mirror of
https://github.com/ptitSeb/Serious-Engine
synced 2024-10-05 15:34:50 +02:00
24cb244d43
This was a _ton_ of changes, made 15 years ago, so there are probably some problems to work out still. Among others: Engine/Base/Stream.* was mostly abandoned and will need to be re-ported. Still, this is a pretty good start, and probably holds a world record for lines of changes or something. :)
415 lines
9.8 KiB
C++
415 lines
9.8 KiB
C++
#ifndef SE_INCL_CLIPPING_INL
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#define SE_INCL_CLIPPING_INL
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#ifdef PRAGMA_ONCE
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#pragma once
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#endif
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/*
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* Line clipping flags
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*/
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#define LCF_REMOVED (0x00L) // the entire edge is invisible
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#define LCF_UNCLIPPED (0x80L) // this point remains unclipped
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#define LCF_NEAR (0x01L) // this point is clipped at near plane
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#define LCF_FAR (0x02L) // this point is clipped at far plane
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#define LCF_LEFT (0x04L) // this point is clipped at left plane
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#define LCF_RIGHT (0x08L) // this point is clipped at right plane
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#define LCF_TOP (0x10L) // this point is clipped at top plane
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#define LCF_BOTTOM (0x20L) // this point is clipped at bottom plane
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#define LCF_EDGEREMOVED (0x0000L) // used for testing if entire edge is removed
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// shifts used for clip flags for start/end vertex
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#define LCS_VERTEX0 (0)
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#define LCS_VERTEX1 (8)
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// masks used for clip flags for start/end vertex
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#define LCM_VERTEX0 (0x00FFL)
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#define LCM_VERTEX1 (0xFF00L)
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// creating line clip flags for start/end vertex
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#define LCFVERTEX0(lcf) ((lcf)<<LCS_VERTEX0)
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#define LCFVERTEX1(lcf) ((lcf)<<LCS_VERTEX1)
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// asm shortcuts
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#define O offset
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#define Q qword ptr
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#define D dword ptr
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#define W word ptr
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#define B byte ptr
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/*
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* Intersecting object (works on edges)
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*/
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class ENGINE_API CIntersector {
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private:
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FLOAT ci_fX0; // relative coordinates of point
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FLOAT ci_fY0;
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INDEX ci_ct;
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public:
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// constructor
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inline CIntersector(FLOAT fX0=0.0f, FLOAT fY0=0.0f)
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: ci_fX0(fX0), ci_fY0(fY0), ci_ct(0) {};
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inline void Clear(void) { ci_ct = 0;}; // Clears intersection count
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inline void AddEdge( FLOAT fedgx1, FLOAT fedgy1, FLOAT fedgx2, FLOAT fedgy2); // Checks for intersection
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inline BOOL IsIntersecting() { return (ci_ct % 2) != 0; }; // Do we have intersection?
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};
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// inline functions implementation
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/////////////////////////////////////////////////////////////////////
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// CIntersector
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/////////////////////////////////////////////////////////////////////
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/*
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* Checks for intersection of edge with +x axis
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*/
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ENGINE_API inline void CIntersector::AddEdge( FLOAT fedgx1, FLOAT fedgy1, FLOAT fedgx2, FLOAT fedgy2)
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{
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// transform edge relative to the origin
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fedgx1-=ci_fX0; fedgy1-=ci_fY0;
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fedgx2-=ci_fX0; fedgy2-=ci_fY0;
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if( fedgy1 > 0)
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{
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if( fedgy2 > 0) return;
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if( fedgx1 <= 0)
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{
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if( fedgx2 <= 0) return;
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}
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else if( fedgx2 > 0)
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{
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ci_ct ++;
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return;
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}
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}
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else
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{
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if( fedgy2 <= 0) return;
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if( fedgx1 <= 0)
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{
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if( fedgx2 <= 0) return;
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}
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else if( fedgx2 > 0)
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{
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ci_ct ++;
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return;
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}
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}
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// here we calculate x coordinate of edge and +x axis intersection point
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FLOAT a, b;
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a = (fedgy2 - fedgy1)/(fedgx2 - fedgx1);
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b = fedgy1 - a*fedgx1;
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if( -b/a < 0) return; // no intersection, intersection coordinate x is left from 0
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ci_ct ++;
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}
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/* rcg10042001 !!! FIXME */
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#ifdef _MSC_VER
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#define ASMOPT 1
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#endif
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// how much are the clip planes offset inside frustum
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#define CLIPPLANE_EPSILON (1E-3f)
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/*
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* Clip a line by a single plane -- helper function.
