//---------------------------------------------------------------------------- // 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. //---------------------------------------------------------------------------- // // Viewport transformer - simple orthogonal conversions from world coordinates // to screen (device) ones. // //---------------------------------------------------------------------------- #ifndef AGG_TRANS_VIEWPORT_INCLUDED #define AGG_TRANS_VIEWPORT_INCLUDED #include <string.h> #include "agg_trans_affine.h" namespace agg { enum aspect_ratio_e { aspect_ratio_stretch, aspect_ratio_meet, aspect_ratio_slice }; //----------------------------------------------------------trans_viewport class trans_viewport { public: //------------------------------------------------------------------- trans_viewport() : m_world_x1(0.0), m_world_y1(0.0), m_world_x2(1.0), m_world_y2(1.0), m_device_x1(0.0), m_device_y1(0.0), m_device_x2(1.0), m_device_y2(1.0), m_aspect(aspect_ratio_stretch), m_is_valid(true), m_align_x(0.5), m_align_y(0.5), m_wx1(0.0), m_wy1(0.0), m_wx2(1.0), m_wy2(1.0), m_dx1(0.0), m_dy1(0.0), m_kx(1.0), m_ky(1.0) {} //------------------------------------------------------------------- void preserve_aspect_ratio(double alignx, double aligny, aspect_ratio_e aspect) { m_align_x = alignx; m_align_y = aligny; m_aspect = aspect; update(); } //------------------------------------------------------------------- void device_viewport(double x1, double y1, double x2, double y2) { m_device_x1 = x1; m_device_y1 = y1; m_device_x2 = x2; m_device_y2 = y2; update(); } //------------------------------------------------------------------- void world_viewport(double x1, double y1, double x2, double y2) { m_world_x1 = x1; m_world_y1 = y1; m_world_x2 = x2; m_world_y2 = y2; update(); } //------------------------------------------------------------------- void device_viewport(double* x1, double* y1, double* x2, double* y2) const { *x1 = m_device_x1; *y1 = m_device_y1; *x2 = m_device_x2; *y2 = m_device_y2; } //------------------------------------------------------------------- void world_viewport(double* x1, double* y1, double* x2, double* y2) const { *x1 = m_world_x1; *y1 = m_world_y1; *x2 = m_world_x2; *y2 = m_world_y2; } //------------------------------------------------------------------- void world_viewport_actual(double* x1, double* y1, double* x2, double* y2) const { *x1 = m_wx1; *y1 = m_wy1; *x2 = m_wx2; *y2 = m_wy2; } //------------------------------------------------------------------- bool is_valid() const { return m_is_valid; } double align_x() const { return m_align_x; } double align_y() const { return m_align_y; } aspect_ratio_e aspect_ratio() const { return m_aspect; } //------------------------------------------------------------------- void transform(double* x, double* y) const { *x = (*x - m_wx1) * m_kx + m_dx1; *y = (*y - m_wy1) * m_ky + m_dy1; } //------------------------------------------------------------------- void transform_scale_only(double* x, double* y) const { *x *= m_kx; *y *= m_ky; } //------------------------------------------------------------------- void inverse_transform(double* x, double* y) const { *x = (*x - m_dx1) / m_kx + m_wx1; *y = (*y - m_dy1) / m_ky + m_wy1; } //------------------------------------------------------------------- void inverse_transform_scale_only(double* x, double* y) const { *x /= m_kx; *y /= m_ky; } //------------------------------------------------------------------- double device_dx() const { return m_dx1 - m_wx1 * m_kx; } double device_dy() const { return m_dy1 - m_wy1 * m_ky; } //------------------------------------------------------------------- double scale_x() const { return m_kx; } //------------------------------------------------------------------- double scale_y() const { return m_ky; } //------------------------------------------------------------------- double scale() const { return (m_kx + m_ky) * 0.5; } //------------------------------------------------------------------- trans_affine to_affine() const { trans_affine mtx = trans_affine_translation(-m_wx1, -m_wy1); mtx *= trans_affine_scaling(m_kx, m_ky); mtx *= trans_affine_translation(m_dx1, m_dy1); return mtx; } //------------------------------------------------------------------- trans_affine to_affine_scale_only() const { return trans_affine_scaling(m_kx, m_ky); } //------------------------------------------------------------------- unsigned byte_size() const { return sizeof(*this); } void serialize(int8u* ptr) const { memcpy(ptr, this, sizeof(*this)); } void deserialize(const int8u* ptr) { memcpy(this, ptr, sizeof(*this)); } private: void update(); double m_world_x1; double m_world_y1; double m_world_x2; double m_world_y2; double m_device_x1; double m_device_y1; double m_device_x2; double m_device_y2; aspect_ratio_e m_aspect; bool m_is_valid; double m_align_x; double m_align_y; double m_wx1; double m_wy1; double m_wx2; double m_wy2; double m_dx1; double m_dy1; double m_kx; double m_ky; }; //----------------------------------------------------------------------- inline void trans_viewport::update() { const double epsilon = 1e-30; if(fabs(m_world_x1 - m_world_x2) < epsilon || fabs(m_world_y1 - m_world_y2) < epsilon || fabs(m_device_x1 - m_device_x2) < epsilon || fabs(m_device_y1 - m_device_y2) < epsilon) { m_wx1 = m_world_x1; m_wy1 = m_world_y1; m_wx2 = m_world_x1 + 1.0; m_wy2 = m_world_y2 + 1.0; m_dx1 = m_device_x1; m_dy1 = m_device_y1; m_kx = 1.0; m_ky = 1.0; m_is_valid = false; return; } double world_x1 = m_world_x1; double world_y1 = m_world_y1; double world_x2 = m_world_x2; double world_y2 = m_world_y2; double device_x1 = m_device_x1; double device_y1 = m_device_y1; double device_x2 = m_device_x2; double device_y2 = m_device_y2; if(m_aspect != aspect_ratio_stretch) { double d; m_kx = (device_x2 - device_x1) / (world_x2 - world_x1); m_ky = (device_y2 - device_y1) / (world_y2 - world_y1); if((m_aspect == aspect_ratio_meet) == (m_kx < m_ky)) { d = (world_y2 - world_y1) * m_ky / m_kx; world_y1 += (world_y2 - world_y1 - d) * m_align_y; world_y2 = world_y1 + d; } else { d = (world_x2 - world_x1) * m_kx / m_ky; world_x1 += (world_x2 - world_x1 - d) * m_align_x; world_x2 = world_x1 + d; } } m_wx1 = world_x1; m_wy1 = world_y1; m_wx2 = world_x2; m_wy2 = world_y2; m_dx1 = device_x1; m_dy1 = device_y1; m_kx = (device_x2 - device_x1) / (world_x2 - world_x1); m_ky = (device_y2 - device_y1) / (world_y2 - world_y1); m_is_valid = true; } } #endif |