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| | #include <math.h> |
| | #include "agg_arc.h" |
| |
|
| |
|
| | namespace agg |
| | { |
| | |
| | arc::arc(double x, double y, |
| | double rx, double ry, |
| | double a1, double a2, |
| | bool ccw) : |
| | m_x(x), m_y(y), m_rx(rx), m_ry(ry), m_scale(1.0) |
| | { |
| | normalize(a1, a2, ccw); |
| | } |
| |
|
| | |
| | void arc::init(double x, double y, |
| | double rx, double ry, |
| | double a1, double a2, |
| | bool ccw) |
| | { |
| | m_x = x; m_y = y; |
| | m_rx = rx; m_ry = ry; |
| | normalize(a1, a2, ccw); |
| | } |
| | |
| | |
| | void arc::approximation_scale(double s) |
| | { |
| | m_scale = s; |
| | if(m_initialized) |
| | { |
| | normalize(m_start, m_end, m_ccw); |
| | } |
| | } |
| |
|
| | |
| | void arc::rewind(unsigned) |
| | { |
| | m_path_cmd = path_cmd_move_to; |
| | m_angle = m_start; |
| | } |
| |
|
| | |
| | unsigned arc::vertex(double* x, double* y) |
| | { |
| | if(is_stop(m_path_cmd)) return path_cmd_stop; |
| | if((m_angle < m_end - m_da/4) != m_ccw) |
| | { |
| | *x = m_x + cos(m_end) * m_rx; |
| | *y = m_y + sin(m_end) * m_ry; |
| | m_path_cmd = path_cmd_stop; |
| | return path_cmd_line_to; |
| | } |
| |
|
| | *x = m_x + cos(m_angle) * m_rx; |
| | *y = m_y + sin(m_angle) * m_ry; |
| |
|
| | m_angle += m_da; |
| |
|
| | unsigned pf = m_path_cmd; |
| | m_path_cmd = path_cmd_line_to; |
| | return pf; |
| | } |
| |
|
| | |
| | void arc::normalize(double a1, double a2, bool ccw) |
| | { |
| | double ra = (fabs(m_rx) + fabs(m_ry)) / 2; |
| | m_da = acos(ra / (ra + 0.125 / m_scale)) * 2; |
| | if(ccw) |
| | { |
| | while(a2 < a1) a2 += pi * 2.0; |
| | } |
| | else |
| | { |
| | while(a1 < a2) a1 += pi * 2.0; |
| | m_da = -m_da; |
| | } |
| | m_ccw = ccw; |
| | m_start = a1; |
| | m_end = a2; |
| | m_initialized = true; |
| | } |
| |
|
| | } |
| |
|
