Amiga Tools 4/Amiga Tools 4.iso/grafix/raytracing/raylab/source/texture.c

C/C++ Source or Header | 1996-02-14 | 4.4 KB | 189 lines

/*
    name:    texture.c

    Textures
    --------

    Texture-calculation and texture-handling.

*/


#include  "defs.h"


void CreateDefTexture(TEXTURE *t)
{
    t->CMap.Colors[0].r=1.0; t->CMap.Colors[0].g=0.3; t->CMap.Colors[0].b=0.0;
    t->CMap.Colors[1].r=0.0; t->CMap.Colors[1].g=0.0; t->CMap.Colors[1].b=0.0;
    t->CMap.LastBound=1;
    t->Pattern=PATTERN_NONE;
    t->Reflect.r=t->Reflect.g=t->Reflect.b=0.0;
    t->Filter.r=t->Filter.g=t->Filter.b=0.0;
    t->Ior=0.0;
    t->Ambient=0.2;
    t->Diffuse=0.8;
    t->Phong=0.3; t->PhongSize=10.0;
    ClearTransform(&t->Transform);
}



void CopyTexture(TEXTURE *t2, TEXTURE *t1)
{
    long    i,lbound;

    lbound=t1->CMap.LastBound;
    for(i=0;i<=lbound;i++) {
        t2->CMap.Bounds[i]=t1->CMap.Bounds[i];
        t2->CMap.Colors[i].r=t1->CMap.Colors[i].r;
        t2->CMap.Colors[i].g=t1->CMap.Colors[i].g;
        t2->CMap.Colors[i].b=t1->CMap.Colors[i].b;
    }
    t2->CMap.LastBound=lbound;
    t2->Pattern=t1->Pattern;
    t2->Reflect.r=t1->Reflect.r;
    t2->Reflect.g=t1->Reflect.g;
    t2->Reflect.b=t1->Reflect.b;
    t2->Filter.r=t1->Filter.r;
    t2->Filter.g=t1->Filter.g;
    t2->Filter.b=t1->Filter.b;
    t2->Ior=t1->Ior;
    t2->Ambient=t1->Ambient;
    t2->Diffuse=t1->Diffuse;
    t2->Phong=t1->Phong;
    t2->PhongSize=t1->PhongSize;
    CopyTransform(&t2->Transform,&t1->Transform);
}



void CopyColor(COLOR *c2, COLOR *c1)
{
    c2->r=c1->r; c2->g=c1->g; c2->b=c1->b;
}

/**************************************************************
 *
 *     Here are some useful (more or less) texture-patterns.
 *
 **************************************************************/

void GetSurfaceColor(COLOR *Color, TEXTURE *t, POINT *ip)
{
    double    MapValue;
    int    indx,foundindx,i;
    COLORMAP *cm;
    VECTOR    tempv;
    POINT    temppoint;

    CopyPoint(&temppoint,ip);

    if((t->Transform.NumTransforms>0)&&(t->Pattern!=PATTERN_NONE)) {
        for(i=t->Transform.NumTransforms-1L;i>=0L;i--) {
        switch(t->Transform.Entry[i].Type) {
            case TRANSFORM_SCALE:
            temppoint.x=temppoint.x/t->Transform.Entry[i].Values.x;
            temppoint.y=temppoint.y/t->Transform.Entry[i].Values.y;
            temppoint.z=temppoint.z/t->Transform.Entry[i].Values.z;
            break;
            case TRANSFORM_MOVE:
            temppoint.x=temppoint.x-t->Transform.Entry[i].Values.x;
            temppoint.y=temppoint.y-t->Transform.Entry[i].Values.y;
            temppoint.z=temppoint.z-t->Transform.Entry[i].Values.z;
            break;
            case TRANSFORM_ROTATE:
            NegVector(&tempv,&t->Transform.Entry[i].Values);
            RotatePoint(&temppoint,&tempv);
            break;
            case TRANSFORM_NONE:
            default:
            break;
        }
        }
    }

    switch(t->Pattern) {
        case PATTERN_CHECKER:
        MapValue=PatternChecker(&temppoint);
        break;
        case PATTERN_CIRCLES:
        MapValue=PatternCircles(&temppoint);
        break;
        case PATTERN_RINGS:
        MapValue=PatternRings(&temppoint);
        break;
        case PATTERN_SPOTS:
        MapValue=PatternSpots(&temppoint);
        break;
        case PATTERN_GRADIENT:
        MapValue=PatternGradient(&temppoint);
        break;
        case PATTERN_NONE:
        default:
        MapValue=0.0;
        break;
    }

    cm=&t->CMap;
    foundindx=-1;

    if(MapValue>EPSILON) {
        indx=0;
        while((indx<cm->LastBound)&&(foundindx!=0)) {
        if((MapValue>=cm->Bounds[indx])&&(MapValue<=cm->Bounds[indx+1]))
            foundindx=0;
        else indx++;
        }
    }
    if(foundindx==0) {
        Color->r=(cm->Colors[indx].r*(cm->Bounds[indx+1]-MapValue)+cm->Colors[indx+1].r*(MapValue-cm->Bounds[indx]))/(cm->Bounds[indx+1]-cm->Bounds[indx]);
        Color->g=(cm->Colors[indx].g*(cm->Bounds[indx+1]-MapValue)+cm->Colors[indx+1].g*(MapValue-cm->Bounds[indx]))/(cm->Bounds[indx+1]-cm->Bounds[indx]);
        Color->b=(cm->Colors[indx].b*(cm->Bounds[indx+1]-MapValue)+cm->Colors[indx+1].b*(MapValue-cm->Bounds[indx]))/(cm->Bounds[indx+1]-cm->Bounds[indx]);
    }
    else {
        Color->r=cm->Colors[0].r;
        Color->g=cm->Colors[0].g;
        Color->b=cm->Colors[0].b;
    }
}


double PatternChecker(POINT *ip)
{
    return( (double)(((long)floor(ip->x+EPSILON)+(long)floor(ip->y+EPSILON)+(long)floor(ip->z+EPSILON))&1L) );
}


double PatternCircles(POINT *ip)
{
    return(fmod(sqrt(ip->x*ip->x+ip->y*ip->y+ip->z*ip->z),1.0));
}

double PatternRings(POINT *ip)
{
    return(fmod(sqrt(ip->x*ip->x+ip->y*ip->y),1.0));
}

double PatternSpots(POINT *ip)
{
    double    d;
    POINT    dgrid;

    dgrid.x=ip->x-floor(ip->x+0.5);
    dgrid.y=ip->y-floor(ip->y+0.5);
    dgrid.z=ip->z-floor(ip->z+0.5);

    d=2.0*sqrt(dgrid.x*dgrid.x+dgrid.y*dgrid.y+dgrid.z*dgrid.z);
    if(d>1.0) d=1.0;
    return(d);
}

double PatternGradient(POINT *ip)
{
    if(ip->z>0) return(fmod(fabs(ip->z),1.0));
    else return(fmod(1.0-fabs(ip->z),1.0));
}