cairo-glitz-surface.c

按照官方的说法：Cairo is a vector graphics library with cross-device output support. 翻译过来

		    return CAIRO_STATUS_NO_MEMORY;
		}

		if (buffer)
		    glitz_buffer_destroy (buffer);

		buffer = glitz_buffer_create_for_data (data);
		if (!buffer) {
		    free (data);
		    _cairo_glitz_pattern_release_surface (src_pattern, src,
							  &attributes);
		    if (src_pattern == &tmp_src_pattern.base)
			_cairo_pattern_fini (&tmp_src_pattern.base);
		    return CAIRO_STATUS_NO_MEMORY;
		}
	    }

	    offset +=
		glitz_add_trapezoids (buffer,
				      offset, size - offset,
				      format.vertex.type, mask->surface,
				      (glitz_trapezoid_t *) traps, n_traps,
				      &n_trap_added);

	    n_traps -= n_trap_added;
	    traps   += n_trap_added;
	    size    *= 2;
	}

	glitz_set_geometry (dst->surface,
			    GLITZ_GEOMETRY_TYPE_VERTEX,
			    &format, buffer);
	glitz_set_array (dst->surface, 0, 3,
			 offset / format.vertex.bytes_per_vertex,
			 0, 0);
    }
    else
    {
	cairo_image_surface_t *image;
	unsigned char	      *ptr;
	int		      stride;

	stride = (width + 3) & -4;
	data = calloc (stride * height, 1);
	if (!data)
	{
	    _cairo_glitz_pattern_release_surface (src_pattern, src, &attributes);
	    if (src_pattern == &tmp_src_pattern.base)
		_cairo_pattern_fini (&tmp_src_pattern.base);
	    return CAIRO_STATUS_NO_MEMORY;
	}

	/* using negative stride */
	ptr = (unsigned char *) data + stride * (height - 1);

	image = (cairo_image_surface_t *)
	    cairo_image_surface_create_for_data (ptr,
						 CAIRO_FORMAT_A8,
						 width, height,
						 -stride);
	if (image->base.status)
	{
	    cairo_surface_destroy (&src->base);
	    free (data);
	    return CAIRO_STATUS_NO_MEMORY;
	}

	pixman_add_trapezoids (image->pixman_image, -dst_x, -dst_y,
			       (pixman_trapezoid_t *) traps, n_traps);

	mask = (cairo_glitz_surface_t *)
	    _cairo_surface_create_similar_scratch (&dst->base,
						   CAIRO_CONTENT_ALPHA,
						   width, height);
	if (mask->base.status)
	{
	    _cairo_glitz_pattern_release_surface (src_pattern, src, &attributes);
	    free (data);
	    cairo_surface_destroy (&image->base);
	    return CAIRO_STATUS_NO_MEMORY;
	}

	_cairo_glitz_surface_set_image (mask, image, 0, 0);
    }

    _cairo_glitz_surface_set_attributes (src, &attributes);

    glitz_composite (_glitz_operator (op),
		     src->surface,
		     mask->surface,
		     dst->surface,
		     src_x + attributes.base.x_offset,
		     src_y + attributes.base.y_offset,
		     0, 0,
		     dst_x, dst_y,
		     width, height);

    if (attributes.n_params)
	free (attributes.params);

    glitz_set_geometry (dst->surface,
			GLITZ_GEOMETRY_TYPE_NONE,
			NULL, NULL);

    if (buffer)
	glitz_buffer_destroy (buffer);

    free (data);

    _cairo_glitz_pattern_release_surface (src_pattern, src, &attributes);
    if (src_pattern == &tmp_src_pattern.base)
	_cairo_pattern_fini (&tmp_src_pattern.base);

    if (mask)
	cairo_surface_destroy (&mask->base);

    if (glitz_surface_get_status (dst->surface) == GLITZ_STATUS_NOT_SUPPORTED)
	return CAIRO_INT_STATUS_UNSUPPORTED;

    return CAIRO_STATUS_SUCCESS;
}

static cairo_int_status_t
_cairo_glitz_surface_set_clip_region (void		*abstract_surface,
				      pixman_region16_t *region)
{
    cairo_glitz_surface_t *surface = abstract_surface;

