/*
 * Copyright © 2004 David Reveman
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without
 * fee, provided that the above copyright notice appear in all copies
 * and that both that copyright notice and this permission notice
 * appear in supporting documentation, and that the name of
 * David Reveman not be used in advertising or publicity pertaining to
 * distribution of the software without specific, written prior permission.
 * David Reveman makes no representations about the suitability of this
 * software for any purpose. It is provided "as is" without express or
 * implied warranty.
 *
 * DAVID REVEMAN DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
 * NO EVENT SHALL DAVID REVEMAN BE LIABLE FOR ANY SPECIAL, 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.
 *
 * Author: David Reveman <davidr@novell.com>
 */

#ifdef HAVE_CONFIG_H
#  include "../config.h"
#endif

#include "glitz_eglint.h"

#include <stdlib.h>

extern glitz_gl_proc_address_list_t _glitz_egl_gl_proc_address;

static void
_glitz_egl_context_create (glitz_egl_screen_info_t *screen_info,
			   EGLConfig               egl_config,
			   EGLContext              egl_share_list,
			   glitz_egl_context_t     *context)
{
    context->id = egl_config;
    context->egl_context =
	eglCreateContext (screen_info->display_info->egl_display,
			  egl_config, egl_share_list, NULL);
}

static glitz_context_t *
_glitz_egl_create_context (void                    *abstract_drawable,
			   glitz_drawable_format_t *format)
{
    glitz_egl_surface_t *drawable = (glitz_egl_surface_t *) abstract_drawable;
    glitz_egl_screen_info_t *screen_info = drawable->screen_info;
    int format_id = screen_info->formats[format->id].u.uval;
    glitz_egl_context_t *context;

    context = malloc (sizeof (glitz_egl_context_t));
    if (!context)
	return NULL;

    _glitz_context_init (&context->base, &drawable->base);

    _glitz_egl_context_create (screen_info,
			       format_id,
			       screen_info->egl_root_context,
			       context);

    return (glitz_context_t *) context;
}

static void
_glitz_egl_context_destroy (void *abstract_context)
{
    glitz_egl_context_t *context = (glitz_egl_context_t *) abstract_context;
    glitz_egl_surface_t *drawable = (glitz_egl_surface_t *)
	context->base.drawable;

    if (drawable->screen_info->display_info->thread_info->cctx ==
	&context->base)
    {
	eglMakeCurrent (drawable->screen_info->display_info->egl_display,
			EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);

	drawable->screen_info->display_info->thread_info->cctx = NULL;
    }

    eglDestroyContext (drawable->screen_info->display_info->egl_display,
		       context->egl_context);

    _glitz_context_fini (&context->base);

    free (context);
}

static void
_glitz_egl_copy_context (void          *abstract_src,
			 void          *abstract_dst,
			 unsigned long mask)
{
    glitz_egl_context_t  *src = (glitz_egl_context_t *) abstract_src;
    glitz_egl_context_t  *dst = (glitz_egl_context_t *) abstract_dst;
    glitz_egl_surface_t *drawable = (glitz_egl_surface_t *)
	src->base.drawable;

    eglCopyContextMESA (drawable->screen_info->display_info->egl_display,
			src->egl_context, dst->egl_context, mask);
}

static void
_glitz_egl_make_current (void *abstract_drawable,
			 void *abstract_context)
{
    glitz_egl_context_t  *context = (glitz_egl_context_t *) abstract_context;
    glitz_egl_surface_t *drawable = (glitz_egl_surface_t *) abstract_drawable;
    glitz_egl_display_info_t *display_info =
	drawable->screen_info->display_info;

    if (drawable->base.width  != drawable->width ||
	drawable->base.height != drawable->height)
	_glitz_egl_drawable_update_size (drawable,
					 drawable->base.width,
					 drawable->base.height);

    if ((eglGetCurrentContext () != context->egl_context) ||
	(eglGetCurrentSurface ( EGL_READ ) != drawable->egl_surface))
    {
	if (display_info->thread_info->cctx)
	{
	    glitz_context_t *ctx = display_info->thread_info->cctx;

	    if (ctx->lose_current)
		ctx->lose_current (ctx->closure);
	}

	eglMakeCurrent (display_info->egl_display, drawable->egl_surface,
			drawable->egl_surface, context->egl_context);
    }

    display_info->thread_info->cctx = &context->base;
}

static void
_glitz_egl_notify_dummy (void            *abstract_drawable,
			 glitz_surface_t *surface) {}

static glitz_function_pointer_t
_glitz_egl_context_get_proc_address (void       *abstract_context,
				     const char *name)
{
    glitz_egl_context_t  *context = (glitz_egl_context_t *) abstract_context;
    glitz_egl_surface_t *drawable = (glitz_egl_surface_t *)
	context->base.drawable;

