;
        } settings;
 
        // Kept here for convenience.
        struct xrt_system_compositor_info sys_info;
 
 
        //! @todo Insert your own required members here
 
        struct
        {
                struct sdl_comp_frame waited;
                struct sdl_comp_frame rendering;
        } frame;
};
 
struct sdl_program_plus;
 
/*!
 * C base class for the SDL program.
 *
 * @implements xrt_instance
 * @implements xrt_device
 * @implements xrt_system_devices
 * @extends sdl_compositor
 * @ingroup sdl_test
 */
struct sdl_program
{
        //! Base class for devices.
        struct xrt_device xdev_base;
 
        //! Instance base.
        struct xrt_instance xinst_base;
 
        //! System, implemented for now using helper code.
        struct u_system *usys;
 
        //! System devices base.
        struct xrt_system_devices xsysd_base;
 
        //! Space overseer, implemented for now using helper code.
        struct xrt_space_overseer *xso;
 
        //! SDL compositor struct.
        struct sdl_compositor c;
 
        //! Created system compositor.
        struct xrt_system_compositor *xsysc;
 
        //! Inputs exposed by the SDL device.
        struct xrt_input inputs[1];
 
        //! HMD parts exposed by the SDL device to become a HMD.
        struct xrt_hmd_parts hmd;
 
        //! Tracking origin that the device is located in.
        struct xrt_tracking_origin origin;
 
        //! The current log level.
        enum u_logging_level log_level;
 
        struct
        {
                struct
                {
                        //! The pose of the head, only used for view space.
                        struct xrt_pose pose;
                } head;
 
                struct
                {
                        //! Pose of each individual eye.
                        struct xrt_pose pose;
 
                        //! Fov of each individual eye.
                        struct xrt_fov fov;
                } left, right;
        } state;
 
        //! The main window.
        SDL_Window *win;
 
        //! Main OpenGL context.
        SDL_GLContext ctx;
 
        //! Protects the OpenGL context.
        struct os_mutex current_mutex;
 
        //! Pointer back to the C++ part of the program.
        struct sdl_program_plus *spp;
};
 
 
static inline struct sdl_program *
from_xinst(struct xrt_instance *xinst)
{
        return container_of(xinst, struct sdl_program, xinst_base);
}
 
static inline struct sdl_program *
from_xsysd(struct xrt_system_devices *xsysd)
{
        return container_of(xsysd, struct sdl_program, xsysd_base);
}
 
static inline struct sdl_program *
from_xdev(struct xrt_device *xdev)
{
        return container_of(xdev, struct sdl_program, xdev_base);
}
 
static inline struct sdl_program *
from_comp(struct xrt_compositor *xc)
{
        return container_of(xc, struct sdl_program, c.base.base);
}
 
 
/*!
 * Spew level logging.
 *
 * @relates sdl_program
 * @ingroup sdl_test
 */
#define ST_TRACE(sp, ...) U_LOG_IFL_T(sp->log_level, __VA_ARGS__);
 
/*!
 * Debug level logging.
 *
 * @relates sdl_program
 */
#define ST_DEBUG(sp, ...) U_LOG_IFL_D(sp->log_level, __VA_ARGS__);
 
/*!
 * Info level logging.
 *
 * @relates sdl_program
 * @ingroup sdl_test
 */
#define ST_INFO(sp, ...) U_LOG_IFL_I(sp->log_level, __VA_ARGS__);
 
/*!
 * Warn level logging.
 *
 * @relates sdl_program
 * @ingroup sdl_test
 */
#define ST_WARN(sp, ...) U_LOG_IFL_W(sp->log_level, __VA_ARGS__);
 
/*!
 * Error level logging.
 *
 * @relates sdl_program
 * @ingroup sdl_test
 */
#define ST_ERROR(sp, ...) U_LOG_IFL_E(sp->log_level, __VA_ARGS__);
 
/*!
 * Check for OpenGL errors, context needs to be current.
 *
 * @ingroup sdl_test
 */
#define CHECK_GL()                                                                                                     \
        do {                                                                                                           \
                GLint err = glGetError();                                                                              \
                if (err != 0) {                                                                                        \
                        U_LOG_RAW("%s:%u: error: 0x%04x", __func__, __LINE__, err);                                    \
                }                                                                                                      \
        } while (false)
 
/*!
 * Makes the OpenGL context current in this thread, takes lock.
 *
 * @ingroup sdl_test
 */
static inline void
sdl_make_current(struct sdl_program *sp)
{
        os_mutex_lock(&sp->current_mutex);
        SDL_GL_MakeCurrent(sp->win, sp->ctx);
}
 
/*!
 * Unmakes the any OpenGL context current in this thread, releases the lock.
 *
 * @ingroup sdl_test
 */
static inline void
sdl_make_uncurrent(struct sdl_program *sp)
{
        SDL_GL_MakeCurrent(NULL, NULL);
        os_mutex_unlock(&sp->current_mutex);
}
 
 
/*
 *
 * sdl_device.c
 *
 */
 
/*!
 * Init the @ref xrt_device sub struct.
 *
 * In sdl_device.c
 *
 * @ingroup sdl_test
 */
void
sdl_device_init(struct sdl_program *sp);
 
 
/*
 *
 * sdl_swapchain.c
 *
 */
 
/*!
 * Implementation of @ref xrt_compositor::create_swapchain.
 *
 * @ingroup sdl_test
 */
xrt_result_t
sdl_swapchain_create(struct xrt_compositor *xc,
                     const struct xrt_swapchain_create_info *info,
                     struct xrt_swapchain **out_xsc);
 
/*!
 * Implementation of @ref xrt_compositor::import_swapchain.
 *
 * @ingroup sdl_test
 */
xrt_result_t
sdl_swapchain_import(struct xrt_compositor *xc,
                     const struct xrt_swapchain_create_info *info,
                     struct xrt_image_native *native_images,
                     uint32_t native_image_count,
                     struct xrt_swapchain **out_xsc);
 
 
/*
 *
 * sdl_compositor.c
 *
 */
 
/*!
 * Initializes the compositor part of the SDL program.
 *
 * @ingroup sdl_test
 */
void
sdl_compositor_init(struct sdl_program *sp);
 
/*!
 * Creates the system compositor that wraps the native compositor.
 *
 * @ingroup sdl_test
 */
xrt_result_t
sdl_compositor_create_system(struct sdl_program *sp, struct xrt_system_compositor **out_xsysc);
 
 
/*
 *
 * sdl_instance.c
 *
 */
 
/*!
 * Init the @ref xrt_system (and @ref u_system) struct.
 *
 * @ingroup sdl_test
 */
void
sdl_system_init(struct sdl_program *sp);
 
/*!
 * Init the @ref xrt_system_devices sub struct.
 *
 * @ingroup sdl_test
 */
void
sdl_system_devices_init(struct sdl_program *sp);
 
/*!
 * Init the @ref xrt_instance sub struct.
 *
 * @ingroup sdl_test
 */
void
sdl_instance_init(struct sdl_program *sp);
 
 
/*
 *
 * sdl_program.cpp
 *
 */
 
/*!
 * Create the SDL program.
 *
 * @ingroup sdl_test
 */
struct sdl_program *
sdl_program_plus_create(void);
 
/*!
 * Render a frame, called by the compositor when layers have been committed.
 *
 * @ingroup sdl_test
 */
void
sdl_program_plus_render(struct sdl_program_plus *spp);
 
/*!
 * Destroy the SDL program.
 *
 * @ingroup sdl_test
 */
void
sdl_program_plus_destroy(struct sdl_program_plus *spp);
 
 
#ifdef __cplusplus
}
#endif