/* Cairo - a vector graphics library with display and print output
 *
 * Copyright © 2009 Chris Wilson
 *
 * This library is free software; you can redistribute it and/or
 * modify it either under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation
 * (the "LGPL") or, at your option, under the terms of the Mozilla
 * Public License Version 1.1 (the "MPL"). If you do not alter this
 * notice, a recipient may use your version of this file under either
 * the MPL or the LGPL.
 *
 * You should have received a copy of the LGPL along with this library
 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
 * You should have received a copy of the MPL along with this library
 * in the file COPYING-MPL-1.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
 * the specific language governing rights and limitations.
 *
 * The Original Code is the cairo graphics library.
 *
 * The Initial Developer of the Original Code is Chris Wilson.
 */

#include "cairo-boilerplate-private.h"

#include <cairo-gl.h>

#include <X11/X.h>
#include <X11/Xutil.h> /* for XDestroyImage */

static const cairo_user_data_key_t gl_closure_key;

typedef struct _gl_target_closure {
    Display *dpy;
    int screen;
    Window drawable;

    GLXContext ctx;
    cairo_device_t *device;
    cairo_surface_t *surface;
} gl_target_closure_t;

static void
_cairo_boilerplate_gl_cleanup (void *closure)
{
    gl_target_closure_t *gltc = closure;

    cairo_device_finish (gltc->device);
    cairo_device_destroy (gltc->device);

    glXDestroyContext (gltc->dpy, gltc->ctx);

    if (gltc->drawable)
	XDestroyWindow (gltc->dpy, gltc->drawable);
    XCloseDisplay (gltc->dpy);

    free (gltc);
}

static cairo_surface_t *
_cairo_boilerplate_gl_create_surface (const char		*name,
				      cairo_content_t		 content,
				      double			 width,
				      double			 height,
				      double			 max_width,
				      double			 max_height,
				      cairo_boilerplate_mode_t	 mode,
				      void		       **closure)
{
    int rgba_attribs[] = { GLX_RGBA,
			   GLX_RED_SIZE, 1,
			   GLX_GREEN_SIZE, 1,
			   GLX_BLUE_SIZE, 1,
			   GLX_ALPHA_SIZE, 1,
			   GLX_DOUBLEBUFFER,
			   None };
    int rgb_attribs[] = { GLX_RGBA,
			  GLX_RED_SIZE, 1,
			  GLX_GREEN_SIZE, 1,
			  GLX_BLUE_SIZE, 1,
			  GLX_DOUBLEBUFFER,
			  None };
    XVisualInfo *visinfo;
    GLXContext ctx;
    gl_target_closure_t *gltc;
    cairo_surface_t *surface;
    Display *dpy;

    gltc = calloc (1, sizeof (gl_target_closure_t));
    *closure = gltc;

    width = ceil (width);
    height = ceil (height);

    if (width == 0)
	width = 1;
    if (height == 0)
	height = 1;

    dpy = XOpenDisplay (NULL);
    gltc->dpy = dpy;
    if (!gltc->dpy) {
	fprintf (stderr, "Failed to open display: %s\n", XDisplayName(0));
	free (gltc);
	return NULL;
    }

    if (mode == CAIRO_BOILERPLATE_MODE_TEST)
	XSynchronize (gltc->dpy, 1);

    if (content == CAIRO_CONTENT_COLOR)
	visinfo = glXChooseVisual (dpy, DefaultScreen (dpy), rgb_attribs);
    else
	visinfo = glXChooseVisual (dpy, DefaultScreen (dpy), rgba_attribs);

    if (visinfo == NULL) {
	fprintf (stderr, "Failed to create RGB, double-buffered visual\n");
	XCloseDisplay (dpy);
	free (gltc);
	return NULL;
    }

    ctx = glXCreateContext (dpy, visinfo, NULL, True);
    XFree (visinfo);

    gltc->ctx = ctx;
    gltc->device = cairo_glx_device_create (dpy, ctx);

    gltc->surface = surface = cairo_gl_surface_create (gltc->device,
						       content, width, height);
    if (cairo_surface_status (surface))
	_cairo_boilerplate_gl_cleanup (gltc);

    return surface;
}

static cairo_surface_t *
_cairo_boilerplate_gl_create_window_common (int				rgba_attribs[],
					    cairo_content_t		content,
					    double			width,
					    double			height,
					    double			max_width,
					    double			max_height,
					    cairo_boilerplate_mode_t	mode,
					    gl_target_closure_t		*gltc)
{
    XVisualInfo *vi;
    GLXContext ctx;
    cairo_surface_t *surface;
    Display *dpy;
    XSetWindowAttributes attr;

    width = ceil (width);
    height = ceil (height);

    if (width == 0)
	width = 1;
    if (height == 0)
	height = 1;