    _glitz_egl_make_current (drawable, context);

    return glitz_egl_get_proc_address (name, drawable->screen_info);
}

glitz_egl_context_t *
glitz_egl_context_get (glitz_egl_screen_info_t *screen_info,
		       glitz_drawable_format_t *format)
{
    glitz_egl_context_t *context;
    glitz_egl_context_t **contexts = screen_info->contexts;
    int index, n_contexts = screen_info->n_contexts;

    for (; n_contexts; n_contexts--, contexts++)
	if ((*contexts)->id == screen_info->formats[format->id].u.uval)
	    return *contexts;

    index = screen_info->n_contexts++;

    screen_info->contexts =
	realloc (screen_info->contexts,
		 sizeof (glitz_egl_context_t *) * screen_info->n_contexts);
    if (!screen_info->contexts)
	return NULL;

    context = malloc (sizeof (glitz_egl_context_t));
    if (!context)
	return NULL;

    screen_info->contexts[index] = context;

    _glitz_egl_context_create (screen_info,
			       screen_info->formats[format->id].u.uval,
			       screen_info->egl_root_context,
			       context);

    if (!screen_info->egl_root_context)
	screen_info->egl_root_context = context->egl_context;

    context->backend.gl = &_glitz_egl_gl_proc_address;

    context->backend.create_pbuffer = glitz_egl_create_pbuffer;
    context->backend.destroy = glitz_egl_destroy;
    context->backend.push_current = glitz_egl_push_current;
    context->backend.pop_current = glitz_egl_pop_current;
    context->backend.attach_notify = _glitz_egl_notify_dummy;
    context->backend.detach_notify = _glitz_egl_notify_dummy;
    context->backend.swap_buffers = glitz_egl_swap_buffers;

    context->backend.create_context = _glitz_egl_create_context;
    context->backend.destroy_context = _glitz_egl_context_destroy;
    context->backend.copy_context = _glitz_egl_copy_context;
    context->backend.make_current = _glitz_egl_make_current;
    context->backend.get_proc_address = _glitz_egl_context_get_proc_address;

    context->backend.draw_buffer = _glitz_drawable_draw_buffer;
    context->backend.read_buffer = _glitz_drawable_read_buffer;

    context->backend.drawable_formats = NULL;
    context->backend.n_drawable_formats = 0;

    if (screen_info->n_formats)
    {
	int size;

	size = sizeof (glitz_int_drawable_format_t) * screen_info->n_formats;
	context->backend.drawable_formats = malloc (size);
	if (context->backend.drawable_formats)
	{
	    memcpy (context->backend.drawable_formats, screen_info->formats,
		    size);
	    context->backend.n_drawable_formats = screen_info->n_formats;
	}
    }

    context->backend.texture_formats = NULL;
    context->backend.formats = NULL;
    context->backend.n_formats = 0;

    context->backend.program_map = &screen_info->program_map;
    context->backend.feature_mask = 0;

    context->initialized = 0;

    return context;
}

void
glitz_egl_context_destroy (glitz_egl_screen_info_t *screen_info,
			   glitz_egl_context_t     *context)
{
    if (context->backend.drawable_formats)
	free (context->backend.drawable_formats);

    if (context->backend.formats)
	free (context->backend.formats);

    if (context->backend.texture_formats)
	free (context->backend.texture_formats);

    eglDestroyContext (screen_info->display_info->egl_display,
		       context->egl_context);
    free (context);
}

static void
_glitz_egl_context_initialize (glitz_egl_screen_info_t *screen_info,
			       glitz_egl_context_t     *context)
{
    const char *version;

    glitz_backend_init (&context->backend,
			glitz_egl_get_proc_address,
			(void *) screen_info);

    glitz_initiate_state (&_glitz_egl_gl_proc_address);