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*/
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inline BOOL ClipLineByNearPlane(FLOAT3D &v0, FLOAT3D &v1, FLOAT fPlaneDistance,
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ULONG &ulCode0, ULONG &ulCode1, ULONG ulCodeClip)
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{
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#if ASMOPT
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static FLOAT f1=1;
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static FLOAT fDistance0, fDistance1;
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__asm {
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mov esi,D [v0]
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mov edi,D [v1]
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fld D [fPlaneDistance]
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fchs
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fld D [esi+ 8]
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fsubr st(0),st(1)
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fld D [edi+ 8]
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fsubp st(2),st(0)
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fstp D [fDistance0]
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fst D [fDistance1]
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fsubr D [fDistance0]
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fdivr D [f1]
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cmp D [fDistance0],0
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jg firstFront
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;firstBack:
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cmp D [fDistance1],0
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jle falseRet
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;secondFront:
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mov eax,D [fPlaneDistance]
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mov ebx,D [ulCode0]
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xor eax,80000000h
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mov edx,D [ulCodeClip]
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mov D [esi+ 8],eax
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mov D [ebx],edx
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fmul D [fDistance0]
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;//st0=fFactor
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fld D [esi+ 0]
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fsub D [edi+ 0]
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fld D [esi+ 4]
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fsub D [edi+ 4]
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;//st0=v0(2)-v1(2), st1=v0(1)-v1(1), st2=fFactor
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fxch st(1)
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fmul st(0),st(2)
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fxch st(1)
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fmulp st(2),st(0)
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;//st0=(v0(1)-v1(1))*fFactor, st1=(v0(2)-v1(2))*fFactor
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fsubr D [esi+ 0]
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fxch st(1)
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fsubr D [esi+ 4]
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fxch st(1)
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fstp D [esi+ 0]
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fst D [esi+ 4]
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jmp trueRet
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firstFront:
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cmp D [fDistance1],0
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jg trueRet
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;secondBack:
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mov eax,D [fPlaneDistance]
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mov ebx,D [ulCode1]
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mov edx,D [ulCodeClip]
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xor eax,80000000h
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shl edx,8
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mov D [edi+ 8],eax
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mov D [ebx],edx
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fmul D [fDistance1]
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;//st0=fFactor
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fld D [esi+ 0]
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fsub D [edi+ 0]
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fld D [esi+ 4]
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fsub D [edi+ 4]
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;//st0=v0(2)-v1(2), st1=v0(1)-v1(1), st2=fFactor
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fxch st(1)
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fmul st(0),st(2)
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fxch st(1)
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fmulp st(2),st(0)
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;//st0=(v0(1)-v1(1))*fFactor, st1=(v0(2)-v1(2))*fFactor
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fsubr D [edi+ 0]
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fxch st(1)
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fsubr D [edi+ 4]
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fxch st(1)
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fstp D [edi+ 0]
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fst D [edi+ 4]
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}
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trueRet:
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_asm fstp st(0)
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return TRUE;
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falseRet:
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_asm fstp st(0)
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return FALSE;
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#else
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// calculate point distances from clip plane
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FLOAT fDistance0 = -fPlaneDistance-v0(3);
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FLOAT fDistance1 = -fPlaneDistance-v1(3);
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if (fDistance0<=0) {
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// if both are back
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if (fDistance1<=0) {
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// no line remains
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return FALSE;
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// if first is back, second front
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} else {
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// clip first
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FLOAT fDivisor = 1.0f/(fDistance0-fDistance1);
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FLOAT fFactor = fDistance0*fDivisor;
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v0(1) = v0(1)-(v0(1)-v1(1))*fFactor;
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v0(2) = v0(2)-(v0(2)-v1(2))*fFactor;
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v0(3) = -fPlaneDistance;
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// mark that first was clipped
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ulCode0 = LCFVERTEX0(ulCodeClip);
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// line remains
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return TRUE;
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}
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} else {
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// if first is front, second back
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if (fDistance1<=0) {
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// clip second
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FLOAT fDivisor = 1.0f/(fDistance0-fDistance1);
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FLOAT fFactor = fDistance1*fDivisor;
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v1(1) = v1(1)-(v0(1)-v1(1))*fFactor;
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v1(2) = v1(2)-(v0(2)-v1(2))*fFactor;
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v1(3) = -fPlaneDistance;
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// mark that second was clipped
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ulCode1 = LCFVERTEX1(ulCodeClip);
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// line remains
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return TRUE;
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// if both are front
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} else {
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// line remains unclipped
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return TRUE;
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}
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}
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#endif
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}
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/*
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* Clip a line by a single plane -- helper function.
