gstreamer/gst-libs/gst/gl/gstglutils.c
Matthew Waters 98249a57db gst: don't use volatile to mean atomic
volatile is not sufficient to provide atomic guarantees and real atomics
should be used instead.  GCC 11 has started warning about using volatile
with atomic operations.

https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1719

Discovered in https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/issues/868

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/1073>
2021-03-19 04:20:19 +00:00

875 lines
25 KiB
C

/*
* GStreamer
* Copyright (C) 2013 Matthew Waters <ystreet00@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstglutils
* @title: GstGLUtils
* @short_description: some miscellaneous utilities for OpenGL
* @see_also: #GstGLContext
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <gst/gst.h>
#include <glib/gprintf.h>
#include "gl.h"
#include "gstglutils.h"
#include "gstglutils_private.h"
#if GST_GL_HAVE_WINDOW_X11
#include <gst/gl/x11/gstgldisplay_x11.h>
#endif
#if GST_GL_HAVE_WINDOW_WAYLAND
#include <gst/gl/wayland/gstgldisplay_wayland.h>
#endif
#define USING_OPENGL(context) (gst_gl_context_check_gl_version (context, GST_GL_API_OPENGL, 1, 0))
#define USING_OPENGL3(context) (gst_gl_context_check_gl_version (context, GST_GL_API_OPENGL3, 3, 1))
#define USING_GLES(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES, 1, 0))
#define USING_GLES2(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES2, 2, 0))
#define USING_GLES3(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES2, 3, 0))
#ifndef GST_DISABLE_GST_DEBUG
GST_DEBUG_CATEGORY_STATIC (gst_gl_utils_debug);
static GstDebugCategory *
_init_gl_utils_debug_category (void)
{
static gsize _init = 0;
if (g_once_init_enter (&_init)) {
GST_DEBUG_CATEGORY_INIT (gst_gl_utils_debug, "glutils", 0,
"OpenGL Utilities");
g_once_init_leave (&_init, 1);
}
return gst_gl_utils_debug;
}
#define GST_CAT_DEFAULT _init_gl_utils_debug_category()
#endif
static gboolean
gst_gl_display_found (GstElement * element, GstGLDisplay * display)
{
if (display) {
GST_LOG_OBJECT (element, "already have a display (%p)", display);
return TRUE;
}
return FALSE;
}
GST_DEBUG_CATEGORY_STATIC (GST_CAT_CONTEXT);
static void
_init_context_debug (void)
{
#ifndef GST_DISABLE_GST_DEBUG
static gsize _init = 0;
if (g_once_init_enter (&_init)) {
GST_DEBUG_CATEGORY_GET (GST_CAT_CONTEXT, "GST_CONTEXT");
g_once_init_leave (&_init, 1);
}
#endif
}
static gboolean
pad_query (const GValue * item, GValue * value, gpointer user_data)
{
GstPad *pad = g_value_get_object (item);
GstQuery *query = user_data;
gboolean res;
_init_context_debug ();
res = gst_pad_peer_query (pad, query);
if (res) {
g_value_set_boolean (value, TRUE);
return FALSE;
}
GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, pad, "pad peer query failed");
return TRUE;
}
gboolean
gst_gl_run_query (GstElement * element, GstQuery * query,
GstPadDirection direction)
{
GstIterator *it;
GstIteratorFoldFunction func = pad_query;
GValue res = { 0 };
g_value_init (&res, G_TYPE_BOOLEAN);
g_value_set_boolean (&res, FALSE);
/* Ask neighbor */
if (direction == GST_PAD_SRC)
it = gst_element_iterate_src_pads (element);
else
it = gst_element_iterate_sink_pads (element);
while (gst_iterator_fold (it, func, &res, query) == GST_ITERATOR_RESYNC)
gst_iterator_resync (it);
gst_iterator_free (it);
return g_value_get_boolean (&res);
}
static void
_gst_context_query (GstElement * element, const gchar * display_type)
{
GstQuery *query;
GstContext *ctxt;
_init_context_debug ();
/* 2a) Query downstream with GST_QUERY_CONTEXT for the context and
* check if downstream already has a context of the specific type
* 2b) Query upstream as above.
