//---------------------------------------------------------------------------- // Anti-Grain Geometry (AGG) - Version 2.5 // A high quality rendering engine for C++ // Copyright (C) 2002-2006 Maxim Shemanarev // Contact: mcseem@antigrain.com // mcseemagg@yahoo.com // http://antigrain.com // // AGG is free software; you can redistribute it and/or // modify it under the terms of the GNU General Public License // as published by the Free Software Foundation; either version 2 // of the License, or (at your option) any later version. // // AGG is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with AGG; if not, write to the Free Software // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, // MA 02110-1301, USA. //---------------------------------------------------------------------------- // // The author gratefully acknowleges the support of David Turner, // Robert Wilhelm, and Werner Lemberg - the authors of the FreeType // libray - in producing this work. See http://www.freetype.org for details. // //---------------------------------------------------------------------------- // // Adaptation for 32-bit screen coordinates has been sponsored by // Liberty Technology Systems, Inc., visit http://lib-sys.com // // Liberty Technology Systems, Inc. is the provider of // PostScript and PDF technology for software developers. // //---------------------------------------------------------------------------- #ifndef AGG_RASTERIZER_CELLS_AA_INCLUDED #define AGG_RASTERIZER_CELLS_AA_INCLUDED #include <string.h> #include <math.h> #include "agg_math.h" #include "agg_array.h" namespace agg { //-----------------------------------------------------rasterizer_cells_aa // An internal class that implements the main rasterization algorithm. // Used in the rasterizer. Should not be used direcly. template<class Cell> class rasterizer_cells_aa { enum cell_block_scale_e { cell_block_shift = 12, cell_block_size = 1 << cell_block_shift, cell_block_mask = cell_block_size - 1, cell_block_pool = 256, cell_block_limit = 1024 }; struct sorted_y { unsigned start; unsigned num; }; public: typedef Cell cell_type; typedef rasterizer_cells_aa<Cell> self_type; ~rasterizer_cells_aa(); rasterizer_cells_aa(); void reset(); void style(const cell_type& style_cell); void line(int x1, int y1, int x2, int y2); int min_x() const { return m_min_x; } int min_y() const { return m_min_y; } int max_x() const { return m_max_x; } int max_y() const { return m_max_y; } void sort_cells(); unsigned total_cells() const { return m_num_cells; } unsigned scanline_num_cells(unsigned y) const { return m_sorted_y[y - m_min_y].num; } const cell_type* const* scanline_cells(unsigned y) const { return m_sorted_cells.data() + m_sorted_y[y - m_min_y].start; } bool sorted() const { return m_sorted; } private: rasterizer_cells_aa(const self_type&); const self_type& operator = (const self_type&); void set_curr_cell(int x, int y); void add_curr_cell(); void render_hline(int ey, int x1, int y1, int x2, int y2); void allocate_block(); private: unsigned m_num_blocks; unsigned m_max_blocks; unsigned m_curr_block; unsigned m_num_cells; cell_type** m_cells; cell_type* m_curr_cell_ptr; pod_vector<cell_type*> m_sorted_cells; pod_vector<sorted_y> m_sorted_y; cell_type m_curr_cell; cell_type m_style_cell; int m_min_x; int m_min_y; int m_max_x; int m_max_y; bool m_sorted; }; //------------------------------------------------------------------------ template<class Cell> rasterizer_cells_aa<Cell>::~rasterizer_cells_aa() { if(m_num_blocks) { cell_type** ptr = m_cells + m_num_blocks - 