brush_primit.cpp

来自「quake3工具源码。包括生成bsp文件」· C++ 代码 · 共 441 行 · 第 1/2 页

#include "stdafx.h"
#include "qe3.h"

// compute a determinant using Sarrus rule
//++timo "inline" this with a macro
// NOTE : the three vec3_t are understood as columns of the matrix
vec_t SarrusDet(vec3_t a, vec3_t b, vec3_t c)
{
	return a[0]*b[1]*c[2]+b[0]*c[1]*a[2]+c[0]*a[1]*b[2]
		-c[0]*b[1]*a[2]-a[1]*b[0]*c[2]-a[0]*b[2]*c[1];
}

//++timo replace everywhere texX by texS etc. ( ----> and in q3map !) 
// NOTE : ComputeAxisBase here and in q3map code must always BE THE SAME !
// WARNING : special case behaviour of atan2(y,x) <-> atan(y/x) might not be the same everywhere when x == 0
// rotation by (0,RotY,RotZ) assigns X to normal
void ComputeAxisBase(vec3_t normal,vec3_t texS,vec3_t texT )
{
	vec_t RotY,RotZ;
	// do some cleaning
	if (fabs(normal[0])<1e-6)
		normal[0]=0.0f;
	if (fabs(normal[1])<1e-6)
		normal[1]=0.0f;
	if (fabs(normal[2])<1e-6)
		normal[2]=0.0f;
	RotY=-atan2(normal[2],sqrt(normal[1]*normal[1]+normal[0]*normal[0]));
	RotZ=atan2(normal[1],normal[0]);
	// rotate (0,1,0) and (0,0,1) to compute texS and texT
	texS[0]=-sin(RotZ);
	texS[1]=cos(RotZ);
	texS[2]=0;
	// the texT vector is along -Z ( T texture coorinates axis )
	texT[0]=-sin(RotY)*cos(RotZ);
	texT[1]=-sin(RotY)*sin(RotZ);
	texT[2]=-cos(RotY);
}

void FaceToBrushPrimitFace(face_t *f)
{
	vec3_t texX,texY;
	vec3_t proj;
	// ST of (0,0) (1,0) (0,1)
	vec_t ST[3][5]; // [ point index ] [ xyz ST ]
	//++timo not used as long as brushprimit_texdef and texdef are static
/*	f->brushprimit_texdef.contents=f->texdef.contents;
	f->brushprimit_texdef.flags=f->texdef.flags;
	f->brushprimit_texdef.value=f->texdef.value;
	strcpy(f->brushprimit_texdef.name,f->texdef.name); */
#ifdef _DEBUG
	if ( f->plane.normal[0]==0.0f && f->plane.normal[1]==0.0f && f->plane.normal[2]==0.0f )
	{
		Sys_Printf("Warning : f->plane.normal is (0,0,0) in FaceToBrushPrimitFace\n");
	}
	// check d_texture
	if (!f->d_texture)
	{
		Sys_Printf("Warning : f.d_texture is NULL in FaceToBrushPrimitFace\n");
		return;
	}
#endif
	// compute axis base
	ComputeAxisBase(f->plane.normal,texX,texY);
	// compute projection vector
	VectorCopy(f->plane.normal,proj);
	VectorScale(proj,f->plane.dist,proj);
	// (0,0) in plane axis base is (0,0,0) in world coordinates + projection on the affine plane
	// (1,0) in plane axis base is texX in world coordinates + projection on the affine plane
	// (0,1) in plane axis base is texY in world coordinates + projection on the affine plane
	// use old texture code to compute the ST coords of these points
	VectorCopy(proj,ST[0]);
	EmitTextureCoordinates(ST[0], f->d_texture, f);
	VectorCopy(texX,ST[1]);
	VectorAdd(ST[1],proj,ST[1]);
	EmitTextureCoordinates(ST[1], f->d_texture, f);
	VectorCopy(texY,ST[2]);
	VectorAdd(ST[2],proj,ST[2]);
	EmitTextureCoordinates(ST[2], f->d_texture, f);
	// compute texture matrix
	f->brushprimit_texdef.coords[0][2]=ST[0][3];
	f->brushprimit_texdef.coords[1][2]=ST[0][4];
	f->brushprimit_texdef.coords[0][0]=ST[1][3]-f->brushprimit_texdef.coords[0][2];
	f->brushprimit_texdef.coords[1][0]=ST[1][4]-f->brushprimit_texdef.coords[1][2];
	f->brushprimit_texdef.coords[0][1]=ST[2][3]-f->brushprimit_texdef.coords[0][2];
	f->brushprimit_texdef.coords[1][1]=ST[2][4]-f->brushprimit_texdef.coords[1][2];
}

