/* * This program source code file is part of KiCad, a free EDA CAD application. * * Copyright (C) 2017 Jean-Pierre Charras, jp.charras at wanadoo.fr * Copyright (C) 2020-2023 KiCad Developers, see AUTHORS.txt for contributors. * * This program 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. * * This program 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 this program; if not, you may find one here: * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html * or you may search the http://www.gnu.org website for the version 2 license, * or you may write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */ /** * @file HPGL_plotter.cpp * @brief KiCad plotter for HPGL file format. * Since this plot engine is mostly intended for import in external programs, * sadly HPGL/2 isn't supported a lot... some of the primitives use overlapped * strokes to fill the shape. */ /* Some HPGL commands: * Note: the HPGL unit is 25 micrometers * All commands MUST be terminated by a semi-colon or a linefeed. * Spaces can NOT be substituted for required commas in the syntax of a command. * * * AA (Arc Absolute): Angle is a floating point # (requires non integer value) * Draws an arc with the center at (X,Y). * A positive angle creates a counter-clockwise arc. * If the chord angle is specified, * this will be the number of degrees used for stepping around the arc. * If no value is given then a default value of five degrees is used. * AA x, y, a {,b}; * * AR (Arc Relative): * AR Dx, Dy, a {, b}; * * CA (Alternate Character Set): * CA {n}; * * CI (Circle): * CI r {,b}; * * CP (Character Plot): * CP {h, v}; * h [-127.9999 .. 127.9999] Number of characters horizontally * v [-127.9999 .. 127.9999] Number of characters vertically * * CS (Standard Character Set): * CS {n}; * * DR (Relative Direction for Label Text): * DR s, a; * * DI (Absolute Direction for Label Text): * DI {s, a}; * * DT (Define Terminator - this character becomes unavailable except to terminate a label string. * Default is ^C control-C): * DT t; * * EA (rEctangle Absolute - Unfilled, from current position to diagonal x,y): * EA x, y; * * ER (rEctangle Relative - Unfilled, from current position to diagonal x,y): * ER x,y; * * FT (Fill Type): * FT {s {,l {a}}}; * * IM (Input Mask): * IM {f}; * * IN (Initialize): This command instructs the controller to begin processing the HPGL plot file. * Without this, the commands in the file are received but never executed. * If multiple IN s are found during execution of the file, * the controller performs a Pause/Cancel operation. * All motion from the previous job, yet to be executed, is lost, * and the new information is executed. * IN; * * IP Input P1 and P2: * IP {P1x, P1y {, P2x, P2y}}; * * IW (Input Window): * IW {XUL, YUL, XOR, YOR}; * * LB (Label): * LB c1 .. cn t; * * PA (Plot Absolute): Moves to an absolute HPGL position and sets absolute mode for * future PU and PD commands. If no arguments follow the command, * only absolute mode is set. * PA {x1, y1 {{PU|PD|,} ..., ..., xn, yn}}; * P1x, P1y, P2x, P2y [Integer in ASCII] * * PD (Pen Down): Executes pen then moves to the requested position * if one is specified. This position is dependent on whether absolute * or relative mode