diff options
Diffstat (limited to 'agg/source/agg_curves.cpp')
| -rwxr-xr-x | agg/source/agg_curves.cpp | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/agg/source/agg_curves.cpp b/agg/source/agg_curves.cpp new file mode 100755 index 000000000000..bae65f26b5a3 --- /dev/null +++ b/agg/source/agg_curves.cpp @@ -0,0 +1,246 @@ +//---------------------------------------------------------------------------- +// Anti-Grain Geometry - Version 2.3 +// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com) +// +// Permission to copy, use, modify, sell and distribute this software +// is granted provided this copyright notice appears in all copies. +// This software is provided "as is" without express or implied +// warranty, and with no claim as to its suitability for any purpose. +// +//---------------------------------------------------------------------------- +// Contact: mcseem@antigrain.com +// mcseemagg@yahoo.com +// http://www.antigrain.com +//---------------------------------------------------------------------------- +// +// classes curve3 and curve4 +// +//---------------------------------------------------------------------------- + +#include <math.h> +#include "agg_curves.h" + +namespace agg +{ + + //------------------------------------------------------------------------ + void curve3::init(double x1, double y1, + double x2, double y2, + double x3, double y3) + { + m_start_x = x1; + m_start_y = y1; + m_end_x = x3; + m_end_y = y3; + + double dx1 = x2 - x1; + double dy1 = y2 - y1; + double dx2 = x3 - x2; + double dy2 = y3 - y2; + + double len = sqrt(dx1 * dx1 + dy1 * dy1) + sqrt(dx2 * dx2 + dy2 * dy2); + + m_num_steps = int(len * 0.25 * m_scale); + + if(m_num_steps < 2) + { + m_num_steps = 2; + } + + double subdivide_step = 1.0 / m_num_steps; + double subdivide_step2 = subdivide_step * subdivide_step; + + double tmpx = (x1 - x2 * 2.0 + x3) * subdivide_step2; + double tmpy = (y1 - y2 * 2.0 + y3) * subdivide_step2; + + m_saved_fx = m_fx = x1; + m_saved_fy = m_fy = y1; + + m_saved_dfx = m_dfx = tmpx + (x2 - x1) * (2.0 * subdivide_step); + m_saved_dfy = m_dfy = tmpy + (y2 - y1) * (2.0 * subdivide_step); + + m_ddfx = tmpx * 2.0; + m_ddfy = tmpy * 2.0; + + m_step = m_num_steps; + } + + + + + //------------------------------------------------------------------------ + void curve3::rewind(unsigned) + { + if(m_num_steps == 0) + { + m_step = -1; + return; + } + m_step = m_num_steps; + m_fx = m_saved_fx; + m_fy = m_saved_fy; + m_dfx = m_saved_dfx; + m_dfy = m_saved_dfy; + } + + + + + //------------------------------------------------------------------------ + unsigned curve3::vertex(double* x, double* y) + { + if(m_step < 0) return path_cmd_stop; + if(m_step == m_num_steps) + { + *x = m_start_x; + *y = m_start_y; + --m_step; + return path_cmd_move_to; + } + if(m_step == 0) + { + *x = m_end_x; + *y = m_end_y; + --m_step; + return path_cmd_line_to; + } + m_fx += m_dfx; + m_fy += m_dfy; + m_dfx += m_ddfx; + m_dfy += m_ddfy; + *x = m_fx; + *y = m_fy; + --m_step; + return path_cmd_line_to; + } + + + + + + + + + + + + + + //------------------------------------------------------------------------ + void curve4::init(double x1, double y1, + double x2, double y2, + double x3, double y3, + double x4, double y4) + { + m_start_x = x1; + m_start_y = y1; + m_end_x = x4; + m_end_y = y4; + + double dx1 = x2 - x1; + double dy1 = y2 - y1; + double dx2 = x3 - x2; + double dy2 = y3 - y2; + double dx3 = x4 - x3; + double dy3 = y4 - y3; + + double len = sqrt(dx1 * dx1 + dy1 * dy1) + + sqrt(dx2 * dx2 + dy2 * dy2) + + sqrt(dx3 * dx3 + dy3 * dy3); + + m_num_steps = int(len * 0.25 * m_scale); + + if(m_num_steps < 2) + { + m_num_steps = 2; + } + + double subdivide_step = 1.0 / m_num_steps; + double subdivide_step2 = subdivide_step * subdivide_step; + double subdivide_step3 = subdivide_step * subdivide_step * subdivide_step; + + double pre1 = 3.0 * subdivide_step; + double pre2 = 3.0 * subdivide_step2; + double pre4 = 6.0 * subdivide_step2; + double pre5 = 6.0 * subdivide_step3; + + double tmp1x = x1 - x2 * 2.0 + x3; + double tmp1y = y1 - y2 * 2.0 + y3; + + double tmp2x = (x2 - x3) * 3.0 - x1 + x4; + double tmp2y = (y2 - y3) * 3.0 - y1 + y4; + + m_saved_fx = m_fx = x1; + m_saved_fy = m_fy = y1; + + m_saved_dfx = m_dfx = (x2 - x1) * pre1 + tmp1x * pre2 + tmp2x * subdivide_step3; + m_saved_dfy = m_dfy = (y2 - y1) * pre1 + tmp1y * pre2 + tmp2y * subdivide_step3; + + m_saved_ddfx = m_ddfx = tmp1x * pre4 + tmp2x * pre5; + m_saved_ddfy = m_ddfy = tmp1y * pre4 + tmp2y * pre5; + + m_dddfx = tmp2x * pre5; + m_dddfy = tmp2y * pre5; + + m_step = m_num_steps; + } + + + + + //------------------------------------------------------------------------ + void curve4::rewind(unsigned) + { + if(m_num_steps == 0) + { + m_step = -1; + return; + } + m_step = m_num_steps; + m_fx = m_saved_fx; + m_fy = m_saved_fy; + m_dfx = m_saved_dfx; + m_dfy = m_saved_dfy; + m_ddfx = m_saved_ddfx; + m_ddfy = m_saved_ddfy; + } + + + + + + //------------------------------------------------------------------------ + unsigned curve4::vertex(double* x, double* y) + { + if(m_step < 0) return path_cmd_stop; + if(m_step == m_num_steps) + { + *x = m_start_x; + *y = m_start_y; + --m_step; + return path_cmd_move_to; + } + if(m_step == 0) + { + *x = m_end_x; + *y = m_end_y; + --m_step; + return path_cmd_line_to; + } + m_fx += m_dfx; + m_fy += m_dfy; + m_dfx += m_ddfx; + m_dfy += m_ddfy; + m_ddfx += m_dddfx; + m_ddfy += m_dddfy; + *x = m_fx; + *y = m_fy; + --m_step; + return path_cmd_line_to; + } + + + + +} + |