source/libs/cairo/cairo-src/src/cairo-spans-private.h

   1 /* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
   2 /* cairo - a vector graphics library with display and print output
   3  *
   4  * Copyright (c) 2008  M Joonas Pihlaja
   5  *
   6  * Permission is hereby granted, free of charge, to any person
   7  * obtaining a copy of this software and associated documentation
   8  * files (the "Software"), to deal in the Software without
   9  * restriction, including without limitation the rights to use,
  10  * copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following
  13  * conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be
  16  * included in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  20  * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  22  * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  23  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  24  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  25  * OTHER DEALINGS IN THE SOFTWARE.
  26  */
  27 #ifndef CAIRO_SPANS_PRIVATE_H
  28 #define CAIRO_SPANS_PRIVATE_H
  29 #include "cairo-types-private.h"
  30 #include "cairo-compiler-private.h"
  31
  32 /* Number of bits of precision used for alpha. */
  33 #define CAIRO_SPANS_UNIT_COVERAGE_BITS 8
  34 #define CAIRO_SPANS_UNIT_COVERAGE ((1 << CAIRO_SPANS_UNIT_COVERAGE_BITS)-1)
  35
  36 /* A structure representing an open-ended horizontal span of constant
  37  * pixel coverage. */
  38 typedef struct _cairo_half_open_span {
  39     int32_t x; /* The inclusive x-coordinate of the start of the span. */
  40     uint8_t coverage; /* The pixel coverage for the pixels to the right. */
  41     uint8_t inverse; /* between regular mask and clip */
  42 } cairo_half_open_span_t;
  43
  44 /* Span renderer interface. Instances of renderers are provided by
  45  * surfaces if they want to composite spans instead of trapezoids. */
  46 typedef struct _cairo_span_renderer cairo_span_renderer_t;
  47 struct _cairo_span_renderer {
  48     /* Private status variable. */
  49     cairo_status_t status;
  50
  51     /* Called to destroy the renderer. */
  52     cairo_destroy_func_t        destroy;
  53
  54     /* Render the spans on row y of the destination by whatever compositing
  55      * method is required. */
  56     cairo_status_t
  57     (*render_rows) (void *abstract_renderer,
  58                     int y, int height,
  59                     const cairo_half_open_span_t        *coverages,
  60                     unsigned num_coverages);
  61
  62     /* Called after all rows have been rendered to perform whatever
  63      * final rendering step is required.  This function is called just
  64      * once before the renderer is destroyed. */
  65     cairo_status_t (*finish) (void *abstract_renderer);
  66 };
  67
  68 /* Scan converter interface. */
  69 typedef struct _cairo_scan_converter cairo_scan_converter_t;
  70 struct _cairo_scan_converter {
  71     /* Destroy this scan converter. */
  72     cairo_destroy_func_t        destroy;
  73
  74     /* Generates coverage spans for rows for the added edges and calls
  75      * the renderer function for each row. After generating spans the
  76      * only valid thing to do with the converter is to destroy it. */
  77     cairo_status_t (*generate) (void                    *abstract_converter,
  78                                 cairo_span_renderer_t   *renderer);
  79
  80     /* Private status. Read with _cairo_scan_converter_status(). */
  81     cairo_status_t status;
  82 };
  83
  84 /* Scan converter constructors. */
  85
  86 cairo_private cairo_scan_converter_t *
  87 _cairo_tor_scan_converter_create (int                   xmin,
  88                                   int                   ymin,
  89                                   int                   xmax,
  90                                   int                   ymax,
  91                                   cairo_fill_rule_t     fill_rule,
  92                                   cairo_antialias_t     antialias);
  93 cairo_private cairo_status_t
  94 _cairo_tor_scan_converter_add_polygon (void             *converter,
  95                                        const cairo_polygon_t *polygon);
  96
  97 cairo_private cairo_scan_converter_t *
  98 _cairo_tor22_scan_converter_create (int                 xmin,
  99                                     int                 ymin,
 100                                     int                 xmax,
 101                                     int                 ymax,
