/*

 * GStreamer

 * Copyright (C) 2015 Matthew Waters <matthew@centricular.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.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <string.h>

#include "gstglbuffer.h"

#include "gstglcontext.h"

#include "gstglfuncs.h"

#include "gstglutils.h"

/**

 * SECTION:gstglbuffer

 * @title: GstGLBuffer

 * @short_description: memory subclass for GL buffers

 * @see_also: #GstMemory, #GstAllocator

 *

 * GstGLBuffer is a #GstMemory subclass providing support for the mapping of

 * GL buffers.

 *

 * Data is uploaded or downloaded from the GPU as is necessary.

 */

/* Implementation notes:

 *

 * Currently does not take into account GLES2 differences (no mapbuffer)

 */

#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))

/* compatibility definitions... */

#ifndef GL_MAP_READ_BIT

#define GL_MAP_READ_BIT 0x0001

#endif

#ifndef GL_MAP_WRITE_BIT

#define GL_MAP_WRITE_BIT 0x0002

#endif

#ifndef GL_COPY_READ_BUFFER

#define GL_COPY_READ_BUFFER 0x8F36

#endif

#ifndef GL_COPY_WRITE_BUFFER

#define GL_COPY_WRITE_BUFFER 0x8F37

#endif

GST_DEBUG_CATEGORY_STATIC (GST_CAT_GL_BUFFER);

#define GST_CAT_DEFUALT GST_CAT_GL_BUFFER

static GstAllocator *_gl_buffer_allocator;

static gboolean

_gl_buffer_create (GstGLBuffer * gl_mem, GError ** error)

{

  const GstGLFuncs *gl = gl_mem->mem.context->gl_vtable;

  gl->GenBuffers (1, &gl_mem->id);

  gl->BindBuffer (gl_mem->target, gl_mem->id);

  gl->BufferData (gl_mem->target, gl_mem->mem.mem.maxsize, NULL,

      gl_mem->usage_hints);

  gl->BindBuffer (gl_mem->target, 0);

  return TRUE;

}

struct create_data

{

  GstGLBuffer *mem;

  gboolean result;

};

static void

_gl_buffer_init (GstGLBuffer * mem, GstAllocator * allocator,

    GstMemory * parent, GstGLContext * context, guint gl_target, guint gl_usage,

    GstAllocationParams * params, gsize size)

{

  mem->target = gl_target;

  mem->usage_hints = gl_usage;

  gst_gl_base_memory_init ((GstGLBaseMemory *) mem, allocator, parent, context,

      params, size, NULL, NULL);

  GST_CAT_DEBUG (GST_CAT_GL_BUFFER, "new GL buffer memory:%p size:%"

      G_GSIZE_FORMAT, mem, mem->mem.mem.maxsize);

}

static GstGLBuffer *

_gl_buffer_new (GstAllocator * allocator, GstMemory * parent,

    GstGLContext * context, guint gl_target, guint gl_usage,

    GstAllocationParams * params, gsize size)

{

  GstGLBuffer *ret = g_new0 (GstGLBuffer, 1);

  _gl_buffer_init (ret, allocator, parent, context, gl_target, gl_usage,

      params, size);

  return ret;

}

static gpointer

gst_gl_buffer_cpu_access (GstGLBuffer * mem, GstMapInfo * info, gsize size)

{

  const GstGLFuncs *gl = mem->mem.context->gl_vtable;

  gpointer data, ret;

  if (!gst_gl_base_memory_alloc_data (GST_GL_BASE_MEMORY_CAST (mem)))

    return NULL;

  ret = mem->mem.data;

  GST_CAT_LOG (GST_CAT_GL_BUFFER, "mapping id %d size %" G_GSIZE_FORMAT,

      mem->id, size);

  /* The extra data pointer indirection/memcpy is needed for coherent across

   * concurrent map()'s in both GL and CPU */

  if (GST_MEMORY_FLAG_IS_SET (mem, GST_GL_BASE_MEMORY_TRANSFER_NEED_DOWNLOAD)

      && (info->flags & GST_MAP_GL) == 0 && (info->flags & GST_MAP_READ) != 0) {

    gl->BindBuffer (mem->target, mem->id);

    if (gl->MapBufferRange) {

      /* FIXME: optionally remove this with a flag and return the

       * glMapBufferRange pointer (requires

       * GL_ARB_buffer_storage/GL4/GL_COHERENT_BIT) */

      guint gl_map_flags = GL_MAP_READ_BIT;

      data = gl->MapBufferRange (mem->target, 0, size, gl_map_flags);

      if (data)

        memcpy (mem->mem.data, data, size);

      gl->UnmapBuffer (mem->target);

      ret = mem->mem.data;

