mpv/libmpv/render_gl.h

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/* Copyright (C) 2018 the mpv developers
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#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)
client API: add a new way to pass X11 Display etc. to render API Hardware decoding things often need access to additional handles from the windowing system, such as the X11 or Wayland display when using vaapi. The opengl-cb had nothing dedicated for this, and used the weird GL_MP_MPGetNativeDisplay GL extension (which was mpv specific and not officially registered with OpenGL). This was awkward, and a pain due to having to emulate GL context behavior (like needing a TLS variable to store context for the pseudo GL extension function). In addition (and not inherently due to this), we could pass only one resource from mpv builtin context backends to hwdecs. It was also all GL specific. Replace this with a newer mechanism. It works for all RA backends, not just GL. the API user can explicitly pass the objects at init time via mpv_render_context_create(). Multiple resources are naturally possible. The API uses MPV_RENDER_PARAM_* defines, but internally we use strings. This is done for 2 reasons: 1. trying to leave libmpv and internal mechanisms decoupled, 2. not having to add public API for some of the internal resource types (especially D3D/GL interop stuff). To remain sane, drop support for obscure half-working opengl-cb things, like the DRM interop (was missing necessary things), the RPI window thing (nobody used it), and obscure D3D interop things (not needed with ANGLE, others were undocumented). In order not to break ABI and the C API, we don't remove the associated structs from opengl_cb.h. The parts which are still needed (in particular DRM interop) needs to be ported to the render API.
2018-03-22 16:05:01 +00:00
* - 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