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*/
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inline BOOL ClipLineByFarPlane(FLOAT3D &v0, FLOAT3D &v1, FLOAT fPlaneDistance,
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ULONG &ulCode0, ULONG &ulCode1, ULONG ulCodeClip)
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{
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#if ASMOPT
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static FLOAT f1=1;
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static FLOAT fDistance0, fDistance1;
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__asm {
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mov esi,D [v0]
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mov edi,D [v1]
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fld D [fPlaneDistance]
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fadd D [esi+ 8]
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fld D [fPlaneDistance]
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fadd D [edi+ 8]
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fxch st(1)
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fstp D [fDistance0]
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fst D [fDistance1]
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fsubr D [fDistance0]
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fdivr D [f1]
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cmp D [fDistance0],0
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jg firstFront
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;firstBack:
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cmp D [fDistance1],0
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jle falseRet
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;secondFront:
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mov eax,D [fPlaneDistance]
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mov ebx,D [ulCode0]
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xor eax,80000000h
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mov edx,D [ulCodeClip]
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mov D [esi+ 8],eax
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mov D [ebx],edx
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fmul D [fDistance0]
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;//st0=fFactor
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fld D [esi+ 0]
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fsub D [edi+ 0]
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fld D [esi+ 4]
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fsub D [edi+ 4]
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;//st0=v0(2)-v1(2), st1=v0(1)-v1(1), st2=fFactor
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fxch st(1)
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fmul st(0),st(2)
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fxch st(1)
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fmulp st(2),st(0)
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;//st0=(v0(1)-v1(1))*fFactor, st1=(v0(2)-v1(2))*fFactor
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fsubr D [esi+ 0]
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fxch st(1)
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fsubr D [esi+ 4]
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fxch st(1)
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fstp D [esi+ 0]
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fst D [esi+ 4]
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jmp trueRet
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firstFront:
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cmp D [fDistance1],0
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jg trueRet
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;secondBack:
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mov eax,D [fPlaneDistance]
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mov ebx,D [ulCode1]
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mov edx,D [ulCodeClip]
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xor eax,80000000h
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shl edx,8
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mov D [edi+8],eax
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mov D [ebx],edx
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fmul D [fDistance1]
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;//st0=fFactor
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fld D [esi+ 0]
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fsub D [edi+ 0]
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fld D [esi+ 4]
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fsub D [edi+ 4]
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;//st0=v0(2)-v1(2), st1=v0(1)-v1(1), st2=fFactor
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fxch st(1)
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fmul st(0),st(2)
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fxch st(1)
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fmulp st(2),st(0)
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;//st0=(v0(1)-v1(1))*fFactor, st1=(v0(2)-v1(2))*fFactor
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fsubr D [edi+ 0]
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fxch st(1)
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fsubr D [edi+ 4]
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fxch st(1)
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fstp D [edi+ 0]
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fst D [edi+ 4]
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}
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trueRet:
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_asm fstp st(0)
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return TRUE;
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falseRet:
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_asm fstp st(0)
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return FALSE;
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#else
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// calculate point distances from clip plane
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FLOAT fDistance0 = fPlaneDistance+v0(3);
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FLOAT fDistance1 = fPlaneDistance+v1(3);
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if (fDistance0<=0) {
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// if both are back
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if (fDistance1<=0) {
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// no line remains
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return FALSE;
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// if first is back, second front
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} else {
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// clip first
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FLOAT fDivisor = 1.0f/(fDistance0-fDistance1);
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FLOAT fFactor = fDistance0*fDivisor;
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v0(1) = v0(1)-(v0(1)-v1(1))*fFactor;
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v0(2) = v0(2)-(v0(2)-v1(2))*fFactor;
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v0(3) = -fPlaneDistance;
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// mark that first was clipped
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ulCode0 = LCFVERTEX0(ulCodeClip);
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// line remains
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return TRUE;
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}
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} else {
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// if first is front, second back
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if (fDistance1<=0) {
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// clip second
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FLOAT fDivisor = 1.0f/(fDistance0-fDistance1);
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FLOAT fFactor = fDistance1*fDivisor;
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v1(1) = v1(1)-(v0(1)-v1(1))*fFactor;
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v1(2) = v1(2)-(v0(2)-v1(2))*fFactor;
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v1(3) = -fPlaneDistance;
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// mark that second was clipped
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ulCode1 = LCFVERTEX1(ulCodeClip);
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// line remains
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return TRUE;
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// if both are front
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} else {
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// line remains unclipped
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return TRUE;
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}
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}
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#endif
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}
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static inline void MakeClipPlane(const FLOAT3D &vN, FLOAT fD, FLOATplane3D &pl)
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{
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FLOAT fOoL = 1.0f/vN.Length();
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pl = FLOATplane3D(vN*fOoL, fD*fOoL);
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}
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#undef ASMOPT
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#undef O
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#undef Q
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#undef D
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#undef W
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#undef B
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#endif /* include-once blocker. */
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