*/
query = gst_query_new_context (display_type);
if (gst_gl_run_query (element, query, GST_PAD_SRC)) {
gst_query_parse_context (query, &ctxt);
GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
"found context (%p) in downstream query", ctxt);
gst_element_set_context (element, ctxt);
} else if (gst_gl_run_query (element, query, GST_PAD_SINK)) {
gst_query_parse_context (query, &ctxt);
GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
"found context (%p) in upstream query", ctxt);
gst_element_set_context (element, ctxt);
} else {
/* 3) Post a GST_MESSAGE_NEED_CONTEXT message on the bus with
* the required context type and afterwards check if a
* usable context was set now as in 1). The message could
* be handled by the parent bins of the element and the
* application.
*/
GstMessage *msg;
GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
"posting need context message");
msg = gst_message_new_need_context (GST_OBJECT_CAST (element),
display_type);
gst_element_post_message (element, msg);
}
/*
* Whomever responds to the need-context message performs a
* GstElement::set_context() with the required context in which the element
* is required to update the display_ptr or call gst_gl_handle_set_context().
*/
gst_query_unref (query);
}
static void
gst_gl_display_context_query (GstElement * element, GstGLDisplay ** display_ptr)
{
_gst_context_query (element, GST_GL_DISPLAY_CONTEXT_TYPE);
if (*display_ptr)
return;
#if GST_GL_HAVE_WINDOW_X11
_gst_context_query (element, "gst.x11.display.handle");
if (*display_ptr)
return;
#endif
#if GST_GL_HAVE_WINDOW_WAYLAND
_gst_context_query (element, "GstWaylandDisplayHandleContextType");
if (*display_ptr)
return;
#endif
}
static void
gst_gl_context_query (GstElement * element)
{
_gst_context_query (element, "gst.gl.app_context");
}
/* 4) Create a context by itself and post a GST_MESSAGE_HAVE_CONTEXT
* message.
*/
void
gst_gl_element_propagate_display_context (GstElement * element,
GstGLDisplay * display)
{
GstContext *context;
GstMessage *msg;
if (!display) {
GST_ERROR_OBJECT (element, "Could not get GL display connection");
return;
}
_init_context_debug ();
context = gst_context_new (GST_GL_DISPLAY_CONTEXT_TYPE, TRUE);
gst_context_set_gl_display (context, display);
gst_element_set_context (element, context);
GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
"posting have context (%p) message with display (%p)", context, display);
msg = gst_message_new_have_context (GST_OBJECT_CAST (element), context);
gst_element_post_message (GST_ELEMENT_CAST (element), msg);
}
/**
* gst_gl_ensure_element_data:
* @element: the #GstElement running the query
* @display_ptr: (inout): the resulting #GstGLDisplay
* @other_context_ptr: (inout): the resulting #GstGLContext
*
* Perform the steps necessary for retrieving a #GstGLDisplay and (optionally)
* an application provided #GstGLContext from the surrounding elements or from
* the application using the #GstContext mechanism.
*
* If the contents of @display_ptr or @other_context_ptr are not %NULL, then no
* #GstContext query is necessary for #GstGLDisplay or #GstGLContext retrieval
* or is performed.
*
* This performs #GstContext queries (if necessary) for a winsys display
* connection with %GST_GL_DISPLAY_CONTEXT_TYPE, "gst.x11.display.handle", and
* "GstWaylandDisplayHandleContextType" stopping after the first successful
* retrieval.
*
* This also performs a #GstContext query (if necessary) for an optional
* application provided #GstGLContext using the name "gst.gl.app_context".
* The returned #GstGLContext will be shared with a GStreamer created OpenGL context.
*
* Returns: whether a #GstGLDisplay exists in @display_ptr
*/
gboolean
gst_gl_ensure_element_data (gpointer element, GstGLDisplay ** display_ptr,
GstGLContext ** other_context_ptr)
{
GstGLDisplay *display;
g_return_val_if_fail (element != NULL, FALSE);
g_return_val_if_fail (display_ptr != NULL, FALSE);
g_return_val_if_fail (other_context_ptr != NULL, FALSE);
/* 1) Check if the element already has a context of the specific
* type.
*/
display = *display_ptr;
if (gst_gl_display_found (element, display))
goto done;
gst_gl_display_context_query (element, display_ptr);
/* Neighbour found and it updated the display */
if (gst_gl_display_found (element, *display_ptr))
goto get_gl_context;
/* If no neighbor, or application not interested, use system default */
display = gst_gl_display_new ();
*display_ptr = display;
gst_gl_element_propagate_display_context (element, display);
get_gl_context:
if (*other_context_ptr)
goto done;
gst_gl_context_query (element);
done:
return *display_ptr != NULL;
}
/**
* gst_gl_handle_set_context:
* @element: a #GstElement
* @context: a #GstContext
* @display: (inout) (transfer full): location of a #GstGLDisplay
* @other_context: (inout) (transfer full): location of a #GstGLContext
*
* Helper function for implementing #GstElementClass.set_context() in
* OpenGL capable elements.
