/*
* yt - A fully featured command line YouTube client
*
* Copyright (C) 2018 the mpv developers
* Copyright (C) 2024 Benedikt Peetz <benedikt.peetz@b-peetz.de>
* SPDX-License-Identifier: GPL-3.0-or-later
*
* This file is part of Yt.
*
* You should have received a copy of the License along with this program.
* If not, see <https://www.gnu.org/licenses/gpl-3.0.txt>.
*/
#ifndef MPV_CLIENT_API_RENDER_GL_H_
#define MPV_CLIENT_API_RENDER_GL_H_
#include "render.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* OpenGL backend
* --------------
*
* This header contains definitions for using OpenGL with the render.h API.
*
* OpenGL interop
* --------------
*
* The OpenGL backend has some special rules, because OpenGL itself uses
* implicit per-thread contexts, which causes additional API problems.
*
* This assumes the OpenGL context lives on a certain thread controlled by the
* API user. All mpv_render_* APIs have to be assumed to implicitly use the
* OpenGL context if you pass a mpv_render_context using the OpenGL backend,
* unless specified otherwise.
*
* The OpenGL context is indirectly accessed through the OpenGL function
* pointers returned by the get_proc_address callback in mpv_opengl_init_params.
* Generally, mpv will not load the system OpenGL library when using this API.
*
* OpenGL state
* ------------
*
* OpenGL has a large amount of implicit state. All the mpv functions mentioned
* above expect that the OpenGL state is reasonably set to OpenGL standard
* defaults. Likewise, mpv will attempt to leave the OpenGL context with
* standard defaults. The following state is excluded from this:
*
* - the glViewport state
* - the glScissor state (but GL_SCISSOR_TEST is in its default value)
* - glBlendFuncSeparate() state (but GL_BLEND is in its default value)
* - glClearColor() state
* - mpv may overwrite the callback set with glDebugMessageCallback()
* - mpv always disables GL_DITHER at init
*
* Messing with the state could be avoided by creating shared OpenGL contexts,
* but this is avoided for the sake of compatibility and interoperability.
*
* On OpenGL 2.1, mpv will strictly call functions like glGenTextures() to
* create OpenGL objects. You will have to do the same. This ensures that
* objects created by mpv and the API users don't clash. Also, legacy state
* must be either in its defaults, or not interfere with core state.
*
* API use
* -------
*
* The mpv_render_* API is used. That API supports multiple backends, and this
* section documents specifics for the OpenGL backend.
*
* Use mpv_render_context_create() with MPV_RENDER_PARAM_API_TYPE set to
* MPV_RENDER_API_TYPE_OPENGL, and MPV_RENDER_PARAM_OPENGL_INIT_PARAMS provided.
*
* Call mpv_render_context_render() with MPV_RENDER_PARAM_OPENGL_FBO to render
* the video frame to an FBO.
*
* Hardware decoding
* -----------------
*
* Hardware decoding via this API is fully supported, but requires some
* additional setup. (At least if direct hardware decoding modes are wanted,
* instead of copying back surface data from GPU to CPU RAM.)
*
* There may be certain requirements on the OpenGL implementation:
*
* - Windows: ANGLE is required (although in theory GL/DX interop could be used)
* - Intel/Linux: EGL is required, and also the native display resource needs
* to be provided (e.g. MPV_RENDER_PARAM_X11_DISPLAY for X11 and
* MPV_RENDER_PARAM_WL_DISPLAY for Wayland)
* - nVidia/Linux: Both GLX and EGL should work (GLX is required if vdpau is
* used, e.g. due to old drivers.)
* - macOS: CGL is required (CGLGetCurrentContext() returning non-NULL)
* - iOS: EAGL is required (EAGLContext.currentContext returning non-nil)
*
* Once these things are setup, hardware decoding can be enabled/disabled at
* any time by setting the "hwdec" property.
*/
/**
* For initializing the mpv OpenGL state via MPV_RENDER_PARAM_OPENGL_INIT_PARAMS.
*/
typedef struct mpv_opengl_init_params {
/**
* This retrieves OpenGL function pointers, and will use them in subsequent
* operation.
* Usually, you can simply call the GL context APIs from this callback (e.g.
* glXGetProcAddressARB or wglGetProcAddress), but some APIs do not always
* return pointers for all standard functions (even if present); in this
* case you have to compensate by looking up these functions yourself when
* libmpv wants to resolve them through this callback.
* libmpv will not normally attempt to resolve GL functions on its own, nor
* does it link to GL libraries directly.
*/
void *(*get_proc_address)(void *ctx, const char *name);
/**
* Value passed as ctx parameter to get_proc_address().
*/
void *get_proc_address_ctx;
} mpv_opengl_init_params;
/**
* For MPV_RENDER_PARAM_OPENGL_FBO.
*/
typedef struct mpv_opengl_fbo {
/**
* Framebuffer object name. This must be either a valid FBO generated by
* glGenFramebuffers() that is complete and color-renderable, or 0. If the
* value is 0, this refers to the OpenGL default framebuffer.
*/
int fbo;
/**
* Valid dimensions. This must refer to the size of the framebuffer. This
* must always be set.
*/
int w, h;
/**
* Underlying texture internal format (e.g. GL_RGBA8), or 0 if unknown. If
* this is the default framebuffer, this can be an equivalent.
*/
int internal_format;
} mpv_opengl_fbo;
/**
* Deprecated. For MPV_RENDER_PARAM_DRM_DISPLAY.
*/
typedef struct mpv_opengl_drm_params {
int fd;
int crtc_id;
int connector_id;
struct _drmModeAtomicReq **atomic_request_ptr;
int render_fd;
} mpv_opengl_drm_params;
/**
* For MPV_RENDER_PARAM_DRM_DRAW_SURFACE_SIZE.
*/
typedef struct mpv_opengl_drm_draw_surface_size {
/**
* size of the draw plane surface in pixels.
*/
int width, height;
} mpv_opengl_drm_draw_surface_size;
/**
* For MPV_RENDER_PARAM_DRM_DISPLAY_V2.
*/
typedef struct mpv_opengl_drm_params_v2 {
/**
* DRM fd (int). Set to -1 if invalid.
*/
int fd;
/**
* Currently used crtc id
*/
int crtc_id;
/**
* Currently used connector id
*/
int connector_id;
/**
* Pointer to a drmModeAtomicReq pointer that is being used for the renderloop.
* This pointer should hold a pointer to the atomic request pointer
* The atomic request pointer is usually changed at every renderloop.
*/
struct _drmModeAtomicReq **atomic_request_ptr;
/**
* DRM render node. Used for VAAPI interop.
* Set to -1 if invalid.
*/
int render_fd;
} mpv_opengl_drm_params_v2;
/**
* For backwards compatibility with the old naming of mpv_opengl_drm_draw_surface_size
*/
#define mpv_opengl_drm_osd_size mpv_opengl_drm_draw_surface_size
#ifdef __cplusplus
}
#endif
#endif