39241fe228
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@9933 a95241bf-73f2-0310-859d-f6bbb57e9c96
772 lines
23 KiB
C++
772 lines
23 KiB
C++
//----------------------------------------------------------------------------
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// Anti-Grain Geometry - Version 2.2
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// Copyright (C) 2002-2004 Maxim Shemanarev (http://www.antigrain.com)
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//
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// Permission to copy, use, modify, sell and distribute this software
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// is granted provided this copyright notice appears in all copies.
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// This software is provided "as is" without express or implied
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// warranty, and with no claim as to its suitability for any purpose.
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//
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// The author gratefully acknowleges the support of David Turner,
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// Robert Wilhelm, and Werner Lemberg - the authors of the FreeType
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// libray - in producing this work. See http://www.freetype.org for details.
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//
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//----------------------------------------------------------------------------
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// Contact: mcseem@antigrain.com
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// mcseemagg@yahoo.com
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// http://www.antigrain.com
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//----------------------------------------------------------------------------
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//
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// Class rasterizer_scanline_aa
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//
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//
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//----------------------------------------------------------------------------
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#ifndef AGG_RASTERIZER_SCANLINE_AA_INCLUDED
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#define AGG_RASTERIZER_SCANLINE_AA_INCLUDED
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#include <string.h>
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#include <math.h>
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#include "agg_basics.h"
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#include "agg_math.h"
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#include "agg_gamma_functions.h"
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#include "agg_clip_liang_barsky.h"
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#include "agg_render_scanlines.h"
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namespace agg
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{
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//------------------------------------------------------------------------
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// These constants determine the subpixel accuracy, to be more precise,
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// the number of bits of the fractional part of the coordinates.
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// The possible coordinate capacity in bits can be calculated by formula:
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// sizeof(int) * 8 - poly_base_shift * 2, i.e, for 32-bit integers and
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// 8-bits fractional part the capacity is 16 bits or [-32768...32767].
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enum
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{
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poly_base_shift = 8, //----poly_base_shift
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poly_base_size = 1 << poly_base_shift, //----poly_base_size
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poly_base_mask = poly_base_size - 1 //----poly_base_mask
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};
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//--------------------------------------------------------------poly_coord
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inline int poly_coord(double c)
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{
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return int(c * poly_base_size);
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}
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//-----------------------------------------------------------------cell_aa
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// A pixel cell. There're no constructors defined and it was done
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// intentionally in order to avoid extra overhead when allocating an
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// array of cells.
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struct cell_aa
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{
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int16 x;
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int16 y;
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int packed_coord;
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int cover;
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int area;
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void set(int x, int y, int c, int a);
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void set_coord(int x, int y);
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void set_cover(int c, int a);
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void add_cover(int c, int a);
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};
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//--------------------------------------------------------------outline_aa
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// An internal class that implements the main rasterization algorithm.
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// Used in the rasterizer. Should not be used direcly.
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class outline_aa
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{
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enum
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{
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cell_block_shift = 12,
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cell_block_size = 1 << cell_block_shift,
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cell_block_mask = cell_block_size - 1,
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cell_block_pool = 256,
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cell_block_limit = 1024
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};
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public:
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~outline_aa();
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outline_aa();
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void reset();
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void move_to(int x, int y);
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void line_to(int x, int y);
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int min_x() const { return m_min_x; }
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int min_y() const { return m_min_y; }
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int max_x() const { return m_max_x; }
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int max_y() const { return m_max_y; }
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const cell_aa* const* cells();
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unsigned num_cells() { cells(); return m_num_cells; }
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bool sorted() const { return m_sorted; }
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private:
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outline_aa(const outline_aa&);
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const outline_aa& operator = (const outline_aa&);
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void set_cur_cell(int x, int y);
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void add_cur_cell();
