| /* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */ |
| /* cairo - a vector graphics library with display and print output |
| * |
| * Copyright © 2009 Adrian Johnson |
| * |
| * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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 Adrian Johnson. |
| * |
| * Contributor(s): |
| * Adrian Johnson <ajohnson@redneon.com> |
| */ |
| |
| #include "cairoint.h" |
| |
| #if CAIRO_HAS_PDF_OPERATORS |
| |
| #include "cairo-pdf-shading-private.h" |
| #include "cairo-error-private.h" |
| #include <float.h> |
| |
| static unsigned char * |
| encode_coordinate (unsigned char *p, double c) |
| { |
| uint32_t f; |
| |
| f = c; |
| *p++ = f >> 24; |
| *p++ = (f >> 16) & 0xff; |
| *p++ = (f >> 8) & 0xff; |
| *p++ = f & 0xff; |
| |
| return p; |
| } |
| |
| static unsigned char * |
| encode_point (unsigned char *p, const cairo_point_double_t *point) |
| { |
| p = encode_coordinate (p, point->x); |
| p = encode_coordinate (p, point->y); |
| |
| return p; |
| } |
| |
| static unsigned char * |
| encode_color_component (unsigned char *p, double color) |
| { |
| uint16_t c; |
| |
| c = _cairo_color_double_to_short (color); |
| *p++ = c >> 8; |
| *p++ = c & 0xff; |
| |
| return p; |
| } |
| |
| static unsigned char * |
| encode_color (unsigned char *p, const cairo_color_t *color) |
| { |
| p = encode_color_component (p, color->red); |
| p = encode_color_component (p, color->green); |
| p = encode_color_component (p, color->blue); |
| |
| return p; |
| } |
| |
| static unsigned char * |
| encode_alpha (unsigned char *p, const cairo_color_t *color) |
| { |
| p = encode_color_component (p, color->alpha); |
| |
| return p; |
| } |
| |
| static cairo_status_t |
| _cairo_pdf_shading_generate_decode_array (cairo_pdf_shading_t *shading, |
| const cairo_mesh_pattern_t *mesh, |
| cairo_bool_t is_alpha) |
| { |
| unsigned int num_color_components, i; |
| cairo_bool_t is_valid; |
| |
| if (is_alpha) |
| num_color_components = 1; |
| else |
| num_color_components = 3; |
| |
| shading->decode_array_length = 4 + num_color_components * 2; |
| shading->decode_array = _cairo_malloc_ab (shading->decode_array_length, |
| sizeof (double)); |
| if (unlikely (shading->decode_array == NULL)) |
| return _cairo_error (CAIRO_STATUS_NO_MEMORY); |
| |
| is_valid = _cairo_mesh_pattern_coord_box (mesh, |
| &shading->decode_array[0], |
| &shading->decode_array[2], |
| &shading->decode_array[1], |
| &shading->decode_array[3]); |
| |
| assert (is_valid); |
| assert (shading->decode_array[1] - shading->decode_array[0] >= DBL_EPSILON); |
| assert (shading->decode_array[3] - shading->decode_array[2] >= DBL_EPSILON); |
| |
| for (i = 0; i < num_color_components; i++) { |
| shading->decode_array[4 + 2*i] = 0; |
| shading->decode_array[5 + 2*i] = 1; |
| } |
| |
| return CAIRO_STATUS_SUCCESS; |
| } |
| |
| /* The ISO32000 specification mandates this order for the points which |
| * define the patch. */ |
| static const int pdf_points_order_i[16] = { |
| 0, 0, 0, 0, 1, 2, 3, 3, 3, 3, 2, 1, 1, 1, 2, 2 }; |
| static const int pdf_points_order_j[16] = { |
| 0, 1, 2, 3, 3, 3, 3, 2, 1, 0, 0, 0, 1, 2, 2, 1 }; |
| |
| static cairo_status_t |
| _cairo_pdf_shading_generate_data (cairo_pdf_shading_t *shading, |
| const cairo_mesh_pattern_t *mesh, |
| cairo_bool_t is_alpha) |
| { |
| const cairo_mesh_patch_t *patch; |
| double x_off, y_off, x_scale, y_scale; |
| unsigned int num_patches; |
| unsigned int num_color_components; |
| unsigned char *p; |
