pixman-image.c

嵌入式图形库

/*
 * Copyright © 2000 SuSE, Inc.
 * Copyright © 2007 Red Hat, Inc.
 *
 * 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 SuSE not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  SuSE makes no representations about the
 * suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * SuSE DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL SuSE
 * 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.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "pixman-private.h"

static void
init_source_image (source_image_t *image)
{
    image->class = SOURCE_IMAGE_CLASS_UNKNOWN;
}

static pixman_bool_t
init_gradient (gradient_t     *gradient,
	       const pixman_gradient_stop_t *stops,
	       int	       n_stops)
{
    return_val_if_fail (n_stops > 0, FALSE);

    init_source_image (&gradient->common);

    gradient->stops = pixman_malloc_ab (n_stops, sizeof (pixman_gradient_stop_t));
    if (!gradient->stops)
	return FALSE;

    memcpy (gradient->stops, stops, n_stops * sizeof (pixman_gradient_stop_t));

    gradient->n_stops = n_stops;

    gradient->stop_range = 0xffff;
    gradient->color_table = NULL;
    gradient->color_table_size = 0;

    return TRUE;
}

static uint32_t
color_to_uint32 (const pixman_color_t *color)
{
    return
	(color->alpha >> 8 << 24) |
	(color->red >> 8 << 16) |
        (color->green & 0xff00) |
	(color->blue >> 8);
}

static pixman_image_t *
allocate_image (void)
{
    pixman_image_t *image = malloc (sizeof (pixman_image_t));

    if (image)
    {
	image_common_t *common = &image->common;

	pixman_region_init (&common->full_region);
	pixman_region_init (&common->clip_region);
	common->src_clip = &common->full_region;
	common->has_client_clip = FALSE;
	common->transform = NULL;
	common->repeat = PIXMAN_REPEAT_NONE;
	common->filter = PIXMAN_FILTER_NEAREST;
	common->filter_params = NULL;
	common->n_filter_params = 0;
	common->alpha_map = NULL;
	common->component_alpha = FALSE;
	common->ref_count = 1;
	common->read_func = NULL;
	common->write_func = NULL;
    }

    return image;
}

/* Ref Counting */
pixman_image_t *
pixman_image_ref (pixman_image_t *image)
{
    image->common.ref_count++;

    return image;
}

/* returns TRUE when the image is freed */
pixman_bool_t
pixman_image_unref (pixman_image_t *image)
{
    image_common_t *common = (image_common_t *)image;

    common->ref_count--;

    if (common->ref_count == 0)
    {
	pixman_region_fini (&common->clip_region);
	pixman_region_fini (&common->full_region);

	if (common->transform)
	    free (common->transform);

	if (common->filter_params)
	    free (common->filter_params);

	if (common->alpha_map)
	    pixman_image_unref ((pixman_image_t *)common->alpha_map);

#if 0
	if (image->type == BITS && image->bits.indexed)
	    free (image->bits.indexed);
#endif

#if 0
	memset (image, 0xaa, sizeof (pixman_image_t));
#endif
	if (image->type == LINEAR || image->type == RADIAL || image->type == CONICAL)
	{
	    if (image->gradient.stops)
		free (image->gradient.stops);
	}


	if (image->type == BITS && image->bits.free_me)
	    free (image->bits.free_me);

	free (image);

	return TRUE;
    }

    return FALSE;
}

/* Constructors */
pixman_image_t *
pixman_image_create_solid_fill (pixman_color_t *color)
{
    pixman_image_t *img = allocate_image();
    if (!img)
	return NULL;

    init_source_image (&img->solid.common);

    img->type = SOLID;
    img->solid.color = color_to_uint32 (color);

    return img;
}

pixman_image_t *
pixman_image_create_linear_gradient (pixman_point_fixed_t         *p1,
				     pixman_point_fixed_t         *p2,
				     const pixman_gradient_stop_t *stops,
				     int                           n_stops)
{
    pixman_image_t *image;
    linear_gradient_t *linear;

    return_val_if_fail (n_stops >= 2, NULL);

    image = allocate_image();

    if (!image)
	return NULL;

    linear = &image->linear;

    if (!init_gradient (&linear->common, stops, n_stops))
    {
	free (image);
	return NULL;
    }