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void sort_cells();
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void render_hline(int ey, int x1, int y1, int x2, int y2);
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void render_line(int x1, int y1, int x2, int y2);
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void allocate_block();
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static void qsort_cells(cell_aa** start, unsigned num);
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private:
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unsigned m_num_blocks;
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unsigned m_max_blocks;
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unsigned m_cur_block;
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unsigned m_num_cells;
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cell_aa** m_cells;
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cell_aa* m_cur_cell_ptr;
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cell_aa** m_sorted_cells;
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unsigned m_sorted_size;
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cell_aa m_cur_cell;
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int m_cur_x;
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int m_cur_y;
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int m_min_x;
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int m_min_y;
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int m_max_x;
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int m_max_y;
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bool m_sorted;
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};
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//----------------------------------------------------------filling_rule_e
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enum filling_rule_e
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{
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fill_non_zero,
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fill_even_odd
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};
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//----------------------------------------------------------clipping_flags
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// Determine the clipping code of the vertex according to the
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// Cyrus-Beck line clipping algorithm
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//
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// | |
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// 0110 | 0010 | 0011
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// | |
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// -------+--------+-------- clip_box.y2
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// | |
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// 0100 | 0000 | 0001
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// | |
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// -------+--------+-------- clip_box.y1
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// | |
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// 1100 | 1000 | 1001
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// | |
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// clip_box.x1 clip_box.x2
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//
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//
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inline unsigned clipping_flags(int x, int y, const rect& clip_box)
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{
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return (x > clip_box.x2) |
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((y > clip_box.y2) << 1) |
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((x < clip_box.x1) << 2) |
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((y < clip_box.y1) << 3);
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}
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//==================================================rasterizer_scanline_aa
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// Polygon rasterizer that is used to render filled polygons with
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// high-quality Anti-Aliasing. Internally, by default, the class uses
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// integer coordinates in format 24.8, i.e. 24 bits for integer part
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// and 8 bits for fractional - see poly_base_shift. This class can be
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// used in the following way:
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//
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// 1. filling_rule(filling_rule_e ft) - optional.
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//
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// 2. gamma() - optional.
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//
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// 3. reset()
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//
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// 4. move_to(x, y) / line_to(x, y) - make the polygon. One can create
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// more than one contour, but each contour must consist of at least 3
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// vertices, i.e. move_to(x1, y1); line_to(x2, y2); line_to(x3, y3);
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// is the absolute minimum of vertices that define a triangle.
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// The algorithm does not check either the number of vertices nor
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// coincidence of their coordinates, but in the worst case it just
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// won't draw anything.
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// The orger of the vertices (clockwise or counterclockwise)
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// is important when using the non-zero filling rule (fill_non_zero).
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// In this case the vertex order of all the contours must be the same
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// if you want your intersecting polygons to be without "holes".
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// You actually can use different vertices order. If the contours do not
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// intersect each other the order is not important anyway. If they do,
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// contours with the same vertex order will be rendered without "holes"
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// while the intersecting contours with different orders will have "holes".
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//
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// filling_rule() and gamma() can be called anytime before "sweeping".
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//------------------------------------------------------------------------
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template<unsigned AA_Shift=8> class rasterizer_scanline_aa
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{
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enum status
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{
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status_initial,
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status_line_to,
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status_closed
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};
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struct iterator
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{
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const cell_aa* const* cells;
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int cover;
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int last_y;
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};
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public:
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enum
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{
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aa_shift = AA_Shift,
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aa_num = 1 << aa_shift,
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aa_mask = aa_num - 1,
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aa_2num = aa_num * 2,