    if (region)
    {
	glitz_box_t *box;
	int	    n;

	if (!surface->clip)
	{
	    surface->clip = pixman_region_create ();
	    if (!surface->clip)
		return CAIRO_STATUS_NO_MEMORY;
	}
	pixman_region_copy (surface->clip, region);

	box = (glitz_box_t *) pixman_region_rects (surface->clip);
	n = pixman_region_num_rects (surface->clip);
	glitz_surface_set_clip_region (surface->surface, 0, 0, box, n);
    }
    else
    {
	glitz_surface_set_clip_region (surface->surface, 0, 0, NULL, 0);

	if (surface->clip)
	    pixman_region_destroy (surface->clip);

	surface->clip = NULL;
    }

    return CAIRO_STATUS_SUCCESS;
}

static cairo_int_status_t
_cairo_glitz_surface_get_extents (void		          *abstract_surface,
				  cairo_rectangle_int16_t *rectangle)
{
    cairo_glitz_surface_t *surface = abstract_surface;

    rectangle->x = 0;
    rectangle->y = 0;
    rectangle->width = glitz_surface_get_width  (surface->surface);
    rectangle->height = glitz_surface_get_height (surface->surface);

    return CAIRO_STATUS_SUCCESS;
}

#define CAIRO_GLITZ_AREA_AVAILABLE 0
#define CAIRO_GLITZ_AREA_DIVIDED   1
#define CAIRO_GLITZ_AREA_OCCUPIED  2

typedef struct _cairo_glitz_root_area cairo_glitz_root_area_t;

typedef struct _cairo_glitz_area {
    int			     state;
    int			     level;
    int			     x, y;
    int			     width, height;
    struct _cairo_glitz_area *area[4];
    cairo_glitz_root_area_t  *root;
    void		     *closure;
} cairo_glitz_area_t;

static cairo_glitz_area_t _empty_area = {
    0, 0, 0, 0, 0, 0,
    { NULL, NULL, NULL, NULL },
    NULL,
    NULL
};

typedef struct _cairo_glitz_area_funcs {
    cairo_status_t (*move_in)	    (cairo_glitz_area_t *area,
				     void		*closure);

    void	   (*move_out)	    (cairo_glitz_area_t *area,
				     void		*closure);

    int		   (*compare_score) (cairo_glitz_area_t *area,
				     void		*closure1,
				     void		*closure2);
} cairo_glitz_area_funcs_t;

struct _cairo_glitz_root_area {
    int				   max_level;
    int				   width, height;
    cairo_glitz_area_t		   *area;
    const cairo_glitz_area_funcs_t *funcs;
};

static cairo_status_t
_cairo_glitz_area_move_in (cairo_glitz_area_t *area,
			   void		      *closure)
{
    area->closure = closure;
    area->state   = CAIRO_GLITZ_AREA_OCCUPIED;

    return (*area->root->funcs->move_in) (area, area->closure);
}

static void
_cairo_glitz_area_move_out (cairo_glitz_area_t *area)
{
    if (area->root)
    {
	(*area->root->funcs->move_out) (area, area->closure);

	area->closure = NULL;
	area->state   = CAIRO_GLITZ_AREA_AVAILABLE;
    }
}

static cairo_glitz_area_t *
_cairo_glitz_area_create (cairo_glitz_root_area_t *root,
			  int			  level,
			  int			  x,
			  int			  y,
			  int			  width,
			  int			  height)
{
    cairo_glitz_area_t *area;
    int		       n = 4;

    area = malloc (sizeof (cairo_glitz_area_t));
    if (!area)
	return NULL;

    area->level   = level;
    area->x	  = x;
    area->y	  = y;
    area->width   = width;
    area->height  = height;
    area->root    = root;
    area->closure = NULL;
    area->state   = CAIRO_GLITZ_AREA_AVAILABLE;

    while (n--)
	area->area[n] = NULL;

    return area;
}

static void
_cairo_glitz_area_destroy (cairo_glitz_area_t *area)
{
    if (area == NULL)
	return;

    if (area->state == CAIRO_GLITZ_AREA_OCCUPIED)
    {
	_cairo_glitz_area_move_out (area);
    }
    else
    {
	int n = 4;