is set. This command performs no motion in 3-D mode, * but the outputs and feedrates are affected. * PD {x, y}; * * PM Polygon mode * associated commands: * PM2 End polygon mode * FP Fill polygon * EP Draw polygon outline * * PR (Plot Relative): Moves to the relative position specified and sets relative mode * for future PU and PD commands. * If no arguments follow the command, only relative mode is set. * PR {Dx1, Dy1 {{PU|PD|,} ..., ..., Dxn, Dyn}}; * * PS (Paper Size): * PS {n}; * * PT (Pen Thickness): in mm * PT {l}; * * PU (Pen Up): Executes pen then moves to the requested position * if one is specified. This position is dependent on whether absolute * or relative mode is set. * This command performs no motion in 3-D mode, but the outputs * and feedrates are affected. * PU {x, y}; * * RA (Rectangle Absolute - Filled, from current position to diagonal x,y): * RA x, y; * * RO (Rotate Coordinate System): * RO; * * RR (Rectangle Relative - Filled, from current position to diagonal x,y): * RR x, y; * * SA (Select Alternate Set): * SA; * * SC (Scale): * SC {Xmin, Xmax, Ymin, Ymax}; * * SI (Absolute Character Size): * SI b, h; * b [-127.9999 .. 127.9999, keine 0] * h [-127.9999 .. 127.9999, keine 0] * * SL (Character Slant): * SL {a}; * a [-3.5 .. -0.5, 0.5 .. 3.5] * * SP (Select Pen): Selects a new pen or tool for use. * If no pen number or a value of zero is given, * the controller performs an EOF (end of file command). * Once an EOF is performed, no motion is executed, * until a new IN command is received. * SP n; * * SR (Relative Character Size): * SR {b, h}; * b [-127.9999 .. 127.9999, keine 0] * h [-127.9999 .. 127.9999, keine 0] * * SS (Select Standard Set): * SS; * * TL (Tick Length): * TL {tp {, tm}}; * * UC (User Defined Character): * UC {i,} x1, y1, {i,} x2, y2, ... {i,} xn, yn; * * VS (Velocity Select): * VS {v {, n}}; * v [1 .. 40] in cm/s * n [1 .. 8] * * XT (X Tick): * XT; * * YT (Y Tick): * YT; */ #include #include #include #include // for KiROUND #include #include /// Compute the distance between two VECTOR2D points. static double dpoint_dist( const VECTOR2D& a, const VECTOR2D& b ); // The hpgl command to close a polygon def, fill it and plot outline: // PM 2; ends the polygon definition and closes it if not closed // FP; fills the polygon // EP; draws the polygon outline. It usually gives a better look to the filled polygon static const char hpgl_end_polygon_cmd[] = "PM 2; FP; EP;\n"; // HPGL scale factor (1 Plotter Logical Unit = 1/40mm = 25 micrometers) // PLUsPERDECIMIL = (25.4 / 10000) / 0.025 static const double PLUsPERDECIMIL = 0.1016; HPGL_PLOTTER::HPGL_PLOTTER() : m_arcTargetChordLength( 0 ), m_arcMinChordDegrees( 5.0, DEGREES_T ), m_lineStyle( LINE_STYLE::SOLID ), m_useUserCoords( false ), m_fitUserCoords( false ), m_current_item( nullptr ) { SetPenSpeed( 40 ); // Default pen speed = 40 cm/s; Pen speed is *always* in cm SetPenNumber( 1 ); // Default pen num = 1 SetPenDiameter( 0.0 ); } void HPGL_PLOTTER::SetViewport( const VECTOR2I& aOffset, double aIusPerDecimil, double aScale, bool aMirror ) { m_plotOffset = aOffset; m_plotScale = aScale; m_IUsPerDecimil = aIusPerDecimil; m_iuPerDeviceUnit = PLUsPERDECIMIL / aIusPerDecimil; // Compute the paper size