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aa_2mask = aa_2num - 1
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};
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//--------------------------------------------------------------------
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rasterizer_scanline_aa() :
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m_filling_rule(fill_non_zero),
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m_clipped_start_x(0),
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m_clipped_start_y(0),
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m_start_x(0),
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m_start_y(0),
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m_prev_x(0),
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m_prev_y(0),
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m_prev_flags(0),
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m_status(status_initial),
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m_clipping(false)
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{
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int i;
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for(i = 0; i < aa_num; i++) m_gamma[i] = i;
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}
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//--------------------------------------------------------------------
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template<class GammaF>
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rasterizer_scanline_aa(const GammaF& gamma_function) :
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m_filling_rule(fill_non_zero),
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m_clipped_start_x(0),
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m_clipped_start_y(0),
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m_start_x(0),
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m_start_y(0),
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m_prev_x(0),
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m_prev_y(0),
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m_prev_flags(0),
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m_status(status_initial),
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m_clipping(false)
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{
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gamma(gamma_function);
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}
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//--------------------------------------------------------------------
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void reset();
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void filling_rule(filling_rule_e filling_rule);
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void clip_box(double x1, double y1, double x2, double y2);
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void reset_clipping();
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//--------------------------------------------------------------------
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template<class GammaF> void gamma(const GammaF& gamma_function)
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{
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int i;
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for(i = 0; i < aa_num; i++)
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{
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m_gamma[i] = int(floor(gamma_function(double(i) / aa_mask) * aa_mask + 0.5));
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}
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}
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//--------------------------------------------------------------------
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unsigned apply_gamma(unsigned cover) const
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{
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return m_gamma[cover];
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}
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//--------------------------------------------------------------------
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void add_vertex(double x, double y, unsigned cmd);
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void move_to(int x, int y);
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void line_to(int x, int y);
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void close_polygon();
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void move_to_d(double x, double y);
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void line_to_d(double x, double y);
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//--------------------------------------------------------------------
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int min_x() const { return m_outline.min_x(); }
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int min_y() const { return m_outline.min_y(); }
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int max_x() const { return m_outline.max_x(); }
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int max_y() const { return m_outline.max_y(); }
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//--------------------------------------------------------------------
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unsigned calculate_alpha(int area) const
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{
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int cover = area >> (poly_base_shift*2 + 1 - aa_shift);
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if(cover < 0) cover = -cover;
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if(m_filling_rule == fill_even_odd)
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{
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cover &= aa_2mask;
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if(cover > aa_num)
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{
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cover = aa_2num - cover;
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}
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}
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if(cover > aa_mask) cover = aa_mask;
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return m_gamma[cover];
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}
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//--------------------------------------------------------------------
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void sort()
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{
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m_outline.cells();
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}
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//--------------------------------------------------------------------
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bool rewind_scanlines()
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{
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close_polygon();
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m_iterator.cells = m_outline.cells();
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if(m_outline.num_cells() == 0)
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{
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return false;
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}
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m_iterator.cover = 0;
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m_iterator.last_y = (*m_iterator.cells)->y;
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return true;
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}
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//--------------------------------------------------------------------
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template<class Scanline> bool sweep_scanline(Scanline& sl)
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{
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sl.reset_spans();
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for(;;)
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{
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const cell_aa* cur_cell = *m_iterator.cells;
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if(cur_cell == 0) return false;
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++m_iterator.cells;
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m_iterator.last_y = cur_cell->y;
