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 //---------------------------------------------------------------------------- // 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 //---------------------------------------------------------------------------- // // Stroke math // //---------------------------------------------------------------------------- #ifndef AGG_STROKE_MATH_INCLUDED #define AGG_STROKE_MATH_INCLUDED #include "agg_math.h" #include "agg_vertex_sequence.h" namespace pdfium { namespace agg { enum line_cap_e { butt_cap, square_cap, round_cap }; enum line_join_e { miter_join = 0, miter_join_revert = 1, miter_join_round = 4, round_join = 2, bevel_join = 3 }; enum inner_join_e { inner_bevel, inner_miter, inner_jag, inner_round }; const float stroke_theta = 1.0f / 1000.0f; template void stroke_calc_arc(VertexConsumer& out_vertices, float x, float y, float dx1, float dy1, float dx2, float dy2, float width, float approximation_scale) { typedef typename VertexConsumer::value_type coord_type; float a1 = atan2(dy1, dx1); float a2 = atan2(dy2, dx2); float da = a1 - a2; bool ccw = da > 0 && da < FX_PI; if(width < 0) { width = -width; } da = acos(width / (width + ((1.0f / 8) / approximation_scale))) * 2; out_vertices.add(coord_type(x + dx1, y + dy1)); if (da > 0) { if (!ccw) { if (a1 > a2) { a2 += 2 * FX_PI; } a2 -= da / 4; a1 += da; while (a1 < a2) { out_vertices.add( coord_type(x + (width * cos(a1)), y + (width * sin(a1)))); a1 += da; } } else { if (a1 < a2) { a2 -= 2 * FX_PI; } a2 += da / 4; a1 -= da; while (a1 > a2) { out_vertices.add( coord_type(x + (width * cos(a1)), y + (width * sin(a1)))); a1 -= da; } } } out_vertices.add(coord_type(x + dx2, y + dy2)); } template void stroke_calc_miter(VertexConsumer& out_vertices, const vertex_dist& v0, const vertex_dist& v1, const vertex_dist& v2, float dx1, float dy1, float dx2, float dy2, float width, line_join_e line_join, float miter_limit, float approximation_scale) { typedef typename VertexConsumer::value_type coord_type; float xi = v1.x; float yi = v1.y; bool miter_limit_exceeded = true; if(calc_intersection(v0.x + dx1, v0.y - dy1, v1.x + dx1, v1.y - dy1, v1.x + dx2, v1.y - dy2, v2.x + dx2, v2.y - dy2, &xi, &yi)) { float d1 = calc_distance(v1.x, v1.y, xi, yi); float lim = width * miter_limit; if(d1 <= lim) { out_vertices.add(coord_type(xi, yi)); miter_limit_exceeded = false; } } else { float x2 = v1.x + dx1; float y2 = v1.y - dy1; if ((((x2 - v0.x) * dy1) - ((v0.y - y2) * dx1) < 0) != (((x2 - v2.x) * dy1) - ((v2.y - y2) * dx1) < 0)) { out_vertices.add(coord_type(v1.x + dx1, v1.y - dy1)); miter_limit_exceeded = false; } } if(miter_limit_exceeded) { switch(line_join) { case miter_join_revert: out_vertices.add(coord_type(v1.x + dx1, v1.y - dy1)); out_vertices.add(coord_type(v1.x + dx2, v1.y - dy2)); break; case miter_join_round: stroke_calc_arc(out_vertices, v1.x, v1.y, dx1, -dy1, dx2, -dy2, width, approximation_scale); break; default: out_vertices.add(coord_type(v1.x + dx1 + (dy1 * miter_limit), v1.y - dy1 + (dx1 * miter_limit))); out_vertices.add(coord_type(v1.x + dx2 - (dy2 * miter_limit), v1.y - dy2 - (dx2 * miter_limit))); break; } } } template