| unsigned int i, j; |
| |
| if (is_alpha) |
| num_color_components = 1; |
| else |
| num_color_components = 3; |
| |
| num_patches = _cairo_array_num_elements (&mesh->patches); |
| patch = _cairo_array_index_const (&mesh->patches, 0); |
| |
| /* Each patch requires: |
| * |
| * 1 flag - 1 byte |
| * 16 points. Each point is 2 coordinates. Each coordinate is |
| * stored in 4 bytes. |
| * |
| * 4 colors. Each color is stored in 2 bytes * num_color_components. |
| */ |
| shading->data_length = num_patches * (1 + 16 * 2 * 4 + 4 * 2 * num_color_components); |
| shading->data = malloc (shading->data_length); |
| if (unlikely (shading->data == NULL)) |
| return _cairo_error (CAIRO_STATUS_NO_MEMORY); |
| |
| x_off = shading->decode_array[0]; |
| y_off = shading->decode_array[2]; |
| x_scale = UINT32_MAX / (shading->decode_array[1] - x_off); |
| y_scale = UINT32_MAX / (shading->decode_array[3] - y_off); |
| |
| p = shading->data; |
| for (i = 0; i < num_patches; i++) { |
| /* edge flag */ |
| *p++ = 0; |
| |
| /* 16 points */ |
| for (j = 0; j < 16; j++) { |
| cairo_point_double_t point; |
| int pi, pj; |
| |
| pi = pdf_points_order_i[j]; |
| pj = pdf_points_order_j[j]; |
| point = patch[i].points[pi][pj]; |
| |
| /* Transform the point as specified in the decode array */ |
| point.x -= x_off; |
| point.y -= y_off; |
| point.x *= x_scale; |
| point.y *= y_scale; |
| |
| /* Make sure that rounding errors don't cause |
| * wraparounds */ |
| point.x = _cairo_restrict_value (point.x, 0, UINT32_MAX); |
| point.y = _cairo_restrict_value (point.y, 0, UINT32_MAX); |
| |
| p = encode_point (p, &point); |
| } |
| |
| /* 4 colors */ |
| for (j = 0; j < 4; j++) { |
| if (is_alpha) |
| p = encode_alpha (p, &patch[i].colors[j]); |
| else |
| p = encode_color (p, &patch[i].colors[j]); |
| } |
| } |
| |
| assert (p == shading->data + shading->data_length); |
| |
| return CAIRO_STATUS_SUCCESS; |
| } |
| |
| static cairo_status_t |
| _cairo_pdf_shading_init (cairo_pdf_shading_t *shading, |
| const cairo_mesh_pattern_t *mesh, |
| cairo_bool_t is_alpha) |
| { |
| cairo_status_t status; |
| |
| assert (mesh->base.status == CAIRO_STATUS_SUCCESS); |
| assert (mesh->current_patch == NULL); |
| |
| shading->shading_type = 7; |
| |
| /* |
| * Coordinates from the minimum to the maximum value of the mesh |
| * map to the [0..UINT32_MAX] range and are represented as |
| * uint32_t values. |
| * |
| * Color components are represented as uint16_t (in a 0.16 fixed |
| * point format, as in the rest of cairo). |
| */ |
| shading->bits_per_coordinate = 32; |
| shading->bits_per_component = 16; |
| shading->bits_per_flag = 8; |
| |
| shading->decode_array = NULL; |
| shading->data = NULL; |
| |
| status = _cairo_pdf_shading_generate_decode_array (shading, mesh, is_alpha); |
| if (unlikely (status)) |
| return status; |
| |
| return _cairo_pdf_shading_generate_data (shading, mesh, is_alpha); |
| } |
| |
| cairo_status_t |
| _cairo_pdf_shading_init_color (cairo_pdf_shading_t *shading, |
| const cairo_mesh_pattern_t *pattern) |
| { |
| return _cairo_pdf_shading_init (shading, pattern, FALSE); |
| } |
| |
| cairo_status_t |
| _cairo_pdf_shading_init_alpha (cairo_pdf_shading_t *shading, |
| const cairo_mesh_pattern_t *pattern) |
| { |
| return _cairo_pdf_shading_init (shading, pattern, TRUE); |
| } |
| |
| void |
| _cairo_pdf_shading_fini (cairo_pdf_shading_t *shading) |
| { |
| free (shading->data); |
| free (shading->decode_array); |
| } |
| |
| #endif /* CAIRO_HAS_PDF_OPERATORS */ |