in IUs. m_paperSize = m_pageInfo.GetSizeMils(); m_paperSize.x *= 10.0 * aIusPerDecimil; m_paperSize.y *= 10.0 * aIusPerDecimil; m_plotMirror = aMirror; } void HPGL_PLOTTER::SetTargetChordLength( double chord_len ) { m_arcTargetChordLength = userToDeviceSize( chord_len ); } bool HPGL_PLOTTER::StartPlot( const wxString& aPageNumber ) { wxASSERT( m_outputFile ); fprintf( m_outputFile, "IN;VS%d;PU;PA;SP%d;\n", m_penSpeed, m_penNumber ); // Set HPGL Pen Thickness (in mm) (useful in polygon fill command) double penThicknessMM = userToDeviceSize( m_penDiameter ) / 40; fprintf( m_outputFile, "PT %.1f;\n", penThicknessMM ); return true; } bool HPGL_PLOTTER::EndPlot() { wxASSERT( m_outputFile ); fputs( "PU;\n", m_outputFile ); flushItem(); sortItems( m_items ); if( m_items.size() > 0 ) { if( m_useUserCoords ) { if( m_fitUserCoords ) { BOX2D bbox = m_items.front().bbox; for( HPGL_ITEM const& item : m_items ) bbox.Merge( item.bbox ); fprintf( m_outputFile, "SC%.0f,%.0f,%.0f,%.0f;\n", bbox.GetX(), bbox.GetX() + bbox.GetWidth(), bbox.GetY(), bbox.GetY() + bbox.GetHeight() ); } else { VECTOR2D pagesize_device( m_paperSize * m_iuPerDeviceUnit ); fprintf( m_outputFile, "SC%.0f,%.0f,%.0f,%.0f;\n", 0.0, pagesize_device.x, 0.0, pagesize_device.y ); } } VECTOR2I loc = m_items.begin()->loc_start; bool pen_up = true; LINE_STYLE current_dash = LINE_STYLE::SOLID; int current_pen = m_penNumber; for( HPGL_ITEM const& item : m_items ) { if( item.loc_start != loc || pen_up ) { if( !pen_up ) { fputs( "PU;", m_outputFile ); pen_up = true; } fprintf( m_outputFile, "PA %.0f,%.0f;", item.loc_start.x, item.loc_start.y ); } if( item.dashType != current_dash ) { current_dash = item.dashType; fputs( lineStyleCommand( item.dashType ), m_outputFile ); } if( item.pen != current_pen ) { if( !pen_up ) { fputs( "PU;", m_outputFile ); pen_up = true; } fprintf( m_outputFile, "SP%d;", item.pen ); current_pen = item.pen; } if( pen_up && !item.lift_before ) { fputs( "PD;", m_outputFile ); pen_up = false; } else if( !pen_up && item.lift_before ) { fputs( "PU;", m_outputFile ); pen_up = true; } fputs( static_cast( item.content.utf8_str() ), m_outputFile ); if( !item.pen_returns ) { // Assume commands drop the pen pen_up = false; } if( item.lift_after ) { fputs( "PU;", m_outputFile ); pen_up = true; } else { loc = item.loc_end; } fputs( "\n", m_outputFile ); } } fputs( "PU;PA;SP0;\n", m_outputFile ); fclose( m_outputFile ); m_outputFile = nullptr; return true; } void HPGL_PLOTTER::SetPenDiameter( double diameter ) { m_penDiameter = diameter; } void HPGL_PLOTTER::Rect( const VECTOR2I& p1, const VECTOR2I& p2, FILL_T aFill, int aWidth ) { wxASSERT( m_outputFile ); // EA command seems to always fill the rectangle, so plot as a polygon instead std::vector cornerList; cornerList.emplace_back( p1.x, p1.y ); cornerList.emplace_back( p2.x, p1.y ); cornerList.emplace_back( p2.x, p2.y ); cornerList.emplace_back( p1.x, p2.y ); cornerList.emplace_back( p1.x, p1.y ); PlotPoly( cornerList, aFill, aWidth, nullptr ); } void HPGL_PLOTTER::Circle( const VECTOR2I& aCenter, int aDiameter, FILL_T aFill, int aWidth ) { wxASSERT( m_outputFile ); double radius = userToDeviceSize( aDiameter / 2 ); VECTOR2D center_dev = userToDeviceCoordinates( aCenter ); SetCurrentLineWidth( aWidth ); double const circumf = 2.0 * M_PI * radius; double const target_chord_length = m_arcTargetChordLength; EDA_ANGLE chord_angle = ANGLE_360 * target_chord_length / circumf; chord_angle = std::clamp( chord_angle, m_arcMinChordDegrees, ANGLE_45 ); if( aFill == FILL_T::FILLED_SHAPE ) { // Draw the filled area MoveTo( aCenter ); startOrAppendItem( center_dev, wxString::Format( "PM 0;CI %g,%g;%s", radius, chord_angle.AsDegrees(), hpgl_end_polygon_cmd ) ); m_current_item->lift_before = true; m_current_item->bbox.Merge( BOX2D( center_dev - radius, VECTOR2D( 2 * radius, 2 * radius ) ) ); PenFinish(); } if( radius > 0 ) { MoveTo( aCenter ); startOrAppendItem( center_dev, wxString::Format( "CI %g,%g;", radius, chord_angle.AsDegrees() ) ); m_current_item->lift_before = true; m_current_item->bbox.Merge( BOX2D( center_dev - radius, VECTOR2D( 2 * radius, 2 * radius ) ) ); PenFinish(); } } void HPGL_PLOTTER::PlotPoly( const std::vector& aCornerList, FILL_T aFill, int aWidth, void* aData ) { if( aCornerList.size() <= 1 ) return; // Width less than zero is occasionally used to create background-only // polygons. Don't set that as the plotter line width, that'll cause // trouble. Also, later, skip plotting the outline if this is the case. if( aWidth > 0 ) { SetCurrentLineWidth( aWidth ); } MoveTo( aCornerList[0] ); startItem( userToDeviceCoordinates( aCornerList[0] ) ); if( aFill == FILL_T::FILLED_SHAPE || aFill == FILL_T::FILLED_WITH_COLOR ) { // Draw the filled area SetCurrentLineWidth( USE_DEFAULT_LINE_WIDTH ); m_current_item->content << wxString( "PM 0;\n" ); // Start polygon for( unsigned ii = 1; ii < aCornerList.size(); ++ii ) LineTo( aCornerList[ii] ); int ii = aCornerList.size() - 1; if( aCornerList[ii] != aCornerList[0] ) LineTo( aCornerList[0] ); m_current_item->content << hpgl_end_polygon_cmd; // Close, fill polygon and draw outlines m_current_item->pen_returns = true; } else if( aWidth != 0 ) { // Plot only the polygon outline. for( unsigned ii = 1; ii < aCornerList.size(); ii++ ) LineTo( aCornerList[ii] ); // Always close polygon if filled. if( aFill != FILL_T::NO_FILL ) { int ii = aCornerList.size() - 1; if( aCornerList[ii] != aCornerList[0] ) LineTo( aCornerList[0] ); } } PenFinish(); } void HPGL_PLOTTER::PenTo( const VECTOR2I& pos, char plume ) { wxASSERT( m_outputFile ); if( plume == 'Z' ) { m_penState = 'Z'; flushItem(); return; } VECTOR2D pos_dev = userToDeviceCoordinates( pos ); VECTOR2D lastpos_dev = userToDeviceCoordinates( m_penLastpos ); if( plume == 'U' ) { m_penState = 'U'; flushItem(); } else if( plume == 'D' ) { m_penState = 'D'; startOrAppendItem( lastpos_dev, wxString::Format( "PA %.0f,%.0f;", pos_dev.x, pos_dev.y ) ); m_current_item->loc_end = pos_dev; m_current_item->bbox.Merge( pos_dev ); } m_penLastpos = pos; } void HPGL_PLOTTER::SetDash( int aLineWidth, LINE_STYLE aLineStyle ) { m_lineStyle = aLineStyle; flushItem(); } void HPGL_PLOTTER::ThickSegment( const VECTOR2I& start, const VECTOR2I& end, int width, OUTLINE_MODE tracemode, void* aData ) { wxASSERT( m_outputFile ); // Suppress overlap if pen is too big if( m_penDiameter >= width ) { MoveTo( start ); FinishTo( end ); } else { segmentAsOval( start, end, width, tracemode ); } } void