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Alex Rivera
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I've managed to implement quadratic and cubic Bezier curves.They are pretty straightforward since we have a formula. Now I want to represent an n-th order Bezier curve using the generalization: Where and I'm using a bitmap library to render the output, so here is my code: // binomialCoef(n, k) = (factorial(n) / (factorial(k) * factorial(n- k))) unsigned int binomialCoef(unsigned int n, const unsigned int k) { unsigned int r = 1; if(k > n) return 0; for(unsigned int d = 1; d <= k; d++) { r *= n--; r /= d; } return r; } void nBezierCurve(Bitmap* obj, const Point* p, const unsigned int nbPoint, float steps, const unsigned char red, const unsigned char green, const unsigned char blue) { int bx1 = p[0].x; int by1 = p[0].y; int bx2; int by2; steps = 1 / steps; for(float i = 0; i < 1; i += steps) { bx2 = by2 = 0; for(int j = 0; (unsigned int)j < nbPoint; j++) { bx2 += (int)(binomialCoef(nbPoint, j) * pow(1 - i, (float)nbPoint - j) * pow(i, j) * p[j].x); by2 += (int)(binomialCoef(nbPoint, j) * pow(1 - i, (float)nbPoint - j) * pow(i, j) * p[j].y); } bresenhamLine(obj, bx1, by1, bx2, by2, red, green, blue); bx1 = bx2; by1 = by2; } // curve must end on the last anchor point bresenhamLine(obj, bx1, by1, p[nbPoint - 1].x, p[nbPoint - 1].y, red, green, blue); } Here's the set of points to render: Point ncurv[] = { 20, 200, 70, 300, 200, 400, 250, 200 }; a
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