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for(;;)
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{
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int coord = cur_cell->packed_coord;
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int area = cur_cell->area;
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int last_x = cur_cell->x;
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m_iterator.cover += cur_cell->cover;
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//accumulate all cells with the same coordinates
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for(; (cur_cell = *m_iterator.cells) != 0; ++m_iterator.cells)
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{
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if(cur_cell->packed_coord != coord) break;
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area += cur_cell->area;
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m_iterator.cover += cur_cell->cover;
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}
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int alpha;
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if(cur_cell == 0 || cur_cell->y != m_iterator.last_y)
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{
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if(area)
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{
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alpha = calculate_alpha((m_iterator.cover << (poly_base_shift + 1)) - area);
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if(alpha)
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{
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sl.add_cell(last_x, alpha);
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}
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++last_x;
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}
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break;
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}
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++m_iterator.cells;
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if(area)
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{
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alpha = calculate_alpha((m_iterator.cover << (poly_base_shift + 1)) - area);
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if(alpha)
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{
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sl.add_cell(last_x, alpha);
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}
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++last_x;
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}
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if(cur_cell->x > last_x)
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{
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alpha = calculate_alpha(m_iterator.cover << (poly_base_shift + 1));
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if(alpha)
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{
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sl.add_span(last_x, cur_cell->x - last_x, alpha);
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}
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}
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}
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if(sl.num_spans())
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{
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sl.finalize(m_iterator.last_y);
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break;
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}
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}
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return true;
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}
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//--------------------------------------------------------------------
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bool hit_test(int tx, int ty);
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//--------------------------------------------------------------------
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void add_xy(const double* x, const double* y, unsigned n)
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{
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if(n > 2)
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{
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move_to_d(*x++, *y++);
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--n;
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do
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{
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line_to_d(*x++, *y++);
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}
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while(--n);
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}
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}
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//-------------------------------------------------------------------
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template<class VertexSource>
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void add_path(VertexSource& vs, unsigned id=0)
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{
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double x;
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double y;
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unsigned cmd;
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vs.rewind(id);
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while(!is_stop(cmd = vs.vertex(&x, &y)))
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{
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add_vertex(x, y, cmd);
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}
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}
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private:
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//--------------------------------------------------------------------
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// Disable copying
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rasterizer_scanline_aa(const rasterizer_scanline_aa<AA_Shift>&);
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const rasterizer_scanline_aa<AA_Shift>&
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operator = (const rasterizer_scanline_aa<AA_Shift>&);
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//--------------------------------------------------------------------
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void move_to_no_clip(int x, int y);
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void line_to_no_clip(int x, int y);
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void close_polygon_no_clip();
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void clip_segment(int x, int y);
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private:
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outline_aa m_outline;
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int m_gamma[aa_num];
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filling_rule_e m_filling_rule;
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int m_clipped_start_x;
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int m_clipped_start_y;
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int m_start_x;
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int m_start_y;
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int m_prev_x;
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int m_prev_y;
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unsigned m_prev_flags;
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unsigned m_status;
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rect m_clip_box;
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bool m_clipping;
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iterator m_iterator;
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};
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//------------------------------------------------------------------------
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template<unsigned AA_Shift>
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void rasterizer_scanline_aa<AA_Shift>::reset()
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{
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m_outline.reset();
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m_status = status_initial;