void stroke_calc_cap(VertexConsumer& out_vertices, const vertex_dist& v0, const vertex_dist& v1, float len, line_cap_e line_cap, float width, float approximation_scale) { typedef typename VertexConsumer::value_type coord_type; out_vertices.remove_all(); float dx1 = (v1.y - v0.y) / len; float dy1 = (v1.x - v0.x) / len; float dx2 = 0; float dy2 = 0; dx1 = dx1 * width; dy1 = dy1 * width; if(line_cap != round_cap) { if(line_cap == square_cap) { dx2 = dy1; dy2 = dx1; } out_vertices.add(coord_type(v0.x - dx1 - dx2, v0.y + dy1 - dy2)); out_vertices.add(coord_type(v0.x + dx1 - dx2, v0.y - dy1 - dy2)); } else { float a1 = atan2(dy1, -dx1); float a2 = a1 + FX_PI; float da = acos(width / (width + ((1.0f / 8) / approximation_scale))) * 2; out_vertices.add(coord_type(v0.x - dx1, v0.y + dy1)); a1 += da; a2 -= da / 4; while (a1 < a2) { out_vertices.add( coord_type(v0.x + (width * cos(a1)), v0.y + (width * sin(a1)))); a1 += da; } out_vertices.add(coord_type(v0.x + dx1, v0.y - dy1)); } } template void stroke_calc_join(VertexConsumer& out_vertices, const vertex_dist& v0, const vertex_dist& v1, const vertex_dist& v2, float len1, float len2, float width, line_join_e line_join, inner_join_e inner_join, float miter_limit, float inner_miter_limit, float approximation_scale) { typedef typename VertexConsumer::value_type coord_type; float dx1, dy1, dx2, dy2; dx1 = width * (v1.y - v0.y) / len1; dy1 = width * (v1.x - v0.x) / len1; dx2 = width * (v2.y - v1.y) / len2; dy2 = width * (v2.x - v1.x) / len2; out_vertices.remove_all(); if(calc_point_location(v0.x, v0.y, v1.x, v1.y, v2.x, v2.y) > 0) { switch(inner_join) { default: out_vertices.add(coord_type(v1.x + dx1, v1.y - dy1)); out_vertices.add(coord_type(v1.x + dx2, v1.y - dy2)); break; case inner_miter: stroke_calc_miter(out_vertices, v0, v1, v2, dx1, dy1, dx2, dy2, width, miter_join_revert, inner_miter_limit, 1.0f); break; case inner_jag: case inner_round: { float d = (dx1 - dx2) * (dx1 - dx2) + (dy1 - dy2) * (dy1 - dy2); if(d < len1 * len1 && d < len2 * len2) { stroke_calc_miter(out_vertices, v0, v1, v2, dx1, dy1, dx2, dy2, width, miter_join_revert, inner_miter_limit, 1.0f); } else { if(inner_join == inner_jag) { out_vertices.add(coord_type(v1.x + dx1, v1.y - dy1)); out_vertices.add(coord_type(v1.x, v1.y )); out_vertices.add(coord_type(v1.x + dx2, v1.y - dy2)); } else { out_vertices.add(coord_type(v1.x + dx1, v1.y - dy1)); out_vertices.add(coord_type(v1.x, v1.y )); stroke_calc_arc(out_vertices, v1.x, v1.y, dx2, -dy2, dx1, -dy1, width, approximation_scale); out_vertices.add(coord_type(v1.x, v1.y )); out_vertices.add(coord_type(v1.x + dx2, v1.y - dy2)); } } } break; } } else { switch(line_join) { case miter_join: case miter_join_revert: case miter_join_round: stroke_calc_miter(out_vertices, v0, v1, v2, dx1, dy1, dx2, dy2, width, line_join, miter_limit, approximation_scale); break; case round_join: stroke_calc_arc(out_vertices, v1.x, v1.y, dx1, -dy1, dx2, -dy2, width, approximation_scale); break; default: out_vertices.add(coord_type(v1.x + dx1, v1.y - dy1)); out_vertices.add(coord_type(v1.x + dx2, v1.y - dy2)); break; } } } } } // namespace pdfium #endif