1; while(m_num_blocks--) { pod_allocator<cell_type>::deallocate(*ptr, cell_block_size); ptr--; } pod_allocator<cell_type*>::deallocate(m_cells, m_max_blocks); } } //------------------------------------------------------------------------ template<class Cell> rasterizer_cells_aa<Cell>::rasterizer_cells_aa() : m_num_blocks(0), m_max_blocks(0), m_curr_block(0), m_num_cells(0), m_cells(0), m_curr_cell_ptr(0), m_sorted_cells(), m_sorted_y(), m_min_x(0x7FFFFFFF), m_min_y(0x7FFFFFFF), m_max_x(-0x7FFFFFFF), m_max_y(-0x7FFFFFFF), m_sorted(false) { m_style_cell.initial(); m_curr_cell.initial(); } //------------------------------------------------------------------------ template<class Cell> void rasterizer_cells_aa<Cell>::reset() { m_num_cells = 0; m_curr_block = 0; m_curr_cell.initial(); m_style_cell.initial(); m_sorted = false; m_min_x = 0x7FFFFFFF; m_min_y = 0x7FFFFFFF; m_max_x = -0x7FFFFFFF; m_max_y = -0x7FFFFFFF; } //------------------------------------------------------------------------ template<class Cell> AGG_INLINE void rasterizer_cells_aa<Cell>::add_curr_cell() { if(m_curr_cell.area | m_curr_cell.cover) { if((m_num_cells & cell_block_mask) == 0) { if(m_num_blocks >= cell_block_limit) return; allocate_block(); } *m_curr_cell_ptr++ = m_curr_cell; ++m_num_cells; } } //------------------------------------------------------------------------ template<class Cell> AGG_INLINE void rasterizer_cells_aa<Cell>::set_curr_cell(int x, int y) { if(m_curr_cell.not_equal(x, y, m_style_cell)) { add_curr_cell(); m_curr_cell.style(m_style_cell); m_curr_cell.x = x; m_curr_cell.y = y; m_curr_cell.cover = 0; m_curr_cell.area = 0; } } //------------------------------------------------------------------------ template<class Cell> AGG_INLINE void rasterizer_cells_aa<Cell>::render_hline(int ey, int x1, int y1, int x2, int y2) { int ex1 = x1 >> poly_subpixel_shift; int ex2 = x2 >> poly_subpixel_shift; int fx1 = x1 & poly_subpixel_mask; int fx2 = x2 & poly_subpixel_mask; int delta, p, first, dx; int incr, lift, mod, rem; //trivial case. Happens often if(y1 == y2) { set_curr_cell(ex2, ey); return; } //everything is located in a single cell. That is easy! if(ex1 == ex2) { delta = y2 - y1; m_curr_cell.cover += delta; m_curr_cell.area += (fx1 + fx2) * delta; return; } //ok, we'll have to render a run of adjacent cells on the same //hline... p = (poly_subpixel_scale - fx1) * (y2 - y1); first = poly_subpixel_scale; incr = 1; dx = x2 - x1; if(dx < 0) { p = fx1 * (y2 - y1); first = 0; incr = -1; dx = -dx; } delta = p / dx; mod = p % dx; if(mod < 0) { delta--; mod += dx; } m_curr_cell.cover += delta; m_curr_cell.area += (fx1 + first) * delta; ex1 += incr; set_curr_cell(ex1, ey); y1 += delta; if(ex1 != ex2) { p = poly_subpixel_scale * (y2 - y1 + delta); lift = p / dx; rem = p % dx; if (rem < 0) { lift--; rem += dx; } mod -= dx; while (ex1 != ex2) { delta = lift; mod += rem; if(mod >= 0) { mod -= dx; delta++; } m_curr_cell.cover += delta; m_curr_cell.area += poly_subpixel_scale * delta; y1 += delta; ex1 += incr; set_curr_cell(ex1, ey); } } delta = y2 - y1; m_curr_cell.cover += delta; m_curr_cell.area += (fx2 + poly_subpixel_scale - first) * delta; } //------------------------------------------------------------------------ template<class Cell> AGG_INLINE void rasterizer_cells_aa<Cell>::style(const cell_type& style_cell) { m_style_cell.style(style_cell); } //------------------------------------------------------------------------ template<class Cell> void rasterizer_cells_aa<Cell>::line(int x1, int y1, int x2, int y2) { enum dx_limit_e { dx_limit = 16384 << poly_subpixel_shift }; int dx = x2 - x1; if(dx >= dx_limit || dx <= -dx_limit) { int cx = (x1 + x2) >> 1; int cy = (y1 + y2) >> 1; line(x1, y1, cx, cy); line(cx, cy, x2, y2); } int dy = y2 - y1; int