summaryrefslogtreecommitdiff
path: root/src/cairo-spans-private.h
blob: 653183fb1c8ec4ffc5e8be3665454d0f56aa67e2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
/* cairo - a vector graphics library with display and print output
 *
 * Copyright (c) 2008  M Joonas Pihlaja
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef CAIRO_SPANS_PRIVATE_H
#define CAIRO_SPANS_PRIVATE_H
#include "cairo-types-private.h"
#include "cairo-compiler-private.h"

/* Number of bits of precision used for alpha. */
#define CAIRO_SPANS_UNIT_COVERAGE_BITS 8
#define CAIRO_SPANS_UNIT_COVERAGE ((1 << CAIRO_SPANS_UNIT_COVERAGE_BITS)-1)

/* A structure representing an open-ended horizontal span of constant
 * pixel coverage. */
typedef struct _cairo_half_open_span {
    int32_t x; /* The inclusive x-coordinate of the start of the span. */
    uint8_t coverage; /* The pixel coverage for the pixels to the right. */
    uint8_t inverse; /* between regular mask and clip */
} cairo_half_open_span_t;

/* Span renderer interface. Instances of renderers are provided by
 * surfaces if they want to composite spans instead of trapezoids. */
typedef struct _cairo_span_renderer cairo_span_renderer_t;
struct _cairo_span_renderer {
    /* Private status variable. */
    cairo_status_t status;

    /* Called to destroy the renderer. */
    cairo_destroy_func_t	destroy;

    /* Render the spans on row y of the destination by whatever compositing
     * method is required. */
    cairo_status_t
    (*render_rows) (void *abstract_renderer,
		    int y, int height,
		    const cairo_half_open_span_t	*coverages,
		    unsigned num_coverages);

    /* Called after all rows have been rendered to perform whatever
     * final rendering step is required.  This function is called just
     * once before the renderer is destroyed. */
    cairo_status_t (*finish) (void *abstract_renderer);
};

/* Scan converter interface. */
typedef struct _cairo_scan_converter cairo_scan_converter_t;
struct _cairo_scan_converter {
    /* Destroy this scan converter. */
    cairo_destroy_func_t	destroy;

    /* Generates coverage spans for rows for the added edges and calls
     * the renderer function for each row. After generating spans the
     * only valid thing to do with the converter is to destroy it. */
    cairo_status_t (*generate) (void			*abstract_converter,
				cairo_span_renderer_t	*renderer);

    /* Private status. Read with _cairo_scan_converter_status(). */
    cairo_status_t status;
};

/* Scan converter constructors. */

cairo_private cairo_scan_converter_t *
_cairo_tor_scan_converter_create (int			xmin,
				  int			ymin,
				  int			xmax,
				  int			ymax,
				  cairo_fill_rule_t	fill_rule,
				  cairo_antialias_t	antialias);
cairo_private cairo_status_t
_cairo_tor_scan_converter_add_polygon (void		*converter,
				       const cairo_polygon_t *polygon);

cairo_private cairo_scan_converter_t *
_cairo_tor22_scan_converter_create (int			xmin,
				    int			ymin,
				    int			xmax,
				    int			ymax,
				    cairo_fill_rule_t	fill_rule,
				    cairo_antialias_t	antialias);
cairo_private cairo_status_t
_cairo_tor22_scan_converter_add_polygon (void		*converter,
					 const cairo_polygon_t *polygon);

cairo_private cairo_scan_converter_t *
_cairo_mono_scan_converter_create (int			xmin,
				   int			ymin,
				   int			xmax,
				   int			ymax,
				   cairo_fill_rule_t	fill_rule);
cairo_private cairo_status_t
_cairo_mono_scan_converter_add_polygon (void		*converter,
					const cairo_polygon_t *polygon);

cairo_private cairo_scan_converter_t *
_cairo_clip_tor_scan_converter_create (cairo_clip_t *clip,
				       cairo_polygon_t *polygon,
				       cairo_fill_rule_t fill_rule,
				       cairo_antialias_t antialias);

typedef struct _cairo_rectangular_scan_converter {
    cairo_scan_converter_t base;

    cairo_box_t extents;

    struct _cairo_rectangular_scan_converter_chunk {
	struct _cairo_rectangular_scan_converter_chunk *next;
	void *base;
	int count;
	int size;
    } chunks, *tail;
    char buf[CAIRO_STACK_BUFFER_SIZE];
    int num_rectangles;
} cairo_rectangular_scan_converter_t;

cairo_private void
_cairo_rectangular_scan_converter_init (cairo_rectangular_scan_converter_t *self,
					const cairo_rectangle_int_t *extents);

cairo_private cairo_status_t
_cairo_rectangular_scan_converter_add_box (cairo_rectangular_scan_converter_t *self,
					   const cairo_box_t *box,
					   int dir);

typedef struct _cairo_botor_scan_converter {
    cairo_scan_converter_t base;

    cairo_box_t extents;
    cairo_fill_rule_t fill_rule;

    int xmin, xmax;

    struct _cairo_botor_scan_converter_chunk {
	struct _cairo_botor_scan_converter_chunk *next;
	void *base;
	int count;
	int size;
    } chunks, *tail;
    char buf[CAIRO_STACK_BUFFER_SIZE];
    int num_edges;
} cairo_botor_scan_converter_t;

cairo_private void
_cairo_botor_scan_converter_init (cairo_botor_scan_converter_t *self,
				  const cairo_box_t *extents,
				  cairo_fill_rule_t fill_rule);

cairo_private cairo_status_t
_cairo_botor_scan_converter_add_polygon (cairo_botor_scan_converter_t *converter,
					const cairo_polygon_t *polygon);

/* cairo-spans.c: */

cairo_private cairo_scan_converter_t *
_cairo_scan_converter_create_in_error (cairo_status_t error);

cairo_private cairo_status_t
_cairo_scan_converter_status (void *abstract_converter);

cairo_private cairo_status_t
_cairo_scan_converter_set_error (void *abstract_converter,
				 cairo_status_t error);

cairo_private cairo_span_renderer_t *
_cairo_span_renderer_create_in_error (cairo_status_t error);

cairo_private cairo_status_t
_cairo_span_renderer_status (void *abstract_renderer);

/* Set the renderer into an error state.  This sets all the method
 * pointers except ->destroy() of the renderer to no-op
 * implementations that just return the error status. */
cairo_private cairo_status_t
_cairo_span_renderer_set_error (void *abstract_renderer,
				cairo_status_t error);

cairo_private cairo_status_t
_cairo_surface_composite_polygon (cairo_surface_t	*surface,
				  cairo_operator_t	 op,
				  const cairo_pattern_t	*pattern,
				  cairo_fill_rule_t	fill_rule,
				  cairo_antialias_t	antialias,
				  const cairo_composite_rectangles_t *rects,
				  cairo_polygon_t	*polygon,
				  cairo_region_t	*clip_region);

#endif /* CAIRO_SPANS_PRIVATE_H */