diff options
Diffstat (limited to 'gfx/cairo/libpixman/src/pixman-conical-gradient.c')
| -rw-r--r-- | gfx/cairo/libpixman/src/pixman-conical-gradient.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/gfx/cairo/libpixman/src/pixman-conical-gradient.c b/gfx/cairo/libpixman/src/pixman-conical-gradient.c new file mode 100644 index 0000000000..a39e20c4eb --- /dev/null +++ b/gfx/cairo/libpixman/src/pixman-conical-gradient.c @@ -0,0 +1,220 @@ +/* + * 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 <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; +} + |