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kc3-lang/ftgl/src/FTContour.cpp
sammy
- src/FTContour.cpp
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/* * FTGL - OpenGL font library * * Copyright (c) 2001-2004 Henry Maddocks <ftgl@opengl.geek.nz> * 2008 Sam Hocevar <sam@zoy.org> * 2008 Éric Beets <ericbeets@free.fr> * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include "config.h" #include "FTContour.h" #include <math.h> static const float BEZIER_STEP_SIZE = 0.2f; void FTContour::AddPoint(FTPoint point) { if(pointList.empty() || (point != pointList[pointList.size() - 1] && point != pointList[0])) { pointList.push_back(point); } } void FTContour::AddOutsetPoint(FTPoint point) { outsetPointList.push_back(point); } void FTContour::AddFrontPoint(FTPoint point) { frontPointList.push_back(point); } void FTContour::AddBackPoint(FTPoint point) { backPointList.push_back(point); } void FTContour::evaluateQuadraticCurve(FTPoint A, FTPoint B, FTPoint C) { for(unsigned int i = 0; i <= (1.0f / BEZIER_STEP_SIZE); i++) { float t = static_cast<float>(i) * BEZIER_STEP_SIZE; FTPoint U = (1.0f - t) * A + t * B; FTPoint V = (1.0f - t) * B + t * C; AddPoint((1.0f - t) * U + t * V); } } void FTContour::evaluateCubicCurve(FTPoint A, FTPoint B, FTPoint C, FTPoint D) { for(unsigned int i = 0; i <= (1.0f / BEZIER_STEP_SIZE); i++) { float t = static_cast<float>(i) * BEZIER_STEP_SIZE; FTPoint U = (1.0f - t) * A + t * B; FTPoint V = (1.0f - t) * B + t * C; FTPoint W = (1.0f - t) * C + t * D; FTPoint M = (1.0f - t) * U + t * V; FTPoint N = (1.0f - t) * V + t * W; AddPoint((1.0f - t) * M + t * N); } } FTGL_DOUBLE FTContour::NormVector(const FTPoint &v) { return sqrt(v.X() * v.X() + v.Y() * v.Y()); } void FTContour::RotationMatrix(const FTPoint &a, const FTPoint &b, FTGL_DOUBLE *matRot, FTGL_DOUBLE *invRot) { FTPoint abVect(b.X() - a.X(), b.Y() - a.Y(), 0); FTGL_DOUBLE abNorm = NormVector(abVect); invRot[0] = matRot[0] = -abVect.X() / abNorm; invRot[2] = matRot[1] = -abVect.Y() / abNorm; invRot[1] = matRot[2] = abVect.Y() / abNorm; invRot[3] = matRot[3] = -abVect.X() / abNorm; } void FTContour::MultMatrixVect(FTGL_DOUBLE *mat, FTPoint &v) { FTPoint res; res.X(v.X() * mat[0] + v.Y() * mat[1]); res.Y(v.X() * mat[2] + v.Y() * mat[3]); v.X(res.X()); v.Y(res.Y()); } void FTContour::ComputeBisec(FTPoint &v) { FTGL_DOUBLE sgn = -64.0; if((v.Y() / NormVector(v)) < 0) sgn = 64.0; v.X(sgn * sqrt((NormVector(v) - v.X()) / (NormVector(v) + v.X()))); v.Y(64.0); } FTPoint FTContour::ComputeOutsetPoint(FTPoint a, FTPoint b, FTPoint c) { FTGL_DOUBLE mat[4], inv[4]; /* Build the rotation matrix from 'ab' vector */ RotationMatrix(b, a, mat, inv); /* 'h' is the second vector 'bc' */ FTPoint h = c - b; /* Apply the rotation to the second vector 'bc' */ MultMatrixVect(mat, h); /* Compute the vector bisecting 'bh' */ ComputeBisec(h); /* Apply the inverted rotation matrix to 'bh' */ MultMatrixVect(inv, h); return h; } void FTContour::outsetContour() { size_t size = PointCount(); FTPoint vOutset; for(unsigned int pointIndex = 0; pointIndex < size; ++pointIndex) { int prev = (pointIndex%size + size - 1) % size; int cur = pointIndex%size; int next = (pointIndex%size + 1) % size; /* Build the outset shape with d = 1.0f */ vOutset = ComputeOutsetPoint(Point(prev), Point(cur), Point(next)); AddOutsetPoint(vOutset); } } FTContour::FTContour(FT_Vector* contour, char* tags, unsigned int n) { for(unsigned int i = 0; i < n; ++ i) { if(tags[i] == FT_Curve_Tag_On || n < 2) { AddPoint(FTPoint(contour[i])); continue; } FTPoint cur(contour[i]); FTPoint prev = (pointList.size() == 0 || i == 0) ? FTPoint(contour[n - 1]) : pointList[pointList.size() - 1]; FTPoint next = (i == n - 1) ? (pointList.size() == 0) ? FTPoint(contour[0]) : pointList[0] : FTPoint(contour[i + 1]); if(tags[i] == FT_Curve_Tag_Conic) { while(tags[(i == n - 1) ? 0 : i + 1] == FT_Curve_Tag_Conic) { next = (cur + next) * 0.5f; evaluateQuadraticCurve(prev, cur, next); ++i; prev = next; cur = FTPoint(contour[i]); next = (i == n - 1) ? pointList[0] : FTPoint(contour[i + 1]); } evaluateQuadraticCurve(prev, cur, next); continue; } if(tags[i] == FT_Curve_Tag_Cubic) { FTPoint next2 = (i == n - 2) ? pointList[0] : FTPoint(contour[i + 2]); evaluateCubicCurve(prev, cur, next, next2); ++i; continue; } } /* Create (or not) front outset and/or back outset */ outsetContour(); } void FTContour::buildFrontOutset(float outset) { for(size_t i = 0; i < PointCount(); ++i) { FTPoint point = FTPoint(Point(i).X() + Outset(i).X() * outset, Point(i).Y() + Outset(i).Y() * outset, 0); AddFrontPoint(point); } } void FTContour::buildBackOutset(float outset) { for(size_t i = 0; i < PointCount(); ++i) { FTPoint point = FTPoint(Point(i).X() + Outset(i).X() * outset, Point(i).Y() + Outset(i).Y() * outset, 0); AddBackPoint(point); } }