    } else if (gl->GetBufferSubData) {

      gl->GetBufferSubData (mem->target, 0, size, mem->mem.data);

      ret = mem->mem.data;

    } else {

      ret = NULL;

    }

    gl->BindBuffer (mem->target, 0);

  }

  return ret;

}

static void

gst_gl_buffer_upload_cpu_write (GstGLBuffer * mem, GstMapInfo * info,

    gsize size)

{

  const GstGLFuncs *gl = mem->mem.context->gl_vtable;

  gpointer data;

  if (!mem->mem.data)

    /* no data pointer has been written */

    return;

  /* The extra data pointer indirection/memcpy is needed for coherent across

   * concurrent map()'s in both GL and CPU */

  /* FIXME: uploading potentially half-written data for libav pushing READWRITE

   * mapped buffers */

  if (GST_MEMORY_FLAG_IS_SET (mem, GST_GL_BASE_MEMORY_TRANSFER_NEED_UPLOAD)

      || (mem->mem.map_flags & GST_MAP_WRITE) != 0) {

    gl->BindBuffer (mem->target, mem->id);

    if (gl->MapBufferRange) {

      /* FIXME: optionally remove this with a flag and return the

       * glMapBufferRange pointer (requires

       * GL_ARB_buffer_storage/GL4/GL_COHERENT_BIT) */

      guint gl_map_flags = GL_MAP_WRITE_BIT;

      data = gl->MapBufferRange (mem->target, 0, size, gl_map_flags);

      if (data)

        memcpy (data, mem->mem.data, size);

      gl->UnmapBuffer (mem->target);

    } else if (gl->BufferSubData) {

      gl->BufferSubData (mem->target, 0, size, mem->mem.data);

    }

    gl->BindBuffer (mem->target, 0);

  }

}

static gpointer

_gl_buffer_map (GstGLBuffer * mem, GstMapInfo * info, gsize size)

{

  const GstGLFuncs *gl = mem->mem.context->gl_vtable;

  if ((info->flags & GST_MAP_GL) != 0) {

    if (info->flags & GST_MAP_READ) {

      gst_gl_buffer_upload_cpu_write (mem, info, size);

    }

    gl->BindBuffer (mem->target, mem->id);

    return &mem->id;

  } else {

    return gst_gl_buffer_cpu_access (mem, info, size);

  }

  return NULL;

}

static void

_gl_buffer_unmap (GstGLBuffer * mem, GstMapInfo * info)

{

  const GstGLFuncs *gl = mem->mem.context->gl_vtable;

  if ((info->flags & GST_MAP_GL) != 0) {

    gl->BindBuffer (mem->target, 0);

  }

  /* XXX: optimistically transfer data */

}

/**

 * gst_gl_buffer_copy_buffer_sub_data:

 * @src: the source #GstGLBuffer

 * @dest: the destination #GstGLBuffer

 * @offset: the offset to copy from @src

 * @size: the size to copy from @src

 *

 * Copies @src into @dest using glCopyBufferSubData().

 *

 * Returns: whether the copy operation succeeded

 *

 * Since: 1.8

 */

static gboolean

gst_gl_buffer_copy_buffer_sub_data (GstGLBuffer * src,

    GstGLBuffer * dest, gssize offset, gssize size)

{

  const GstGLFuncs *gl = src->mem.context->gl_vtable;

  GstMapInfo sinfo, dinfo;

  if (!gl->CopyBufferSubData)

    /* This is GL(ES) 3.0+ only */

    return FALSE;

  if (!gst_memory_map ((GstMemory *) src, &sinfo, GST_MAP_READ | GST_MAP_GL)) {

    GST_CAT_WARNING (GST_CAT_GL_BUFFER,

        "failed to read map source memory %p", src);

    return FALSE;

  }

  if (!gst_memory_map ((GstMemory *) dest, &dinfo, GST_MAP_WRITE | GST_MAP_GL)) {

    GST_CAT_WARNING (GST_CAT_GL_BUFFER,

        "failed to write map destination memory %p", dest);

    gst_memory_unmap ((GstMemory *) src, &sinfo);

    return FALSE;