ex1 = x1 >> poly_subpixel_shift; int ex2 = x2 >> poly_subpixel_shift; int ey1 = y1 >> poly_subpixel_shift; int ey2 = y2 >> poly_subpixel_shift; int fy1 = y1 & poly_subpixel_mask; int fy2 = y2 & poly_subpixel_mask; int x_from, x_to; int p, rem, mod, lift, delta, first, incr; if(ex1 < m_min_x) m_min_x = ex1; if(ex1 > m_max_x) m_max_x = ex1; if(ey1 < m_min_y) m_min_y = ey1; if(ey1 > m_max_y) m_max_y = ey1; if(ex2 < m_min_x) m_min_x = ex2; if(ex2 > m_max_x) m_max_x = ex2; if(ey2 < m_min_y) m_min_y = ey2; if(ey2 > m_max_y) m_max_y = ey2; set_curr_cell(ex1, ey1); //everything is on a single hline if(ey1 == ey2) { render_hline(ey1, x1, fy1, x2, fy2); return; } //Vertical line - we have to calculate start and end cells, //and then - the common values of the area and coverage for //all cells of the line. We know exactly there's only one //cell, so, we don't have to call render_hline(). incr = 1; if(dx == 0) { int ex = x1 >> poly_subpixel_shift; int two_fx = (x1 - (ex << poly_subpixel_shift)) << 1; int area; first = poly_subpixel_scale; if(dy < 0) { first = 0; incr = -1; } x_from = x1; //render_hline(ey1, x_from, fy1, x_from, first); delta = first - fy1; m_curr_cell.cover += delta; m_curr_cell.area += two_fx * delta; ey1 += incr; set_curr_cell(ex, ey1); delta = first + first - poly_subpixel_scale; area = two_fx * delta; while(ey1 != ey2) { //render_hline(ey1, x_from, poly_subpixel_scale - first, x_from, first); m_curr_cell.cover = delta; m_curr_cell.area = area; ey1 += incr; set_curr_cell(ex, ey1); } //render_hline(ey1, x_from, poly_subpixel_scale - first, x_from, fy2); delta = fy2 - poly_subpixel_scale + first; m_curr_cell.cover += delta; m_curr_cell.area += two_fx * delta; return; } //ok, we have to render several hlines p = (poly_subpixel_scale - fy1) * dx; first = poly_subpixel_scale; if(dy < 0) { p = fy1 * dx; first = 0; incr = -1; dy = -dy; } delta = p / dy; mod = p % dy; if(mod < 0) { delta--; mod += dy; } x_from = x1 + delta; render_hline(ey1, x1, fy1, x_from, first); ey1 += incr; set_curr_cell(x_from >> poly_subpixel_shift, ey1); if(ey1 != ey2) { p = poly_subpixel_scale * dx; lift = p / dy; rem = p % dy; if(rem < 0) { lift--; rem += dy; } mod -= dy; while(ey1 != ey2) { delta = lift; mod += rem; if (mod >= 0) { mod -= dy; delta++; } x_to = x_from + delta; render_hline(ey1, x_from, poly_subpixel_scale - first, x_to, first); x_from = x_to; ey1 += incr; set_curr_cell(x_from >> poly_subpixel_shift, ey1); } } render_hline(ey1, x_from, poly_subpixel_scale - first, x2, fy2); } //------------------------------------------------------------------------ template<class Cell> void rasterizer_cells_aa<Cell>::allocate_block() { if(m_curr_block >= m_num_blocks) { if(m_num_blocks >= m_max_blocks) { cell_type** new_cells = pod_allocator<cell_type*>::allocate(m_max_blocks + cell_block_pool); if(m_cells) { memcpy(new_cells, m_cells, m_max_blocks * sizeof(cell_type*)); pod_allocator<cell_type*>::deallocate(m_cells, m_max_blocks); } m_cells = new_cells; m_max_blocks += cell_block_pool; } m_cells[m_num_blocks++] = pod_allocator<cell_type>::allocate(cell_block_size); } m_curr_cell_ptr = m_cells[m_curr_block++]; } //------------------------------------------------------------------------ template <class T> static AGG_INLINE void swap_cells(T* a, T* b) { T temp = *a; *a = *b; *b = temp; } //------------------------------------------------------------------------ enum { qsort_threshold = 9 }; //------------------------------------------------------------------------ template<class Cell> void qsort_cells(Cell** start, unsigned num) { Cell** stack[80]; Cell*** top; Cell** limit; Cell** base; limit = start + num; base = start; top = stack; for (;;) { int len = int(limit - base); Cell** i; Cell** j; Cell** pivot; if(len > qsort_threshold) { // we use base + len/2 as the pivot pivot = base + len / 2; swap_cells(base, pivot); i = base + 1; j = limit - 1; // now ensure that *i <= *base <= *j if((*j)->x < (*i)->x) { swap_cells(i, j); } if((*base)->x < (*i)->x) { swap_cells(base, i); } if((*j)->x < (*base)->x) { swap_cells(base, j); } for(;;) { int x = (*base)->x; do i++; while( (*i)->x < x ); do j--; while( x < (*j)->x ); if(i > j) { break; } swap_cells(i, j); } swap_cells(base, j); // now, push the largest sub-array if(j - base > limit - i) { top[0] = base; top[1] = j; base = i; } else { top[0] = i; top[1] = limit; limit = j; } top += 2; } else { // the sub-array is small, perform insertion sort j = base; i = j + 1; for(; i < limit; j = i, i++) { for(; j[1]->x < (*j)->x; j--) { swap_cells(j + 1, j); if (j == base) { break; } } } if(top > stack) { top -= 2; base = top[0]; limit = top[1]; } else { break; } } } } //------------------------------------------------------------------------ template<class Cell> void rasterizer_cells_aa<Cell>::sort_cells() { if(m_sorted) return; //Perform sort only the first time. add_curr_cell(); m_curr_cell.x = 0x7FFFFFFF; m_curr_cell.y = 0x7FFFFFFF; m_curr_cell.cover = 0; m_curr_cell.area = 0; if(m_num_cells == 0) return; // DBG: Check to see if min/max works well. //for(unsigned nc = 0; nc < m_num_cells; nc++) //{ // cell_type* cell = m_cells[nc >> cell_block_shift] + (nc & cell_block_mask); // if(cell->x < m_min_x || // cell->y < m_min_y || // cell->x > m_max_x || // cell->y > m_max_y) // { // cell = cell; // Breakpoint here // } //} // Allocate the array of cell pointers m_sorted_cells.allocate(m_num_cells, 16); // Allocate and zero the Y array m_sorted_y.allocate(m_max_y - m_min_y + 1, 16); m_sorted_y.zero(); // Create the Y-histogram (count the numbers of cells for each Y) cell_type** block_ptr = m_cells; cell_type* cell_ptr; unsigned nb = m_num_cells >> cell_block_shift; unsigned i; while(nb--) { cell_ptr = *block_ptr++; i = cell_block_size; while(i--) { m_sorted_y[cell_ptr->y - m_min_y].start++; ++cell_ptr; } } cell_ptr = *block_ptr++; i = m_num_cells & cell_block_mask; while(i--) { m_sorted_y[cell_ptr->y - m_min_y].start++; ++cell_ptr; } // Convert the Y-histogram into the array of starting indexes unsigned start = 0; for(i = 0; i < m_sorted_y.size(); i++) { unsigned v = m_sorted_y[i].start; m_sorted_y[i].start = start; start += v; } // Fill the cell pointer array sorted by Y block_ptr = m_cells; nb = m_num_cells >> cell_block_shift; while(nb--) { cell_ptr = *block_ptr++; i = cell_block_size; while(i--) { sorted_y& curr_y = m_sorted_y[cell_ptr->y - m_min_y]; m_sorted_cells[curr_y.start + curr_y.num] = cell_ptr; ++curr_y.num; ++cell_ptr; } } cell_ptr = *block_ptr++; i = m_num_cells & cell_block_mask; while(i--) { sorted_y& curr_y = m_sorted_y[cell_ptr->y - m_min_y]; m_sorted_cells[curr_y.start + curr_y.num] = cell_ptr; ++curr_y.num; ++cell_ptr; } // Finally arrange the X-arrays for(i = 0; i < m_sorted_y.size(); i++) { const sorted_y& curr_y = m_sorted_y[i]; if(curr_y.num) { qsort_cells(m_sorted_cells.data() + curr_y.start, curr_y.num); } } m_sorted = true; } //------------------------------------------------------scanline_hit_test class scanline_hit_test { public: scanline_hit_test(int x) : m_x(x), m_hit(false) {} void reset_spans() {} void finalize(int) {} void add_cell(int x, int) { if(m_x == x) m_hit = true; } void add_span(int x, int len, int) { if(m_x >= x && m_x < x+len) m_hit = true; } unsigned num_spans() const { return 1; } bool hit() const { return m_hit; } private: int m_x; bool m_hit; }; } #endif |