*
* Retrieve's the #GstGLDisplay or #GstGLContext in @context and places the
* result in @display or @other_context respectively.
*
* Returns: whether the @display or @other_context could be set successfully
*/
gboolean
gst_gl_handle_set_context (GstElement * element, GstContext * context,
GstGLDisplay ** display, GstGLContext ** other_context)
{
GstGLDisplay *display_replacement = NULL;
GstGLContext *context_replacement = NULL;
const gchar *context_type;
g_return_val_if_fail (display != NULL, FALSE);
g_return_val_if_fail (other_context != NULL, FALSE);
if (!context)
return FALSE;
context_type = gst_context_get_context_type (context);
if (g_strcmp0 (context_type, GST_GL_DISPLAY_CONTEXT_TYPE) == 0) {
if (!gst_context_get_gl_display (context, &display_replacement)) {
GST_WARNING_OBJECT (element, "Failed to get display from context");
return FALSE;
}
}
#if GST_GL_HAVE_WINDOW_X11
else if (g_strcmp0 (context_type, "gst.x11.display.handle") == 0) {
const GstStructure *s;
Display *display;
s = gst_context_get_structure (context);
if (gst_structure_get (s, "display", G_TYPE_POINTER, &display, NULL))
display_replacement =
(GstGLDisplay *) gst_gl_display_x11_new_with_display (display);
}
#endif
#if GST_GL_HAVE_WINDOW_WAYLAND
else if (g_strcmp0 (context_type, "GstWaylandDisplayHandleContextType") == 0) {
const GstStructure *s;
struct wl_display *display;
s = gst_context_get_structure (context);
if (gst_structure_get (s, "display", G_TYPE_POINTER, &display, NULL))
display_replacement =
(GstGLDisplay *) gst_gl_display_wayland_new_with_display (display);
}
#endif
else if (g_strcmp0 (context_type, "gst.gl.app_context") == 0) {
const GstStructure *s = gst_context_get_structure (context);
GstGLDisplay *context_display;
GstGLDisplay *element_display;
if (gst_structure_get (s, "context", GST_TYPE_GL_CONTEXT,
&context_replacement, NULL)) {
context_display = gst_gl_context_get_display (context_replacement);
element_display = display_replacement ? display_replacement : *display;
if (element_display
&& (gst_gl_display_get_handle_type (element_display) &
gst_gl_display_get_handle_type (context_display)) == 0) {
GST_ELEMENT_WARNING (element, LIBRARY, SETTINGS, ("%s",
"Cannot set a GL context with a different display type"), ("%s",
"Cannot set a GL context with a different display type"));
gst_object_unref (context_replacement);
context_replacement = NULL;
}
gst_object_unref (context_display);
}
}
if (display_replacement) {
GstGLDisplay *old = *display;
*display = display_replacement;
if (old)
gst_object_unref (old);
}
if (context_replacement) {
GstGLContext *old = *other_context;
*other_context = context_replacement;
if (old)
gst_object_unref (old);
}
return TRUE;
}
/**
* gst_gl_handle_context_query:
* @element: a #GstElement
* @query: a #GstQuery of type %GST_QUERY_CONTEXT
* @display: (transfer none) (nullable): a #GstGLDisplay
* @context: (transfer none) (nullable): a #GstGLContext
* @other_context: (transfer none) (nullable): application provided #GstGLContext
*
* Returns: Whether the @query was successfully responded to from the passed
* @display, @context, and @other_context.