// compute texture coordinates for the winding points
void EmitBrushPrimitTextureCoordinates(face_t * f, winding_t * w)
{
	vec3_t texX,texY;
	vec_t x,y;
	// compute axis base
	ComputeAxisBase(f->plane.normal,texX,texY);
	// in case the texcoords matrix is empty, build a default one
	// same behaviour as if scale[0]==0 && scale[1]==0 in old code
	if (f->brushprimit_texdef.coords[0][0]==0 && f->brushprimit_texdef.coords[1][0]==0 && f->brushprimit_texdef.coords[0][1]==0 && f->brushprimit_texdef.coords[1][1]==0)
	{
		f->brushprimit_texdef.coords[0][0] = 1.0f;
		f->brushprimit_texdef.coords[1][1] = 1.0f;
		ConvertTexMatWithQTexture( &f->brushprimit_texdef, NULL, &f->brushprimit_texdef, f->d_texture );
	}
	int i;
    for (i=0 ; i<w->numpoints ; i++)
	{
		x=DotProduct(w->points[i],texX);
		y=DotProduct(w->points[i],texY);
#ifdef _DEBUG
		if (g_qeglobals.bNeedConvert)
		{
			// check we compute the same ST as the traditional texture computation used before
			vec_t S=f->brushprimit_texdef.coords[0][0]*x+f->brushprimit_texdef.coords[0][1]*y+f->brushprimit_texdef.coords[0][2];
			vec_t T=f->brushprimit_texdef.coords[1][0]*x+f->brushprimit_texdef.coords[1][1]*y+f->brushprimit_texdef.coords[1][2];
			if ( fabs(S-w->points[i][3])>1e-2 || fabs(T-w->points[i][4])>1e-2 )
			{
				if ( fabs(S-w->points[i][3])>1e-4 || fabs(T-w->points[i][4])>1e-4 )
					Sys_Printf("Warning : precision loss in brush -> brush primitive texture computation\n");
				else
					Sys_Printf("Warning : brush -> brush primitive texture computation bug detected\n");
			}
		}
#endif
		w->points[i][3]=f->brushprimit_texdef.coords[0][0]*x+f->brushprimit_texdef.coords[0][1]*y+f->brushprimit_texdef.coords[0][2];
		w->points[i][4]=f->brushprimit_texdef.coords[1][0]*x+f->brushprimit_texdef.coords[1][1]*y+f->brushprimit_texdef.coords[1][2];
	}
}

// parse a brush in brush primitive format
void BrushPrimit_Parse(brush_t	*b)
{
	epair_t		*ep;
	face_t		*f;
	int			i,j;
	GetToken (true);
	if (strcmp (token, "{"))
	{
		Warning ("parsing brush primitive");
		return;
	}
	do
	{
		if (!GetToken (true))
			break;
		if (!strcmp (token, "}") )
			break;
		// reading of b->epairs if any
		if (strcmp (token, "(") )
		{
			ep = ParseEpair();
			ep->next = b->epairs;
			b->epairs = ep;
		}
		else
		// it's a face
		{
			f = Face_Alloc();
			f->next = NULL;
			if (!b->brush_faces)
			  	b->brush_faces = f;
		  	else
			{
				face_t *scan;
				for (scan=b->brush_faces ; scan->next ; scan=scan->next)
					;
				scan->next = f;
		  	}

			// read the three point plane definition
			for (i=0 ; i<3 ; i++)
			{
				if (i != 0)
					GetToken (true);
				if (strcmp (token, "(") )
				{
					Warning ("parsing brush");
					return;
				}
				for (j=0 ; j<3 ; j++)
				{
					GetToken (false);
					f->planepts[i][j] = atof(token);
				}
				GetToken (false);
				if (strcmp (token, ")") )
				{
					Warning ("parsing brush");
					return;
				}
			}
			// texture coordinates
			GetToken (false);
			if (strcmp(token, "("))
			{
				Warning ("parsing brush primitive");
				return;
			}
			GetToken (false);
			if (strcmp(token, "("))
			{
				Warning ("parsing brush primitive");
				return;
			}
			for (j=0;j<3;j++)
			{
				GetToken(false);
				f->brushprimit_texdef.coords[0][j]=atof(token);
			}
			GetToken (false);
			if (strcmp(token, ")"))
			{
				Warning ("parsing brush primitive");
				return;
			}
			GetToken (false);
			if (strcmp(token, "("))
			{
				Warning ("parsing brush primitive");
				return;
			}
			for (j=0;j<3;j++)
			{