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/*
* Copyright © 2000 SuSE, Inc.
* Copyright © 2007 Red Hat, Inc.
* Copyright © 2000 Keith Packard, member of The XFree86 Project, Inc.
* 2005 Lars Knoll & Zack Rusin, Trolltech
*
* 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 Keith Packard not be used in
* advertising or publicity pertaining to distribution of the software without
* specific, written prior permission. Keith Packard makes no
* representations about the suitability of this software for any purpose. It
* is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS 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 <pixman-config.h>
#endif
#include <stdlib.h>
#include <math.h>
#include "pixman-private.h"
static force_inline double
coordinates_to_parameter (double x, double y, double angle)
{
double t;
t = atan2 (y, x) + angle;
while (t < 0)
t += 2 * M_PI;
while (t >= 2 * M_PI)
t -= 2 * M_PI;
return 1 - t * (1 / (2 * M_PI)); /* Scale t to [0, 1] and
* make rotation CCW
*/
}
static uint32_t *
conical_get_scanline (pixman_iter_t *iter,
const uint32_t *mask,
int Bpp,
pixman_gradient_walker_write_t write_pixel)
{
pixman_image_t *image = iter->image;
int x = iter->x;
int y = iter->y;
int width = iter->width;
uint32_t *buffer = iter->buffer;
gradient_t *gradient = (gradient_t *)image;
conical_gradient_t *conical = (conical_gradient_t *)image;
uint32_t *end = buffer + width * (Bpp / 4);
pixman_gradient_walker_t walker;
pixman_bool_t affine = TRUE;
double cx = 1.;
double cy = 0.;
double cz = 0.;
double rx = x + 0.5;
double ry = y + 0.5;
double rz = 1.;
_pixman_gradient_walker_init (&walker, gradient, image->common.repeat);
if (image->common.transform)
{
pixman_vector_t v;
/* reference point is the center of the pixel */
v.vector[0] = pixman_int_to_fixed (x) + pixman_fixed_1 / 2;
v.vector[1] = pixman_int_to_fixed (y) + pixman_fixed_1 / 2;
v.vector[2] = pixman_fixed_1;
if (!pixman_transform_point_3d (image->common.transform, &v))
return iter->buffer;
cx = image->common.transform->matrix[0][0] / 65536.;
cy = image->common.transform->matrix[1][0] / 65536.;
cz = image->common.transform->matrix[2][0] / 65536.;
rx = v.vector[0] / 65536.;
ry = v.vector[1] / 65536.;
rz = v.vector[2] / 65536.;
affine =
image->common.transform->matrix[2][0] == 0 &&
v.vector[2] == pixman_fixed_1;
}
if (affine)
{
rx -= conical->center.x / 65536.;
ry -= conical->center.y / 65536.;
while (buffer < end)
{
if (!mask || *mask++)
{
double t = coordinates_to_parameter (rx, ry, conical->angle);
write_pixel (&walker,
(pixman_fixed_48_16_t)pixman_double_to_fixed (t),
buffer);
}
buffer += (Bpp / 4);
rx += cx;
ry += cy;
}
}
else
{
while (buffer < end)
{
double x, y;
if (!mask || *mask++)
{
double t;
if (rz != 0)
{
x = rx / rz;
y = ry / rz;
}
else
{
x = y = 0.;
}
x -= conical->center.x / 65536.;
y -= conical->center.y / 65536.;
t = coordinates_to_parameter (x, y, conical->angle);
write_pixel (&walker,
(pixman_fixed_48_16_t)pixman_double_to_fixed (t),
buffer);
}
buffer += (Bpp / 4);
rx += cx;
ry += cy;
rz += cz;
}
}
iter->y++;
return iter->buffer;
}
static uint32_t *
conical_get_scanline_narrow (pixman_iter_t *iter, const uint32_t *mask)
{
return conical_get_scanline (iter, mask, 4,
_pixman_gradient_walker_write_narrow);
}
static uint32_t *
conical_get_scanline_wide (pixman_iter_t *iter, const uint32_t *mask)
{
return conical_get_scanline (iter, NULL, 16,
_pixman_gradient_walker_write_wide);
}
void
_pixman_conical_gradient_iter_init (pixman_image_t *image, pixman_iter_t *iter)
{
if (iter->iter_flags & ITER_NARROW)
iter->get_scanline = conical_get_scanline_narrow;
else
iter->get_scanline = conical_get_scanline_wide;
}
PIXMAN_EXPORT pixman_image_t *
pixman_image_create_conical_gradient (const pixman_point_fixed_t * center,
pixman_fixed_t angle,
const pixman_gradient_stop_t *stops,
int n_stops)
{
pixman_image_t *image = _pixman_image_allocate ();
conical_gradient_t *conical;
if (!image)
return NULL;
conical = &image->conical;
if (!_pixman_init_gradient (&conical->common, stops, n_stops))
{
free (image);
return NULL;
}
angle = MOD (angle, pixman_int_to_fixed (360));
image->type = CONICAL;
conical->center = *center;
conical->angle = (pixman_fixed_to_double (angle) / 180.0) * M_PI;
return image;
}
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