Subversion Repositories Kolibri OS

/* -*- 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 */