plib源代码(The PLIB Portable Interactive Applications Library distr...

/* PLIB - A Suite of Portable Game Libraries Copyright (C) 1998,2002 Steve Baker This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA For further information visit http://plib.sourceforge.net $Id: sg.h 2121 2007-09-15 03:36:21Z fayjf $ */ #ifndef SG_H #define SG_H 1 #include <stdio.h> #include "ul.h" #define sgFloat float #define SGfloat float #define SG_ZERO 0.0f #define SG_HALF 0.5f #define SG_ONE 1.0f #define SG_TWO 2.0f #define SG_THREE 3.0f #define SG_FOUR 4.0f #define SG_45 45.0f #define SG_60 60.0f #define SG_90 90.0f #define SG_180 180.0f #define SG_MAX FLT_MAX #define SG_X 0 #define SG_Y 1 #define SG_Z 2 #define SG_W 3 #ifndef M_PI #define SG_PI 3.1415926535f #else #define SG_PI ((SGfloat) M_PI) #endif #define SG_DEGREES_TO_RADIANS (SG_PI/SG_180) #define SG_RADIANS_TO_DEGREES (SG_180/SG_PI) /* These are just convenient redefinitions of standard math library functions to stop float/double warnings. */ inline SGfloat sgSqrt ( const SGfloat x ) { return (SGfloat) sqrt ( x ) ; } inline SGfloat sgSquare ( const SGfloat x ) { return x * x ; } inline SGfloat sgAbs ( const SGfloat a ) { return (a<SG_ZERO) ? -a : a ; } inline SGfloat sgHypot ( const SGfloat x, const SGfloat y ) { return sgSqrt( sgSquare(x) + sgSquare(y) ); } /* Type-casted sin/cos/tan/asin/acos/atan2 ANGLES IN DEGREES */ inline SGfloat sgASin ( SGfloat s ) { return (SGfloat) asin ( s ) * SG_RADIANS_TO_DEGREES ; } inline SGfloat sgACos ( SGfloat s ) { return (SGfloat) acos ( s ) * SG_RADIANS_TO_DEGREES ; } inline SGfloat sgATan ( SGfloat s ) { return (SGfloat) atan ( s ) * SG_RADIANS_TO_DEGREES ; } inline SGfloat sgATan2 ( SGfloat y, SGfloat x ) { return (SGfloat) atan2 ( y,x ) * SG_RADIANS_TO_DEGREES ; } inline SGfloat sgSin ( SGfloat s ) { return (SGfloat) sin ( s * SG_DEGREES_TO_RADIANS ) ; } inline SGfloat sgCos ( SGfloat s ) { return (SGfloat) cos ( s * SG_DEGREES_TO_RADIANS ) ; } inline SGfloat sgTan ( SGfloat s ) { return (SGfloat) tan ( s * SG_DEGREES_TO_RADIANS ) ; } inline int sgCompareFloat ( const SGfloat a, const SGfloat b, const SGfloat tol ) { if ( ( a + tol ) < b ) return -1 ; if ( ( b + tol ) < a ) return 1 ; return 0 ; } /* Types used in SG. */ typedef SGfloat sgVec2 [ 2 ] ; typedef SGfloat sgVec3 [ 3 ] ; typedef SGfloat sgVec4 [ 4 ] ; typedef sgVec4 sgQuat ; typedef SGfloat sgMat3 [3][3] ; typedef SGfloat sgMat4 [4][4] ; struct sgCoord { sgVec3 xyz ; sgVec3 hpr ; } ; class sgSphere ; class sgBox ; class sgFrustum ; /* Some handy constants */ #define SG_OUTSIDE FALSE #define SG_INSIDE TRUE #define SG_STRADDLE 2 inline SGfloat sgHeightOfPlaneVec2 ( const sgVec4 plane, const sgVec2 pnt ) { if ( plane[2] == SG_ZERO ) return SG_ZERO ; else return -( plane[0] * pnt[0] + plane[1] * pnt[1] + plane[3] ) / plane[2] ; } /* Convert a direction vector into a set of euler angles, (with zero roll) The direction vector is X-coordinate = north, Y-coordinate = east, Z-coordinate = down The heading ( = hpr[0] ) is in degrees south of east -- this is VERY nonstandard The pitch ( = hpr[1] ) is in degrees positive up The roll ( = hpr[2] ) is zero */ extern void sgHPRfromVec3 ( sgVec3 hpr, const sgVec3 src ) ; extern void sgMakeCoordMat4 ( sgMat4 dst, const SGfloat x, const SGfloat y, const SGfloat z, const SGfloat h, const SGfloat p, const SGfloat r ) ; inline void sgMakeCoordMat4( sgMat4 dst, const sgVec3 xyz, const sgVec3 hpr ) { sgMakeCoordMat4 ( dst, xyz[0], xyz[1], xyz[2], hpr[0], hpr[1], hpr[2] ) ; } inline void sgMakeCoordMat4( sgMat4 dst, const sgCoord *src ) { sgMakeCoordMat4 ( dst, src->xyz, src->hpr ) ; } extern void sgMakeLookAtMat4 ( sgMat4 dst, const sgVec3 eye, const sgVec3 center, const sgVec3 up ) ; extern void sgMakeRotMat4 ( sgMat4 dst, const SGfloat angle, const sgVec3 axis ) ; inline void sgMakeRotMat4 ( sgMat4 dst, const sgVec3 hpr ) { sgMakeCoordMat4 ( dst, SG_ZERO, SG_ZERO, SG_ZERO, hpr[0], hpr[1], hpr[2] ) ; } inline void sgMakeRotMat4 ( sgMat4 dst,const SGfloat h, const SGfloat p, const SGfloat r ) { sgMakeCoordMat4 ( dst, SG_ZERO, SG_ZERO, SG_ZERO, h, p, r ) ; } extern void sgMakeTransMat4 ( sgMat4 dst, const sgVec3 xyz ) ; extern void sgMakeTransMat4 ( sgMat4 dst, const SGfloat x, const SGfloat y, const SGfloat z ) ; extern void sgSetCoord ( sgCoord *coord, const sgMat4 src ) ; extern void sgMultMat4 ( sgMat4 dst, const sgMat4 a, const sgMat4 b ) ; extern void sgPostMultMat4 ( sgMat4 dst, const sgMat4 a ) ; extern void sgPreMultMat4 ( sgMat4 dst, const sgMat4 a ) ; extern void sgTransposeNegateMat4 ( sgMat4 dst ) ; extern void sgTransposeNegateMat4 ( sgMat4 dst, const sgMat4 src ) ; extern void sgInvertMat4 ( sgMat4 dst, const sgMat4 src ) ; inline void sgInvertMat4 ( sgMat4 dst ) { sgInvertMat4 ( dst, dst ) ; } extern void sgXformVec3 ( sgVec3 dst, const sgVec3 src, const sgMat4 mat ) ; extern void sgXformPnt3 ( sgVec3 dst, const sgVec3 src, const sgMat4 mat ) ; extern void sgXformVec4 ( sgVec4 dst, const sgVec4 src, const sgMat4 mat ) ; extern void sgXformPnt4 ( sgVec4 dst, const sgVec4 src, const sgMat4 mat ) ; extern void sgFullXformPnt3 ( sgVec3 dst, const sgVec3 src, const sgMat4 mat ) ; extern void sgFullXformPnt4 ( sgVec4 dst, const sgVec4 src, const sgMat4 mat ) ; inline void sgXformVec3 ( sgVec3 dst, const sgMat4 mat ) { sgXformVec3 ( dst, dst, mat ) ; } inline void sgXformPnt3 ( sgVec3 dst, const sgMat4 mat ) { sgXformPnt3 ( dst, dst, mat ) ; } inline void sgXformVec4 ( sgVec4 dst, const sgMat4 mat ) { sgXformVec4 ( dst, dst, mat ) ; } inline void sgXformPnt4 ( sgVec4 dst, const sgMat4 mat ) { sgXformPnt4 ( dst, dst, mat ) ; } inline void sgFullXformPnt3 ( sgVec3 dst, const sgMat4 mat ) { sgFullXformPnt3 ( dst, dst, mat ) ; } inline void sgFullXformPnt4 ( sgVec4 dst, const sgMat4 mat ) { sgFullXformPnt4 ( dst, dst, mat ) ; } /* Bits returned by sgClassifyMat4 */ #define SG_IDENTITY 0x00 // for clarity #define SG_ROTATION 0x01 // includes a rotational component #define SG_MIRROR 0x02 // changes handedness (det < 0) #define SG_SCALE 0x04 // uniform scaling #define SG_NONORTHO 0x10 // 3x3 not orthogonal #define SG_TRANSLATION 0x20 // translates #define SG_PROJECTION 0x40 // forth column not 0,0,0,1 /* Are these needed? sgClassifyMat4() does set the general scale bit for some matrices, * but it is not easily defined. Use SG_NONORTHO instead (which is also set). */ #define SG_UNIFORM_SCALE SG_SCALE #define SG_GENERAL_SCALE 0x08 // x, y and z scaled differently extern int sgClassifyMat4 ( const sgMat4 mat ) ; /* Basic low-level vector functions. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For each of Vec2, Vec3 and Vec4, we provide inlines for Zero - set all elements to zero. Set - set each element individually. Add - add vectors element by element. Sub - subtract vectors element by element. Scale - multiply each element of a vector by a variable. AddScaled