  }

  gl->BindBuffer (GL_COPY_READ_BUFFER, src->id);

  gl->BindBuffer (GL_COPY_WRITE_BUFFER, dest->id);

  gl->CopyBufferSubData (GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER,

      offset, 0, size);

  gst_memory_unmap ((GstMemory *) src, &sinfo);

  gst_memory_unmap ((GstMemory *) dest, &dinfo);

  return TRUE;

}

static GstGLBuffer *

_gl_buffer_copy (GstGLBuffer * src, gssize offset, gssize size)

{

  GstAllocator *allocator = src->mem.mem.allocator;

  GstAllocationParams params = { 0, src->mem.mem.align, 0, 0 };

  GstGLBuffer *dest = NULL;

  dest = _gl_buffer_new (allocator, NULL, src->mem.context,

      src->target, src->usage_hints, &params, src->mem.mem.maxsize);

  /* If not doing a full copy, then copy to sysmem, the 2D represention of the

   * texture would become wrong */

  if (GST_MEMORY_FLAG_IS_SET (src, GST_GL_BASE_MEMORY_TRANSFER_NEED_UPLOAD)) {

    if (!gst_gl_base_memory_memcpy (GST_GL_BASE_MEMORY_CAST (src),

            GST_GL_BASE_MEMORY_CAST (dest), offset, size)) {

      GST_CAT_WARNING (GST_CAT_GL_BUFFER, "Could not copy GL Buffer");

      gst_memory_unref (GST_MEMORY_CAST (dest));

      dest = NULL;

    }

  } else {

    if (!gst_gl_buffer_copy_buffer_sub_data (src, dest, offset, size)) {

      if (!gst_gl_base_memory_memcpy (GST_GL_BASE_MEMORY_CAST (src),

              GST_GL_BASE_MEMORY_CAST (dest), offset, size)) {

        GST_CAT_WARNING (GST_CAT_GL_BUFFER, "Could not copy GL Buffer");

        gst_memory_unref (GST_MEMORY_CAST (dest));

        dest = NULL;

      }

    }

  }

  return dest;

}

static GstMemory *

_gl_buffer_alloc (GstAllocator * allocator, gsize size,

    GstAllocationParams * params)

{

  g_critical ("Need to use gst_gl_base_memory_alloc() to allocate from "

      "this allocator");

  return NULL;

}

static void

_gl_buffer_destroy (GstGLBuffer * mem)

{

  const GstGLFuncs *gl = mem->mem.context->gl_vtable;

  gl->DeleteBuffers (1, &mem->id);

}

static void

_gst_gl_buffer_allocation_params_copy_data (GstGLBufferAllocationParams * src,

    GstGLBufferAllocationParams * dest)

{

  memset (dest, 0, sizeof (*dest));

  gst_gl_allocation_params_copy_data (&src->parent, &dest->parent);

  dest->gl_target = src->gl_target;

  dest->gl_usage = src->gl_usage;

}

static void

_gst_gl_buffer_allocation_params_free_data (GstGLBufferAllocationParams *

    params)

{

  gst_gl_allocation_params_free_data (&params->parent);

}

G_DEFINE_BOXED_TYPE (GstGLBufferAllocationParams,

    gst_gl_buffer_allocation_params,

    (GBoxedCopyFunc) gst_gl_allocation_params_copy,

    (GBoxedFreeFunc) gst_gl_allocation_params_free);

/**

 * gst_gl_buffer_allocation_params_new:

 * @context: a #GstGLContext

 * @alloc_size: the size in bytes to allocate

 * @alloc_params: (allow-none): the #GstAllocationParams for @tex_id

 * @gl_target: the OpenGL target to allocate

 * @gl_usage: the OpenGL usage hint to allocate with

 *

 * Returns: a new #GstGLBufferAllocationParams for allocating OpenGL buffer

 *          objects

 *

 * Since: 1.8

 */

GstGLBufferAllocationParams *

gst_gl_buffer_allocation_params_new (GstGLContext * context, gsize alloc_size,

    GstAllocationParams * alloc_params, guint gl_target, guint gl_usage)

{

  GstGLBufferAllocationParams *params;

  g_return_val_if_fail (GST_IS_GL_CONTEXT (context), NULL);

  g_return_val_if_fail (alloc_size > 0, NULL);

  params = g_new0 (GstGLBufferAllocationParams, 1);

  if (!gst_gl_allocation_params_init (&params->parent, sizeof (*params),

          GST_GL_ALLOCATION_PARAMS_ALLOC_FLAG_BUFFER |

          GST_GL_ALLOCATION_PARAMS_ALLOC_FLAG_ALLOC,

          (GstGLAllocationParamsCopyFunc)

