| /* -*- 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 { |
| /* The inclusive x-coordinate of the start of the span. */ |
| int x; |
| |
| /* The pixel coverage for the pixels to the right. */ |
| int coverage; |
| } 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_warn 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; |
| |
| /* Add a single edge to the converter. */ |
| cairo_status_t (*add_edge) (void *abstract_converter, |
| const cairo_point_t *p1, |
| const cairo_point_t *p2, |
| int top, int bottom, |
| int dir); |
| |
| /* Add a polygon (set of edges) to the converter. */ |
| cairo_status_t (*add_polygon) (void *abstract_converter, |
| const cairo_polygon_t *polygon); |
| |
| /* 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); |
| |
| typedef struct _cairo_rectangular_scan_converter { |
| cairo_scan_converter_t base; |
| |
| int xmin, xmax; |
| int ymin, ymax; |
| |
| 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-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 */ |