*/
gboolean
gst_gl_handle_context_query (GstElement * element, GstQuery * query,
GstGLDisplay * display, GstGLContext * gl_context,
GstGLContext * other_context)
{
const gchar *context_type;
GstContext *context, *old_context;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
g_return_val_if_fail (display == NULL || GST_IS_GL_DISPLAY (display), FALSE);
g_return_val_if_fail (gl_context == NULL
|| GST_IS_GL_CONTEXT (gl_context), FALSE);
g_return_val_if_fail (other_context == NULL
|| GST_IS_GL_CONTEXT (other_context), FALSE);
GST_LOG_OBJECT (element, "handle context query %" GST_PTR_FORMAT, query);
gst_query_parse_context_type (query, &context_type);
if (display && g_strcmp0 (context_type, GST_GL_DISPLAY_CONTEXT_TYPE) == 0) {
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new (GST_GL_DISPLAY_CONTEXT_TYPE, TRUE);
gst_context_set_gl_display (context, display);
gst_query_set_context (query, context);
gst_context_unref (context);
GST_DEBUG_OBJECT (element, "successfully set %" GST_PTR_FORMAT
" on %" GST_PTR_FORMAT, display, query);
return TRUE;
}
#if GST_GL_HAVE_WINDOW_X11
else if (display && g_strcmp0 (context_type, "gst.x11.display.handle") == 0) {
GstStructure *s;
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new ("gst.x11.display.handle", TRUE);
if (gst_gl_display_get_handle_type (display) & GST_GL_DISPLAY_TYPE_X11) {
Display *x11_display = (Display *) gst_gl_display_get_handle (display);
if (x11_display) {
s = gst_context_writable_structure (context);
gst_structure_set (s, "display", G_TYPE_POINTER, x11_display, NULL);
gst_query_set_context (query, context);
gst_context_unref (context);
GST_DEBUG_OBJECT (element, "successfully set x11 display %p (from %"
GST_PTR_FORMAT ") on %" GST_PTR_FORMAT, x11_display, display,
query);
return TRUE;
}
}
}
#endif
#if GST_GL_HAVE_WINDOW_WAYLAND
else if (display
&& g_strcmp0 (context_type, "GstWaylandDisplayHandleContextType") == 0) {
GstStructure *s;
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new ("GstWaylandDisplayHandleContextType", TRUE);
if (gst_gl_display_get_handle_type (display) & GST_GL_DISPLAY_TYPE_WAYLAND) {
struct wl_display *wayland_display =
(struct wl_display *) gst_gl_display_get_handle (display);
if (wayland_display) {
s = gst_context_writable_structure (context);
gst_structure_set (s, "display", G_TYPE_POINTER, wayland_display, NULL);
gst_query_set_context (query, context);
gst_context_unref (context);
GST_DEBUG_OBJECT (element, "successfully set wayland display %p (from %"
GST_PTR_FORMAT ") on %" GST_PTR_FORMAT, wayland_display, display,
query);
return TRUE;
}
}
}
#endif
else if (other_context && g_strcmp0 (context_type, "gst.gl.app_context") == 0) {
GstStructure *s;
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new ("gst.gl.app_context", TRUE);
s = gst_context_writable_structure (context);
gst_structure_set (s, "context", GST_TYPE_GL_CONTEXT, other_context, NULL);
gst_query_set_context (query, context);
gst_context_unref (context);
GST_DEBUG_OBJECT (element, "successfully set application GL context %"
GST_PTR_FORMAT " on %" GST_PTR_FORMAT, other_context, query);
return TRUE;
} else if (gl_context
&& g_strcmp0 (context_type, "gst.gl.local_context") == 0) {
GstStructure *s;
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new ("gst.gl.local_context", TRUE);
s = gst_context_writable_structure (context);
gst_structure_set (s, "context", GST_TYPE_GL_CONTEXT, gl_context, NULL);
gst_query_set_context (query, context);
gst_context_unref (context);
GST_DEBUG_OBJECT (element, "successfully set GL context %"
GST_PTR_FORMAT " on %" GST_PTR_FORMAT, gl_context, query);
return TRUE;
}
return FALSE;
}
/**
* gst_gl_query_local_gl_context:
* @element: a #GstElement to query from
* @direction: the #GstPadDirection to query
* @context_ptr: (inout): location containing the current and/or resulting
* #GstGLContext
*
* Performs a GST_QUERY_CONTEXT query of type "gst.gl.local_context" on all
* #GstPads in @element of @direction for the local OpenGL context used by
* GStreamer elements.