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}
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//------------------------------------------------------------------------
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template<unsigned AA_Shift>
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void rasterizer_scanline_aa<AA_Shift>::filling_rule(filling_rule_e filling_rule)
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{
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m_filling_rule = filling_rule;
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}
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//------------------------------------------------------------------------
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template<unsigned AA_Shift>
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void rasterizer_scanline_aa<AA_Shift>::clip_box(double x1, double y1, double x2, double y2)
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{
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reset();
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m_clip_box = rect(poly_coord(x1), poly_coord(y1),
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poly_coord(x2), poly_coord(y2));
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m_clip_box.normalize();
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m_clipping = true;
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}
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//------------------------------------------------------------------------
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template<unsigned AA_Shift>
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void rasterizer_scanline_aa<AA_Shift>::reset_clipping()
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{
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reset();
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m_clipping = false;
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}
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//------------------------------------------------------------------------
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template<unsigned AA_Shift>
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void rasterizer_scanline_aa<AA_Shift>::move_to_no_clip(int x, int y)
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{
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if(m_status == status_line_to)
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{
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close_polygon_no_clip();
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}
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m_outline.move_to(x, y);
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m_clipped_start_x = x;
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m_clipped_start_y = y;
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m_status = status_line_to;
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}
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//------------------------------------------------------------------------
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template<unsigned AA_Shift>
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void rasterizer_scanline_aa<AA_Shift>::line_to_no_clip(int x, int y)
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{
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if(m_status != status_initial)
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{
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m_outline.line_to(x, y);
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m_status = status_line_to;
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}
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}
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//------------------------------------------------------------------------
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template<unsigned AA_Shift>
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void rasterizer_scanline_aa<AA_Shift>::close_polygon_no_clip()
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{
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if(m_status == status_line_to)
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{
|
|
m_outline.line_to(m_clipped_start_x, m_clipped_start_y);
|
|
m_status = status_closed;
|
|
}
|
|
}
|
|
|
|
|
|
//------------------------------------------------------------------------
|
|
template<unsigned AA_Shift>
|
|
void rasterizer_scanline_aa<AA_Shift>::clip_segment(int x, int y)
|
|
{
|
|
unsigned flags = clipping_flags(x, y, m_clip_box);
|
|
if(m_prev_flags == flags)
|
|
{
|
|
if(flags == 0)
|
|
{
|
|
if(m_status == status_initial)
|
|
{
|
|
move_to_no_clip(x, y);
|
|
}
|
|
else
|
|
{
|
|
line_to_no_clip(x, y);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
int cx[4];
|
|
int cy[4];
|
|
unsigned n = clip_liang_barsky(m_prev_x, m_prev_y,
|
|
x, y,
|
|
m_clip_box,
|
|
cx, cy);
|
|
const int* px = cx;
|
|
const int* py = cy;
|
|
while(n--)
|
|
{
|
|
if(m_status == status_initial)
|
|
{
|
|
move_to_no_clip(*px++, *py++);
|
|
}
|
|
else
|
|
{
|
|
line_to_no_clip(*px++, *py++);
|
|
}
|
|
}
|
|
}
|
|
m_prev_flags = flags;
|
|
m_prev_x = x;
|
|
m_prev_y = y;
|
|
}
|
|
|
|
|
|
|
|
//------------------------------------------------------------------------
|
|
template<unsigned AA_Shift>
|
|
void rasterizer_scanline_aa<AA_Shift>::add_vertex(double x, double y, unsigned cmd)
|
|
{
|
|
if(is_close(cmd))
|
|
{
|
|
close_polygon();
|
|
}
|
|
else
|
|
{
|
|
if(is_move_to(cmd))
|
|
{
|
|
move_to(poly_coord(x), poly_coord(y));
|
|
}
|
|
else
|
|
{
|
|
if(is_vertex(cmd))
|
|
{
|
|
line_to(poly_coord(x), poly_coord(y));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
|
|
//------------------------------------------------------------------------
|
|
template<unsigned AA_Shift>
|
|
void rasterizer_scanline_aa<AA_Shift>::move_to(int x, int y)
|
|
{
|
|
if(m_clipping)
|
|
{
|
|
if(m_outline.sorted())
|
|
{
|
|
reset();
|
|
}
|
|
if(m_status == status_line_to)
|
|
{
|
|
close_polygon();
|
|
}
|
|
m_prev_x = m_start_x = x;
|
|
m_prev_y = m_start_y = y;
|
|
m_status = status_initial;
|
|
m_prev_flags = clipping_flags(x, y, m_clip_box);
|
|
if(m_prev_flags == 0)
|
|
{
|
|
move_to_no_clip(x, y);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
move_to_no_clip(x, y);
|
|
}
|
|
}
|
|
|
|
//------------------------------------------------------------------------
|
|
template<unsigned AA_Shift>
|
|
void rasterizer_scanline_aa<AA_Shift>::line_to(int x, int y)
|
|
{
|
|
if(m_clipping)
|
|
{
|
|
clip_segment(x, y);
|
|
}
|
|
else
|
|
{
|
|
line_to_no_clip(x, y);
|
|
}
|
|
}
|
|
|
|
//------------------------------------------------------------------------
|
|
template<unsigned AA_Shift>
|
|
void rasterizer_scanline_aa<AA_Shift>::close_polygon()
|
|
{
|
|
if(m_clipping)
|
|
{
|
|
clip_segment(m_start_x, m_start_y);
|
|
}
|
|
close_polygon_no_clip();
|
|
}
|
|
|
|
//------------------------------------------------------------------------
|
|
template<unsigned AA_Shift>
|
|
void rasterizer_scanline_aa<AA_Shift>::move_to_d(double x, double y)
|
|
{
|
|
move_to(poly_coord(x), poly_coord(y));
|
|
}
|
|
|
|
//------------------------------------------------------------------------
|
|
template<unsigned AA_Shift>
|
|
void rasterizer_scanline_aa<AA_Shift>::line_to_d(double x, double y)
|
|
{
|
|
line_to(poly_coord(x), poly_coord(y));
|
|
}
|
|
|
|
|
|
//------------------------------------------------------------------------
|
|
template<unsigned AA_Shift>
|
|
bool rasterizer_scanline_aa<AA_Shift>::hit_test(int tx, int ty)
|
|
{
|
|
close_polygon();
|
|
const cell_aa* const* cells = m_outline.cells();
|
|
if(m_outline.num_cells() == 0) return false;
|
|
|
|
int cover = 0;
|
|
|
|
const cell_aa* cur_cell = *cells++;
|
|
for(;;)
|
|
{
|
|
int alpha;
|
|
int coord = cur_cell->packed_coord;
|
|
int x = cur_cell->x;
|
|
int y = cur_cell->y;
|
|
|
|
if(y > ty) return false;
|
|
|
|
int area = cur_cell->area;
|
|
cover += cur_cell->cover;
|
|
|
|
while((cur_cell = *cells++) != 0)
|
|
{
|
|
if(cur_cell->packed_coord != coord) break;
|
|
area += cur_cell->area;
|
|
cover += cur_cell->cover;
|
|
}
|
|
|
|
if(area)
|
|
{
|
|
alpha = calculate_alpha((cover << (poly_base_shift + 1)) - area);
|
|
if(alpha)
|
|
{
|
|
if(tx == x && ty == y) return true;
|
|
}
|
|
x++;
|
|
}
|
|
|
|
if(!cur_cell) break;
|
|
|
|
if(cur_cell->x > x)
|
|
{
|
|
alpha = calculate_alpha(cover << (poly_base_shift + 1));
|
|
if(alpha)
|
|
{
|
|
if(ty == y && tx >= x && tx <= cur_cell->x) return true;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
#endif
|
|
|