          _gst_gl_buffer_allocation_params_copy_data,

          (GstGLAllocationParamsFreeFunc)

          _gst_gl_buffer_allocation_params_free_data, context, alloc_size,

          alloc_params, NULL, 0, NULL, NULL)) {

    g_free (params);

    return NULL;

  }

  params->gl_target = gl_target;

  params->gl_usage = gl_usage;

  return params;

}

static GstGLBuffer *

_gl_buffer_alloc_mem (GstGLBufferAllocator * allocator,

    GstGLBufferAllocationParams * params)

{

  guint alloc_flags = params->parent.alloc_flags;

  g_return_val_if_fail (alloc_flags &

      GST_GL_ALLOCATION_PARAMS_ALLOC_FLAG_BUFFER, NULL);

  g_return_val_if_fail (alloc_flags & GST_GL_ALLOCATION_PARAMS_ALLOC_FLAG_ALLOC,

      NULL);

  return _gl_buffer_new (GST_ALLOCATOR (allocator), NULL,

      params->parent.context, params->gl_target, params->gl_usage,

      params->parent.alloc_params, params->parent.alloc_size);

}

G_DEFINE_TYPE (GstGLBufferAllocator, gst_gl_buffer_allocator,

    GST_TYPE_GL_BASE_MEMORY_ALLOCATOR);

static void

gst_gl_buffer_allocator_class_init (GstGLBufferAllocatorClass * klass)

{

  GstAllocatorClass *allocator_class = (GstAllocatorClass *) klass;

  GstGLBaseMemoryAllocatorClass *gl_base;

  gl_base = (GstGLBaseMemoryAllocatorClass *) klass;

  gl_base->alloc = (GstGLBaseMemoryAllocatorAllocFunction) _gl_buffer_alloc_mem;

  gl_base->create = (GstGLBaseMemoryAllocatorCreateFunction) _gl_buffer_create;

  gl_base->map = (GstGLBaseMemoryAllocatorMapFunction) _gl_buffer_map;

  gl_base->unmap = (GstGLBaseMemoryAllocatorUnmapFunction) _gl_buffer_unmap;

  gl_base->copy = (GstGLBaseMemoryAllocatorCopyFunction) _gl_buffer_copy;

  gl_base->destroy =

      (GstGLBaseMemoryAllocatorDestroyFunction) _gl_buffer_destroy;

  allocator_class->alloc = _gl_buffer_alloc;

}

static void

gst_gl_buffer_allocator_init (GstGLBufferAllocator * allocator)

{

  GstAllocator *alloc = GST_ALLOCATOR_CAST (allocator);

  alloc->mem_type = GST_GL_BUFFER_ALLOCATOR_NAME;

  GST_OBJECT_FLAG_SET (allocator, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC);

}

/**

 * gst_gl_buffer_init_once:

 *

 * Initializes the GL Buffer allocator. It is safe to call this function

 * multiple times.  This must be called before any other #GstGLBuffer operation.

 *

 * Since: 1.8

 */

void

gst_gl_buffer_init_once (void)

{

  static volatile gsize _init = 0;

  if (g_once_init_enter (&_init)) {

    gst_gl_base_memory_init_once ();

    GST_DEBUG_CATEGORY_INIT (GST_CAT_GL_BUFFER, "glbuffer", 0, "OpenGL Buffer");

    _gl_buffer_allocator =

        g_object_new (gst_gl_buffer_allocator_get_type (), NULL);

    gst_object_ref_sink (_gl_buffer_allocator);

    /* The allocator is never unreffed */

    GST_OBJECT_FLAG_SET (_gl_buffer_allocator, GST_OBJECT_FLAG_MAY_BE_LEAKED);

    gst_allocator_register (GST_GL_BUFFER_ALLOCATOR_NAME,

        gst_object_ref (_gl_buffer_allocator));

    g_once_init_leave (&_init, 1);

  }

}

/**

 * gst_is_gl_buffer:

 * @mem:a #GstMemory

 *

 * Returns: whether the memory at @mem is a #GstGLBuffer

 *

 * Since: 1.8

 */

gboolean

gst_is_gl_buffer (GstMemory * mem)

{

  return mem != NULL && mem->allocator != NULL &&

      g_type_is_a (G_OBJECT_TYPE (mem->allocator),

      GST_TYPE_GL_BUFFER_ALLOCATOR);

}