	while (n--)
	    _cairo_glitz_area_destroy (area->area[n]);
    }

    free (area);
}

static cairo_glitz_area_t *
_cairo_glitz_area_get_top_scored_sub_area (cairo_glitz_area_t *area)
{
    if (!area)
	return NULL;

    switch (area->state) {
    case CAIRO_GLITZ_AREA_OCCUPIED:
	return area;
    case CAIRO_GLITZ_AREA_AVAILABLE:
	break;
    case CAIRO_GLITZ_AREA_DIVIDED: {
	cairo_glitz_area_t *tmp, *top = NULL;
	int		   i;

	for (i = 0; i < 4; i++)
	{
	    tmp = _cairo_glitz_area_get_top_scored_sub_area (area->area[i]);
	    if (tmp && top)
	    {
		if ((*area->root->funcs->compare_score) (tmp,
							 tmp->closure,
							 top->closure) > 0)
		    top = tmp;
	    }
	    else if (tmp)
	    {
		top = tmp;
	    }
	}
	return top;
    }
    }

    return NULL;
}

static cairo_int_status_t
_cairo_glitz_area_find (cairo_glitz_area_t *area,
			int		   width,
			int		   height,
			cairo_bool_t	   kick_out,
			void		   *closure)
{
    cairo_status_t status;

    if (area->width < width || area->height < height)
	return CAIRO_INT_STATUS_UNSUPPORTED;

    switch (area->state) {
    case CAIRO_GLITZ_AREA_OCCUPIED:
	if (kick_out)
	{
	    if ((*area->root->funcs->compare_score) (area,
						     area->closure,
						     closure) >= 0)
		return CAIRO_INT_STATUS_UNSUPPORTED;

	    _cairo_glitz_area_move_out (area);
	} else {
	    return CAIRO_INT_STATUS_UNSUPPORTED;
	}

    /* fall-through */
    case CAIRO_GLITZ_AREA_AVAILABLE: {
	if (area->level == area->root->max_level ||
	    (area->width == width && area->height == height))
	{
	    return _cairo_glitz_area_move_in (area, closure);
	}
	else
	{
	    int dx[4], dy[4], w[4], h[4], i;

	    dx[0] = dx[2] = dy[0] = dy[1] = 0;

	    w[0] = w[2] = dx[1] = dx[3] = width;
	    h[0] = h[1] = dy[2] = dy[3] = height;

	    w[1] = w[3] = area->width - width;
	    h[2] = h[3] = area->height - height;

	    for (i = 0; i < 2; i++)
	    {
		if (w[i])
		    area->area[i] =
			_cairo_glitz_area_create (area->root,
						  area->level + 1,
						  area->x + dx[i],
						  area->y + dy[i],
						  w[i], h[i]);
	    }

	    for (; i < 4; i++)
	    {
		if (w[i] && h[i])
		    area->area[i] =
			_cairo_glitz_area_create (area->root,
						  area->level + 1,
						  area->x + dx[i],
						  area->y + dy[i],
						  w[i], h[i]);
	    }

	    area->state = CAIRO_GLITZ_AREA_DIVIDED;

	    status = _cairo_glitz_area_find (area->area[0],
					     width, height,
					     kick_out, closure);
	    if (status == CAIRO_STATUS_SUCCESS)
		return CAIRO_STATUS_SUCCESS;
	}
    } break;
    case CAIRO_GLITZ_AREA_DIVIDED: {
	cairo_glitz_area_t *to_area;
	int		   i, rejected = FALSE;

	for (i = 0; i < 4; i++)
	{
	    if (area->area[i])
	    {
		if (area->area[i]->width >= width &&
		    area->area[i]->height >= height)
		{
		    status = _cairo_glitz_area_find (area->area[i],
						     width, height,
						     kick_out, closure);
		    if (status == CAIRO_STATUS_SUCCESS)
			return CAIRO_STATUS_SUCCESS;

		    rejected = TRUE;
		}
	    }
	}

	if (rejected)
	    return CAIRO_INT_STATUS_UNSUPPORTED;