HPGL_PLOTTER::Arc( const VECTOR2D& aCenter, const EDA_ANGLE& aStartAngle, const EDA_ANGLE& aAngle, double aRadius, FILL_T aFill, int aWidth ) { if( aRadius <= 0 ) return; double const radius_device = userToDeviceSize( aRadius ); double const circumf_device = 2.0 * M_PI * radius_device; double const target_chord_length = m_arcTargetChordLength; EDA_ANGLE chord_angle = ANGLE_360 * target_chord_length / circumf_device; chord_angle = std::max( m_arcMinChordDegrees, std::min( chord_angle, ANGLE_45 ) ); VECTOR2D centre_device = userToDeviceCoordinates( aCenter ); EDA_ANGLE angle = aAngle; if( !m_plotMirror ) angle = -angle; EDA_ANGLE startAngle = -aStartAngle; // Calculate arc start point: VECTOR2I cmap( aCenter.x + KiROUND( aRadius * startAngle.Cos() ), aCenter.y - KiROUND( aRadius * startAngle.Sin() ) ); VECTOR2D cmap_dev = userToDeviceCoordinates( cmap ); startOrAppendItem( cmap_dev, wxString::Format( "AA %.0f,%.0f,%.0f,%g", centre_device.x, centre_device.y, angle.AsDegrees(), chord_angle.AsDegrees() ) ); // TODO We could compute the final position and full bounding box instead... m_current_item->bbox.Merge( BOX2D( centre_device - radius_device, VECTOR2D( radius_device * 2, radius_device * 2 ) ) ); m_current_item->lift_after = true; flushItem(); } void HPGL_PLOTTER::FlashPadOval( const VECTOR2I& aPos, const VECTOR2I& aSize, const EDA_ANGLE& aOrient, OUTLINE_MODE aTraceMode, void* aData ) { wxASSERT( m_outputFile ); VECTOR2I size( aSize ); EDA_ANGLE orient( aOrient ); // The pad will be drawn as an oblong shape with size.y > size.x (Oval vertical orientation 0). if( size.x > size.y ) { std::swap( size.x, size.y ); orient += ANGLE_90; } if( aTraceMode == FILLED ) { int deltaxy = size.y - size.x; // distance between centers of the oval FlashPadRect( aPos, VECTOR2I( size.x, deltaxy + KiROUND( m_penDiameter ) ), orient, aTraceMode, aData ); VECTOR2I pt( 0, deltaxy / 2 ); RotatePoint( pt, orient ); FlashPadCircle( pt + aPos, size.x, aTraceMode, aData ); pt = VECTOR2I( 0, -deltaxy / 2 ); RotatePoint( pt, orient ); FlashPadCircle( pt + aPos, size.x, aTraceMode, aData ); } else // Plot in outline mode. { sketchOval( aPos, size, orient, KiROUND( m_penDiameter ) ); } } void HPGL_PLOTTER::FlashPadCircle( const VECTOR2I& pos, int diametre, OUTLINE_MODE trace_mode, void* aData ) { wxASSERT( m_outputFile ); VECTOR2D pos_dev = userToDeviceCoordinates( pos ); int radius = diametre / 2; if( trace_mode == FILLED ) { // if filled mode, the pen diameter is removed from diameter // to keep the pad size radius -= KiROUND( m_penDiameter ) / 2; if( radius < 0 ) radius = 0; } double rsize = userToDeviceSize( radius ); if( trace_mode == FILLED ) // Plot in filled mode. { // A filled polygon uses always the current point to start the polygon. // Gives a correct current starting point for the circle MoveTo( VECTOR2I( pos.x + radius, pos.y ) ); // Plot filled area and its outline startOrAppendItem( userToDeviceCoordinates( VECTOR2I( pos.x + radius, pos.y ) ), wxString::Format( "PM 0; PA %.0f,%.0f;CI %.0f;%s", pos_dev.x, pos_dev.y, rsize, hpgl_end_polygon_cmd ) ); m_current_item->lift_before = true; m_current_item->pen_returns = true; } else { // Draw outline only: startOrAppendItem( pos_dev, wxString::Format( "CI %.0f;", rsize ) ); m_current_item->lift_before = true; m_current_item->pen_returns = true; } PenFinish(); } void HPGL_PLOTTER::FlashPadRect( const VECTOR2I& aPos, const VECTOR2I& aPadSize, const EDA_ANGLE& aOrient, OUTLINE_MODE aTraceMode, void* aData ) { // Build rect polygon: std::vector corners; int dx = aPadSize.x / 2; int dy = aPadSize.y / 2; if( aTraceMode == FILLED ) { // in filled mode, the pen diameter is removed from size // to compensate the extra size due to this pen size dx -= KiROUND( m_penDiameter ) / 2; dx = std::max( dx, 0); dy -= KiROUND( m_penDiameter ) / 2; dy = std::max( dy, 0); } corners.emplace_back( - dx, - dy ); corners.emplace_back( - dx, + dy ); corners.emplace_back( + dx, + dy ); corners.emplace_back( + dx, - dy ); // Close polygon corners.emplace_back( - dx, - dy ); for( unsigned ii = 0; ii < corners.size(); ii++ ) { RotatePoint( corners[ii], aOrient ); corners[ii] += aPos; } PlotPoly( corners, aTraceMode == FILLED ? FILL_T::FILLED_SHAPE : FILL_T::NO_FILL ); } void HPGL_PLOTTER::FlashPadRoundRect( const VECTOR2I& aPadPos, const VECTOR2I& aSize, int aCornerRadius, const EDA_ANGLE& aOrient, OUTLINE_MODE aTraceMode, void* aData ) { SHAPE_POLY_SET outline; VECTOR2I size = aSize; if( aTraceMode == FILLED ) { // In filled mode, the pen diameter is removed from size to keep the pad size. size.x -= KiROUND( m_penDiameter ) / 2; size.x = std::max( size.x, 0); size.y -= KiROUND( m_penDiameter ) / 2; size.y = std::max( size.y, 0); // keep aCornerRadius to a value < min size x,y < 2: aCornerRadius = std::min( aCornerRadius, std::min( size.x, size.y ) /2 ); } TransformRoundChamferedRectToPolygon( outline, aPadPos, size, aOrient, aCornerRadius, 0.0, 0, 0, GetPlotterArcHighDef(), ERROR_INSIDE ); // TransformRoundRectToPolygon creates only one convex polygon std::vector cornerList; SHAPE_LINE_CHAIN& poly = outline.Outline( 0 ); cornerList.reserve( poly.PointCount() ); for( int ii = 0; ii < poly.PointCount(); ++ii ) cornerList.emplace_back( poly.CPoint( ii ).x, poly.CPoint( ii ).y ); if( cornerList.back() != cornerList.front() ) cornerList.push_back( cornerList.front() ); PlotPoly( cornerList, aTraceMode == FILLED ? FILL_T::FILLED_SHAPE : FILL_T::NO_FILL ); } void HPGL_PLOTTER::FlashPadCustom( const VECTOR2I& aPadPos, const VECTOR2I& aSize, const EDA_ANGLE& aOrient, SHAPE_POLY_SET* aPolygons, OUTLINE_MODE aTraceMode, void* aData ) { std::vector cornerList; for( int cnt = 0; cnt < aPolygons->OutlineCount(); ++cnt ) { SHAPE_LINE_CHAIN& poly = aPolygons->Outline( cnt ); cornerList.clear(); cornerList.reserve( poly.PointCount() ); for( int ii = 0; ii < poly.PointCount(); ++ii ) cornerList.emplace_back( poly.CPoint( ii ).x, poly.CPoint( ii ).y ); if( cornerList.back() != cornerList.front() ) cornerList.push_back( cornerList.front() ); PlotPoly( cornerList, aTraceMode == FILLED ? FILL_T::FILLED_SHAPE : FILL_T::NO_FILL ); } } void HPGL_PLOTTER::FlashPadTrapez( const VECTOR2I& aPadPos, const VECTOR2I* aCorners, const EDA_ANGLE& aPadOrient, OUTLINE_MODE aTraceMode, void* aData ) { std::vector cornerList; cornerList.reserve( 5 ); for( int ii = 0; ii < 4; ii++ ) { VECTOR2I coord( aCorners[ii] ); RotatePoint( coord, aPadOrient ); coord += aPadPos; cornerList.push_back( coord ); } // Close polygon cornerList.push_back( cornerList.front() ); PlotPoly( cornerList, aTraceMode == FILLED ? FILL_T::FILLED_SHAPE : FILL_T::NO_FILL ); } void HPGL_PLOTTER::FlashRegularPolygon( const VECTOR2I& aShapePos, int aRadius, int aCornerCount, const EDA_ANGLE& aOrient, OUTLINE_MODE aTraceMode, void* aData ) { // Do nothing wxASSERT( 0 ); } bool HPGL_PLOTTER::startItem( const VECTOR2D& location ) { return startOrAppendItem( location, wxEmptyString ); } void HPGL_PLOTTER::flushItem() { m_current_item = nullptr; } bool HPGL_PLOTTER::startOrAppendItem( const VECTOR2D& location, wxString const& content ) { if( m_current_item == nullptr ) { HPGL_ITEM item; item.loc_start = location; item.loc_end = location; item.bbox = BOX2D( location ); item.pen = m_penNumber; item.dashType = m_lineStyle; item.content = content; m_items.push_back( item ); m_current_item = &m_items.back(); return true; } else { m_current_item->content << content; return false; } } void HPGL_PLOTTER::sortItems( std::list& items ) { if( items.size() < 2 ) return; std::list target; // Plot items are sorted to improve print time on mechanical plotters. This // means // 1) Avoid excess pen-switching - once a pen is selected, keep printing // with it until no more items using that pen remain. // 2) Within the items for one pen, avoid bouncing back and forth around // the page; items should be sequenced with nearby items. // // This is essentially a variant of the Traveling Salesman Problem where // the cities are themselves edges that must be traversed. This is of course // a famously NP-Hard problem and this particular variant has a monstrous // number of "cities". For now, we're using a naive nearest-neighbor search, // which is less than optimal but (usually!) better than nothing, very // simple to implement, and fast enough. // // Items are moved one at a time from `items` into `target`, searching // each time for the first one matching the above criteria. Then, all of // `target` is moved back into `items`. // Get the first one started HPGL_ITEM last_item = items.front(); items.pop_front(); target.emplace_back( last_item ); while( !items.empty() ) { auto best_it = items.begin(); double best_dist = dpoint_dist( last_item.loc_end, best_it->loc_start ); for( auto search_it = best_it; search_it != items.end(); search_it++ ) { // Immediately forget an item as "best" if another one is a better pen match if( best_it->pen != last_item.pen && search_it->pen == last_item.pen ) { best_it = search_it; continue; } double const dist = dpoint_dist( last_item.loc_end, search_it->loc_start ); if( dist < best_dist ) { best_it = search_it; best_dist = dist; continue; } } target.emplace_back( *best_it ); last_item = *best_it; items.erase( best_it ); } items.splice( items.begin(), target ); } const char* HPGL_PLOTTER::lineStyleCommand( LINE_STYLE aLineStyle ) { switch( aLineStyle ) { case LINE_STYLE::DASH: return "LT 2 4 1;"; case LINE_STYLE::DOT: return "LT 1 1 1;"; case LINE_STYLE::DASHDOT: return "LT 4 6 1;"; case LINE_STYLE::DASHDOTDOT: return "LT 7 8 1;"; default: return "LT;"; } } static double dpoint_dist( const VECTOR2D& a, const VECTOR2D& b ) { VECTOR2D diff = a - b; return sqrt( diff.x * diff.x + diff.y * diff.y ); }