quadsquare_update.cpp File Reference

#include "quadsquare.h"

Go to the source code of this file.

Functions
bool	VertexTest (float x, float y, float z, float error, const Vector &Viewer)
bool	BoxTest (float x, float z, float size, float miny, float maxy, float error, const Vector &Viewer)
static unsigned int	calculatestage (unsigned int numstages, unsigned int whichstage)
static unsigned int	transformstage (unsigned int stage, updateparity *updateorder)
	transforms our stages to little endian notation so most significant half-byte is on the right :-) More...
int	identityparity (int i)
int	sideparityodd (int i)
int	upparityodd (int i)
int	sideupparityodd (int i)
Vector	Normalise (const Vector &vec, const float scale)

Variables
int	MaxCreateDepth = 0
static float	DetailThreshold = 100

Function Documentation

bool BoxTest	(	float	x,
		float	z,
		float	size,
		float	miny,
		float	maxy,
		float	error,
		const Vector &	Viewer
	)

Definition at line 138 of file quadsquare_update.cpp.

References d, and miny.

{
//Returns true if any vertex within the specified box (origin at x,z,
//edges of length size) with the given error value could be enabled
//based on the given viewer location.
    //Find the minimum distance to the box.
    float half = size*0.5;
    float dx   = fabs( x+half-Viewer.i )-half;
    float dy   = fabs( (miny+maxy)*0.5-Viewer.j )-(maxy-miny)*0.5;
    float dz   = fabs( z+half-Viewer.k )-half;
    float d    = dx;
    if (dy > d) d = dy;
    if (dz > d) d = dz;
    return (error*DetailThreshold) > d;
}

static unsigned int calculatestage ( unsigned int  numstages, unsigned int  whichstage  )

static

calculates the bitmasks for which children to do and not to do Tries to preserve some locality for 16 the results are Stage 0 Number: 00000000000000000000000000010001 Stage 1 Number: 00000000000000000000000000010010 Stage 2 Number: 00000000000000000000000000010100 Stage 3 Number: 00000000000000000000000000011000 Stage 4 Number: 00000000000000000000000000100001 Stage 5 Number: 00000000000000000000000000100010 Stage 6 Number: 00000000000000000000000000100100 Stage 7 Number: 00000000000000000000000000101000 Stage 8 Number: 00000000000000000000000001000001 Stage 9 Number: 00000000000000000000000001000010 Stage 0 Number: 00000000000000000000000001000100 Stage 1 Number: 00000000000000000000000001001000 Stage 2 Number: 00000000000000000000000010000001 Stage 3 Number: 00000000000000000000000010000010 Stage 4 Number: 00000000000000000000000010000100 Stage 5 Number: 00000000000000000000000010001000

Definition at line 174 of file quadsquare_update.cpp.

Referenced by quadsquare::Update().

{
    unsigned int stage = 0;
    int count = 0;
    numstages -= 1;
    while (numstages) {
        int tmp = 1<<(whichstage%4);
        stage += ( tmp<<( (count++)*4 ) );
        whichstage /= 4;
        numstages /= 4;
    }
    return stage;
}

int identityparity

(

int

i)

Definition at line 201 of file quadsquare_update.cpp.

{
    return i;
}

Vector Normalise ( const Vector &  vec, const float  scale  )

inline

Definition at line 374 of file quadsquare_update.cpp.

{
    return vec*( scale/vec.Magnitude() );
}

int sideparityodd

(

int

i)

Definition at line 206 of file quadsquare_update.cpp.

{
    switch (i)
    {
    case 1:
        return 2;

    case 2:
        return 1;

    case 4:
        return 8;

    case 8:
        return 4;
    }
    return 0;
}

int sideupparityodd

(

int

i)

Definition at line 244 of file quadsquare_update.cpp.

{
    switch (i)
    {
    case 8:
        return 1;

    case 4:
        return 2;

    case 2:
        return 4;

    case 1:
        return 8;
    }
    return 0;
}

static unsigned int transformstage ( unsigned int  stage, updateparity *  updateorder  )

static

transforms our stages to little endian notation so most significant half-byte is on the right :-)

Definition at line 189 of file quadsquare_update.cpp.

Referenced by quadsquare::Update().

{
    int tmp;
    unsigned int transformedstage = 0;
    while ( ( tmp = ( stage&(1|2|4|8) ) ) != 0 ) {
        stage >>= 4;
        transformedstage <<= 4;
        transformedstage |= ( (*updateorder)(tmp) );
    }
    return transformedstage;
}

int upparityodd

(

int

i)

Definition at line 225 of file quadsquare_update.cpp.

{
    switch (i)
    {
    case 1:
        return 4;

    case 2:
        return 8;

    case 4:
        return 1;

    case 8:
        return 2;
    }
    return 0;
}

bool VertexTest	(	float	x,
		float	y,
		float	z,
		float	error,
		const Vector &	Viewer
	)

Definition at line 124 of file quadsquare_update.cpp.

References d.

{
//Returns true if the vertex at (x,z) with the given world-space error between
//its interpolated location and its true location, should be enabled, given that
//the viewpoint is located at Viewer[].
    float dx = fabs( x-Viewer.i );
    float dy = fabs( y-Viewer.j );
    float dz = fabs( z-Viewer.k );
    float d  = dx;
    if (dy > d) d = dy;
    if (dz > d) d = dz;
    return (error*DetailThreshold) > d;
}

Variable Documentation

float DetailThreshold = 100

static

Definition at line 122 of file quadsquare_update.cpp.

int MaxCreateDepth = 0

Definition at line 2 of file quadsquare_update.cpp.