标签：style blog class c code http
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#include <osgViewer/Viewer>#include <osgDB/WriteFile>const
int GRID_WIDTH = 1024;const
int GRID_HEIGHT = 800;#pragma comment(lib, "osgd.lib")#pragma comment(lib, "osgViewerd.lib")#pragma comment(lib, "osgDBd.lib")class
CRay{public: CRay(osg::Vec3 orgin, osg::Vec3 direction) :_orgin(orgin) ,_direction(direction) { } osg::Vec3 GetOrgin() { return
_orgin; } void
SetOrgin(osg::Vec3 orgin) { _orgin = orgin; } osg::Vec3 GetDirection() { return
_direction; } void
SetDirection(osg::Vec3 dir) { _direction = dir; } osg::Vec3 GetPoint(float
t) { return
_orgin + _direction * t; }private: osg::Vec3 _orgin; osg::Vec3 _direction; float
_t;};class
CIntersectResult{public: CIntersectResult() :_isHit(false) { } static
CIntersectResult NoHit() { return
CIntersectResult(); }public: bool
_isHit; float
_distance; osg::Vec3 _position; osg::Vec3 _normal;};class
CGeometry{public: CGeometry() { } virtual
CIntersectResult IsIntersect(CRay ray) = 0;};class
CSphere : public
CGeometry{public: CSphere() :CGeometry() { } CSphere(osg::Vec3 center, double
radius) :CGeometry() ,_center(center) ,_radius(radius) { } CSphere(CSphere & s) { _center = s.GetCenter(); _radius = s.GetRadius(); } void
SetCenter(osg::Vec3 & center) { _center = center; } void
SetRadius(float
radius) { _radius = radius; } osg::Vec3 GetCenter() { return
_center; } float
GetRadius() { return
_radius; } osg::Vec3 GetNormal(osg::Vec3 p) { return
p - _center; } virtual
CIntersectResult IsIntersect(CRay ray) { CIntersectResult result = CIntersectResult::NoHit(); osg::Vec3 v = ray.GetOrgin() - _center; float
a0 = v * v - _radius * _radius; float
dir_dot_v = ray.GetDirection() * v; if
(dir_dot_v < 0) { float
discr = dir_dot_v * dir_dot_v - a0; if
(discr >= 0) { result._isHit = true; result._distance = -dir_dot_v - std::sqrt(discr); result._position = ray.GetPoint(result._distance); result._normal = result._position - _center; result._normal.normalize(); } } return
result; }private: osg::Vec3 _center; float
_radius;};class
CPerspectiveCamera{public: CPerspectiveCamera() { } ~CPerspectiveCamera() { } CPerspectiveCamera(const
osg::Vec3 & eye, const
osg::Vec3 & front, const
osg::Vec3 & refUp, float
fov) { _eye = eye; _front = front; _refUp = refUp; _fov = fov; _right = _front ^ _refUp; _up = _right ^ _front; _fovScale = std::tan(fov * osg::PI * 0.5 / 180.0) * 2.0; } CRay GenerateRay(float
x, float
y) { osg::Vec3 r = _right * ((x - 0.5f) * _fovScale); osg::Vec3 u = _up * ((y - 0.5f) * _fovScale); osg::Vec3 temp = _front + r + u; temp.normalize(); return
CRay(_eye, temp); }private: osg::Vec3 _eye; osg::Vec3 _front; osg::Vec3 _refUp; float
_fov; osg::Vec3 _right; osg::Vec3 _up; float
_fovScale;};osg::ref_ptr<osg::Image> CreateImage(){ osg::ref_ptr<osg::Image> image = new
osg::Image; image->allocateImage(1024, 800, 1, GL_RGBA, GL_UNSIGNED_BYTE); unsigned char
* data = image->data(); CPerspectiveCamera camera(osg::Vec3(0.0, 10.0, 10), osg::Vec3(0.0, 0.0, -1.0), osg::Vec3(0.0, 1.0, 0.0), 90); float
depth = 7.0; float
maxDepth = 18.0; CSphere sphere(osg::Vec3(0.0, 10, -10.0), 10.0); float
dx = 1.0f/GRID_WIDTH; float
dy = 1.0f/GRID_HEIGHT; float
dDepth = 255.0f/maxDepth; int
i = 0; for
(int
y = 0; y < GRID_HEIGHT; ++y) { float
sy = 1 - dy * y; for
(int
x = 0; x < GRID_WIDTH; ++x) { float
sx = dx * x; CRay ray(camera.GenerateRay(sx, sy)); CIntersectResult result = sphere.IsIntersect(ray); if
(result._isHit) { float
t = std::min(result._distance * dDepth, 255.0f); int
depth = (int)(255 - t); data[i] = depth; data[i+1] = depth; data[i+2] = depth; data[i+3] = 255; } i += 4; } } return
image.get();}int
main(){ osg::ref_ptr<osg::Image> image = CreateImage(); osgDB::writeImageFile(*image.get(), "H:/1.png"); return
0;} |
标签：style blog class c code http
原文地址：http://www.cnblogs.com/nmgxbc/p/3739745.html