    linear->p1 = *p1;
    linear->p2 = *p2;

    image->type = LINEAR;

    return image;
}


pixman_image_t *
pixman_image_create_radial_gradient (pixman_point_fixed_t         *inner,
				     pixman_point_fixed_t         *outer,
				     pixman_fixed_t                inner_radius,
				     pixman_fixed_t                outer_radius,
				     const pixman_gradient_stop_t *stops,
				     int                           n_stops)
{
    pixman_image_t *image;
    radial_gradient_t *radial;

    return_val_if_fail (n_stops >= 2, NULL);

    image = allocate_image();

    if (!image)
	return NULL;

    radial = &image->radial;

    if (!init_gradient (&radial->common, stops, n_stops))
    {
	free (image);
	return NULL;
    }

    image->type = RADIAL;

    radial->c1.x = inner->x;
    radial->c1.y = inner->y;
    radial->c1.radius = inner_radius;
    radial->c2.x = outer->x;
    radial->c2.y = outer->y;
    radial->c2.radius = outer_radius;
    radial->cdx = pixman_fixed_to_double (radial->c2.x - radial->c1.x);
    radial->cdy = pixman_fixed_to_double (radial->c2.y - radial->c1.y);
    radial->dr = pixman_fixed_to_double (radial->c2.radius - radial->c1.radius);
    radial->A = (radial->cdx * radial->cdx
		 + radial->cdy * radial->cdy
		 - radial->dr  * radial->dr);

    return image;
}

pixman_image_t *
pixman_image_create_conical_gradient (pixman_point_fixed_t *center,
				      pixman_fixed_t angle,
				      const pixman_gradient_stop_t *stops,
				      int n_stops)
{
    pixman_image_t *image = allocate_image();
    conical_gradient_t *conical;

    if (!image)
	return NULL;

    conical = &image->conical;

    if (!init_gradient (&conical->common, stops, n_stops))
    {
	free (image);
	return NULL;
    }

    image->type = CONICAL;
    conical->center = *center;
    conical->angle = angle;

    return image;
}

static uint32_t *
create_bits (pixman_format_code_t format,
	     int		  width,
	     int		  height,
	     int		 *rowstride_bytes)
{
    int stride;
    int buf_size;
    int bpp;

    /* what follows is a long-winded way, avoiding any possibility of integer
     * overflows, of saying:
     * stride = ((width * bpp + FB_MASK) >> FB_SHIFT) * sizeof (uint32_t);
     */

    bpp = PIXMAN_FORMAT_BPP (format);
    if (pixman_multiply_overflows_int (width, bpp))
	return NULL;

    stride = width * bpp;
    if (pixman_addition_overflows_int (stride, FB_MASK))
	return NULL;

    stride += FB_MASK;
    stride >>= FB_SHIFT;

#if FB_SHIFT < 2
    if (pixman_multiply_overflows_int (stride, sizeof (uint32_t)))
	return NULL;
#endif
    stride *= sizeof (uint32_t);

    if (pixman_multiply_overflows_int (height, stride))
	return NULL;

    buf_size = height * stride;

    if (rowstride_bytes)
	*rowstride_bytes = stride;

    return calloc (buf_size, 1);
}

static void
reset_clip_region (pixman_image_t *image)
{
    pixman_region_fini (&image->common.clip_region);

    if (image->type == BITS)
    {
	pixman_region_init_rect (&image->common.clip_region, 0, 0,
				 image->bits.width, image->bits.height);
    }
    else
    {
	pixman_region_init (&image->common.clip_region);
    }
}

pixman_image_t *
pixman_image_create_bits (pixman_format_code_t  format,
			  int                   width,
			  int                   height,
			  uint32_t	       *bits,
			  int			rowstride_bytes)
{
    pixman_image_t *image;
    uint32_t *free_me = NULL;

    /* must be a whole number of uint32_t's
     */
    return_val_if_fail (bits == NULL ||
			(rowstride_bytes % sizeof (uint32_t)) == 0, NULL);

    if (!bits && width && height)
    {
	free_me = bits = create_bits (format, width, height, &rowstride_bytes);
	if (!bits)
	    return NULL;
    }

    image = allocate_image();