	to_area = _cairo_glitz_area_get_top_scored_sub_area (area);
	if (to_area)
	{
	    if (kick_out)
	    {
		if ((*area->root->funcs->compare_score) (to_area,
							 to_area->closure,
							 closure) >= 0)
		    return CAIRO_INT_STATUS_UNSUPPORTED;
	    } else {
		return CAIRO_INT_STATUS_UNSUPPORTED;
	    }
	}

	for (i = 0; i < 4; i++)
	{
	    _cairo_glitz_area_destroy (area->area[i]);
	    area->area[i] = NULL;
	}

	area->closure = NULL;
	area->state   = CAIRO_GLITZ_AREA_AVAILABLE;

	status = _cairo_glitz_area_find (area, width, height,
					 TRUE, closure);
	if (status == CAIRO_STATUS_SUCCESS)
	    return CAIRO_STATUS_SUCCESS;

    } break;
    }

    return CAIRO_INT_STATUS_UNSUPPORTED;
}

static cairo_status_t
_cairo_glitz_root_area_init (cairo_glitz_root_area_t	    *root,
			     int			    max_level,
			     int			    width,
			     int			    height,
			     const cairo_glitz_area_funcs_t *funcs)
{
    root->max_level = max_level;
    root->funcs     = funcs;

    root->area = _cairo_glitz_area_create (root, 0, 0, 0, width, height);
    if (!root->area)
	return CAIRO_STATUS_NO_MEMORY;

    return CAIRO_STATUS_SUCCESS;
}

static void
_cairo_glitz_root_area_fini (cairo_glitz_root_area_t *root)
{
    _cairo_glitz_area_destroy (root->area);
}

typedef struct _cairo_glitz_surface_font_private {
    cairo_glitz_root_area_t root;
    glitz_surface_t	    *surface;
} cairo_glitz_surface_font_private_t;

typedef struct _cairo_glitz_surface_glyph_private {
    cairo_glitz_area_t	 *area;
    cairo_bool_t	 locked;
    cairo_point_double_t p1, p2;
} cairo_glitz_surface_glyph_private_t;

static cairo_status_t
_cairo_glitz_glyph_move_in (cairo_glitz_area_t *area,
			    void	       *closure)
{
    cairo_glitz_surface_glyph_private_t *glyph_private = closure;

    glyph_private->area = area;

    return CAIRO_STATUS_SUCCESS;
}

static void
_cairo_glitz_glyph_move_out (cairo_glitz_area_t	*area,
			     void	        *closure)
{
    cairo_glitz_surface_glyph_private_t *glyph_private = closure;

    glyph_private->area = NULL;
}

static int
_cairo_glitz_glyph_compare (cairo_glitz_area_t *area,
			    void	       *closure1,
			    void	       *closure2)
{
    cairo_glitz_surface_glyph_private_t *glyph_private = closure1;

    if (glyph_private->locked)
	return 1;

    return -1;
}

static const cairo_glitz_area_funcs_t _cairo_glitz_area_funcs = {
    _cairo_glitz_glyph_move_in,
    _cairo_glitz_glyph_move_out,
    _cairo_glitz_glyph_compare
};

#define GLYPH_CACHE_TEXTURE_SIZE 512
#define GLYPH_CACHE_MAX_LEVEL     64
#define GLYPH_CACHE_MAX_HEIGHT    72
#define GLYPH_CACHE_MAX_WIDTH     72

#define WRITE_VEC2(ptr, _x, _y) \
    *(ptr)++ = (_x);		\
    *(ptr)++ = (_y)

#define WRITE_BOX(ptr, _vx1, _vy1, _vx2, _vy2, p1, p2) \
    WRITE_VEC2 (ptr, _vx1, _vy1);		       \
    WRITE_VEC2 (ptr, (p1)->x, (p2)->y);		       \
    WRITE_VEC2 (ptr, _vx2, _vy1);		       \
    WRITE_VEC2 (ptr, (p2)->x, (p2)->y);		       \
    WRITE_VEC2 (ptr, _vx2, _vy2);		       \
    WRITE_VEC2 (ptr, (p2)->x, (p1)->y);		       \
    WRITE_VEC2 (ptr, _vx1, _vy2);		       \