    dpy = XOpenDisplay (NULL);
    gltc->dpy = dpy;
    if (!gltc->dpy) {
	fprintf (stderr, "Failed to open display: %s\n", XDisplayName(0));
	free (gltc);
	return NULL;
    }

    if (mode == CAIRO_BOILERPLATE_MODE_TEST)
	XSynchronize (gltc->dpy, 1);

    vi = glXChooseVisual (dpy, DefaultScreen (dpy), rgba_attribs);
    if (vi == NULL) {
	fprintf (stderr, "Failed to create RGBA, double-buffered visual\n");
	XCloseDisplay (dpy);
	free (gltc);
	return NULL;
    }

    attr.colormap = XCreateColormap (dpy,
				     RootWindow (dpy, vi->screen),
				     vi->visual,
				     AllocNone);
    attr.border_pixel = 0;
    attr.override_redirect = True;
    gltc->drawable = XCreateWindow (dpy, DefaultRootWindow (dpy), 0, 0,
				    width, height, 0, vi->depth,
				    InputOutput, vi->visual,
				    CWOverrideRedirect | CWBorderPixel | CWColormap,
				    &attr);
    XMapWindow (dpy, gltc->drawable);

    ctx = glXCreateContext (dpy, vi, NULL, True);
    XFree (vi);

    gltc->ctx = ctx;
    gltc->device = cairo_glx_device_create (dpy, ctx);

    gltc->surface = surface = cairo_gl_surface_create_for_window (gltc->device,
								  gltc->drawable,
								  width, height);
    if (cairo_surface_status (surface)) {
	_cairo_boilerplate_gl_cleanup (gltc);
	return NULL;
    }
    return surface;
}

static cairo_surface_t *
_cairo_boilerplate_gl_create_window (const char		       *name,
				     cairo_content_t		content,
				     double			width,
				     double			height,
				     double			max_width,
				     double			max_height,
				     cairo_boilerplate_mode_t	mode,
				     void		      **closure)
{
    gl_target_closure_t *gltc;

    int rgba_attribs[] = { GLX_RGBA,
			   GLX_RED_SIZE, 1,
			   GLX_GREEN_SIZE, 1,
			   GLX_BLUE_SIZE, 1,
			   GLX_ALPHA_SIZE, 1,
			   GLX_DOUBLEBUFFER,
			   None };

    gltc = calloc (1, sizeof (gl_target_closure_t));
    *closure = gltc;

    return _cairo_boilerplate_gl_create_window_common (rgba_attribs, content,
						       width, height,
						       max_width, max_height,
						       mode, gltc);
}

static cairo_surface_t *
_cairo_boilerplate_gl_create_window_msaa (const char		       *name,
					  cairo_content_t		content,
					  double			width,
					  double			height,
					  double			max_width,
					  double			max_height,
					  cairo_boilerplate_mode_t	mode,
					  void			      **closure)
{
    gl_target_closure_t *gltc;

    int rgba_attribs[] = { GLX_RGBA,
			   GLX_RED_SIZE, 1,
			   GLX_GREEN_SIZE, 1,
			   GLX_BLUE_SIZE, 1,
			   GLX_ALPHA_SIZE, 1,
			   GLX_STENCIL_SIZE, 1,
			   GLX_SAMPLES, 4,
			   GLX_SAMPLE_BUFFERS, 1,
			   GLX_DOUBLEBUFFER,
			   None };

    gltc = calloc (1, sizeof (gl_target_closure_t));
    *closure = gltc;
    return _cairo_boilerplate_gl_create_window_common (rgba_attribs, content,
						       width, height,
						       max_width, max_height,
						       mode, gltc);

}

static cairo_surface_t *
_cairo_boilerplate_gl_create_window_db (const char		  *name,
					cairo_content_t		   content,
					double			   width,
					double			   height,
					double			   max_width,
					double			   max_height,
					cairo_boilerplate_mode_t   mode,
					void			 **closure)
{
    cairo_status_t status;
    cairo_surface_t *surface;
    gl_target_closure_t *gltc;

    int rgba_attribs[] = { GLX_RGBA,
			   GLX_RED_SIZE, 1,
			   GLX_GREEN_SIZE, 1,
			   GLX_BLUE_SIZE, 1,
			   GLX_ALPHA_SIZE, 1,
			   GLX_DOUBLEBUFFER,
			   None };

    gltc = calloc (1, sizeof (gl_target_closure_t));
    *closure = gltc;

    surface = _cairo_boilerplate_gl_create_window_common (rgba_attribs, content,
							  width, height,
							  max_width, max_height,
							  mode, gltc);

   if (! surface)
	return NULL;

    surface = cairo_surface_create_similar (gltc->surface, content, width, height);
    status = cairo_surface_set_user_data (surface, &gl_closure_key, gltc, NULL);
    if (status == CAIRO_STATUS_SUCCESS)
	return surface;

    cairo_surface_destroy (surface);
    _cairo_boilerplate_gl_cleanup (gltc);
    return cairo_boilerplate_surface_create_in_error (status);
}