 102                                     cairo_fill_rule_t   fill_rule,
 103                                     cairo_antialias_t   antialias);
 104 cairo_private cairo_status_t
 105 _cairo_tor22_scan_converter_add_polygon (void           *converter,
 106                                          const cairo_polygon_t *polygon);
 107
 108 cairo_private cairo_scan_converter_t *
 109 _cairo_mono_scan_converter_create (int                  xmin,
 110                                    int                  ymin,
 111                                    int                  xmax,
 112                                    int                  ymax,
 113                                    cairo_fill_rule_t    fill_rule);
 114 cairo_private cairo_status_t
 115 _cairo_mono_scan_converter_add_polygon (void            *converter,
 116                                         const cairo_polygon_t *polygon);
 117
 118 cairo_private cairo_scan_converter_t *
 119 _cairo_clip_tor_scan_converter_create (cairo_clip_t *clip,
 120                                        cairo_polygon_t *polygon,
 121                                        cairo_fill_rule_t fill_rule,
 122                                        cairo_antialias_t antialias);
 123
 124 typedef struct _cairo_rectangular_scan_converter {
 125     cairo_scan_converter_t base;
 126
 127     cairo_box_t extents;
 128
 129     struct _cairo_rectangular_scan_converter_chunk {
 130         struct _cairo_rectangular_scan_converter_chunk *next;
 131         void *base;
 132         int count;
 133         int size;
 134     } chunks, *tail;
 135     char buf[CAIRO_STACK_BUFFER_SIZE];
 136     int num_rectangles;
 137 } cairo_rectangular_scan_converter_t;
 138
 139 cairo_private void
 140 _cairo_rectangular_scan_converter_init (cairo_rectangular_scan_converter_t *self,
 141                                         const cairo_rectangle_int_t *extents);
 142
 143 cairo_private cairo_status_t
 144 _cairo_rectangular_scan_converter_add_box (cairo_rectangular_scan_converter_t *self,
 145                                            const cairo_box_t *box,
 146                                            int dir);
 147
 148 typedef struct _cairo_botor_scan_converter {
 149     cairo_scan_converter_t base;
 150
 151     cairo_box_t extents;
 152     cairo_fill_rule_t fill_rule;
 153
 154     int xmin, xmax;
 155
 156     struct _cairo_botor_scan_converter_chunk {
 157         struct _cairo_botor_scan_converter_chunk *next;
 158         void *base;
 159         int count;
 160         int size;
 161     } chunks, *tail;
 162     char buf[CAIRO_STACK_BUFFER_SIZE];
 163     int num_edges;
 164 } cairo_botor_scan_converter_t;
 165
 166 cairo_private void
 167 _cairo_botor_scan_converter_init (cairo_botor_scan_converter_t *self,
 168                                   const cairo_box_t *extents,
 169                                   cairo_fill_rule_t fill_rule);
 170
 171 /* cairo-spans.c: */
 172
 173 cairo_private cairo_scan_converter_t *
 174 _cairo_scan_converter_create_in_error (cairo_status_t error);
 175
 176 cairo_private cairo_status_t
 177 _cairo_scan_converter_status (void *abstract_converter);
 178
 179 cairo_private cairo_status_t
 180 _cairo_scan_converter_set_error (void *abstract_converter,
 181                                  cairo_status_t error);
 182
 183 cairo_private cairo_span_renderer_t *
 184 _cairo_span_renderer_create_in_error (cairo_status_t error);
 185
 186 cairo_private cairo_status_t
 187 _cairo_span_renderer_status (void *abstract_renderer);
 188
 189 /* Set the renderer into an error state.  This sets all the method
 190  * pointers except ->destroy() of the renderer to no-op
 191  * implementations that just return the error status. */
 192 cairo_private cairo_status_t
 193 _cairo_span_renderer_set_error (void *abstract_renderer,
 194                                 cairo_status_t error);
 195
 196 cairo_private cairo_status_t
 197 _cairo_surface_composite_polygon (cairo_surface_t       *surface,
 198                                   cairo_operator_t       op,
 199                                   const cairo_pattern_t *pattern,
 200                                   cairo_fill_rule_t     fill_rule,
 201                                   cairo_antialias_t     antialias,
 202                                   const cairo_composite_rectangles_t *rects,
 203                                   cairo_polygon_t       *polygon,
 204                                   cairo_region_t        *clip_region);
 205
 206 #endif /* CAIRO_SPANS_PRIVATE_H */