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A few more fixes to the heightfield tesselator

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This commit is contained in:
Josh Yelon 2006-08-08 17:39:51 +00:00
parent e399531009
commit eb2aa16c66
2 changed files with 40 additions and 2 deletions
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40
panda/src/grutil/heightfieldTesselator.cxx
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@ -66,6 +66,42 @@ fix_heightfield(int size) {
}
}
////////////////////////////////////////////////////////////////////
// Function: HeightfieldTesselator::get_elevation
// Access: Private
// Description: Fetches the elevation at (x,y), where the input
// coordinate is specified in pixels. This ignores the
// current tesselation level and instead provides an
// accurate number. Linear blending is used for
// non-integral coordinates. The current vertical
// scale is taken into account.
////////////////////////////////////////////////////////////////////
double HeightfieldTesselator::
get_elevation(double x, double y) {
int scale = 7;
int size = 1 << scale;
fix_heightfield(size);
int xlo = (int)x;
int ylo = (int)y;
if (xlo < 0) xlo = 0;
if (ylo < 0) ylo = 0;
if (xlo > _heightfield.get_x_size()-2)
xlo = _heightfield.get_x_size()-2;
if (ylo > _heightfield.get_y_size()-2)
ylo = _heightfield.get_y_size()-2;
int xhi = xlo+1;
int yhi = ylo+1;
double xoffs = x - xlo;
double yoffs = y - ylo;
double grayxlyl = _heightfield.get_gray(xlo,ylo);
double grayxhyl = _heightfield.get_gray(xhi,ylo);
double grayxlyh = _heightfield.get_gray(xlo,yhi);
double grayxhyh = _heightfield.get_gray(xhi,yhi);
double lerpyl = grayxhyl * xoffs + grayxlyl * (1.0 - xoffs);
double lerpyh = grayxhyh * xoffs + grayxlyh * (1.0 - xoffs);
return lerpyh * yoffs + lerpyl * (1.0 - yoffs);
}
////////////////////////////////////////////////////////////////////
// Function: HeightfieldTesselator::get_vertex
// Access: Private
@ -342,10 +378,10 @@ count_triangles(int scale, int x, int y) {
void HeightfieldTesselator::
add_quad_to_strip(int v1, int v2, int v3, int v4) {
if ((v1 != v2)&&(v2 != v3)&&(v1 != v3)) {
_triangles->add_vertices(v1,v2,v3);
_triangles->add_vertices(v1,v3,v2);
}
if ((v3 != v2)&&(v2 != v4)&&(v4 != v3)) {
_triangles->add_vertices(v3,v2,v4);
_triangles->add_vertices(v3,v4,v2);
}
// if ((v1 == _last_vertex_a)&&(v2 == _last_vertex_b)) {
// _tristrip->add_vertices(v3,v4);

2
panda/src/grutil/heightfieldTesselator.h
View File

@ -82,6 +82,8 @@ PUBLISHED:
INLINE void set_horizontal_scale(double h);
INLINE void set_vertical_scale(double v);
INLINE void set_max_triangles(int n);
double get_elevation(double x, double y);
NodePath generate();