static cairo_status_t
_cairo_boilerplate_gl_finish_window (cairo_surface_t *surface)
{
    gl_target_closure_t *gltc = cairo_surface_get_user_data (surface,
							     &gl_closure_key);

    if (gltc != NULL && gltc->surface != NULL) {
	cairo_t *cr;

	cr = cairo_create (gltc->surface);
	cairo_surface_set_device_offset (surface, 0, 0);
	cairo_set_source_surface (cr, surface, 0, 0);
	cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
	cairo_paint (cr);
	cairo_destroy (cr);

	surface = gltc->surface;
    }

    cairo_gl_surface_swapbuffers (surface);
    return CAIRO_STATUS_SUCCESS;
}

static void
_cairo_boilerplate_gl_synchronize (void *closure)
{
    gl_target_closure_t *gltc = closure;

    if (cairo_device_acquire (gltc->device))
	return;

    glFinish ();

    cairo_device_release (gltc->device);
}

static char *
_cairo_boilerplate_gl_describe (void *closure)
{
    gl_target_closure_t *gltc = closure;
    char *s;
    const GLubyte *vendor, *renderer, *version;

    if (cairo_device_acquire (gltc->device))
	return NULL;

    vendor   = glGetString (GL_VENDOR);
    renderer = glGetString (GL_RENDERER);
    version  = glGetString (GL_VERSION);

    xasprintf (&s, "%s %s %s", vendor, renderer, version);

    cairo_device_release (gltc->device);

    return s;
}

static const cairo_boilerplate_target_t targets[] = {
    {
	"gl", "gl", NULL, NULL,
	CAIRO_SURFACE_TYPE_GL, CAIRO_CONTENT_COLOR_ALPHA, 1,
	"cairo_gl_surface_create",
	_cairo_boilerplate_gl_create_surface,
	cairo_surface_create_similar,
	NULL, NULL,
	_cairo_boilerplate_get_image_surface,
	cairo_surface_write_to_png,
	_cairo_boilerplate_gl_cleanup,
	_cairo_boilerplate_gl_synchronize,
        _cairo_boilerplate_gl_describe,
	TRUE, FALSE, FALSE
    },
    {
	"gl", "gl", NULL, NULL,
	CAIRO_SURFACE_TYPE_GL, CAIRO_CONTENT_COLOR, 1,
	"cairo_gl_surface_create",
	_cairo_boilerplate_gl_create_surface,
	cairo_surface_create_similar,
	NULL, NULL,
	_cairo_boilerplate_get_image_surface,
	cairo_surface_write_to_png,
	_cairo_boilerplate_gl_cleanup,
	_cairo_boilerplate_gl_synchronize,
        _cairo_boilerplate_gl_describe,
	FALSE, FALSE, FALSE
    },
    {
	"gl-window", "gl", NULL, NULL,
	CAIRO_SURFACE_TYPE_GL, CAIRO_CONTENT_COLOR_ALPHA, 1,
	"cairo_gl_surface_create_for_window",
	_cairo_boilerplate_gl_create_window,
	cairo_surface_create_similar,
	NULL,
	_cairo_boilerplate_gl_finish_window,
	_cairo_boilerplate_get_image_surface,
	cairo_surface_write_to_png,
	_cairo_boilerplate_gl_cleanup,
	_cairo_boilerplate_gl_synchronize,
        _cairo_boilerplate_gl_describe,
	FALSE, FALSE, FALSE
    },
    {
	"gl-window-msaa", "gl", NULL, NULL,
	CAIRO_SURFACE_TYPE_GL, CAIRO_CONTENT_COLOR_ALPHA, 1,
	"cairo_gl_surface_create_for_window",
	_cairo_boilerplate_gl_create_window_msaa,
	cairo_surface_create_similar,
	NULL,
	_cairo_boilerplate_gl_finish_window,
	_cairo_boilerplate_get_image_surface,
	cairo_surface_write_to_png,
	_cairo_boilerplate_gl_cleanup,
	_cairo_boilerplate_gl_synchronize,
        _cairo_boilerplate_gl_describe,
	FALSE, FALSE, FALSE
    },
    {
	"gl-window&", "gl", NULL, NULL,
	CAIRO_SURFACE_TYPE_GL, CAIRO_CONTENT_COLOR_ALPHA, 1,
	"cairo_gl_surface_create_for_window",
	_cairo_boilerplate_gl_create_window_db,
	cairo_surface_create_similar,
	NULL,
	_cairo_boilerplate_gl_finish_window,
	_cairo_boilerplate_get_image_surface,
	cairo_surface_write_to_png,
	_cairo_boilerplate_gl_cleanup,
	_cairo_boilerplate_gl_synchronize,
        _cairo_boilerplate_gl_describe,
	FALSE, FALSE, FALSE
    },
};
CAIRO_BOILERPLATE (gl, targets)