How can I calculate where the line will meet the rectangle A' and A"?
And in the case where the line does not 'exit' the rectangle, (CD)?
I am developing in C++ but that shouldn't matter to convert any other languages.
Many thanks in advance.
FFMG
Line intercept a rectangle
Author
Hi,
If I have a rectangle, (a,b,c,d) and a line AB goes thru the rectangle.
How can I calculate where the line will meet the rectangle A' and A"?
And in the case where the line does not 'exit' the rectangle, (CD)?
I am developing in C++ but that shouldn't matter to convert any other languages.
Many thanks in advance.
FFMG
How can I calculate where the line will meet the rectangle A' and A"?
And in the case where the line does not 'exit' the rectangle, (CD)?
I am developing in C++ but that shouldn't matter to convert any other languages.
Many thanks in advance.
FFMG
Simplest way would be to test the line against each of the 4 edges (line segments).
Theres a line line intersection description here http://ozviz.wasp.uwa.edu.au/~pbourke/geometry/lineline2d/
Theres a line line intersection description here http://ozviz.wasp.uwa.edu.au/~pbourke/geometry/lineline2d/
bool intersect(float p, float d, float min, float max, float& tenter, float& texit){ if(fabs(d) < 1.0E-6f) return (p >= min && p <= max); float t0 = (min - p) / d; float t1 = (max - p) / d; if(t0 > t1) { float temp(t0); t0 = t1; t1 = temp; } if(t0 > texit || t1 < tenter) return false; if(t0 > tenter) tenter = t0; if(t1 < texit) texit = t1; return true;}bool intersect(const float* min, const float* max, const float* p, const float* d, float* penter, float* pexit){ float tenter = 0.0f, texit = 1.0f; if(!intersect(p[0], d[0], min[0], max[0], tenter, texit)) return false; if(!intersect(p[1], d[1], min[1], max[1], tenter, texit)) return false; //if(!intersect(p[2], d[2], min[2], max[2], tenter, texit)) return false; // for 3D penter[0] = p[0] + d[0] * tenter; penter[1] = p[1] + d[1] * tenter; //penter[2] = p[2] + d[2] * tenter; // for 3D pexit[0] = p[0] + d[0] * texit; pexit[1] = p[1] + d[1] * texit; //pexit[2] = p[2] + d[2] * texit; // for 3D return true;}This topic is closed to new replies.
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