*
* Returns: whether @context_ptr contains a #GstGLContext
*/
gboolean
gst_gl_query_local_gl_context (GstElement * element, GstPadDirection direction,
GstGLContext ** context_ptr)
{
GstQuery *query;
GstContext *context;
const GstStructure *s;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (context_ptr != NULL, FALSE);
if (*context_ptr)
return TRUE;
query = gst_query_new_context ("gst.gl.local_context");
if (gst_gl_run_query (GST_ELEMENT (element), query, direction)) {
gst_query_parse_context (query, &context);
if (context) {
s = gst_context_get_structure (context);
gst_structure_get (s, "context", GST_TYPE_GL_CONTEXT, context_ptr, NULL);
}
}
gst_query_unref (query);
return *context_ptr != NULL;
}
/**
* gst_gl_get_plane_data_size:
* @info: a #GstVideoInfo
* @align: a #GstVideoAlignment or %NULL
* @plane: plane number in @info to retrieve the data size of
*
* Retrieve the size in bytes of a video plane of data with a certain alignment
*/
gsize
gst_gl_get_plane_data_size (const GstVideoInfo * info,
const GstVideoAlignment * align, guint plane)
{
gint padded_height;
gsize plane_size;
padded_height = info->height;
if (align)
padded_height += align->padding_top + align->padding_bottom;
padded_height =
GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (info->finfo, plane, padded_height);
plane_size = GST_VIDEO_INFO_PLANE_STRIDE (info, plane) * padded_height;
return plane_size;
}
/**
* gst_gl_get_plane_start:
* @info: a #GstVideoInfo
* @valign: a #GstVideoAlignment or %NULL
* @plane: plane number in @info to retrieve the data size of
*
* Returns: difference between the supposed start of the plane from the @info
* and where the data from the previous plane ends.
*/
gsize
gst_gl_get_plane_start (const GstVideoInfo * info,
const GstVideoAlignment * valign, guint plane)
{
gsize plane_start;
gint i;
/* find the start of the plane data including padding */
plane_start = 0;
for (i = 0; i < plane; i++) {
plane_start += gst_gl_get_plane_data_size (info, valign, i);
}
/* offset between the plane data start and where the video frame starts */
return (GST_VIDEO_INFO_PLANE_OFFSET (info, plane)) - plane_start;
}
/**
* gst_gl_value_get_texture_target_mask:
* @value: an initialized #GValue of type G_TYPE_STRING
*
* See gst_gl_value_set_texture_target_from_mask() for what entails a mask
*
* Returns: the mask of #GstGLTextureTarget's in @value or
* %GST_GL_TEXTURE_TARGET_NONE on failure
*/
GstGLTextureTarget
gst_gl_value_get_texture_target_mask (const GValue * targets)
{
guint new_targets = 0;
g_return_val_if_fail (targets != NULL, GST_GL_TEXTURE_TARGET_NONE);
if (G_TYPE_CHECK_VALUE_TYPE (targets, G_TYPE_STRING)) {
GstGLTextureTarget target;
const gchar *str;
str = g_value_get_string (targets);
target = gst_gl_texture_target_from_string (str);
if (target)
new_targets |= 1 << target;
} else if (G_TYPE_CHECK_VALUE_TYPE (targets, GST_TYPE_LIST)) {
gint j, m;
m = gst_value_list_get_size (targets);
for (j = 0; j < m; j++) {
const GValue *val = gst_value_list_get_value (targets, j);
GstGLTextureTarget target;
const gchar *str;
str = g_value_get_string (val);
target = gst_gl_texture_target_from_string (str);
if (target)
new_targets |= 1 << target;
}
}
return new_targets;
}
/**
* gst_gl_value_set_texture_target:
* @value: an initialized #GValue of type G_TYPE_STRING
* @target: a #GstGLTextureTarget's
*
* Returns: whether the @target could be set on @value
*/
gboolean
gst_gl_value_set_texture_target (GValue * value, GstGLTextureTarget target)
{
g_return_val_if_fail (value != NULL, FALSE);
g_return_val_if_fail (target != GST_GL_TEXTURE_TARGET_NONE, FALSE);
if (target == GST_GL_TEXTURE_TARGET_2D) {
g_value_set_static_string (value, GST_GL_TEXTURE_TARGET_2D_STR);
} else if (target == GST_GL_TEXTURE_TARGET_RECTANGLE) {