    version = (const char *)
	context->backend.gl->get_string (GLITZ_GL_VERSION);
    if (version)
    {
	/* Having trouble with TexSubImage2D to NPOT GL_TEXTURE_2D textures
	   when using nvidia's binary driver. Seems like a driver issue, but
	   I'm not sure yet. Turning of NPOT GL_TEXTURE_2D textures until
	   this have been solved. */
	if (strstr (version, "NVIDIA 61.11") ||
	    strstr (version, "NVIDIA 66.29"))
	{
	    context->backend.feature_mask &=
		~GLITZ_FEATURE_TEXTURE_NON_POWER_OF_TWO_MASK;
	}
    }

    context->initialized = 1;
}

static void
_glitz_egl_context_make_current (glitz_egl_surface_t *drawable,
				 glitz_bool_t         finish)
{
    glitz_egl_display_info_t *display_info =
	drawable->screen_info->display_info;

    if (finish)
	glFinish ();

    if (display_info->thread_info->cctx)
    {
	glitz_context_t *ctx = display_info->thread_info->cctx;

	if (ctx->lose_current)
	    ctx->lose_current (ctx->closure);

	display_info->thread_info->cctx = NULL;
    }

    eglMakeCurrent (display_info->egl_display,
		    drawable->egl_surface, drawable->egl_surface,
		    drawable->context->egl_context);

    drawable->base.update_all = 1;

    if (!drawable->context->initialized)
	_glitz_egl_context_initialize (drawable->screen_info,
				       drawable->context);
}

static void
_glitz_egl_context_update (glitz_egl_surface_t *drawable,
			   glitz_constraint_t   constraint)
{
    EGLContext egl_context;

    switch (constraint) {
    case GLITZ_NONE:
	break;
    case GLITZ_ANY_CONTEXT_CURRENT: {
	glitz_egl_display_info_t *dinfo = drawable->screen_info->display_info;

	if (dinfo->thread_info->cctx)
	{
	    _glitz_egl_context_make_current (drawable, 0);
	}
	else
	{
	    egl_context = eglGetCurrentContext ();
	    if (egl_context == (EGLContext) 0)
		_glitz_egl_context_make_current (drawable, 0);
	}
    } break;
    case GLITZ_CONTEXT_CURRENT:
	egl_context = eglGetCurrentContext ();
	if (egl_context != drawable->context->egl_context)
	    _glitz_egl_context_make_current (drawable, (egl_context)? 1: 0);
	break;
    case GLITZ_DRAWABLE_CURRENT:
	if (drawable->base.width  != drawable->width ||
	    drawable->base.height != drawable->height)
	    _glitz_egl_drawable_update_size (drawable,
					     drawable->base.width,
					     drawable->base.height);

	egl_context = eglGetCurrentContext ();
	if ((egl_context != drawable->context->egl_context) ||
	    (eglGetCurrentSurface ( 0 ) != drawable->egl_surface))
	    _glitz_egl_context_make_current (drawable, (egl_context)? 1: 0);
	break;
    }
}

glitz_bool_t
glitz_egl_push_current (void               *abstract_drawable,
			glitz_surface_t    *surface,
			glitz_constraint_t constraint)
{
    glitz_egl_surface_t *drawable = (glitz_egl_surface_t *) abstract_drawable;
    glitz_egl_context_info_t *context_info;
    int index;

    index = drawable->screen_info->context_stack_size++;

    context_info = &drawable->screen_info->context_stack[index];
    context_info->drawable = drawable;
    context_info->surface = surface;
    context_info->constraint = constraint;

    _glitz_egl_context_update (context_info->drawable, constraint);

    return 1;
}

glitz_surface_t *
glitz_egl_pop_current (void *abstract_drawable)
{
    glitz_egl_surface_t *drawable = (glitz_egl_surface_t *) abstract_drawable;
    glitz_egl_context_info_t *context_info = NULL;
    int index;

    drawable->screen_info->context_stack_size--;
    index = drawable->screen_info->context_stack_size - 1;

    context_info = &drawable->screen_info->context_stack[index];

    if (context_info->drawable)
	_glitz_egl_context_update (context_info->drawable,
				   context_info->constraint);

    if (context_info->constraint == GLITZ_DRAWABLE_CURRENT)
	return context_info->surface;

    return NULL;
}