g_value_set_static_string (value, GST_GL_TEXTURE_TARGET_RECTANGLE_STR);
} else if (target == GST_GL_TEXTURE_TARGET_EXTERNAL_OES) {
g_value_set_static_string (value, GST_GL_TEXTURE_TARGET_EXTERNAL_OES_STR);
} else {
return FALSE;
}
return TRUE;
}
static guint64
_gst_gl_log2_int64 (guint64 value)
{
guint64 ret = 0;
while (value >>= 1)
ret++;
return ret;
}
/**
* gst_gl_value_set_texture_target_from_mask:
* @value: an uninitialized #GValue
* @target_mask: a bitwise mask of #GstGLTextureTarget's
*
* A mask is a bitwise OR of (1 << target) where target is a valid
* #GstGLTextureTarget
*
* Returns: whether the @target_mask could be set on @value
*/
gboolean
gst_gl_value_set_texture_target_from_mask (GValue * value,
GstGLTextureTarget target_mask)
{
g_return_val_if_fail (value != NULL, FALSE);
g_return_val_if_fail (target_mask != GST_GL_TEXTURE_TARGET_NONE, FALSE);
if ((target_mask & (target_mask - 1)) == 0) {
/* only one texture target set */
g_value_init (value, G_TYPE_STRING);
return gst_gl_value_set_texture_target (value,
_gst_gl_log2_int64 (target_mask));
} else {
GValue item = G_VALUE_INIT;
gboolean ret = FALSE;
g_value_init (value, GST_TYPE_LIST);
g_value_init (&item, G_TYPE_STRING);
if (target_mask & (1 << GST_GL_TEXTURE_TARGET_2D)) {
gst_gl_value_set_texture_target (&item, GST_GL_TEXTURE_TARGET_2D);
gst_value_list_append_value (value, &item);
ret = TRUE;
}
if (target_mask & (1 << GST_GL_TEXTURE_TARGET_RECTANGLE)) {
gst_gl_value_set_texture_target (&item, GST_GL_TEXTURE_TARGET_RECTANGLE);
gst_value_list_append_value (value, &item);
ret = TRUE;
}
if (target_mask & (1 << GST_GL_TEXTURE_TARGET_EXTERNAL_OES)) {
gst_gl_value_set_texture_target (&item,
GST_GL_TEXTURE_TARGET_EXTERNAL_OES);
gst_value_list_append_value (value, &item);
ret = TRUE;
}
g_value_unset (&item);
return ret;
}
}
static const gfloat identity_matrix[] = {
1.0, 0.0, 0.0, 0.0,
0.0, 1.0, 0.0, 0.0,
0.0, 0.0, 1.0, 0.0,
0.0, 0.0, 0.0, 1.0,
};
static const gfloat from_ndc_matrix[] = {
0.5, 0.0, 0.0, 0.0,
0.0, 0.5, 0.0, 0.0,
0.0, 0.0, 0.5, 0.0,
0.5, 0.5, 0.5, 1.0,
};
static const gfloat to_ndc_matrix[] = {
2.0, 0.0, 0.0, 0.0,
0.0, 2.0, 0.0, 0.0,
0.0, 0.0, 2.0, 0.0,
-1.0, -1.0, -1.0, 1.0,
};
/* multiplies two 4x4 matrices, @a X @b, and stores the result in @result
* https://en.wikipedia.org/wiki/Matrix_multiplication
*/
static void
gst_gl_multiply_matrix4 (const gfloat * a, const gfloat * b, gfloat * result)
{
int i, j, k;
gfloat tmp[16] = { 0.0f };
if (!a || !b || !result)
return;
for (i = 0; i < 4; i++) { /* column */
for (j = 0; j < 4; j++) { /* row */
for (k = 0; k < 4; k++) {
tmp[j + (i * 4)] += a[k + (i * 4)] * b[j + (k * 4)];
}
}
}
for (i = 0; i < 16; i++)
result[i] = tmp[i];
}
/*
* gst_gl_get_affine_transformation_meta_as_ndc:
* @meta: (nullable): a #GstVideoAffineTransformationMeta
* @matrix: (out): result of the 4x4 matrix
*
* Retrieves the stored 4x4 affine transformation matrix stored in @meta in
* NDC coordinates. if @meta is NULL, an identity matrix is returned.
*
* NDC is a left-handed coordinate system
* - x - [-1, 1] - +ve X moves right
* - y - [-1, 1] - +ve Y moves up
* - z - [-1, 1] - +ve Z moves into
*/
void
gst_gl_get_affine_transformation_meta_as_ndc (GstVideoAffineTransformationMeta *
meta, gfloat * matrix)
{
if (!meta) {
int i;
for (i = 0; i < 16; i++) {
matrix[i] = identity_matrix[i];
}
} else {
float tmp[16];
/* change of basis multiplications */
gst_gl_multiply_matrix4 (from_ndc_matrix, meta->matrix, tmp);
gst_gl_multiply_matrix4 (tmp, to_ndc_matrix, matrix);
}
}
void gst_gl_set_affine_transformation_meta_from_ndc
(GstVideoAffineTransformationMeta * meta, const gfloat * matrix)
{
float tmp[16];
g_return_if_fail (meta != NULL);
/* change of basis multiplications */
gst_gl_multiply_matrix4 (to_ndc_matrix, matrix, tmp);
gst_gl_multiply_matrix4 (tmp, from_ndc_matrix, meta->matrix);
}